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llvm-project/clang/lib/Parse/ParseStmt.cpp

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//===--- ParseStmt.cpp - Statement and Block Parser -----------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the Statement and Block portions of the Parser
// interface.
//
//===----------------------------------------------------------------------===//
#include "clang/Parse/Parser.h"
#include "RAIIObjectsForParser.h"
#include "clang/AST/ASTContext.h"
#include "clang/Basic/Diagnostic.h"
#include "clang/Basic/PrettyStackTrace.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Basic/TargetInfo.h"
#include "clang/Sema/DeclSpec.h"
#include "clang/Sema/PrettyDeclStackTrace.h"
#include "clang/Sema/Scope.h"
#include "clang/Sema/TypoCorrection.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCObjectFileInfo.h"
#include "llvm/MC/MCParser/MCAsmParser.h"
#include "llvm/MC/MCRegisterInfo.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/MC/MCSubtargetInfo.h"
#include "llvm/MC/MCTargetAsmParser.h"
#include "llvm/Support/SourceMgr.h"
#include "llvm/Support/TargetRegistry.h"
#include "llvm/Support/TargetSelect.h"
using namespace clang;
//===----------------------------------------------------------------------===//
// C99 6.8: Statements and Blocks.
//===----------------------------------------------------------------------===//
/// \brief Parse a standalone statement (for instance, as the body of an 'if',
/// 'while', or 'for').
StmtResult Parser::ParseStatement(SourceLocation *TrailingElseLoc) {
StmtResult Res;
// We may get back a null statement if we found a #pragma. Keep going until
// we get an actual statement.
do {
StmtVector Stmts;
Res = ParseStatementOrDeclaration(Stmts, true, TrailingElseLoc);
} while (!Res.isInvalid() && !Res.get());
return Res;
}
/// ParseStatementOrDeclaration - Read 'statement' or 'declaration'.
/// StatementOrDeclaration:
/// statement
/// declaration
///
/// statement:
/// labeled-statement
/// compound-statement
/// expression-statement
/// selection-statement
/// iteration-statement
/// jump-statement
/// [C++] declaration-statement
/// [C++] try-block
/// [MS] seh-try-block
/// [OBC] objc-throw-statement
/// [OBC] objc-try-catch-statement
/// [OBC] objc-synchronized-statement
/// [GNU] asm-statement
/// [OMP] openmp-construct [TODO]
///
/// labeled-statement:
/// identifier ':' statement
/// 'case' constant-expression ':' statement
/// 'default' ':' statement
///
/// selection-statement:
/// if-statement
/// switch-statement
///
/// iteration-statement:
/// while-statement
/// do-statement
/// for-statement
///
/// expression-statement:
/// expression[opt] ';'
///
/// jump-statement:
/// 'goto' identifier ';'
/// 'continue' ';'
/// 'break' ';'
/// 'return' expression[opt] ';'
/// [GNU] 'goto' '*' expression ';'
///
/// [OBC] objc-throw-statement:
/// [OBC] '@' 'throw' expression ';'
/// [OBC] '@' 'throw' ';'
///
StmtResult
Parser::ParseStatementOrDeclaration(StmtVector &Stmts, bool OnlyStatement,
SourceLocation *TrailingElseLoc) {
ParenBraceBracketBalancer BalancerRAIIObj(*this);
ParsedAttributesWithRange Attrs(AttrFactory);
MaybeParseCXX11Attributes(Attrs, 0, /*MightBeObjCMessageSend*/ true);
StmtResult Res = ParseStatementOrDeclarationAfterAttributes(Stmts,
OnlyStatement, TrailingElseLoc, Attrs);
assert((Attrs.empty() || Res.isInvalid() || Res.isUsable()) &&
"attributes on empty statement");
if (Attrs.empty() || Res.isInvalid())
return Res;
return Actions.ProcessStmtAttributes(Res.get(), Attrs.getList(), Attrs.Range);
}
namespace {
class StatementFilterCCC : public CorrectionCandidateCallback {
public:
StatementFilterCCC(Token nextTok) : NextToken(nextTok) {
WantTypeSpecifiers = nextTok.is(tok::l_paren) || nextTok.is(tok::less) ||
nextTok.is(tok::identifier) || nextTok.is(tok::star) ||
nextTok.is(tok::amp) || nextTok.is(tok::l_square);
WantExpressionKeywords = nextTok.is(tok::l_paren) ||
nextTok.is(tok::identifier) ||
nextTok.is(tok::arrow) || nextTok.is(tok::period);
WantRemainingKeywords = nextTok.is(tok::l_paren) || nextTok.is(tok::semi) ||
nextTok.is(tok::identifier) ||
nextTok.is(tok::l_brace);
WantCXXNamedCasts = false;
}
virtual bool ValidateCandidate(const TypoCorrection &candidate) {
if (FieldDecl *FD = candidate.getCorrectionDeclAs<FieldDecl>())
return !candidate.getCorrectionSpecifier() || isa<ObjCIvarDecl>(FD);
if (NextToken.is(tok::equal))
return candidate.getCorrectionDeclAs<VarDecl>();
if (NextToken.is(tok::period) &&
candidate.getCorrectionDeclAs<NamespaceDecl>())
return false;
return CorrectionCandidateCallback::ValidateCandidate(candidate);
}
private:
Token NextToken;
};
}
StmtResult
Parser::ParseStatementOrDeclarationAfterAttributes(StmtVector &Stmts,
bool OnlyStatement, SourceLocation *TrailingElseLoc,
ParsedAttributesWithRange &Attrs) {
const char *SemiError = 0;
StmtResult Res;
// Cases in this switch statement should fall through if the parser expects
// the token to end in a semicolon (in which case SemiError should be set),
// or they directly 'return;' if not.
Retry:
tok::TokenKind Kind = Tok.getKind();
SourceLocation AtLoc;
switch (Kind) {
case tok::at: // May be a @try or @throw statement
{
ProhibitAttributes(Attrs); // TODO: is it correct?
AtLoc = ConsumeToken(); // consume @
return ParseObjCAtStatement(AtLoc);
}
case tok::code_completion:
Actions.CodeCompleteOrdinaryName(getCurScope(), Sema::PCC_Statement);
cutOffParsing();
return StmtError();
case tok::identifier: {
Token Next = NextToken();
if (Next.is(tok::colon)) { // C99 6.8.1: labeled-statement
// identifier ':' statement
return ParseLabeledStatement(Attrs);
}
// Look up the identifier, and typo-correct it to a keyword if it's not
// found.
if (Next.isNot(tok::coloncolon)) {
// Try to limit which sets of keywords should be included in typo
// correction based on what the next token is.
StatementFilterCCC Validator(Next);
if (TryAnnotateName(/*IsAddressOfOperand*/false, &Validator)
== ANK_Error) {
// Handle errors here by skipping up to the next semicolon or '}', and
// eat the semicolon if that's what stopped us.
SkipUntil(tok::r_brace, StopAtSemi | StopBeforeMatch);
if (Tok.is(tok::semi))
ConsumeToken();
return StmtError();
}
// If the identifier was typo-corrected, try again.
if (Tok.isNot(tok::identifier))
goto Retry;
}
// Fall through
}
default: {
if ((getLangOpts().CPlusPlus || !OnlyStatement) && isDeclarationStatement()) {
SourceLocation DeclStart = Tok.getLocation(), DeclEnd;
DeclGroupPtrTy Decl = ParseDeclaration(Stmts, Declarator::BlockContext,
DeclEnd, Attrs);
return Actions.ActOnDeclStmt(Decl, DeclStart, DeclEnd);
}
if (Tok.is(tok::r_brace)) {
Diag(Tok, diag::err_expected_statement);
return StmtError();
}
return ParseExprStatement();
}
case tok::kw_case: // C99 6.8.1: labeled-statement
return ParseCaseStatement();
case tok::kw_default: // C99 6.8.1: labeled-statement
return ParseDefaultStatement();
case tok::l_brace: // C99 6.8.2: compound-statement
return ParseCompoundStatement();
case tok::semi: { // C99 6.8.3p3: expression[opt] ';'
bool HasLeadingEmptyMacro = Tok.hasLeadingEmptyMacro();
return Actions.ActOnNullStmt(ConsumeToken(), HasLeadingEmptyMacro);
}
case tok::kw_if: // C99 6.8.4.1: if-statement
return ParseIfStatement(TrailingElseLoc);
case tok::kw_switch: // C99 6.8.4.2: switch-statement
return ParseSwitchStatement(TrailingElseLoc);
case tok::kw_while: // C99 6.8.5.1: while-statement
return ParseWhileStatement(TrailingElseLoc);
case tok::kw_do: // C99 6.8.5.2: do-statement
Res = ParseDoStatement();
SemiError = "do/while";
break;
case tok::kw_for: // C99 6.8.5.3: for-statement
return ParseForStatement(TrailingElseLoc);
case tok::kw_goto: // C99 6.8.6.1: goto-statement
Res = ParseGotoStatement();
SemiError = "goto";
break;
case tok::kw_continue: // C99 6.8.6.2: continue-statement
Res = ParseContinueStatement();
SemiError = "continue";
break;
case tok::kw_break: // C99 6.8.6.3: break-statement
Res = ParseBreakStatement();
SemiError = "break";
break;
case tok::kw_return: // C99 6.8.6.4: return-statement
Res = ParseReturnStatement();
SemiError = "return";
break;
case tok::kw_asm: {
ProhibitAttributes(Attrs);
bool msAsm = false;
Res = ParseAsmStatement(msAsm);
Res = Actions.ActOnFinishFullStmt(Res.get());
if (msAsm) return Res;
SemiError = "asm";
break;
}
case tok::kw_try: // C++ 15: try-block
return ParseCXXTryBlock();
case tok::kw___try:
ProhibitAttributes(Attrs); // TODO: is it correct?
return ParseSEHTryBlock();
case tok::annot_pragma_vis:
ProhibitAttributes(Attrs);
HandlePragmaVisibility();
return StmtEmpty();
case tok::annot_pragma_pack:
ProhibitAttributes(Attrs);
HandlePragmaPack();
return StmtEmpty();
case tok::annot_pragma_msstruct:
ProhibitAttributes(Attrs);
HandlePragmaMSStruct();
return StmtEmpty();
case tok::annot_pragma_align:
ProhibitAttributes(Attrs);
HandlePragmaAlign();
return StmtEmpty();
case tok::annot_pragma_weak:
ProhibitAttributes(Attrs);
HandlePragmaWeak();
return StmtEmpty();
case tok::annot_pragma_weakalias:
ProhibitAttributes(Attrs);
HandlePragmaWeakAlias();
return StmtEmpty();
case tok::annot_pragma_redefine_extname:
ProhibitAttributes(Attrs);
HandlePragmaRedefineExtname();
return StmtEmpty();
case tok::annot_pragma_fp_contract:
ProhibitAttributes(Attrs);
Diag(Tok, diag::err_pragma_fp_contract_scope);
ConsumeToken();
return StmtError();
case tok::annot_pragma_opencl_extension:
ProhibitAttributes(Attrs);
HandlePragmaOpenCLExtension();
return StmtEmpty();
case tok::annot_pragma_captured:
ProhibitAttributes(Attrs);
return HandlePragmaCaptured();
case tok::annot_pragma_openmp:
ProhibitAttributes(Attrs);
return ParseOpenMPDeclarativeOrExecutableDirective();
case tok::annot_pragma_ms_pointers_to_members:
ProhibitAttributes(Attrs);
HandlePragmaMSPointersToMembers();
return StmtEmpty();
}
// If we reached this code, the statement must end in a semicolon.
if (!TryConsumeToken(tok::semi) && !Res.isInvalid()) {
// If the result was valid, then we do want to diagnose this. Use
// ExpectAndConsume to emit the diagnostic, even though we know it won't
// succeed.
ExpectAndConsume(tok::semi, diag::err_expected_semi_after_stmt, SemiError);
// Skip until we see a } or ;, but don't eat it.
SkipUntil(tok::r_brace, StopAtSemi | StopBeforeMatch);
}
return Res;
}
/// \brief Parse an expression statement.
StmtResult Parser::ParseExprStatement() {
// If a case keyword is missing, this is where it should be inserted.
Token OldToken = Tok;
// expression[opt] ';'
ExprResult Expr(ParseExpression());
if (Expr.isInvalid()) {
// If the expression is invalid, skip ahead to the next semicolon or '}'.
