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llvm-project/clang/lib/Lex/PPDirectives.cpp

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//===--- PPDirectives.cpp - Directive Handling for Preprocessor -----------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements # directive processing for the Preprocessor.
//
//===----------------------------------------------------------------------===//
#include "clang/Lex/Preprocessor.h"
#include "clang/Lex/HeaderSearch.h"
#include "clang/Lex/MacroInfo.h"
#include "clang/Lex/PPCallbacks.h"
#include "clang/Basic/Diagnostic.h"
#include "clang/Basic/SourceManager.h"
using namespace clang;
//===----------------------------------------------------------------------===//
// Utility Methods for Preprocessor Directive Handling.
//===----------------------------------------------------------------------===//
/// DiscardUntilEndOfDirective - Read and discard all tokens remaining on the
/// current line until the tok::eom token is found.
void Preprocessor::DiscardUntilEndOfDirective() {
Token Tmp;
do {
LexUnexpandedToken(Tmp);
} while (Tmp.isNot(tok::eom));
}
/// isCXXNamedOperator - Returns "true" if the token is a named operator in C++.
static bool isCXXNamedOperator(const std::string &Spelling) {
return Spelling == "and" || Spelling == "bitand" || Spelling == "bitor" ||
Spelling == "compl" || Spelling == "not" || Spelling == "not_eq" ||
Spelling == "or" || Spelling == "xor";
}
/// ReadMacroName - Lex and validate a macro name, which occurs after a
/// #define or #undef. This sets the token kind to eom and discards the rest
/// of the macro line if the macro name is invalid. isDefineUndef is 1 if
/// this is due to a a #define, 2 if #undef directive, 0 if it is something
/// else (e.g. #ifdef).
void Preprocessor::ReadMacroName(Token &MacroNameTok, char isDefineUndef) {
// Read the token, don't allow macro expansion on it.
LexUnexpandedToken(MacroNameTok);
// Missing macro name?
if (MacroNameTok.is(tok::eom))
return Diag(MacroNameTok, diag::err_pp_missing_macro_name);
IdentifierInfo *II = MacroNameTok.getIdentifierInfo();
if (II == 0) {
std::string Spelling = getSpelling(MacroNameTok);
if (isCXXNamedOperator(Spelling))
// C++ 2.5p2: Alternative tokens behave the same as its primary token
// except for their spellings.
Diag(MacroNameTok, diag::err_pp_operator_used_as_macro_name, Spelling);
else
Diag(MacroNameTok, diag::err_pp_macro_not_identifier);
// Fall through on error.
} else if (isDefineUndef && II->getPPKeywordID() == tok::pp_defined) {
// Error if defining "defined": C99 6.10.8.4.
Diag(MacroNameTok, diag::err_defined_macro_name);
} else if (isDefineUndef && II->hasMacroDefinition() &&
getMacroInfo(II)->isBuiltinMacro()) {
// Error if defining "__LINE__" and other builtins: C99 6.10.8.4.
if (isDefineUndef == 1)
Diag(MacroNameTok, diag::pp_redef_builtin_macro);
else
Diag(MacroNameTok, diag::pp_undef_builtin_macro);
} else {
// Okay, we got a good identifier node. Return it.
return;
}
// Invalid macro name, read and discard the rest of the line. Then set the
// token kind to tok::eom.
MacroNameTok.setKind(tok::eom);
return DiscardUntilEndOfDirective();
}
/// CheckEndOfDirective - Ensure that the next token is a tok::eom token. If
/// not, emit a diagnostic and consume up until the eom.
void Preprocessor::CheckEndOfDirective(const char *DirType) {
Token Tmp;
// Lex unexpanded tokens: macros might expand to zero tokens, causing us to
// miss diagnosing invalid lines.
LexUnexpandedToken(Tmp);
// There should be no tokens after the directive, but we allow them as an
// extension.
while (Tmp.is(tok::comment)) // Skip comments in -C mode.
LexUnexpandedToken(Tmp);
if (Tmp.isNot(tok::eom)) {
Diag(Tmp, diag::ext_pp_extra_tokens_at_eol, DirType);
DiscardUntilEndOfDirective();
}
}
/// SkipExcludedConditionalBlock - We just read a #if or related directive and
/// decided that the subsequent tokens are in the #if'd out portion of the
/// file. Lex the rest of the file, until we see an #endif. If
/// FoundNonSkipPortion is true, then we have already emitted code for part of
/// this #if directive, so #else/#elif blocks should never be entered. If ElseOk
/// is true, then #else directives are ok, if not, then we have already seen one
/// so a #else directive is a duplicate. When this returns, the caller can lex
/// the first valid token.
void Preprocessor::SkipExcludedConditionalBlock(SourceLocation IfTokenLoc,
bool FoundNonSkipPortion,
bool FoundElse) {
++NumSkipped;
assert(CurTokenLexer == 0 && CurLexer &&
"Lexing a macro, not a file?");
CurLexer->pushConditionalLevel(IfTokenLoc, /*isSkipping*/false,
FoundNonSkipPortion, FoundElse);
// Enter raw mode to disable identifier lookup (and thus macro expansion),
// disabling warnings, etc.