// Not doing this opens us up to the possibility of infinite loops if
// ParseExpression does not consume any tokens.
SkipUntil(tok::r_brace, StopAtSemi | StopBeforeMatch);
if (Tok.is(tok::semi))
ConsumeToken();
return Actions.ActOnExprStmtError();
}
if (Tok.is(tok::colon) && getCurScope()->isSwitchScope() &&
Actions.CheckCaseExpression(Expr.get())) {
// If a constant expression is followed by a colon inside a switch block,
// suggest a missing case keyword.
Diag(OldToken, diag::err_expected_case_before_expression)
<< FixItHint::CreateInsertion(OldToken.getLocation(), "case ");
// Recover parsing as a case statement.
return ParseCaseStatement(/*MissingCase=*/true, Expr);
}
// Otherwise, eat the semicolon.
ExpectAndConsumeSemi(diag::err_expected_semi_after_expr);
return Actions.ActOnExprStmt(Expr);
}
StmtResult Parser::ParseSEHTryBlock() {
assert(Tok.is(tok::kw___try) && "Expected '__try'");
SourceLocation Loc = ConsumeToken();
return ParseSEHTryBlockCommon(Loc);
}
/// ParseSEHTryBlockCommon
///
/// seh-try-block:
/// '__try' compound-statement seh-handler
///
/// seh-handler:
/// seh-except-block
/// seh-finally-block
///
StmtResult Parser::ParseSEHTryBlockCommon(SourceLocation TryLoc) {
if(Tok.isNot(tok::l_brace))
return StmtError(Diag(Tok, diag::err_expected) << tok::l_brace);
StmtResult TryBlock(ParseCompoundStatement());
if(TryBlock.isInvalid())
return TryBlock;
StmtResult Handler;
if (Tok.is(tok::identifier) &&
Tok.getIdentifierInfo() == getSEHExceptKeyword()) {
SourceLocation Loc = ConsumeToken();
Handler = ParseSEHExceptBlock(Loc);
} else if (Tok.is(tok::kw___finally)) {
SourceLocation Loc = ConsumeToken();
Handler = ParseSEHFinallyBlock(Loc);
} else {
return StmtError(Diag(Tok,diag::err_seh_expected_handler));
}
if(Handler.isInvalid())
return Handler;
return Actions.ActOnSEHTryBlock(false /* IsCXXTry */,
TryLoc,
TryBlock.take(),
Handler.take());
}
/// ParseSEHExceptBlock - Handle __except
///
/// seh-except-block:
/// '__except' '(' seh-filter-expression ')' compound-statement
///
StmtResult Parser::ParseSEHExceptBlock(SourceLocation ExceptLoc) {
PoisonIdentifierRAIIObject raii(Ident__exception_code, false),
raii2(Ident___exception_code, false),
raii3(Ident_GetExceptionCode, false);
if (ExpectAndConsume(tok::l_paren))
return StmtError();
ParseScope ExpectScope(this, Scope::DeclScope | Scope::ControlScope);
if (getLangOpts().Borland) {
Ident__exception_info->setIsPoisoned(false);
Ident___exception_info->setIsPoisoned(false);
Ident_GetExceptionInfo->setIsPoisoned(false);
}
ExprResult FilterExpr(ParseExpression());
if (getLangOpts().Borland) {
Ident__exception_info->setIsPoisoned(true);
Ident___exception_info->setIsPoisoned(true);
Ident_GetExceptionInfo->setIsPoisoned(true);
}
if(FilterExpr.isInvalid())
return StmtError();
if (ExpectAndConsume(tok::r_paren))
return StmtError();
StmtResult Block(ParseCompoundStatement());
if(Block.isInvalid())
return Block;
return Actions.ActOnSEHExceptBlock(ExceptLoc, FilterExpr.take(), Block.take());
}
/// ParseSEHFinallyBlock - Handle __finally
///
/// seh-finally-block:
/// '__finally' compound-statement
///
StmtResult Parser::ParseSEHFinallyBlock(SourceLocation FinallyBlock) {
PoisonIdentifierRAIIObject raii(Ident__abnormal_termination, false),
raii2(Ident___abnormal_termination, false),
raii3(Ident_AbnormalTermination, false);
StmtResult Block(ParseCompoundStatement());
if(Block.isInvalid())
return Block;
return Actions.ActOnSEHFinallyBlock(FinallyBlock,Block.take());
}
/// ParseLabeledStatement - We have an identifier and a ':' after it.
///
/// labeled-statement:
/// identifier ':' statement
/// [GNU] identifier ':' attributes[opt] statement
///
StmtResult Parser::ParseLabeledStatement(ParsedAttributesWithRange &attrs) {
assert(Tok.is(tok::identifier) && Tok.getIdentifierInfo() &&
"Not an identifier!");
Token IdentTok = Tok; // Save the whole token.
ConsumeToken(); // eat the identifier.
assert(Tok.is(tok::colon) && "Not a label!");
// identifier ':' statement
SourceLocation ColonLoc = ConsumeToken();
// Read label attributes, if present.
StmtResult SubStmt;
if (Tok.is(tok::kw___attribute)) {
ParsedAttributesWithRange TempAttrs(AttrFactory);
ParseGNUAttributes(TempAttrs);
// In C++, GNU attributes only apply to the label if they are followed by a
// semicolon, to disambiguate label attributes from attributes on a labeled
// declaration.
//
// This doesn't quite match what GCC does; if the attribute list is empty
// and followed by a semicolon, GCC will reject (it appears to parse the
// attributes as part of a statement in that case). That looks like a bug.
if (!getLangOpts().CPlusPlus || Tok.is(tok::semi))
attrs.takeAllFrom(TempAttrs);
else if (isDeclarationStatement()) {
StmtVector Stmts;
// FIXME: We should do this whether or not we have a declaration
// statement, but that doesn't work correctly (because ProhibitAttributes
// can't handle GNU attributes), so only call it in the one case where
// GNU attributes are allowed.
SubStmt = ParseStatementOrDeclarationAfterAttributes(
Stmts, /*OnlyStmts*/ true, 0, TempAttrs);
if (!TempAttrs.empty() && !SubStmt.isInvalid())
SubStmt = Actions.ProcessStmtAttributes(
SubStmt.get(), TempAttrs.getList(), TempAttrs.Range);
} else {
Diag(Tok, diag::err_expected_after) << "__attribute__" << tok::semi;
}
}
// If we've not parsed a statement yet, parse one now.
if (!SubStmt.isInvalid() && !SubStmt.isUsable())
SubStmt = ParseStatement();
// Broken substmt shouldn't prevent the label from being added to the AST.
if (SubStmt.isInvalid())
SubStmt = Actions.ActOnNullStmt(ColonLoc);
LabelDecl *LD = Actions.LookupOrCreateLabel(IdentTok.getIdentifierInfo(),
IdentTok.getLocation());
if (AttributeList *Attrs = attrs.getList()) {
Actions.ProcessDeclAttributeList(Actions.CurScope, LD, Attrs);
attrs.clear();
}
return Actions.ActOnLabelStmt(IdentTok.getLocation(), LD, ColonLoc,
SubStmt.get());
}
/// ParseCaseStatement
/// labeled-statement:
/// 'case' constant-expression ':' statement
/// [GNU] 'case' constant-expression '...' constant-expression ':' statement
///
StmtResult Parser::ParseCaseStatement(bool MissingCase, ExprResult Expr) {
assert((MissingCase || Tok.is(tok::kw_case)) && "Not a case stmt!");
// It is very very common for code to contain many case statements recursively
// nested, as in (but usually without indentation):
// case 1:
// case 2:
// case 3:
// case 4:
// case 5: etc.
//
// Parsing this naively works, but is both inefficient and can cause us to run
// out of stack space in our recursive descent parser. As a special case,
// flatten this recursion into an iterative loop. This is complex and gross,
// but all the grossness is constrained to ParseCaseStatement (and some
// weirdness in the actions), so this is just local grossness :).
// TopLevelCase - This is the highest level we have parsed. 'case 1' in the
// example above.
StmtResult TopLevelCase(true);
// DeepestParsedCaseStmt - This is the deepest statement we have parsed, which
// gets updated each time a new case is parsed, and whose body is unset so
// far. When parsing 'case 4', this is the 'case 3' node.
Stmt *DeepestParsedCaseStmt = 0;
// While we have case statements, eat and stack them.
SourceLocation ColonLoc;
do {
SourceLocation CaseLoc = MissingCase ? Expr.get()->getExprLoc() :
ConsumeToken(); // eat the 'case'.
if (Tok.is(tok::code_completion)) {
Actions.CodeCompleteCase(getCurScope());
cutOffParsing();
return StmtError();
}
/// We don't want to treat 'case x : y' as a potential typo for 'case x::y'.
/// Disable this form of error recovery while we're parsing the case
/// expression.
ColonProtectionRAIIObject ColonProtection(*this);
ExprResult LHS(MissingCase ? Expr : ParseConstantExpression());
MissingCase = false;
if (LHS.isInvalid()) {
SkipUntil(tok::colon, StopAtSemi);
return StmtError();
}
// GNU case range extension.
SourceLocation DotDotDotLoc;
ExprResult RHS;
if (TryConsumeToken(tok::ellipsis, DotDotDotLoc)) {
Diag(DotDotDotLoc, diag::ext_gnu_case_range);
RHS = ParseConstantExpression();
if (RHS.isInvalid()) {
SkipUntil(tok::colon, StopAtSemi);
return StmtError();
}
}
ColonProtection.restore();
if (TryConsumeToken(tok::colon, ColonLoc)) {
} else if (TryConsumeToken(tok::semi, ColonLoc)) {
// Treat "case blah;" as a typo for "case blah:".
Diag(ColonLoc, diag::err_expected_after)
<< "'case'" << tok::colon
<< FixItHint::CreateReplacement(ColonLoc, ":");
} else {
SourceLocation ExpectedLoc = PP.getLocForEndOfToken(PrevTokLocation);
Diag(ExpectedLoc, diag::err_expected_after)
<< "'case'" << tok::colon
<< FixItHint::CreateInsertion(ExpectedLoc, ":");
ColonLoc = ExpectedLoc;
}
StmtResult Case =
Actions.ActOnCaseStmt(CaseLoc, LHS.get(), DotDotDotLoc,
RHS.get(), ColonLoc);
// If we had a sema error parsing this case, then just ignore it and
// continue parsing the sub-stmt.
if (Case.isInvalid()) {
if (TopLevelCase.isInvalid()) // No parsed case stmts.
return ParseStatement();
// Otherwise, just don't add it as a nested case.
} else {
// If this is the first case statement we parsed, it becomes TopLevelCase.
// Otherwise we link it into the current chain.
Stmt *NextDeepest = Case.get();
if (TopLevelCase.isInvalid())
TopLevelCase = Case;
else
Actions.ActOnCaseStmtBody(DeepestParsedCaseStmt, Case.get());
DeepestParsedCaseStmt = NextDeepest;
}
// Handle all case statements.
} while (Tok.is(tok::kw_case));
assert(!TopLevelCase.isInvalid() && "Should have parsed at least one case!");
// If we found a non-case statement, start by parsing it.
StmtResult SubStmt;
if (Tok.isNot(tok::r_brace)) {
SubStmt = ParseStatement();
} else {
// Nicely diagnose the common error "switch (X) { case 4: }", which is
// not valid.
SourceLocation AfterColonLoc = PP.getLocForEndOfToken(ColonLoc);
Diag(AfterColonLoc, diag::err_label_end_of_compound_statement)
<< FixItHint::CreateInsertion(AfterColonLoc, " ;");
SubStmt = true;
}
// Broken sub-stmt shouldn't prevent forming the case statement properly.
if (SubStmt.isInvalid())
SubStmt = Actions.ActOnNullStmt(SourceLocation());
// Install the body into the most deeply-nested case.
Actions.ActOnCaseStmtBody(DeepestParsedCaseStmt, SubStmt.get());
// Return the top level parsed statement tree.
return TopLevelCase;
}
/// ParseDefaultStatement
/// labeled-statement:
/// 'default' ':' statement
/// Note that this does not parse the 'statement' at the end.
///
StmtResult Parser::ParseDefaultStatement() {
assert(Tok.is(tok::kw_default) && "Not a default stmt!");
SourceLocation DefaultLoc = ConsumeToken(); // eat the 'default'.