CurLexer->LexingRawMode = true;
Token Tok;
while (1) {
CurLexer->Lex(Tok);
// If this is the end of the buffer, we have an error.
if (Tok.is(tok::eof)) {
// Emit errors for each unterminated conditional on the stack, including
// the current one.
while (!CurLexer->ConditionalStack.empty()) {
Diag(CurLexer->ConditionalStack.back().IfLoc,
diag::err_pp_unterminated_conditional);
CurLexer->ConditionalStack.pop_back();
}
// Just return and let the caller lex after this #include.
break;
}
// If this token is not a preprocessor directive, just skip it.
if (Tok.isNot(tok::hash) || !Tok.isAtStartOfLine())
continue;
// We just parsed a # character at the start of a line, so we're in
// directive mode. Tell the lexer this so any newlines we see will be
// converted into an EOM token (this terminates the macro).
CurLexer->ParsingPreprocessorDirective = true;
CurLexer->KeepCommentMode = false;
// Read the next token, the directive flavor.
LexUnexpandedToken(Tok);
// If this isn't an identifier directive (e.g. is "# 1\n" or "#\n", or
// something bogus), skip it.
if (Tok.isNot(tok::identifier)) {
CurLexer->ParsingPreprocessorDirective = false;
// Restore comment saving mode.
CurLexer->KeepCommentMode = KeepComments;
continue;
}
// If the first letter isn't i or e, it isn't intesting to us. We know that
// this is safe in the face of spelling differences, because there is no way
// to spell an i/e in a strange way that is another letter. Skipping this
// allows us to avoid looking up the identifier info for #define/#undef and
// other common directives.
const char *RawCharData = SourceMgr.getCharacterData(Tok.getLocation());
char FirstChar = RawCharData[0];
if (FirstChar >= 'a' && FirstChar <= 'z' &&
FirstChar != 'i' && FirstChar != 'e') {
CurLexer->ParsingPreprocessorDirective = false;
// Restore comment saving mode.
CurLexer->KeepCommentMode = KeepComments;
continue;
}
// Get the identifier name without trigraphs or embedded newlines. Note
// that we can't use Tok.getIdentifierInfo() because its lookup is disabled
// when skipping.
// TODO: could do this with zero copies in the no-clean case by using
// strncmp below.
char Directive[20];
unsigned IdLen;
if (!Tok.needsCleaning() && Tok.getLength() < 20) {
IdLen = Tok.getLength();
memcpy(Directive, RawCharData, IdLen);
Directive[IdLen] = 0;
} else {
std::string DirectiveStr = getSpelling(Tok);
IdLen = DirectiveStr.size();
if (IdLen >= 20) {
CurLexer->ParsingPreprocessorDirective = false;
// Restore comment saving mode.
CurLexer->KeepCommentMode = KeepComments;
continue;
}
memcpy(Directive, &DirectiveStr[0], IdLen);
Directive[IdLen] = 0;
}
if (FirstChar == 'i' && Directive[1] == 'f') {
if ((IdLen == 2) || // "if"
(IdLen == 5 && !strcmp(Directive+2, "def")) || // "ifdef"
(IdLen == 6 && !strcmp(Directive+2, "ndef"))) { // "ifndef"
// We know the entire #if/#ifdef/#ifndef block will be skipped, don't
// bother parsing the condition.
DiscardUntilEndOfDirective();
CurLexer->pushConditionalLevel(Tok.getLocation(), /*wasskipping*/true,
/*foundnonskip*/false,
/*fnddelse*/false);
}
} else if (FirstChar == 'e') {
if (IdLen == 5 && !strcmp(Directive+1, "ndif")) { // "endif"
CheckEndOfDirective("#endif");
PPConditionalInfo CondInfo;
CondInfo.WasSkipping = true; // Silence bogus warning.
bool InCond = CurLexer->popConditionalLevel(CondInfo);
InCond = InCond; // Silence warning in no-asserts mode.
assert(!InCond && "Can't be skipping if not in a conditional!");
// If we popped the outermost skipping block, we're done skipping!
if (!CondInfo.WasSkipping)
break;
} else if (IdLen == 4 && !strcmp(Directive+1, "lse")) { // "else".
// #else directive in a skipping conditional. If not in some other
// skipping conditional, and if #else hasn't already been seen, enter it
// as a non-skipping conditional.
CheckEndOfDirective("#else");
PPConditionalInfo &CondInfo = CurLexer->peekConditionalLevel();
// If this is a #else with a #else before it, report the error.
if (CondInfo.FoundElse) Diag(Tok, diag::pp_err_else_after_else);
// Note that we've seen a #else in this conditional.
CondInfo.FoundElse = true;
// If the conditional is at the top level, and the #if block wasn't
// entered, enter the #else block now.
if (!CondInfo.WasSkipping && !CondInfo.FoundNonSkip) {
CondInfo.FoundNonSkip = true;
break;
}
} else if (IdLen == 4 && !strcmp(Directive+1, "lif")) { // "elif".
PPConditionalInfo &CondInfo = CurLexer->peekConditionalLevel();
bool ShouldEnter;
// If this is in a skipping block or if we're already handled this #if
// block, don't bother parsing the condition.
if (CondInfo.WasSkipping || CondInfo.FoundNonSkip) {
DiscardUntilEndOfDirective();
ShouldEnter = false;
} else {
// Restore the value of LexingRawMode so that identifiers are
// looked up, etc, inside the #elif expression.
assert(CurLexer->LexingRawMode && "We have to be skipping here!");
CurLexer->LexingRawMode = false;
IdentifierInfo *IfNDefMacro = 0;
ShouldEnter = EvaluateDirectiveExpression(IfNDefMacro);
CurLexer->LexingRawMode = true;
}
// If this is a #elif with a #else before it, report the error.
if (CondInfo.FoundElse) Diag(Tok, diag::pp_err_elif_after_else);
// If this condition is true, enter it!
if (ShouldEnter) {
CondInfo.FoundNonSkip = true;
break;
}
}
}
CurLexer->ParsingPreprocessorDirective = false;
// Restore comment saving mode.
CurLexer->KeepCommentMode = KeepComments;
}
// Finally, if we are out of the conditional (saw an #endif or ran off the end
// of the file, just stop skipping and return to lexing whatever came after
// the #if block.
CurLexer->LexingRawMode = false;
}
/// LookupFile - Given a "foo" or <foo> reference, look up the indicated file,
/// return null on failure. isAngled indicates whether the file reference is
/// for system #include's or not (i.e. using <> instead of "").
const FileEntry *Preprocessor::LookupFile(const char *FilenameStart,
const char *FilenameEnd,
bool isAngled,
const DirectoryLookup *FromDir,
const DirectoryLookup *&CurDir) {
// If the header lookup mechanism may be relative to the current file, pass in
// info about where the current file is.
const FileEntry *CurFileEnt = 0;
if (!FromDir) {
SourceLocation FileLoc = getCurrentFileLexer()->getFileLoc();
CurFileEnt = SourceMgr.getFileEntryForLoc(FileLoc);
}
// Do a standard file entry lookup.
CurDir = CurDirLookup;
const FileEntry *FE =
HeaderInfo.LookupFile(FilenameStart, FilenameEnd,
isAngled, FromDir, CurDir, CurFileEnt);
if (FE) return FE;
// Otherwise, see if this is a subframework header. If so, this is relative
// to one of the headers on the #include stack. Walk the list of the current
// headers on the #include stack and pass them to HeaderInfo.
if (CurLexer && !CurLexer->Is_PragmaLexer) {
if ((CurFileEnt = SourceMgr.getFileEntryForLoc(CurLexer->getFileLoc())))
if ((FE = HeaderInfo.LookupSubframeworkHeader(FilenameStart, FilenameEnd,
CurFileEnt)))
return FE;
}
for (unsigned i = 0, e = IncludeMacroStack.size(); i != e; ++i) {
IncludeStackInfo &ISEntry = IncludeMacroStack[e-i-1];
if (ISEntry.TheLexer && !ISEntry.TheLexer->Is_PragmaLexer) {
if ((CurFileEnt =
SourceMgr.getFileEntryForLoc(ISEntry.TheLexer->getFileLoc())))
if ((FE = HeaderInfo.LookupSubframeworkHeader(FilenameStart,
FilenameEnd, CurFileEnt)))
return FE;
}
}
// Otherwise, we really couldn't find the file.
return 0;
}
//===----------------------------------------------------------------------===//
// Preprocessor Directive Handling.
//===----------------------------------------------------------------------===//
/// HandleDirective - This callback is invoked when the lexer sees a # token
/// at the start of a line. This consumes the directive, modifies the
/// lexer/preprocessor state, and advances the lexer(s) so that the next token
/// read is the correct one.
void Preprocessor::HandleDirective(Token &Result) {
// FIXME: Traditional: # with whitespace before it not recognized by K&R?
// We just parsed a # character at the start of a line, so we're in directive
// mode. Tell the lexer this so any newlines we see will be converted into an
// EOM token (which terminates the directive).
CurLexer->ParsingPreprocessorDirective = true;
++NumDirectives;
// We are about to read a token. For the multiple-include optimization FA to
// work, we have to remember if we had read any tokens *before* this
// pp-directive.
bool ReadAnyTokensBeforeDirective = CurLexer->MIOpt.getHasReadAnyTokensVal();
// Read the next token, the directive flavor. This isn't expanded due to
// C99 6.10.3p8.
LexUnexpandedToken(Result);
// C99 6.10.3p11: Is this preprocessor directive in macro invocation? e.g.:
// #define A(x) #x
// A(abc
// #warning blah
// def)
// If so, the user is relying on non-portable behavior, emit a diagnostic.
if (InMacroArgs)
Diag(Result, diag::ext_embedded_directive);
TryAgain:
switch (Result.getKind()) {
case tok::eom:
return; // null directive.
case tok::comment:
// Handle stuff like "# /*foo*/ define X" in -E -C mode.
LexUnexpandedToken(Result);
goto TryAgain;
case tok::numeric_constant:
// FIXME: implement # 7 line numbers!
DiscardUntilEndOfDirective();
return;
default:
IdentifierInfo *II = Result.getIdentifierInfo();
if (II == 0) break; // Not an identifier.
// Ask what the preprocessor keyword ID is.
switch (II->getPPKeywordID()) {
default: break;
// C99 6.10.1 - Conditional Inclusion.
case tok::pp_if:
return HandleIfDirective(Result, ReadAnyTokensBeforeDirective);
case tok::pp_ifdef:
return HandleIfdefDirective(Result, false, true/*not valid for miopt*/);
case tok::pp_ifndef:
return HandleIfdefDirective(Result, true, ReadAnyTokensBeforeDirective);
case tok::pp_elif:
return HandleElifDirective(Result);
case tok::pp_else:
return HandleElseDirective(Result);
case tok::pp_endif:
return HandleEndifDirective(Result);
// C99 6.10.2 - Source File Inclusion.
case tok::pp_include:
return HandleIncludeDirective(Result); // Handle #include.