SourceLocation ColonLoc;
if (TryConsumeToken(tok::colon, ColonLoc)) {
} else if (TryConsumeToken(tok::semi, ColonLoc)) {
// Treat "default;" as a typo for "default:".
Diag(ColonLoc, diag::err_expected_after)
<< "'default'" << tok::colon
<< FixItHint::CreateReplacement(ColonLoc, ":");
} else {
SourceLocation ExpectedLoc = PP.getLocForEndOfToken(PrevTokLocation);
Diag(ExpectedLoc, diag::err_expected_after)
<< "'default'" << tok::colon
<< FixItHint::CreateInsertion(ExpectedLoc, ":");
ColonLoc = ExpectedLoc;
}
StmtResult SubStmt;
if (Tok.isNot(tok::r_brace)) {
SubStmt = ParseStatement();
} else {
// Diagnose the common error "switch (X) {... default: }", which is
// not valid.
SourceLocation AfterColonLoc = PP.getLocForEndOfToken(ColonLoc);
Diag(AfterColonLoc, diag::err_label_end_of_compound_statement)
<< FixItHint::CreateInsertion(AfterColonLoc, " ;");
SubStmt = true;
}
// Broken sub-stmt shouldn't prevent forming the case statement properly.
if (SubStmt.isInvalid())
SubStmt = Actions.ActOnNullStmt(ColonLoc);
return Actions.ActOnDefaultStmt(DefaultLoc, ColonLoc,
SubStmt.get(), getCurScope());
}
StmtResult Parser::ParseCompoundStatement(bool isStmtExpr) {
return ParseCompoundStatement(isStmtExpr, Scope::DeclScope);
}
/// ParseCompoundStatement - Parse a "{}" block.
///
/// compound-statement: [C99 6.8.2]
/// { block-item-list[opt] }
/// [GNU] { label-declarations block-item-list } [TODO]
///
/// block-item-list:
/// block-item
/// block-item-list block-item
///
/// block-item:
/// declaration
/// [GNU] '__extension__' declaration
/// statement
/// [OMP] openmp-directive [TODO]
///
/// [GNU] label-declarations:
/// [GNU] label-declaration
/// [GNU] label-declarations label-declaration
///
/// [GNU] label-declaration:
/// [GNU] '__label__' identifier-list ';'
///
/// [OMP] openmp-directive: [TODO]
/// [OMP] barrier-directive
/// [OMP] flush-directive
///
StmtResult Parser::ParseCompoundStatement(bool isStmtExpr,
unsigned ScopeFlags) {
assert(Tok.is(tok::l_brace) && "Not a compount stmt!");
// Enter a scope to hold everything within the compound stmt. Compound
// statements can always hold declarations.
ParseScope CompoundScope(this, ScopeFlags);
// Parse the statements in the body.
return ParseCompoundStatementBody(isStmtExpr);
}
/// Parse any pragmas at the start of the compound expression. We handle these
/// separately since some pragmas (FP_CONTRACT) must appear before any C
/// statement in the compound, but may be intermingled with other pragmas.
void Parser::ParseCompoundStatementLeadingPragmas() {
bool checkForPragmas = true;
while (checkForPragmas) {
switch (Tok.getKind()) {
case tok::annot_pragma_vis:
HandlePragmaVisibility();
break;
case tok::annot_pragma_pack:
HandlePragmaPack();
break;
case tok::annot_pragma_msstruct:
HandlePragmaMSStruct();
break;
case tok::annot_pragma_align:
HandlePragmaAlign();
break;
case tok::annot_pragma_weak:
HandlePragmaWeak();
break;
case tok::annot_pragma_weakalias:
HandlePragmaWeakAlias();
break;
case tok::annot_pragma_redefine_extname:
HandlePragmaRedefineExtname();
break;
case tok::annot_pragma_opencl_extension:
HandlePragmaOpenCLExtension();
break;
case tok::annot_pragma_fp_contract:
HandlePragmaFPContract();
break;
case tok::annot_pragma_ms_pointers_to_members:
HandlePragmaMSPointersToMembers();
break;
default:
checkForPragmas = false;
break;
}
}
}
/// ParseCompoundStatementBody - Parse a sequence of statements and invoke the
/// ActOnCompoundStmt action. This expects the '{' to be the current token, and
/// consume the '}' at the end of the block. It does not manipulate the scope
/// stack.
StmtResult Parser::ParseCompoundStatementBody(bool isStmtExpr) {
PrettyStackTraceLoc CrashInfo(PP.getSourceManager(),
Tok.getLocation(),
"in compound statement ('{}')");
// Record the state of the FP_CONTRACT pragma, restore on leaving the
// compound statement.
Sema::FPContractStateRAII SaveFPContractState(Actions);
InMessageExpressionRAIIObject InMessage(*this, false);
BalancedDelimiterTracker T(*this, tok::l_brace);
if (T.consumeOpen())
return StmtError();
Sema::CompoundScopeRAII CompoundScope(Actions);
// Parse any pragmas at the beginning of the compound statement.
ParseCompoundStatementLeadingPragmas();
StmtVector Stmts;
// "__label__ X, Y, Z;" is the GNU "Local Label" extension. These are
// only allowed at the start of a compound stmt regardless of the language.
while (Tok.is(tok::kw___label__)) {
SourceLocation LabelLoc = ConsumeToken();
SmallVector<Decl *, 8> DeclsInGroup;
while (1) {
if (Tok.isNot(tok::identifier)) {
Diag(Tok, diag::err_expected) << tok::identifier;
break;
}
IdentifierInfo *II = Tok.getIdentifierInfo();
SourceLocation IdLoc = ConsumeToken();
DeclsInGroup.push_back(Actions.LookupOrCreateLabel(II, IdLoc, LabelLoc));
if (!TryConsumeToken(tok::comma))
break;
}
DeclSpec DS(AttrFactory);
DeclGroupPtrTy Res =
Actions.FinalizeDeclaratorGroup(getCurScope(), DS, DeclsInGroup);
StmtResult R = Actions.ActOnDeclStmt(Res, LabelLoc, Tok.getLocation());
ExpectAndConsumeSemi(diag::err_expected_semi_declaration);
if (R.isUsable())
Stmts.push_back(R.release());
}
while (Tok.isNot(tok::r_brace) && !isEofOrEom()) {
if (Tok.is(tok::annot_pragma_unused)) {
HandlePragmaUnused();
continue;
}
if (getLangOpts().MicrosoftExt && (Tok.is(tok::kw___if_exists) ||
Tok.is(tok::kw___if_not_exists))) {
ParseMicrosoftIfExistsStatement(Stmts);
continue;
}
StmtResult R;
if (Tok.isNot(tok::kw___extension__)) {
R = ParseStatementOrDeclaration(Stmts, false);
} else {
// __extension__ can start declarations and it can also be a unary
// operator for expressions. Consume multiple __extension__ markers here
// until we can determine which is which.
// FIXME: This loses extension expressions in the AST!
SourceLocation ExtLoc = ConsumeToken();
while (Tok.is(tok::kw___extension__))
ConsumeToken();
ParsedAttributesWithRange attrs(AttrFactory);
MaybeParseCXX11Attributes(attrs, 0, /*MightBeObjCMessageSend*/ true);
// If this is the start of a declaration, parse it as such.
if (isDeclarationStatement()) {
// __extension__ silences extension warnings in the subdeclaration.
// FIXME: Save the __extension__ on the decl as a node somehow?
ExtensionRAIIObject O(Diags);
SourceLocation DeclStart = Tok.getLocation(), DeclEnd;
DeclGroupPtrTy Res = ParseDeclaration(Stmts,
Declarator::BlockContext, DeclEnd,
attrs);
R = Actions.ActOnDeclStmt(Res, DeclStart, DeclEnd);
} else {
// Otherwise this was a unary __extension__ marker.
ExprResult Res(ParseExpressionWithLeadingExtension(ExtLoc));
if (Res.isInvalid()) {
SkipUntil(tok::semi);
continue;
}
// FIXME: Use attributes?
// Eat the semicolon at the end of stmt and convert the expr into a
// statement.
ExpectAndConsumeSemi(diag::err_expected_semi_after_expr);
R = Actions.ActOnExprStmt(Res);
}
}
if (R.isUsable())
Stmts.push_back(R.release());
}
SourceLocation CloseLoc = Tok.getLocation();
// We broke out of the while loop because we found a '}' or EOF.
if (!T.consumeClose())
// Recover by creating a compound statement with what we parsed so far,
// instead of dropping everything and returning StmtError();
CloseLoc = T.getCloseLocation();
return Actions.ActOnCompoundStmt(T.getOpenLocation(), CloseLoc,
Stmts, isStmtExpr);
}
/// ParseParenExprOrCondition:
/// [C ] '(' expression ')'
/// [C++] '(' condition ')' [not allowed if OnlyAllowCondition=true]
///
/// This function parses and performs error recovery on the specified condition
/// or expression (depending on whether we're in C++ or C mode). This function
/// goes out of its way to recover well. It returns true if there was a parser
/// error (the right paren couldn't be found), which indicates that the caller
/// should try to recover harder. It returns false if the condition is
/// successfully parsed. Note that a successful parse can still have semantic
/// errors in the condition.
bool Parser::ParseParenExprOrCondition(ExprResult &ExprResult,
Decl *&DeclResult,
SourceLocation Loc,
bool ConvertToBoolean) {
BalancedDelimiterTracker T(*this, tok::l_paren);
T.consumeOpen();
if (getLangOpts().CPlusPlus)
ParseCXXCondition(ExprResult, DeclResult, Loc, ConvertToBoolean);
else {
ExprResult = ParseExpression();
DeclResult = 0;
// If required, convert to a boolean value.
if (!ExprResult.isInvalid() && ConvertToBoolean)
ExprResult
= Actions.ActOnBooleanCondition(getCurScope(), Loc, ExprResult.get());
}
// If the parser was confused by the condition and we don't have a ')', try to
// recover by skipping ahead to a semi and bailing out. If condexp is
// semantically invalid but we have well formed code, keep going.
if (ExprResult.isInvalid() && !DeclResult && Tok.isNot(tok::r_paren)) {
SkipUntil(tok::semi);
// Skipping may have stopped if it found the containing ')'. If so, we can
// continue parsing the if statement.
if (Tok.isNot(tok::r_paren))
return true;
}
// Otherwise the condition is valid or the rparen is present.
T.consumeClose();
// Check for extraneous ')'s to catch things like "if (foo())) {". We know
// that all callers are looking for a statement after the condition, so ")"
// isn't valid.
while (Tok.is(tok::r_paren)) {
Diag(Tok, diag::err_extraneous_rparen_in_condition)
<< FixItHint::CreateRemoval(Tok.getLocation());
ConsumeParen();
}
return false;
}
/// ParseIfStatement
/// if-statement: [C99 6.8.4.1]
/// 'if' '(' expression ')' statement
/// 'if' '(' expression ')' statement 'else' statement
/// [C++] 'if' '(' condition ')' statement
/// [C++] 'if' '(' condition ')' statement 'else' statement
///
StmtResult Parser::ParseIfStatement(SourceLocation *TrailingElseLoc) {
assert(Tok.is(tok::kw_if) && "Not an if stmt!");
SourceLocation IfLoc = ConsumeToken(); // eat the 'if'.
if (Tok.isNot(tok::l_paren)) {
Diag(Tok, diag::err_expected_lparen_after) << "if";
SkipUntil(tok::semi);
return StmtError();
}
bool C99orCXX = getLangOpts().C99 || getLangOpts().CPlusPlus;
// C99 6.8.4p3 - In C99, the if statement is a block. This is not
// the case for C90.
//
// C++ 6.4p3:
// A name introduced by a declaration in a condition is in scope from its
// point of declaration until the end of the substatements controlled by the
// condition.
// C++ 3.3.2p4:
// Names declared in the for-init-statement, and in the condition of if,
// while, for, and switch statements are local to the if, while, for, or
// switch statement (including the controlled statement).
//
ParseScope IfScope(this, Scope::DeclScope | Scope::ControlScope, C99orCXX);
// Parse the condition.