// C99 6.10.3 - Macro Replacement.
case tok::pp_define:
return HandleDefineDirective(Result);
case tok::pp_undef:
return HandleUndefDirective(Result);
// C99 6.10.4 - Line Control.
case tok::pp_line:
// FIXME: implement #line
DiscardUntilEndOfDirective();
return;
// C99 6.10.5 - Error Directive.
case tok::pp_error:
return HandleUserDiagnosticDirective(Result, false);
// C99 6.10.6 - Pragma Directive.
case tok::pp_pragma:
return HandlePragmaDirective();
// GNU Extensions.
case tok::pp_import:
return HandleImportDirective(Result);
case tok::pp_include_next:
return HandleIncludeNextDirective(Result);
case tok::pp_warning:
Diag(Result, diag::ext_pp_warning_directive);
return HandleUserDiagnosticDirective(Result, true);
case tok::pp_ident:
return HandleIdentSCCSDirective(Result);
case tok::pp_sccs:
return HandleIdentSCCSDirective(Result);
case tok::pp_assert:
//isExtension = true; // FIXME: implement #assert
break;
case tok::pp_unassert:
//isExtension = true; // FIXME: implement #unassert
break;
}
break;
}
// If we reached here, the preprocessing token is not valid!
Diag(Result, diag::err_pp_invalid_directive);
// Read the rest of the PP line.
DiscardUntilEndOfDirective();
// Okay, we're done parsing the directive.
}
void Preprocessor::HandleUserDiagnosticDirective(Token &Tok,
bool isWarning) {
// Read the rest of the line raw. We do this because we don't want macros
// to be expanded and we don't require that the tokens be valid preprocessing
// tokens. For example, this is allowed: "#warning ` 'foo". GCC does
// collapse multiple consequtive white space between tokens, but this isn't
// specified by the standard.
std::string Message = CurLexer->ReadToEndOfLine();
unsigned DiagID = isWarning ? diag::pp_hash_warning : diag::err_pp_hash_error;
return Diag(Tok, DiagID, Message);
}
/// HandleIdentSCCSDirective - Handle a #ident/#sccs directive.
///
void Preprocessor::HandleIdentSCCSDirective(Token &Tok) {
// Yes, this directive is an extension.
Diag(Tok, diag::ext_pp_ident_directive);
// Read the string argument.
Token StrTok;
Lex(StrTok);
// If the token kind isn't a string, it's a malformed directive.
if (StrTok.isNot(tok::string_literal) &&
StrTok.isNot(tok::wide_string_literal))
return Diag(StrTok, diag::err_pp_malformed_ident);
// Verify that there is nothing after the string, other than EOM.
CheckEndOfDirective("#ident");
if (Callbacks)
Callbacks->Ident(Tok.getLocation(), getSpelling(StrTok));
}
//===----------------------------------------------------------------------===//
// Preprocessor Include Directive Handling.
//===----------------------------------------------------------------------===//
/// GetIncludeFilenameSpelling - Turn the specified lexer token into a fully
/// checked and spelled filename, e.g. as an operand of #include. This returns
/// true if the input filename was in <>'s or false if it were in ""'s. The
/// caller is expected to provide a buffer that is large enough to hold the
/// spelling of the filename, but is also expected to handle the case when
/// this method decides to use a different buffer.
bool Preprocessor::GetIncludeFilenameSpelling(SourceLocation Loc,
const char *&BufStart,
const char *&BufEnd) {
// Get the text form of the filename.
assert(BufStart != BufEnd && "Can't have tokens with empty spellings!");
// Make sure the filename is <x> or "x".
bool isAngled;
if (BufStart[0] == '<') {
if (BufEnd[-1] != '>') {
Diag(Loc, diag::err_pp_expects_filename);
BufStart = 0;
return true;
}
isAngled = true;
} else if (BufStart[0] == '"') {
if (BufEnd[-1] != '"') {
Diag(Loc, diag::err_pp_expects_filename);
BufStart = 0;
return true;
}
isAngled = false;
} else {
Diag(Loc, diag::err_pp_expects_filename);
BufStart = 0;
return true;
}
// Diagnose #include "" as invalid.
if (BufEnd-BufStart <= 2) {
Diag(Loc, diag::err_pp_empty_filename);
BufStart = 0;
return "";
}
// Skip the brackets.
++BufStart;
--BufEnd;
return isAngled;
}
/// ConcatenateIncludeName - Handle cases where the #include name is expanded
/// from a macro as multiple tokens, which need to be glued together. This
/// occurs for code like:
/// #define FOO <a/b.h>
/// #include FOO
/// because in this case, "<a/b.h>" is returned as 7 tokens, not one.