ExprResult CondExp;
Decl *CondVar = 0;
if (ParseParenExprOrCondition(CondExp, CondVar, IfLoc, true))
return StmtError();
FullExprArg FullCondExp(Actions.MakeFullExpr(CondExp.get(), IfLoc));
// C99 6.8.4p3 - In C99, the body of the if statement is a scope, even if
// there is no compound stmt. C90 does not have this clause. We only do this
// if the body isn't a compound statement to avoid push/pop in common cases.
//
// C++ 6.4p1:
// The substatement in a selection-statement (each substatement, in the else
// form of the if statement) implicitly defines a local scope.
//
// For C++ we create a scope for the condition and a new scope for
// substatements because:
// -When the 'then' scope exits, we want the condition declaration to still be
// active for the 'else' scope too.
// -Sema will detect name clashes by considering declarations of a
// 'ControlScope' as part of its direct subscope.
// -If we wanted the condition and substatement to be in the same scope, we
// would have to notify ParseStatement not to create a new scope. It's
// simpler to let it create a new scope.
//
ParseScope InnerScope(this, Scope::DeclScope, C99orCXX, Tok.is(tok::l_brace));
// Read the 'then' stmt.
SourceLocation ThenStmtLoc = Tok.getLocation();
SourceLocation InnerStatementTrailingElseLoc;
StmtResult ThenStmt(ParseStatement(&InnerStatementTrailingElseLoc));
// Pop the 'if' scope if needed.
InnerScope.Exit();
// If it has an else, parse it.
SourceLocation ElseLoc;
SourceLocation ElseStmtLoc;
StmtResult ElseStmt;
if (Tok.is(tok::kw_else)) {
if (TrailingElseLoc)
*TrailingElseLoc = Tok.getLocation();
ElseLoc = ConsumeToken();
ElseStmtLoc = Tok.getLocation();
// C99 6.8.4p3 - In C99, the body of the if statement is a scope, even if
// there is no compound stmt. C90 does not have this clause. We only do
// this if the body isn't a compound statement to avoid push/pop in common
// cases.
//
// C++ 6.4p1:
// The substatement in a selection-statement (each substatement, in the else
// form of the if statement) implicitly defines a local scope.
//
ParseScope InnerScope(this, Scope::DeclScope, C99orCXX, Tok.is(tok::l_brace));
ElseStmt = ParseStatement();
// Pop the 'else' scope if needed.
InnerScope.Exit();
} else if (Tok.is(tok::code_completion)) {
Actions.CodeCompleteAfterIf(getCurScope());
cutOffParsing();
return StmtError();
} else if (InnerStatementTrailingElseLoc.isValid()) {
Diag(InnerStatementTrailingElseLoc, diag::warn_dangling_else);
}
IfScope.Exit();
// If the then or else stmt is invalid and the other is valid (and present),
// make turn the invalid one into a null stmt to avoid dropping the other
// part. If both are invalid, return error.
if ((ThenStmt.isInvalid() && ElseStmt.isInvalid()) ||
(ThenStmt.isInvalid() && ElseStmt.get() == 0) ||
(ThenStmt.get() == 0 && ElseStmt.isInvalid())) {
// Both invalid, or one is invalid and other is non-present: return error.
return StmtError();
}
// Now if either are invalid, replace with a ';'.
if (ThenStmt.isInvalid())
ThenStmt = Actions.ActOnNullStmt(ThenStmtLoc);
if (ElseStmt.isInvalid())
ElseStmt = Actions.ActOnNullStmt(ElseStmtLoc);
return Actions.ActOnIfStmt(IfLoc, FullCondExp, CondVar, ThenStmt.get(),
ElseLoc, ElseStmt.get());
}
/// ParseSwitchStatement
/// switch-statement:
/// 'switch' '(' expression ')' statement
/// [C++] 'switch' '(' condition ')' statement
StmtResult Parser::ParseSwitchStatement(SourceLocation *TrailingElseLoc) {
assert(Tok.is(tok::kw_switch) && "Not a switch stmt!");
SourceLocation SwitchLoc = ConsumeToken(); // eat the 'switch'.
if (Tok.isNot(tok::l_paren)) {
Diag(Tok, diag::err_expected_lparen_after) << "switch";
SkipUntil(tok::semi);
return StmtError();
}
bool C99orCXX = getLangOpts().C99 || getLangOpts().CPlusPlus;
// C99 6.8.4p3 - In C99, the switch statement is a block. This is
// not the case for C90. Start the switch scope.
//
// C++ 6.4p3:
// A name introduced by a declaration in a condition is in scope from its
// point of declaration until the end of the substatements controlled by the
// condition.
// C++ 3.3.2p4:
// Names declared in the for-init-statement, and in the condition of if,
// while, for, and switch statements are local to the if, while, for, or
// switch statement (including the controlled statement).
//
unsigned ScopeFlags = Scope::SwitchScope;
if (C99orCXX)
ScopeFlags |= Scope::DeclScope | Scope::ControlScope;
ParseScope SwitchScope(this, ScopeFlags);
// Parse the condition.
ExprResult Cond;
Decl *CondVar = 0;
if (ParseParenExprOrCondition(Cond, CondVar, SwitchLoc, false))
return StmtError();
StmtResult Switch
= Actions.ActOnStartOfSwitchStmt(SwitchLoc, Cond.get(), CondVar);
if (Switch.isInvalid()) {
// Skip the switch body.
// FIXME: This is not optimal recovery, but parsing the body is more
// dangerous due to the presence of case and default statements, which
// will have no place to connect back with the switch.
if (Tok.is(tok::l_brace)) {
ConsumeBrace();
SkipUntil(tok::r_brace);
} else
SkipUntil(tok::semi);
return Switch;
}
// C99 6.8.4p3 - In C99, the body of the switch statement is a scope, even if
// there is no compound stmt. C90 does not have this clause. We only do this
// if the body isn't a compound statement to avoid push/pop in common cases.
//
// C++ 6.4p1:
// The substatement in a selection-statement (each substatement, in the else
// form of the if statement) implicitly defines a local scope.
//
// See comments in ParseIfStatement for why we create a scope for the
// condition and a new scope for substatement in C++.
//
getCurScope()->AddFlags(Scope::BreakScope);
ParseScope InnerScope(this, Scope::DeclScope, C99orCXX, Tok.is(tok::l_brace));
// Read the body statement.
StmtResult Body(ParseStatement(TrailingElseLoc));
// Pop the scopes.
InnerScope.Exit();
SwitchScope.Exit();
if (Body.isInvalid()) {
// FIXME: Remove the case statement list from the Switch statement.
// Put the synthesized null statement on the same line as the end of switch
// condition.
SourceLocation SynthesizedNullStmtLocation = Cond.get()->getLocEnd();
Body = Actions.ActOnNullStmt(SynthesizedNullStmtLocation);
}
return Actions.ActOnFinishSwitchStmt(SwitchLoc, Switch.get(), Body.get());
}
/// ParseWhileStatement
/// while-statement: [C99 6.8.5.1]
/// 'while' '(' expression ')' statement
/// [C++] 'while' '(' condition ')' statement
StmtResult Parser::ParseWhileStatement(SourceLocation *TrailingElseLoc) {
assert(Tok.is(tok::kw_while) && "Not a while stmt!");
SourceLocation WhileLoc = Tok.getLocation();
ConsumeToken(); // eat the 'while'.
if (Tok.isNot(tok::l_paren)) {
Diag(Tok, diag::err_expected_lparen_after) << "while";
SkipUntil(tok::semi);
return StmtError();
}
bool C99orCXX = getLangOpts().C99 || getLangOpts().CPlusPlus;
// C99 6.8.5p5 - In C99, the while statement is a block. This is not
// the case for C90. Start the loop scope.
//
// C++ 6.4p3:
// A name introduced by a declaration in a condition is in scope from its
// point of declaration until the end of the substatements controlled by the
// condition.
// C++ 3.3.2p4:
// Names declared in the for-init-statement, and in the condition of if,
// while, for, and switch statements are local to the if, while, for, or
// switch statement (including the controlled statement).
//
unsigned ScopeFlags;
if (C99orCXX)
ScopeFlags = Scope::BreakScope | Scope::ContinueScope |
Scope::DeclScope | Scope::ControlScope;
else
ScopeFlags = Scope::BreakScope | Scope::ContinueScope;
ParseScope WhileScope(this, ScopeFlags);
// Parse the condition.
ExprResult Cond;
Decl *CondVar = 0;
if (ParseParenExprOrCondition(Cond, CondVar, WhileLoc, true))
return StmtError();
FullExprArg FullCond(Actions.MakeFullExpr(Cond.get(), WhileLoc));
// C99 6.8.5p5 - In C99, the body of the while statement is a scope, even if
// there is no compound stmt. C90 does not have this clause. We only do this
// if the body isn't a compound statement to avoid push/pop in common cases.
//
// C++ 6.5p2:
// The substatement in an iteration-statement implicitly defines a local scope
// which is entered and exited each time through the loop.
//
// See comments in ParseIfStatement for why we create a scope for the
// condition and a new scope for substatement in C++.
//
ParseScope InnerScope(this, Scope::DeclScope, C99orCXX, Tok.is(tok::l_brace));
// Read the body statement.
StmtResult Body(ParseStatement(TrailingElseLoc));
// Pop the body scope if needed.
InnerScope.Exit();
WhileScope.Exit();
if ((Cond.isInvalid() && !CondVar) || Body.isInvalid())
return StmtError();
return Actions.ActOnWhileStmt(WhileLoc, FullCond, CondVar, Body.get());
}
/// ParseDoStatement
/// do-statement: [C99 6.8.5.2]
/// 'do' statement 'while' '(' expression ')' ';'
/// Note: this lets the caller parse the end ';'.
StmtResult Parser::ParseDoStatement() {
assert(Tok.is(tok::kw_do) && "Not a do stmt!");
SourceLocation DoLoc = ConsumeToken(); // eat the 'do'.
// C99 6.8.5p5 - In C99, the do statement is a block. This is not
// the case for C90. Start the loop scope.
unsigned ScopeFlags;
if (getLangOpts().C99)
ScopeFlags = Scope::BreakScope | Scope::ContinueScope | Scope::DeclScope;
else
ScopeFlags = Scope::BreakScope | Scope::ContinueScope;
ParseScope DoScope(this, ScopeFlags);
// C99 6.8.5p5 - In C99, the body of the do statement is a scope, even if
// there is no compound stmt. C90 does not have this clause. We only do this
// if the body isn't a compound statement to avoid push/pop in common cases.
//
// C++ 6.5p2:
// The substatement in an iteration-statement implicitly defines a local scope
// which is entered and exited each time through the loop.
//
bool C99orCXX = getLangOpts().C99 || getLangOpts().CPlusPlus;
ParseScope InnerScope(this, Scope::DeclScope, C99orCXX, Tok.is(tok::l_brace));
// Read the body statement.
StmtResult Body(ParseStatement());
// Pop the body scope if needed.
InnerScope.Exit();
if (Tok.isNot(tok::kw_while)) {
if (!Body.isInvalid()) {
Diag(Tok, diag::err_expected_while);
Diag(DoLoc, diag::note_matching) << "'do'";
SkipUntil(tok::semi, StopBeforeMatch);
}
return StmtError();
}
SourceLocation WhileLoc = ConsumeToken();
if (Tok.isNot(tok::l_paren)) {
Diag(Tok, diag::err_expected_lparen_after) << "do/while";
SkipUntil(tok::semi, StopBeforeMatch);
return StmtError();
}
// Parse the parenthesized expression.
BalancedDelimiterTracker T(*this, tok::l_paren);
T.consumeOpen();
// A do-while expression is not a condition, so can't have attributes.
DiagnoseAndSkipCXX11Attributes();
ExprResult Cond = ParseExpression();
T.consumeClose();
DoScope.Exit();
if (Cond.isInvalid() || Body.isInvalid())
return StmtError();
return Actions.ActOnDoStmt(DoLoc, Body.get(), WhileLoc, T.getOpenLocation(),
Cond.get(), T.getCloseLocation());
}
/// ParseForStatement
/// for-statement: [C99 6.8.5.3]
/// 'for' '(' expr[opt] ';' expr[opt] ';' expr[opt] ')' statement
/// 'for' '(' declaration expr[opt] ';' expr[opt] ')' statement
/// [C++] 'for' '(' for-init-statement condition[opt] ';' expression[opt] ')'
/// [C++] statement
/// [C++0x] 'for' '(' for-range-declaration : for-range-initializer ) statement
/// [OBJC2] 'for' '(' declaration 'in' expr ')' statement
/// [OBJC2] 'for' '(' expr 'in' expr ')' statement
///
/// [C++] for-init-statement:
/// [C++] expression-statement
/// [C++] simple-declaration
///
/// [C++0x] for-range-declaration:
/// [C++0x] attribute-specifier-seq[opt] type-specifier-seq declarator
/// [C++0x] for-range-initializer:
/// [C++0x] expression
/// [C++0x] braced-init-list [TODO]
StmtResult Parser::ParseForStatement(SourceLocation *TrailingElseLoc) {
assert(Tok.is(tok::kw_for) && "Not a for stmt!");
SourceLocation ForLoc = ConsumeToken(); // eat the 'for'.
if (Tok.isNot(tok::l_paren)) {
Diag(Tok, diag::err_expected_lparen_after) << "for";
SkipUntil(tok::semi);
return StmtError();
}
bool C99orCXXorObjC = getLangOpts().C99 || getLangOpts().CPlusPlus ||
getLangOpts().ObjC1;
// C99 6.8.5p5 - In C99, the for statement is a block. This is not
// the case for C90. Start the loop scope.
//
// C++ 6.4p3:
// A name introduced by a declaration in a condition is in scope from its
// point of declaration until the end of the substatements controlled by the
// condition.
// C++ 3.3.2p4:
// Names declared in the for-init-statement, and in the condition of if,
// while, for, and switch statements are local to the if, while, for, or
// switch statement (including the controlled statement).
// C++ 6.5.3p1:
// Names declared in the for-init-statement are in the same declarative-region
// as those declared in the condition.
//
unsigned ScopeFlags = 0;
if (C99orCXXorObjC)
ScopeFlags = Scope::DeclScope | Scope::ControlScope;
ParseScope ForScope(this, ScopeFlags);
BalancedDelimiterTracker T(*this, tok::l_paren);
T.consumeOpen();
ExprResult Value;
bool ForEach = false, ForRange = false;
StmtResult FirstPart;
bool SecondPartIsInvalid = false;
FullExprArg SecondPart(Actions);
ExprResult Collection;
ForRangeInit ForRangeInit;
FullExprArg ThirdPart(Actions);
Decl *SecondVar = 0;
if (Tok.is(tok::code_completion)) {
Actions.CodeCompleteOrdinaryName(getCurScope(),
C99orCXXorObjC? Sema::PCC_ForInit
: Sema::PCC_Expression);
cutOffParsing();
return StmtError();
}
ParsedAttributesWithRange attrs(AttrFactory);
MaybeParseCXX11Attributes(attrs);
// Parse the first part of the for specifier.
if (Tok.is(tok::semi)) { // for (;
ProhibitAttributes(attrs);
// no first part, eat the ';'.
ConsumeToken();
} else if (isForInitDeclaration()) { // for (int X = 4;
// Parse declaration, which eats the ';'.
if (!C99orCXXorObjC) // Use of C99-style for loops in C90 mode?
Diag(Tok, diag::ext_c99_variable_decl_in_for_loop);
// In C++0x, "for (T NS:a" might not be a typo for ::
bool MightBeForRangeStmt = getLangOpts().CPlusPlus;
ColonProtectionRAIIObject ColonProtection(*this, MightBeForRangeStmt);
SourceLocation DeclStart = Tok.getLocation(), DeclEnd;
StmtVector Stmts;
DeclGroupPtrTy DG = ParseSimpleDeclaration(Stmts, Declarator::ForContext,
DeclEnd, attrs, false,
MightBeForRangeStmt ?
&ForRangeInit : 0);
FirstPart = Actions.ActOnDeclStmt(DG, DeclStart, Tok.getLocation());
if (ForRangeInit.ParsedForRangeDecl()) {
Diag(ForRangeInit.ColonLoc, getLangOpts().CPlusPlus11 ?
diag::warn_cxx98_compat_for_range : diag::ext_for_range);
ForRange = true;
} else if (Tok.is(tok::semi)) { // for (int x = 4;
ConsumeToken();
} else if ((ForEach = isTokIdentifier_in())) {
Actions.ActOnForEachDeclStmt(DG);
// ObjC: for (id x in expr)
ConsumeToken(); // consume 'in'
if (Tok.is(tok::code_completion)) {
Actions.CodeCompleteObjCForCollection(getCurScope(), DG);
cutOffParsing();
return StmtError();
}
Collection = ParseExpression();
} else {
Diag(Tok, diag::err_expected_semi_for);
}
} else {
ProhibitAttributes(attrs);
Value = ParseExpression();
ForEach = isTokIdentifier_in();
// Turn the expression into a stmt.
if (!Value.isInvalid()) {
if (ForEach)
FirstPart = Actions.ActOnForEachLValueExpr(Value.get());
else
FirstPart = Actions.ActOnExprStmt(Value);
}
if (Tok.is(tok::semi)) {
ConsumeToken();
} else if (ForEach) {
ConsumeToken(); // consume 'in'
if (Tok.is(tok::code_completion)) {
Actions.CodeCompleteObjCForCollection(getCurScope(), DeclGroupPtrTy());
cutOffParsing();
return StmtError();
}
Collection = ParseExpression();
} else if (getLangOpts().CPlusPlus11 && Tok.is(tok::colon) && FirstPart.get()) {
// User tried to write the reasonable, but ill-formed, for-range-statement
// for (expr : expr) { ... }
Diag(Tok, diag::err_for_range_expected_decl)
<< FirstPart.get()->getSourceRange();
SkipUntil(tok::r_paren, StopBeforeMatch);
SecondPartIsInvalid = true;
} else {
if (!Value.isInvalid()) {
Diag(Tok, diag::err_expected_semi_for);
} else {
// Skip until semicolon or rparen, don't consume it.
SkipUntil(tok::r_paren, StopAtSemi | StopBeforeMatch);
if (Tok.is(tok::semi))
ConsumeToken();
}
}
}
// Parse the second part of the for specifier.
getCurScope()->AddFlags(Scope::BreakScope | Scope::ContinueScope);
if (!ForEach && !ForRange) {
assert(!SecondPart.get() && "Shouldn't have a second expression yet.");
// Parse the second part of the for specifier.
if (Tok.is(tok::semi)) { // for (...;;
// no second part.
} else if (Tok.is(tok::r_paren)) {
// missing both semicolons.
} else {
ExprResult Second;
if (getLangOpts().CPlusPlus)
ParseCXXCondition(Second, SecondVar, ForLoc, true);
else {
Second = ParseExpression();
if (!Second.isInvalid())
Second = Actions.ActOnBooleanCondition(getCurScope(), ForLoc,
Second.get());
}
SecondPartIsInvalid = Second.isInvalid();
SecondPart = Actions.MakeFullExpr(Second.get(), ForLoc);
}
if (Tok.isNot(tok::semi)) {
if (!SecondPartIsInvalid || SecondVar)
Diag(Tok, diag::err_expected_semi_for);
else
// Skip until semicolon or rparen, don't consume it.
SkipUntil(tok::r_paren, StopAtSemi | StopBeforeMatch);
}
if (Tok.is(tok::semi)) {
ConsumeToken();
}
// Parse the third part of the for specifier.
if (Tok.isNot(tok::r_paren)) { // for (...;...;)
ExprResult Third = ParseExpression();
// FIXME: The C++11 standard doesn't actually say that this is a
// discarded-value expression, but it clearly should be.
ThirdPart = Actions.MakeFullDiscardedValueExpr(Third.take());
}
}
// Match the ')'.
T.consumeClose();
// We need to perform most of the semantic analysis for a C++0x for-range
// statememt before parsing the body, in order to be able to deduce the type
// of an auto-typed loop variable.
StmtResult ForRangeStmt;
StmtResult ForEachStmt;
if (ForRange) {
ForRangeStmt = Actions.ActOnCXXForRangeStmt(ForLoc, FirstPart.take(),
ForRangeInit.ColonLoc,
ForRangeInit.RangeExpr.get(),
T.getCloseLocation(),
Sema::BFRK_Build);
// Similarly, we need to do the semantic analysis for a for-range
// statement immediately in order to close over temporaries correctly.
} else if (ForEach) {
ForEachStmt = Actions.ActOnObjCForCollectionStmt(ForLoc,
FirstPart.take(),
Collection.take(),
T.getCloseLocation());
}
// C99 6.8.5p5 - In C99, the body of the for statement is a scope, even if
// there is no compound stmt. C90 does not have this clause. We only do this
// if the body isn't a compound statement to avoid push/pop in common cases.
//
// C++ 6.5p2:
// The substatement in an iteration-statement implicitly defines a local scope
// which is entered and exited each time through the loop.
//
// See comments in ParseIfStatement for why we create a scope for
// for-init-statement/condition and a new scope for substatement in C++.
//
ParseScope InnerScope(this, Scope::DeclScope, C99orCXXorObjC,
Tok.is(tok::l_brace));
// The body of the for loop has the same local mangling number as the
// for-init-statement.
// It will only be incremented if the body contains other things that would
// normally increment the mangling number (like a compound statement).
if (C99orCXXorObjC)
getCurScope()->decrementMSLocalManglingNumber();
// Read the body statement.
StmtResult Body(ParseStatement(TrailingElseLoc));
// Pop the body scope if needed.
InnerScope.Exit();
// Leave the for-scope.
ForScope.Exit();
if (Body.isInvalid())
return StmtError();
if (ForEach)
return Actions.FinishObjCForCollectionStmt(ForEachStmt.take(),
Body.take());
if (ForRange)
return Actions.FinishCXXForRangeStmt(ForRangeStmt.take(), Body.take());
return Actions.ActOnForStmt(ForLoc, T.getOpenLocation(), FirstPart.take(),
SecondPart, SecondVar, ThirdPart,
T.getCloseLocation(), Body.take());
}
/// ParseGotoStatement
/// jump-statement:
/// 'goto' identifier ';'
/// [GNU] 'goto' '*' expression ';'
///
/// Note: this lets the caller parse the end ';'.
///
StmtResult Parser::ParseGotoStatement() {
assert(Tok.is(tok::kw_goto) && "Not a goto stmt!");
SourceLocation GotoLoc = ConsumeToken(); // eat the 'goto'.
StmtResult Res;
if (Tok.is(tok::identifier)) {
LabelDecl *LD = Actions.LookupOrCreateLabel(Tok.getIdentifierInfo(),
Tok.getLocation());
Res = Actions.ActOnGotoStmt(GotoLoc, Tok.getLocation(), LD);
ConsumeToken();
} else if (Tok.is(tok::star)) {
// GNU indirect goto extension.
Diag(Tok, diag::ext_gnu_indirect_goto);
SourceLocation StarLoc = ConsumeToken();
ExprResult R(ParseExpression());
if (R.isInvalid()) { // Skip to the semicolon, but don't consume it.
SkipUntil(tok::semi, StopBeforeMatch);
return StmtError();
}
Res = Actions.ActOnIndirectGotoStmt(GotoLoc, StarLoc, R.take());
} else {
Diag(Tok, diag::err_expected) << tok::identifier;
return StmtError();
}
return Res;
}
/// ParseContinueStatement
/// jump-statement:
/// 'continue' ';'
///
/// Note: this lets the caller parse the end ';'.
///
StmtResult Parser::ParseContinueStatement() {
SourceLocation ContinueLoc = ConsumeToken(); // eat the 'continue'.
return Actions.ActOnContinueStmt(ContinueLoc, getCurScope());
}
/// ParseBreakStatement
/// jump-statement:
/// 'break' ';'
///
/// Note: this lets the caller parse the end ';'.
///
StmtResult Parser::ParseBreakStatement() {
SourceLocation BreakLoc = ConsumeToken(); // eat the 'break'.
return Actions.ActOnBreakStmt(BreakLoc, getCurScope());
}
/// ParseReturnStatement
/// jump-statement:
/// 'return' expression[opt] ';'
StmtResult Parser::ParseReturnStatement() {
assert(Tok.is(tok::kw_return) && "Not a return stmt!");
SourceLocation ReturnLoc = ConsumeToken(); // eat the 'return'.