///
/// This code concatenates and consumes tokens up to the '>' token. It returns
/// false if the > was found, otherwise it returns true if it finds and consumes
/// the EOM marker.
static bool ConcatenateIncludeName(llvm::SmallVector<char, 128> &FilenameBuffer,
Preprocessor &PP) {
Token CurTok;
PP.Lex(CurTok);
while (CurTok.isNot(tok::eom)) {
// Append the spelling of this token to the buffer. If there was a space
// before it, add it now.
if (CurTok.hasLeadingSpace())
FilenameBuffer.push_back(' ');
// Get the spelling of the token, directly into FilenameBuffer if possible.
unsigned PreAppendSize = FilenameBuffer.size();
FilenameBuffer.resize(PreAppendSize+CurTok.getLength());
const char *BufPtr = &FilenameBuffer[PreAppendSize];
unsigned ActualLen = PP.getSpelling(CurTok, BufPtr);
// If the token was spelled somewhere else, copy it into FilenameBuffer.
if (BufPtr != &FilenameBuffer[PreAppendSize])
memcpy(&FilenameBuffer[PreAppendSize], BufPtr, ActualLen);
// Resize FilenameBuffer to the correct size.
if (CurTok.getLength() != ActualLen)
FilenameBuffer.resize(PreAppendSize+ActualLen);
// If we found the '>' marker, return success.
if (CurTok.is(tok::greater))
return false;
PP.Lex(CurTok);
}
// If we hit the eom marker, emit an error and return true so that the caller
// knows the EOM has been read.
PP.Diag(CurTok.getLocation(), diag::err_pp_expects_filename);
return true;
}
/// HandleIncludeDirective - The "#include" tokens have just been read, read the
/// file to be included from the lexer, then include it! This is a common
/// routine with functionality shared between #include, #include_next and
/// #import.
void Preprocessor::HandleIncludeDirective(Token &IncludeTok,
const DirectoryLookup *LookupFrom,
bool isImport) {
Token FilenameTok;
CurLexer->LexIncludeFilename(FilenameTok);
// Reserve a buffer to get the spelling.
llvm::SmallVector<char, 128> FilenameBuffer;
const char *FilenameStart, *FilenameEnd;
switch (FilenameTok.getKind()) {
case tok::eom:
// If the token kind is EOM, the error has already been diagnosed.
return;
case tok::angle_string_literal:
case tok::string_literal: {
FilenameBuffer.resize(FilenameTok.getLength());
FilenameStart = &FilenameBuffer[0];
unsigned Len = getSpelling(FilenameTok, FilenameStart);
FilenameEnd = FilenameStart+Len;
break;
}
case tok::less:
// This could be a <foo/bar.h> file coming from a macro expansion. In this
// case, glue the tokens together into FilenameBuffer and interpret those.
FilenameBuffer.push_back('<');
if (ConcatenateIncludeName(FilenameBuffer, *this))
return; // Found <eom> but no ">"? Diagnostic already emitted.
FilenameStart = &FilenameBuffer[0];
FilenameEnd = &FilenameBuffer[FilenameBuffer.size()];
break;
default:
Diag(FilenameTok.getLocation(), diag::err_pp_expects_filename);
DiscardUntilEndOfDirective();
return;
}
bool isAngled = GetIncludeFilenameSpelling(FilenameTok.getLocation(),
FilenameStart, FilenameEnd);
// If GetIncludeFilenameSpelling set the start ptr to null, there was an
// error.
if (FilenameStart == 0) {
DiscardUntilEndOfDirective();
return;
}
// Verify that there is nothing after the filename, other than EOM. Use the
// preprocessor to lex this in case lexing the filename entered a macro.
CheckEndOfDirective("#include");
// Check that we don't have infinite #include recursion.
if (IncludeMacroStack.size() == MaxAllowedIncludeStackDepth-1)
return Diag(FilenameTok, diag::err_pp_include_too_deep);
// Search include directories.
const DirectoryLookup *CurDir;
const FileEntry *File = LookupFile(FilenameStart, FilenameEnd,
isAngled, LookupFrom, CurDir);
if (File == 0)
return Diag(FilenameTok, diag::err_pp_file_not_found,
std::string(FilenameStart, FilenameEnd));
// Ask HeaderInfo if we should enter this #include file.
if (!HeaderInfo.ShouldEnterIncludeFile(File, isImport)) {
// If it returns true, #including this file will have no effect.
return;
}
// Look up the file, create a File ID for it.
unsigned FileID = SourceMgr.createFileID(File, FilenameTok.getLocation());
if (FileID == 0)
return Diag(FilenameTok, diag::err_pp_file_not_found,
std::string(FilenameStart, FilenameEnd));
// Finally, if all is good, enter the new file!
EnterSourceFile(FileID, CurDir);
}
/// HandleIncludeNextDirective - Implements #include_next.
///
void Preprocessor::HandleIncludeNextDirective(Token &IncludeNextTok) {
Diag(IncludeNextTok, diag::ext_pp_include_next_directive);
// #include_next is like #include, except that we start searching after
// the current found directory. If we can't do this, issue a
// diagnostic.
const DirectoryLookup *Lookup = CurDirLookup;
if (isInPrimaryFile()) {
Lookup = 0;
Diag(IncludeNextTok, diag::pp_include_next_in_primary);
} else if (Lookup == 0) {
Diag(IncludeNextTok, diag::pp_include_next_absolute_path);
} else {
// Start looking up in the next directory.
++Lookup;
}
return HandleIncludeDirective(IncludeNextTok, Lookup);
}
/// HandleImportDirective - Implements #import.