ExprResult R;
if (Tok.isNot(tok::semi)) {
if (Tok.is(tok::code_completion)) {
Actions.CodeCompleteReturn(getCurScope());
cutOffParsing();
return StmtError();
}
if (Tok.is(tok::l_brace) && getLangOpts().CPlusPlus) {
R = ParseInitializer();
if (R.isUsable())
Diag(R.get()->getLocStart(), getLangOpts().CPlusPlus11 ?
diag::warn_cxx98_compat_generalized_initializer_lists :
diag::ext_generalized_initializer_lists)
<< R.get()->getSourceRange();
} else
R = ParseExpression();
if (R.isInvalid()) {
SkipUntil(tok::r_brace, StopAtSemi | StopBeforeMatch);
return StmtError();
}
}
return Actions.ActOnReturnStmt(ReturnLoc, R.take());
}
namespace {
class ClangAsmParserCallback : public llvm::MCAsmParserSemaCallback {
Parser &TheParser;
SourceLocation AsmLoc;
StringRef AsmString;
/// The tokens we streamed into AsmString and handed off to MC.
ArrayRef<Token> AsmToks;
/// The offset of each token in AsmToks within AsmString.
ArrayRef<unsigned> AsmTokOffsets;
public:
ClangAsmParserCallback(Parser &P, SourceLocation Loc,
StringRef AsmString,
ArrayRef<Token> Toks,
ArrayRef<unsigned> Offsets)
: TheParser(P), AsmLoc(Loc), AsmString(AsmString),
AsmToks(Toks), AsmTokOffsets(Offsets) {
assert(AsmToks.size() == AsmTokOffsets.size());
}
void *LookupInlineAsmIdentifier(StringRef &LineBuf,
InlineAsmIdentifierInfo &Info,
bool IsUnevaluatedContext) {
// Collect the desired tokens.
SmallVector<Token, 16> LineToks;
const Token *FirstOrigToken = 0;
findTokensForString(LineBuf, LineToks, FirstOrigToken);
unsigned NumConsumedToks;
ExprResult Result =
TheParser.ParseMSAsmIdentifier(LineToks, NumConsumedToks, &Info,
IsUnevaluatedContext);
// If we consumed the entire line, tell MC that.
// Also do this if we consumed nothing as a way of reporting failure.
if (NumConsumedToks == 0 || NumConsumedToks == LineToks.size()) {
// By not modifying LineBuf, we're implicitly consuming it all.
// Otherwise, consume up to the original tokens.
} else {
assert(FirstOrigToken && "not using original tokens?");
// Since we're using original tokens, apply that offset.
assert(FirstOrigToken[NumConsumedToks].getLocation()
== LineToks[NumConsumedToks].getLocation());
unsigned FirstIndex = FirstOrigToken - AsmToks.begin();
unsigned LastIndex = FirstIndex + NumConsumedToks - 1;
// The total length we've consumed is the relative offset
// of the last token we consumed plus its length.
unsigned TotalOffset = (AsmTokOffsets[LastIndex]
+ AsmToks[LastIndex].getLength()
- AsmTokOffsets[FirstIndex]);
LineBuf = LineBuf.substr(0, TotalOffset);
}
// Initialize the "decl" with the lookup result.
Info.OpDecl = static_cast<void*>(Result.take());
return Info.OpDecl;
}
bool LookupInlineAsmField(StringRef Base, StringRef Member,
unsigned &Offset) {
return TheParser.getActions().LookupInlineAsmField(Base, Member,
Offset, AsmLoc);
}
static void DiagHandlerCallback(const llvm::SMDiagnostic &D,
void *Context) {
((ClangAsmParserCallback*) Context)->handleDiagnostic(D);
}
private:
/// Collect the appropriate tokens for the given string.
void findTokensForString(StringRef Str, SmallVectorImpl<Token> &TempToks,
const Token *&FirstOrigToken) const {
// For now, assert that the string we're working with is a substring
// of what we gave to MC. This lets us use the original tokens.
assert(!std::less<const char*>()(Str.begin(), AsmString.begin()) &&
!std::less<const char*>()(AsmString.end(), Str.end()));
// Try to find a token whose offset matches the first token.
unsigned FirstCharOffset = Str.begin() - AsmString.begin();
const unsigned *FirstTokOffset
= std::lower_bound(AsmTokOffsets.begin(), AsmTokOffsets.end(),
FirstCharOffset);
// For now, assert that the start of the string exactly
// corresponds to the start of a token.
assert(*FirstTokOffset == FirstCharOffset);
// Use all the original tokens for this line. (We assume the
// end of the line corresponds cleanly to a token break.)
unsigned FirstTokIndex = FirstTokOffset - AsmTokOffsets.begin();
FirstOrigToken = &AsmToks[FirstTokIndex];
unsigned LastCharOffset = Str.end() - AsmString.begin();
for (unsigned i = FirstTokIndex, e = AsmTokOffsets.size(); i != e; ++i) {
if (AsmTokOffsets[i] >= LastCharOffset) break;
TempToks.push_back(AsmToks[i]);
}
}
void handleDiagnostic(const llvm::SMDiagnostic &D) {
// Compute an offset into the inline asm buffer.
// FIXME: This isn't right if .macro is involved (but hopefully, no
// real-world code does that).
const llvm::SourceMgr &LSM = *D.getSourceMgr();
const llvm::MemoryBuffer *LBuf =
LSM.getMemoryBuffer(LSM.FindBufferContainingLoc(D.getLoc()));
unsigned Offset = D.getLoc().getPointer() - LBuf->getBufferStart();
// Figure out which token that offset points into.
const unsigned *TokOffsetPtr =
std::lower_bound(AsmTokOffsets.begin(), AsmTokOffsets.end(), Offset);
unsigned TokIndex = TokOffsetPtr - AsmTokOffsets.begin();
unsigned TokOffset = *TokOffsetPtr;
// If we come up with an answer which seems sane, use it; otherwise,
// just point at the __asm keyword.
// FIXME: Assert the answer is sane once we handle .macro correctly.
SourceLocation Loc = AsmLoc;
if (TokIndex < AsmToks.size()) {
const Token &Tok = AsmToks[TokIndex];
Loc = Tok.getLocation();
Loc = Loc.getLocWithOffset(Offset - TokOffset);
}
TheParser.Diag(Loc, diag::err_inline_ms_asm_parsing)
<< D.getMessage();
}
};
}
/// Parse an identifier in an MS-style inline assembly block.
///
/// \param CastInfo - a void* so that we don't have to teach Parser.h
/// about the actual type.
ExprResult Parser::ParseMSAsmIdentifier(llvm::SmallVectorImpl<Token> &LineToks,
unsigned &NumLineToksConsumed,
void *CastInfo,
bool IsUnevaluatedContext) {
llvm::InlineAsmIdentifierInfo &Info =
*(llvm::InlineAsmIdentifierInfo *) CastInfo;
// Push a fake token on the end so that we don't overrun the token
// stream. We use ';' because it expression-parsing should never
// overrun it.
const tok::TokenKind EndOfStream = tok::semi;
Token EndOfStreamTok;
EndOfStreamTok.startToken();
EndOfStreamTok.setKind(EndOfStream);
LineToks.push_back(EndOfStreamTok);
// Also copy the current token over.
LineToks.push_back(Tok);
PP.EnterTokenStream(LineToks.begin(),
LineToks.size(),
/*disable macros*/ true,
/*owns tokens*/ false);
// Clear the current token and advance to the first token in LineToks.
ConsumeAnyToken();
// Parse an optional scope-specifier if we're in C++.
CXXScopeSpec SS;
if (getLangOpts().CPlusPlus) {
ParseOptionalCXXScopeSpecifier(SS, ParsedType(), /*EnteringContext=*/false);
}
// Require an identifier here.
SourceLocation TemplateKWLoc;
UnqualifiedId Id;
bool Invalid = ParseUnqualifiedId(SS,
/*EnteringContext=*/false,
/*AllowDestructorName=*/false,
/*AllowConstructorName=*/false,
/*ObjectType=*/ ParsedType(),
TemplateKWLoc,
Id);
// Figure out how many tokens we are into LineToks.
unsigned LineIndex = 0;
if (Tok.is(EndOfStream)) {
LineIndex = LineToks.size() - 2;
} else {
while (LineToks[LineIndex].getLocation() != Tok.getLocation()) {
LineIndex++;
assert(LineIndex < LineToks.size() - 2); // we added two extra tokens
}
}
// If we've run into the poison token we inserted before, or there
// was a parsing error, then claim the entire line.
if (Invalid || Tok.is(EndOfStream)) {
NumLineToksConsumed = LineToks.size() - 2;
} else {
// Otherwise, claim up to the start of the next token.
NumLineToksConsumed = LineIndex;
}
// Finally, restore the old parsing state by consuming all the tokens we
// staged before, implicitly killing off the token-lexer we pushed.
for (unsigned i = 0, e = LineToks.size() - LineIndex - 2; i != e; ++i) {
ConsumeAnyToken();
}
assert(Tok.is(EndOfStream));
ConsumeToken();
// Leave LineToks in its original state.
LineToks.pop_back();
LineToks.pop_back();
// Perform the lookup.
return Actions.LookupInlineAsmIdentifier(SS, TemplateKWLoc, Id, Info,
IsUnevaluatedContext);
}
/// Turn a sequence of our tokens back into a string that we can hand
/// to the MC asm parser.
static bool buildMSAsmString(Preprocessor &PP,
SourceLocation AsmLoc,
ArrayRef<Token> AsmToks,
SmallVectorImpl<unsigned> &TokOffsets,
SmallString<512> &Asm) {
assert (!AsmToks.empty() && "Didn't expect an empty AsmToks!");
// Is this the start of a new assembly statement?
bool isNewStatement = true;
for (unsigned i = 0, e = AsmToks.size(); i < e; ++i) {
const Token &Tok = AsmToks[i];
// Start each new statement with a newline and a tab.
if (!isNewStatement &&
(Tok.is(tok::kw_asm) || Tok.isAtStartOfLine())) {
Asm += "\n\t";
isNewStatement = true;
}
// Preserve the existence of leading whitespace except at the
// start of a statement.
if (!isNewStatement && Tok.hasLeadingSpace())
Asm += ' ';
// Remember the offset of this token.
TokOffsets.push_back(Asm.size());
// Don't actually write '__asm' into the assembly stream.
if (Tok.is(tok::kw_asm)) {
// Complain about __asm at the end of the stream.
if (i + 1 == e) {
PP.Diag(AsmLoc, diag::err_asm_empty);
return true;
}
continue;
}
// Append the spelling of the token.
SmallString<32> SpellingBuffer;
bool SpellingInvalid = false;
Asm += PP.getSpelling(Tok, SpellingBuffer, &SpellingInvalid);
assert(!SpellingInvalid && "spelling was invalid after correct parse?");
// We are no longer at the start of a statement.
isNewStatement = false;
}
// Ensure that the buffer is null-terminated.
Asm.push_back('\0');
Asm.pop_back();
assert(TokOffsets.size() == AsmToks.size());
return false;
}
/// ParseMicrosoftAsmStatement. When -fms-extensions/-fasm-blocks is enabled,
/// this routine is called to collect the tokens for an MS asm statement.
///
/// [MS] ms-asm-statement:
/// ms-asm-block
/// ms-asm-block ms-asm-statement
///
/// [MS] ms-asm-block:
/// '__asm' ms-asm-line '\n'
/// '__asm' '{' ms-asm-instruction-block[opt] '}' ';'[opt]
///
/// [MS] ms-asm-instruction-block
/// ms-asm-line
/// ms-asm-line '\n' ms-asm-instruction-block
///
StmtResult Parser::ParseMicrosoftAsmStatement(SourceLocation AsmLoc) {
SourceManager &SrcMgr = PP.getSourceManager();
SourceLocation EndLoc = AsmLoc;
SmallVector<Token, 4> AsmToks;
bool InBraces = false;
unsigned short savedBraceCount = 0;
bool InAsmComment = false;
FileID FID;
unsigned LineNo = 0;
unsigned NumTokensRead = 0;
SourceLocation LBraceLoc;
if (Tok.is(tok::l_brace)) {
// Braced inline asm: consume the opening brace.
InBraces = true;
savedBraceCount = BraceCount;
EndLoc = LBraceLoc = ConsumeBrace();
++NumTokensRead;
} else {
// Single-line inline asm; compute which line it is on.
std::pair<FileID, unsigned> ExpAsmLoc =
SrcMgr.getDecomposedExpansionLoc(EndLoc);
FID = ExpAsmLoc.first;
LineNo = SrcMgr.getLineNumber(FID, ExpAsmLoc.second);
}
SourceLocation TokLoc = Tok.getLocation();
do {
// If we hit EOF, we're done, period.
if (isEofOrEom())
break;
if (!InAsmComment && Tok.is(tok::semi)) {
// A semicolon in an asm is the start of a comment.