///
void Preprocessor::HandleImportDirective(Token &ImportTok) {
Diag(ImportTok, diag::ext_pp_import_directive);
return HandleIncludeDirective(ImportTok, 0, true);
}
//===----------------------------------------------------------------------===//
// Preprocessor Macro Directive Handling.
//===----------------------------------------------------------------------===//
/// ReadMacroDefinitionArgList - The ( starting an argument list of a macro
/// definition has just been read. Lex the rest of the arguments and the
/// closing ), updating MI with what we learn. Return true if an error occurs
/// parsing the arg list.
bool Preprocessor::ReadMacroDefinitionArgList(MacroInfo *MI) {
llvm::SmallVector<IdentifierInfo*, 32> Arguments;
Token Tok;
while (1) {
LexUnexpandedToken(Tok);
switch (Tok.getKind()) {
case tok::r_paren:
// Found the end of the argument list.
if (Arguments.empty()) { // #define FOO()
MI->setArgumentList(Arguments.begin(), Arguments.end());
return false;
}
// Otherwise we have #define FOO(A,)
Diag(Tok, diag::err_pp_expected_ident_in_arg_list);
return true;
case tok::ellipsis: // #define X(... -> C99 varargs
// Warn if use of C99 feature in non-C99 mode.
if (!Features.C99) Diag(Tok, diag::ext_variadic_macro);
// Lex the token after the identifier.
LexUnexpandedToken(Tok);
if (Tok.isNot(tok::r_paren)) {
Diag(Tok, diag::err_pp_missing_rparen_in_macro_def);
return true;
}
// Add the __VA_ARGS__ identifier as an argument.
Arguments.push_back(Ident__VA_ARGS__);
MI->setIsC99Varargs();
MI->setArgumentList(Arguments.begin(), Arguments.end());
return false;
case tok::eom: // #define X(
Diag(Tok, diag::err_pp_missing_rparen_in_macro_def);
return true;
default:
// Handle keywords and identifiers here to accept things like
// #define Foo(for) for.
IdentifierInfo *II = Tok.getIdentifierInfo();
if (II == 0) {
// #define X(1
Diag(Tok, diag::err_pp_invalid_tok_in_arg_list);
return true;
}
// If this is already used as an argument, it is used multiple times (e.g.
// #define X(A,A.
if (std::find(Arguments.begin(), Arguments.end(), II) !=
Arguments.end()) { // C99 6.10.3p6
Diag(Tok, diag::err_pp_duplicate_name_in_arg_list, II->getName());
return true;
}
// Add the argument to the macro info.
Arguments.push_back(II);
// Lex the token after the identifier.
LexUnexpandedToken(Tok);
switch (Tok.getKind()) {
default: // #define X(A B
Diag(Tok, diag::err_pp_expected_comma_in_arg_list);
return true;
case tok::r_paren: // #define X(A)
MI->setArgumentList(Arguments.begin(), Arguments.end());
return false;
case tok::comma: // #define X(A,
break;
case tok::ellipsis: // #define X(A... -> GCC extension
// Diagnose extension.
Diag(Tok, diag::ext_named_variadic_macro);
// Lex the token after the identifier.
LexUnexpandedToken(Tok);
if (Tok.isNot(tok::r_paren)) {
Diag(Tok, diag::err_pp_missing_rparen_in_macro_def);
return true;
}
MI->setIsGNUVarargs();
MI->setArgumentList(Arguments.begin(), Arguments.end());
return false;
}
}
}
}
/// HandleDefineDirective - Implements #define. This consumes the entire macro
/// line then lets the caller lex the next real token.
void Preprocessor::HandleDefineDirective(Token &DefineTok) {
++NumDefined;
Token MacroNameTok;
ReadMacroName(MacroNameTok, 1);
// Error reading macro name? If so, diagnostic already issued.
if (MacroNameTok.is(tok::eom))
return;
// If we are supposed to keep comments in #defines, reenable comment saving
// mode.
CurLexer->KeepCommentMode = KeepMacroComments;
// Create the new macro.
MacroInfo *MI = new MacroInfo(MacroNameTok.getLocation());
Token Tok;
LexUnexpandedToken(Tok);
// If this is a function-like macro definition, parse the argument list,
// marking each of the identifiers as being used as macro arguments. Also,
// check other constraints on the first token of the macro body.
if (Tok.is(tok::eom)) {
// If there is no body to this macro, we have no special handling here.
} else if (Tok.is(tok::l_paren) && !Tok.hasLeadingSpace()) {
// This is a function-like macro definition. Read the argument list.
MI->setIsFunctionLike();
if (ReadMacroDefinitionArgList(MI)) {
// Forget about MI.
delete MI;
// Throw away the rest of the line.
if (CurLexer->ParsingPreprocessorDirective)
DiscardUntilEndOfDirective();
return;
}
// Read the first token after the arg list for down below.
LexUnexpandedToken(Tok);
} else if (!Tok.hasLeadingSpace()) {
// C99 requires whitespace between the macro definition and the body. Emit
// a diagnostic for something like "#define X+".
if (Features.C99) {
Diag(Tok, diag::ext_c99_whitespace_required_after_macro_name);
} else {
// FIXME: C90/C++ do not get this diagnostic, but it does get a similar
// one in some cases!
}
} else {
// This is a normal token with leading space. Clear the leading space
// marker on the first token to get proper expansion.
Tok.clearFlag(Token::LeadingSpace);
}
// If this is a definition of a variadic C99 function-like macro, not using
// the GNU named varargs extension, enabled __VA_ARGS__.
// "Poison" __VA_ARGS__, which can only appear in the expansion of a macro.
// This gets unpoisoned where it is allowed.
assert(Ident__VA_ARGS__->isPoisoned() && "__VA_ARGS__ should be poisoned!");
if (MI->isC99Varargs())
Ident__VA_ARGS__->setIsPoisoned(false);
// Read the rest of the macro body.
if (MI->isObjectLike()) {
// Object-like macros are very simple, just read their body.
while (Tok.isNot(tok::eom)) {
MI->AddTokenToBody(Tok);
// Get the next token of the macro.
LexUnexpandedToken(Tok);
}
} else {
// Otherwise, read the body of a function-like macro. This has to validate
// the # (stringize) operator.
while (Tok.isNot(tok::eom)) {
MI->AddTokenToBody(Tok);
// Check C99 6.10.3.2p1: ensure that # operators are followed by macro
// parameters in function-like macro expansions.
if (Tok.isNot(tok::hash)) {
// Get the next token of the macro.
LexUnexpandedToken(Tok);
continue;
}
// Get the next token of the macro.
LexUnexpandedToken(Tok);
// Not a macro arg identifier?
if (!Tok.getIdentifierInfo() ||
MI->getArgumentNum(Tok.getIdentifierInfo()) == -1) {
Diag(Tok, diag::err_pp_stringize_not_parameter);
delete MI;
// Disable __VA_ARGS__ again.
Ident__VA_ARGS__->setIsPoisoned(true);
return;
}
// Things look ok, add the param name token to the macro.
MI->AddTokenToBody(Tok);
// Get the next token of the macro.
LexUnexpandedToken(Tok);
}
}
// Disable __VA_ARGS__ again.
Ident__VA_ARGS__->setIsPoisoned(true);
// Check that there is no paste (##) operator at the begining or end of the
// replacement list.
unsigned NumTokens = MI->getNumTokens();
if (NumTokens != 0) {
if (MI->getReplacementToken(0).is(tok::hashhash)) {
Diag(MI->getReplacementToken(0), diag::err_paste_at_start);
delete MI;
return;
}
if (MI->getReplacementToken(NumTokens-1).is(tok::hashhash)) {
Diag(MI->getReplacementToken(NumTokens-1), diag::err_paste_at_end);
delete MI;
return;
}
}
// If this is the primary source file, remember that this macro hasn't been
// used yet.
if (isInPrimaryFile())
MI->setIsUsed(false);
// Finally, if this identifier already had a macro defined for it, verify that
// the macro bodies are identical and free the old definition.
if (MacroInfo *OtherMI = getMacroInfo(MacroNameTok.getIdentifierInfo())) {
if (!OtherMI->isUsed())
Diag(OtherMI->getDefinitionLoc(), diag::pp_macro_not_used);
// Macros must be identical. This means all tokes and whitespace separation
// must be the same. C99 6.10.3.2.
if (!MI->isIdenticalTo(*OtherMI, *this)) {
Diag(MI->getDefinitionLoc(), diag::ext_pp_macro_redef,
MacroNameTok.getIdentifierInfo()->getName());
Diag(OtherMI->getDefinitionLoc(), diag::ext_pp_macro_redef2);
}
delete OtherMI;
}
setMacroInfo(MacroNameTok.getIdentifierInfo(), MI);
}
/// HandleUndefDirective - Implements #undef.
///
void Preprocessor::HandleUndefDirective(Token &UndefTok) {
++NumUndefined;
Token MacroNameTok;
ReadMacroName(MacroNameTok, 2);
// Error reading macro name? If so, diagnostic already issued.
if (MacroNameTok.is(tok::eom))
return;
// Check to see if this is the last token on the #undef line.
CheckEndOfDirective("#undef");
// Okay, we finally have a valid identifier to undef.
MacroInfo *MI = getMacroInfo(MacroNameTok.getIdentifierInfo());
// If the macro is not defined, this is a noop undef, just return.
if (MI == 0) return;
if (!MI->isUsed())
Diag(MI->getDefinitionLoc(), diag::pp_macro_not_used);
// Free macro definition.
delete MI;
setMacroInfo(MacroNameTok.getIdentifierInfo(), 0);
}
//===----------------------------------------------------------------------===//
// Preprocessor Conditional Directive Handling.
//===----------------------------------------------------------------------===//
/// HandleIfdefDirective - Implements the #ifdef/#ifndef directive. isIfndef is
/// true when this is a #ifndef directive. ReadAnyTokensBeforeDirective is true
/// if any tokens have been returned or pp-directives activated before this
/// #ifndef has been lexed.
///
void Preprocessor::HandleIfdefDirective(Token &Result, bool isIfndef,
bool ReadAnyTokensBeforeDirective) {
++NumIf;
Token DirectiveTok = Result;
Token MacroNameTok;
ReadMacroName(MacroNameTok);
// Error reading macro name? If so, diagnostic already issued.
if (MacroNameTok.is(tok::eom)) {
// Skip code until we get to #endif. This helps with recovery by not
// emitting an error when the #endif is reached.