InAsmComment = true;
if (InBraces) {
// Compute which line the comment is on.
std::pair<FileID, unsigned> ExpSemiLoc =
SrcMgr.getDecomposedExpansionLoc(TokLoc);
FID = ExpSemiLoc.first;
LineNo = SrcMgr.getLineNumber(FID, ExpSemiLoc.second);
}
} else if (!InBraces || InAsmComment) {
// If end-of-line is significant, check whether this token is on a
// new line.
std::pair<FileID, unsigned> ExpLoc =
SrcMgr.getDecomposedExpansionLoc(TokLoc);
if (ExpLoc.first != FID ||
SrcMgr.getLineNumber(ExpLoc.first, ExpLoc.second) != LineNo) {
// If this is a single-line __asm, we're done.
if (!InBraces)
break;
// We're no longer in a comment.
InAsmComment = false;
} else if (!InAsmComment && Tok.is(tok::r_brace)) {
// Single-line asm always ends when a closing brace is seen.
// FIXME: This is compatible with Apple gcc's -fasm-blocks; what
// does MSVC do here?
break;
}
}
if (!InAsmComment && InBraces && Tok.is(tok::r_brace) &&
BraceCount == (savedBraceCount + 1)) {
// Consume the closing brace, and finish
EndLoc = ConsumeBrace();
break;
}
// Consume the next token; make sure we don't modify the brace count etc.
// if we are in a comment.
EndLoc = TokLoc;
if (InAsmComment)
PP.Lex(Tok);
else {
AsmToks.push_back(Tok);
ConsumeAnyToken();
}
TokLoc = Tok.getLocation();
++NumTokensRead;
} while (1);
if (InBraces && BraceCount != savedBraceCount) {
// __asm without closing brace (this can happen at EOF).
Diag(Tok, diag::err_expected) << tok::r_brace;
Diag(LBraceLoc, diag::note_matching) << tok::l_brace;
return StmtError();
} else if (NumTokensRead == 0) {
// Empty __asm.
Diag(Tok, diag::err_expected) << tok::l_brace;
return StmtError();
}
// Okay, prepare to use MC to parse the assembly.
SmallVector<StringRef, 4> ConstraintRefs;
SmallVector<Expr*, 4> Exprs;
SmallVector<StringRef, 4> ClobberRefs;
// We need an actual supported target.
const llvm::Triple &TheTriple = Actions.Context.getTargetInfo().getTriple();
llvm::Triple::ArchType ArchTy = TheTriple.getArch();
const std::string &TT = TheTriple.getTriple();
const llvm::Target *TheTarget = 0;
bool UnsupportedArch = (ArchTy != llvm::Triple::x86 &&
ArchTy != llvm::Triple::x86_64);
if (UnsupportedArch) {
Diag(AsmLoc, diag::err_msasm_unsupported_arch) << TheTriple.getArchName();
} else {
std::string Error;
TheTarget = llvm::TargetRegistry::lookupTarget(TT, Error);
if (!TheTarget)
Diag(AsmLoc, diag::err_msasm_unable_to_create_target) << Error;
}
// If we don't support assembly, or the assembly is empty, we don't
// need to instantiate the AsmParser, etc.
if (!TheTarget || AsmToks.empty()) {
return Actions.ActOnMSAsmStmt(AsmLoc, LBraceLoc, AsmToks, StringRef(),
/*NumOutputs*/ 0, /*NumInputs*/ 0,
ConstraintRefs, ClobberRefs, Exprs, EndLoc);
}
// Expand the tokens into a string buffer.
SmallString<512> AsmString;
SmallVector<unsigned, 8> TokOffsets;
if (buildMSAsmString(PP, AsmLoc, AsmToks, TokOffsets, AsmString))
return StmtError();
std::unique_ptr<llvm::MCRegisterInfo> MRI(TheTarget->createMCRegInfo(TT));
std::unique_ptr<llvm::MCAsmInfo> MAI(TheTarget->createMCAsmInfo(*MRI, TT));
// Get the instruction descriptor.
const llvm::MCInstrInfo *MII = TheTarget->createMCInstrInfo();
std::unique_ptr<llvm::MCObjectFileInfo> MOFI(new llvm::MCObjectFileInfo());
std::unique_ptr<llvm::MCSubtargetInfo> STI(
TheTarget->createMCSubtargetInfo(TT, "", ""));
llvm::SourceMgr TempSrcMgr;
llvm::MCContext Ctx(MAI.get(), MRI.get(), MOFI.get(), &TempSrcMgr);
llvm::MemoryBuffer *Buffer =
llvm::MemoryBuffer::getMemBuffer(AsmString, "<MS inline asm>");
// Tell SrcMgr about this buffer, which is what the parser will pick up.
TempSrcMgr.AddNewSourceBuffer(Buffer, llvm::SMLoc());
std::unique_ptr<llvm::MCStreamer> Str(createNullStreamer(Ctx));
std::unique_ptr<llvm::MCAsmParser> Parser(
createMCAsmParser(TempSrcMgr, Ctx, *Str.get(), *MAI));
std::unique_ptr<llvm::MCTargetAsmParser> TargetParser(
TheTarget->createMCAsmParser(*STI, *Parser, *MII));
llvm::MCInstPrinter *IP =
TheTarget->createMCInstPrinter(1, *MAI, *MII, *MRI, *STI);
// Change to the Intel dialect.
Parser->setAssemblerDialect(1);
Parser->setTargetParser(*TargetParser.get());
Parser->setParsingInlineAsm(true);
TargetParser->setParsingInlineAsm(true);
ClangAsmParserCallback Callback(*this, AsmLoc, AsmString,
AsmToks, TokOffsets);
TargetParser->setSemaCallback(&Callback);
TempSrcMgr.setDiagHandler(ClangAsmParserCallback::DiagHandlerCallback,
&Callback);
unsigned NumOutputs;
unsigned NumInputs;
std::string AsmStringIR;
SmallVector<std::pair<void *, bool>, 4> OpExprs;
SmallVector<std::string, 4> Constraints;
SmallVector<std::string, 4> Clobbers;
if (Parser->parseMSInlineAsm(AsmLoc.getPtrEncoding(), AsmStringIR,
NumOutputs, NumInputs, OpExprs, Constraints,
Clobbers, MII, IP, Callback))
return StmtError();
// Build the vector of clobber StringRefs.
unsigned NumClobbers = Clobbers.size();
ClobberRefs.resize(NumClobbers);
for (unsigned i = 0; i != NumClobbers; ++i)
ClobberRefs[i] = StringRef(Clobbers[i]);
// Recast the void pointers and build the vector of constraint StringRefs.
unsigned NumExprs = NumOutputs + NumInputs;
ConstraintRefs.resize(NumExprs);
Exprs.resize(NumExprs);
for (unsigned i = 0, e = NumExprs; i != e; ++i) {
Expr *OpExpr = static_cast<Expr *>(OpExprs[i].first);
if (!OpExpr)
return StmtError();
// Need address of variable.
if (OpExprs[i].second)
OpExpr = Actions.BuildUnaryOp(getCurScope(), AsmLoc, UO_AddrOf, OpExpr)
.take();
ConstraintRefs[i] = StringRef(Constraints[i]);
Exprs[i] = OpExpr;
}
// FIXME: We should be passing source locations for better diagnostics.
return Actions.ActOnMSAsmStmt(AsmLoc, LBraceLoc, AsmToks, AsmStringIR,
NumOutputs, NumInputs,
ConstraintRefs, ClobberRefs, Exprs, EndLoc);
}
/// ParseAsmStatement - Parse a GNU extended asm statement.
/// asm-statement:
/// gnu-asm-statement
/// ms-asm-statement
///
/// [GNU] gnu-asm-statement:
/// 'asm' type-qualifier[opt] '(' asm-argument ')' ';'
///
/// [GNU] asm-argument:
/// asm-string-literal
/// asm-string-literal ':' asm-operands[opt]
/// asm-string-literal ':' asm-operands[opt] ':' asm-operands[opt]
/// asm-string-literal ':' asm-operands[opt] ':' asm-operands[opt]
/// ':' asm-clobbers
///
/// [GNU] asm-clobbers:
/// asm-string-literal
/// asm-clobbers ',' asm-string-literal
///
StmtResult Parser::ParseAsmStatement(bool &msAsm) {
assert(Tok.is(tok::kw_asm) && "Not an asm stmt");
SourceLocation AsmLoc = ConsumeToken();
if (getLangOpts().AsmBlocks && Tok.isNot(tok::l_paren) &&
!isTypeQualifier()) {
msAsm = true;
return ParseMicrosoftAsmStatement(AsmLoc);
}
DeclSpec DS(AttrFactory);
SourceLocation Loc = Tok.getLocation();
ParseTypeQualifierListOpt(DS, true, false);
// GNU asms accept, but warn, about type-qualifiers other than volatile.
if (DS.getTypeQualifiers() & DeclSpec::TQ_const)
Diag(Loc, diag::w_asm_qualifier_ignored) << "const";
if (DS.getTypeQualifiers() & DeclSpec::TQ_restrict)
Diag(Loc, diag::w_asm_qualifier_ignored) << "restrict";
// FIXME: Once GCC supports _Atomic, check whether it permits it here.
if (DS.getTypeQualifiers() & DeclSpec::TQ_atomic)
Diag(Loc, diag::w_asm_qualifier_ignored) << "_Atomic";
// Remember if this was a volatile asm.
bool isVolatile = DS.getTypeQualifiers() & DeclSpec::TQ_volatile;
if (Tok.isNot(tok::l_paren)) {
Diag(Tok, diag::err_expected_lparen_after) << "asm";
SkipUntil(tok::r_paren, StopAtSemi);
return StmtError();
}
BalancedDelimiterTracker T(*this, tok::l_paren);
T.consumeOpen();
ExprResult AsmString(ParseAsmStringLiteral());
if (AsmString.isInvalid()) {
// Consume up to and including the closing paren.
T.skipToEnd();
return StmtError();
}
SmallVector<IdentifierInfo *, 4> Names;
ExprVector Constraints;
ExprVector Exprs;
ExprVector Clobbers;
if (Tok.is(tok::r_paren)) {
// We have a simple asm expression like 'asm("foo")'.
T.consumeClose();
return Actions.ActOnGCCAsmStmt(AsmLoc, /*isSimple*/ true, isVolatile,
/*NumOutputs*/ 0, /*NumInputs*/ 0, 0,
Constraints, Exprs, AsmString.take(),
Clobbers, T.getCloseLocation());
}
// Parse Outputs, if present.
bool AteExtraColon = false;
if (Tok.is(tok::colon) || Tok.is(tok::coloncolon)) {
// In C++ mode, parse "::" like ": :".
AteExtraColon = Tok.is(tok::coloncolon);
ConsumeToken();
if (!AteExtraColon &&
ParseAsmOperandsOpt(Names, Constraints, Exprs))
return StmtError();
}
unsigned NumOutputs = Names.size();
// Parse Inputs, if present.
if (AteExtraColon ||
Tok.is(tok::colon) || Tok.is(tok::coloncolon)) {
// In C++ mode, parse "::" like ": :".
if (AteExtraColon)
AteExtraColon = false;
else {
AteExtraColon = Tok.is(tok::coloncolon);
ConsumeToken();
}
if (!AteExtraColon &&
ParseAsmOperandsOpt(Names, Constraints, Exprs))
return StmtError();
}
assert(Names.size() == Constraints.size() &&
Constraints.size() == Exprs.size() &&
"Input operand size mismatch!");
unsigned NumInputs = Names.size() - NumOutputs;
// Parse the clobbers, if present.
if (AteExtraColon || Tok.is(tok::colon)) {
if (!AteExtraColon)
ConsumeToken();
// Parse the asm-string list for clobbers if present.
if (Tok.isNot(tok::r_paren)) {
while (1) {
ExprResult Clobber(ParseAsmStringLiteral());
if (Clobber.isInvalid())
break;
Clobbers.push_back(Clobber.release());
if (!TryConsumeToken(tok::comma))
break;
}
}
}
T.consumeClose();
return Actions.ActOnGCCAsmStmt(AsmLoc, false, isVolatile, NumOutputs,
NumInputs, Names.data(), Constraints, Exprs,
AsmString.take(), Clobbers,
T.getCloseLocation());
}
/// ParseAsmOperands - Parse the asm-operands production as used by
/// asm-statement, assuming the leading ':' token was eaten.