SkipExcludedConditionalBlock(DirectiveTok.getLocation(),
/*Foundnonskip*/false, /*FoundElse*/false);
return;
}
// Check to see if this is the last token on the #if[n]def line.
CheckEndOfDirective(isIfndef ? "#ifndef" : "#ifdef");
if (CurLexer->getConditionalStackDepth() == 0) {
// If the start of a top-level #ifdef, inform MIOpt.
if (!ReadAnyTokensBeforeDirective) {
assert(isIfndef && "#ifdef shouldn't reach here");
CurLexer->MIOpt.EnterTopLevelIFNDEF(MacroNameTok.getIdentifierInfo());
} else
CurLexer->MIOpt.EnterTopLevelConditional();
}
IdentifierInfo *MII = MacroNameTok.getIdentifierInfo();
MacroInfo *MI = getMacroInfo(MII);
// If there is a macro, process it.
if (MI) // Mark it used.
MI->setIsUsed(true);
// Should we include the stuff contained by this directive?
if (!MI == isIfndef) {
// Yes, remember that we are inside a conditional, then lex the next token.
CurLexer->pushConditionalLevel(DirectiveTok.getLocation(), /*wasskip*/false,
/*foundnonskip*/true, /*foundelse*/false);
} else {
// No, skip the contents of this block and return the first token after it.
SkipExcludedConditionalBlock(DirectiveTok.getLocation(),
/*Foundnonskip*/false,
/*FoundElse*/false);
}
}
/// HandleIfDirective - Implements the #if directive.
///
void Preprocessor::HandleIfDirective(Token &IfToken,
bool ReadAnyTokensBeforeDirective) {
++NumIf;
// Parse and evaluation the conditional expression.
IdentifierInfo *IfNDefMacro = 0;
bool ConditionalTrue = EvaluateDirectiveExpression(IfNDefMacro);
// Should we include the stuff contained by this directive?
if (ConditionalTrue) {
// If this condition is equivalent to #ifndef X, and if this is the first
// directive seen, handle it for the multiple-include optimization.
if (CurLexer->getConditionalStackDepth() == 0) {
if (!ReadAnyTokensBeforeDirective && IfNDefMacro)
CurLexer->MIOpt.EnterTopLevelIFNDEF(IfNDefMacro);
else
CurLexer->MIOpt.EnterTopLevelConditional();
}
// Yes, remember that we are inside a conditional, then lex the next token.
CurLexer->pushConditionalLevel(IfToken.getLocation(), /*wasskip*/false,
/*foundnonskip*/true, /*foundelse*/false);
} else {
// No, skip the contents of this block and return the first token after it.
SkipExcludedConditionalBlock(IfToken.getLocation(), /*Foundnonskip*/false,
/*FoundElse*/false);
}
}
/// HandleEndifDirective - Implements the #endif directive.
///
void Preprocessor::HandleEndifDirective(Token &EndifToken) {
++NumEndif;
// Check that this is the whole directive.
CheckEndOfDirective("#endif");
PPConditionalInfo CondInfo;
if (CurLexer->popConditionalLevel(CondInfo)) {
// No conditionals on the stack: this is an #endif without an #if.
return Diag(EndifToken, diag::err_pp_endif_without_if);
}
// If this the end of a top-level #endif, inform MIOpt.
if (CurLexer->getConditionalStackDepth() == 0)
CurLexer->MIOpt.ExitTopLevelConditional();
assert(!CondInfo.WasSkipping && !CurLexer->LexingRawMode &&
"This code should only be reachable in the non-skipping case!");
}
void Preprocessor::HandleElseDirective(Token &Result) {
++NumElse;
// #else directive in a non-skipping conditional... start skipping.
CheckEndOfDirective("#else");
PPConditionalInfo CI;
if (CurLexer->popConditionalLevel(CI))
return Diag(Result, diag::pp_err_else_without_if);
// If this is a top-level #else, inform the MIOpt.
if (CurLexer->getConditionalStackDepth() == 0)
CurLexer->MIOpt.EnterTopLevelConditional();
// If this is a #else with a #else before it, report the error.
if (CI.FoundElse) Diag(Result, diag::pp_err_else_after_else);
// Finally, skip the rest of the contents of this block and return the first
// token after it.
return SkipExcludedConditionalBlock(CI.IfLoc, /*Foundnonskip*/true,
/*FoundElse*/true);
}
void Preprocessor::HandleElifDirective(Token &ElifToken) {
++NumElse;
// #elif directive in a non-skipping conditional... start skipping.
// We don't care what the condition is, because we will always skip it (since
// the block immediately before it was included).
DiscardUntilEndOfDirective();
PPConditionalInfo CI;
if (CurLexer->popConditionalLevel(CI))
return Diag(ElifToken, diag::pp_err_elif_without_if);
// If this is a top-level #elif, inform the MIOpt.
if (CurLexer->getConditionalStackDepth() == 0)
CurLexer->MIOpt.EnterTopLevelConditional();
// If this is a #elif with a #else before it, report the error.
if (CI.FoundElse) Diag(ElifToken, diag::pp_err_elif_after_else);
// Finally, skip the rest of the contents of this block and return the first
// token after it.
return SkipExcludedConditionalBlock(CI.IfLoc, /*Foundnonskip*/true,
/*FoundElse*/CI.FoundElse);
}
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