///
/// [GNU] asm-operands:
/// asm-operand
/// asm-operands ',' asm-operand
///
/// [GNU] asm-operand:
/// asm-string-literal '(' expression ')'
/// '[' identifier ']' asm-string-literal '(' expression ')'
///
//
// FIXME: Avoid unnecessary std::string trashing.
bool Parser::ParseAsmOperandsOpt(SmallVectorImpl<IdentifierInfo *> &Names,
SmallVectorImpl<Expr *> &Constraints,
SmallVectorImpl<Expr *> &Exprs) {
// 'asm-operands' isn't present?
if (!isTokenStringLiteral() && Tok.isNot(tok::l_square))
return false;
while (1) {
// Read the [id] if present.
if (Tok.is(tok::l_square)) {
BalancedDelimiterTracker T(*this, tok::l_square);
T.consumeOpen();
if (Tok.isNot(tok::identifier)) {
Diag(Tok, diag::err_expected) << tok::identifier;
SkipUntil(tok::r_paren, StopAtSemi);
return true;
}
IdentifierInfo *II = Tok.getIdentifierInfo();
ConsumeToken();
Names.push_back(II);
T.consumeClose();
} else
Names.push_back(0);
ExprResult Constraint(ParseAsmStringLiteral());
if (Constraint.isInvalid()) {
SkipUntil(tok::r_paren, StopAtSemi);
return true;
}
Constraints.push_back(Constraint.release());
if (Tok.isNot(tok::l_paren)) {
Diag(Tok, diag::err_expected_lparen_after) << "asm operand";
SkipUntil(tok::r_paren, StopAtSemi);
return true;
}
// Read the parenthesized expression.
BalancedDelimiterTracker T(*this, tok::l_paren);
T.consumeOpen();
ExprResult Res(ParseExpression());
T.consumeClose();
if (Res.isInvalid()) {
SkipUntil(tok::r_paren, StopAtSemi);
return true;
}
Exprs.push_back(Res.release());
// Eat the comma and continue parsing if it exists.
if (!TryConsumeToken(tok::comma))
return false;
}
}
Decl *Parser::ParseFunctionStatementBody(Decl *Decl, ParseScope &BodyScope) {
assert(Tok.is(tok::l_brace));
SourceLocation LBraceLoc = Tok.getLocation();
if (SkipFunctionBodies && (!Decl || Actions.canSkipFunctionBody(Decl)) &&
trySkippingFunctionBody()) {
BodyScope.Exit();
return Actions.ActOnSkippedFunctionBody(Decl);
}
PrettyDeclStackTraceEntry CrashInfo(Actions, Decl, LBraceLoc,
"parsing function body");
// Do not enter a scope for the brace, as the arguments are in the same scope
// (the function body) as the body itself. Instead, just read the statement
// list and put it into a CompoundStmt for safe keeping.
StmtResult FnBody(ParseCompoundStatementBody());
// If the function body could not be parsed, make a bogus compoundstmt.
if (FnBody.isInvalid()) {
Sema::CompoundScopeRAII CompoundScope(Actions);
FnBody = Actions.ActOnCompoundStmt(LBraceLoc, LBraceLoc, None, false);
}
BodyScope.Exit();
return Actions.ActOnFinishFunctionBody(Decl, FnBody.take());
}
/// ParseFunctionTryBlock - Parse a C++ function-try-block.
///
/// function-try-block:
/// 'try' ctor-initializer[opt] compound-statement handler-seq
///
Decl *Parser::ParseFunctionTryBlock(Decl *Decl, ParseScope &BodyScope) {
assert(Tok.is(tok::kw_try) && "Expected 'try'");
SourceLocation TryLoc = ConsumeToken();
PrettyDeclStackTraceEntry CrashInfo(Actions, Decl, TryLoc,
"parsing function try block");
// Constructor initializer list?
if (Tok.is(tok::colon))
ParseConstructorInitializer(Decl);
else
Actions.ActOnDefaultCtorInitializers(Decl);
if (SkipFunctionBodies && Actions.canSkipFunctionBody(Decl) &&
trySkippingFunctionBody()) {
BodyScope.Exit();
return Actions.ActOnSkippedFunctionBody(Decl);
}
SourceLocation LBraceLoc = Tok.getLocation();
StmtResult FnBody(ParseCXXTryBlockCommon(TryLoc, /*FnTry*/true));
// If we failed to parse the try-catch, we just give the function an empty
// compound statement as the body.
if (FnBody.isInvalid()) {
Sema::CompoundScopeRAII CompoundScope(Actions);
FnBody = Actions.ActOnCompoundStmt(LBraceLoc, LBraceLoc, None, false);
}
BodyScope.Exit();
return Actions.ActOnFinishFunctionBody(Decl, FnBody.take());
}
bool Parser::trySkippingFunctionBody() {
assert(Tok.is(tok::l_brace));
assert(SkipFunctionBodies &&
"Should only be called when SkipFunctionBodies is enabled");
if (!PP.isCodeCompletionEnabled()) {
ConsumeBrace();
SkipUntil(tok::r_brace);
return true;
}
// We're in code-completion mode. Skip parsing for all function bodies unless
// the body contains the code-completion point.
TentativeParsingAction PA(*this);
ConsumeBrace();
if (SkipUntil(tok::r_brace, StopAtCodeCompletion)) {
PA.Commit();
return true;
}
PA.Revert();
return false;
}
/// ParseCXXTryBlock - Parse a C++ try-block.
///
/// try-block:
/// 'try' compound-statement handler-seq
///
StmtResult Parser::ParseCXXTryBlock() {
assert(Tok.is(tok::kw_try) && "Expected 'try'");
SourceLocation TryLoc = ConsumeToken();
return ParseCXXTryBlockCommon(TryLoc);
}
/// ParseCXXTryBlockCommon - Parse the common part of try-block and
/// function-try-block.
///
/// try-block:
/// 'try' compound-statement handler-seq
///
/// function-try-block:
/// 'try' ctor-initializer[opt] compound-statement handler-seq
///
/// handler-seq:
/// handler handler-seq[opt]
///
/// [Borland] try-block:
/// 'try' compound-statement seh-except-block
/// 'try' compound-statement seh-finally-block
///
StmtResult Parser::ParseCXXTryBlockCommon(SourceLocation TryLoc, bool FnTry) {
if (Tok.isNot(tok::l_brace))
return StmtError(Diag(Tok, diag::err_expected) << tok::l_brace);
// FIXME: Possible draft standard bug: attribute-specifier should be allowed?
StmtResult TryBlock(ParseCompoundStatement(/*isStmtExpr=*/false,
Scope::DeclScope | Scope::TryScope |
(FnTry ? Scope::FnTryCatchScope : 0)));
if (TryBlock.isInvalid())
return TryBlock;
// Borland allows SEH-handlers with 'try'
if ((Tok.is(tok::identifier) &&
Tok.getIdentifierInfo() == getSEHExceptKeyword()) ||
Tok.is(tok::kw___finally)) {
// TODO: Factor into common return ParseSEHHandlerCommon(...)
StmtResult Handler;
if(Tok.getIdentifierInfo() == getSEHExceptKeyword()) {
SourceLocation Loc = ConsumeToken();
Handler = ParseSEHExceptBlock(Loc);
}
else {
SourceLocation Loc = ConsumeToken();
Handler = ParseSEHFinallyBlock(Loc);
}
if(Handler.isInvalid())
return Handler;
return Actions.ActOnSEHTryBlock(true /* IsCXXTry */,
TryLoc,
TryBlock.take(),
Handler.take());
}
else {
StmtVector Handlers;
// C++11 attributes can't appear here, despite this context seeming
// statement-like.
DiagnoseAndSkipCXX11Attributes();
if (Tok.isNot(tok::kw_catch))
return StmtError(Diag(Tok, diag::err_expected_catch));
while (Tok.is(tok::kw_catch)) {
StmtResult Handler(ParseCXXCatchBlock(FnTry));
if (!Handler.isInvalid())
Handlers.push_back(Handler.release());
}
// Don't bother creating the full statement if we don't have any usable
// handlers.
if (Handlers.empty())
return StmtError();
return Actions.ActOnCXXTryBlock(TryLoc, TryBlock.take(), Handlers);
}
}
/// ParseCXXCatchBlock - Parse a C++ catch block, called handler in the standard
///
/// handler:
/// 'catch' '(' exception-declaration ')' compound-statement
///
/// exception-declaration:
/// attribute-specifier-seq[opt] type-specifier-seq declarator
/// attribute-specifier-seq[opt] type-specifier-seq abstract-declarator[opt]
/// '...'
///
StmtResult Parser::ParseCXXCatchBlock(bool FnCatch) {
assert(Tok.is(tok::kw_catch) && "Expected 'catch'");
SourceLocation CatchLoc = ConsumeToken();
BalancedDelimiterTracker T(*this, tok::l_paren);
if (T.expectAndConsume())
return StmtError();
// C++ 3.3.2p3:
// The name in a catch exception-declaration is local to the handler and
// shall not be redeclared in the outermost block of the handler.
ParseScope CatchScope(this, Scope::DeclScope | Scope::ControlScope |
(FnCatch ? Scope::FnTryCatchScope : 0));
// exception-declaration is equivalent to '...' or a parameter-declaration
// without default arguments.
Decl *ExceptionDecl = 0;
if (Tok.isNot(tok::ellipsis)) {
ParsedAttributesWithRange Attributes(AttrFactory);
MaybeParseCXX11Attributes(Attributes);
DeclSpec DS(AttrFactory);
DS.takeAttributesFrom(Attributes);
if (ParseCXXTypeSpecifierSeq(DS))
return StmtError();
Declarator ExDecl(DS, Declarator::CXXCatchContext);
ParseDeclarator(ExDecl);
ExceptionDecl = Actions.ActOnExceptionDeclarator(getCurScope(), ExDecl);
} else
ConsumeToken();
T.consumeClose();
if (T.getCloseLocation().isInvalid())
return StmtError();
if (Tok.isNot(tok::l_brace))
return StmtError(Diag(Tok, diag::err_expected) << tok::l_brace);
// FIXME: Possible draft standard bug: attribute-specifier should be allowed?
StmtResult Block(ParseCompoundStatement());
if (Block.isInvalid())
return Block;
return Actions.ActOnCXXCatchBlock(CatchLoc, ExceptionDecl, Block.take());
}
void Parser::ParseMicrosoftIfExistsStatement(StmtVector &Stmts) {
IfExistsCondition Result;
if (ParseMicrosoftIfExistsCondition(Result))
return;
// Handle dependent statements by parsing the braces as a compound statement.
// This is not the same behavior as Visual C++, which don't treat this as a
// compound statement, but for Clang's type checking we can't have anything
// inside these braces escaping to the surrounding code.
if (Result.Behavior == IEB_Dependent) {
if (!Tok.is(tok::l_brace)) {
Diag(Tok, diag::err_expected) << tok::l_brace;
return;
}
StmtResult Compound = ParseCompoundStatement();
if (Compound.isInvalid())
return;
StmtResult DepResult = Actions.ActOnMSDependentExistsStmt(Result.KeywordLoc,
Result.IsIfExists,
Result.SS,
Result.Name,
Compound.get());
if (DepResult.isUsable())
Stmts.push_back(DepResult.get());
return;
}
BalancedDelimiterTracker Braces(*this, tok::l_brace);
if (Braces.consumeOpen()) {
Diag(Tok, diag::err_expected) << tok::l_brace;
return;
}
switch (Result.Behavior) {
case IEB_Parse:
// Parse the statements below.
break;
case IEB_Dependent:
llvm_unreachable("Dependent case handled above");
case IEB_Skip:
Braces.skipToEnd();
return;
}
// Condition is true, parse the statements.
while (Tok.isNot(tok::r_brace)) {
StmtResult R = ParseStatementOrDeclaration(Stmts, false);
if (R.isUsable())
Stmts.push_back(R.release());
}
Braces.consumeClose();
}
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