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

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//===--- Preprocess.cpp - C Language Family Preprocessor Implementation ---===//
//
// 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 Preprocessor interface.
//
//===----------------------------------------------------------------------===//
//
// Options to support:
// -H - Print the name of each header file used.
// -d[MDNI] - Dump various things.
// -fworking-directory - #line's with preprocessor's working dir.
// -fpreprocessed
// -dependency-file,-M,-MM,-MF,-MG,-MP,-MT,-MQ,-MD,-MMD
// -W*
// -w
//
// Messages to emit:
// "Multiple include guards may be useful for:\n"
//
//===----------------------------------------------------------------------===//
#include "clang/Lex/Preprocessor.h"
#include "clang/Lex/HeaderSearch.h"
#include "clang/Lex/MacroInfo.h"
#include "clang/Lex/Pragma.h"
#include "clang/Lex/ScratchBuffer.h"
#include "clang/Basic/Diagnostic.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Basic/TargetInfo.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/Streams.h"
#include <ctime>
using namespace clang;
//===----------------------------------------------------------------------===//
Preprocessor::Preprocessor(Diagnostic &diags, const LangOptions &opts,
TargetInfo &target, SourceManager &SM,
HeaderSearch &Headers)
: Diags(diags), Features(opts), Target(target), FileMgr(Headers.getFileMgr()),
SourceMgr(SM), HeaderInfo(Headers), Identifiers(opts),
CurLexer(0), CurDirLookup(0), CurTokenLexer(0), Callbacks(0) {
ScratchBuf = new ScratchBuffer(SourceMgr);
// Clear stats.
NumDirectives = NumDefined = NumUndefined = NumPragma = 0;
NumIf = NumElse = NumEndif = 0;
NumEnteredSourceFiles = 0;
NumMacroExpanded = NumFnMacroExpanded = NumBuiltinMacroExpanded = 0;
NumFastMacroExpanded = NumTokenPaste = NumFastTokenPaste = 0;
MaxIncludeStackDepth = 0;
NumSkipped = 0;
// Default to discarding comments.
KeepComments = false;
KeepMacroComments = false;
// Macro expansion is enabled.
DisableMacroExpansion = false;
InMacroArgs = false;
NumCachedTokenLexers = 0;
// "Poison" __VA_ARGS__, which can only appear in the expansion of a macro.
// This gets unpoisoned where it is allowed.
(Ident__VA_ARGS__ = getIdentifierInfo("__VA_ARGS__"))->setIsPoisoned();
Predefines = 0;
// Initialize the pragma handlers.
PragmaHandlers = new PragmaNamespace(0);
RegisterBuiltinPragmas();
// Initialize builtin macros like __LINE__ and friends.
RegisterBuiltinMacros();
}
Preprocessor::~Preprocessor() {
// Free any active lexers.
delete CurLexer;
while (!IncludeMacroStack.empty()) {
delete IncludeMacroStack.back().TheLexer;
delete IncludeMacroStack.back().TheTokenLexer;
IncludeMacroStack.pop_back();
}
// Free any macro definitions.
for (llvm::DenseMap<IdentifierInfo*, MacroInfo*>::iterator I =
Macros.begin(), E = Macros.end(); I != E; ++I) {
// Free the macro definition.
delete I->second;
I->second = 0;
I->first->setHasMacroDefinition(false);
}
// Free any cached macro expanders.
for (unsigned i = 0, e = NumCachedTokenLexers; i != e; ++i)
delete TokenLexerCache[i];
// Release pragma information.
delete PragmaHandlers;
// Delete the scratch buffer info.
delete ScratchBuf;
delete Callbacks;
}
/// Diag - Forwarding function for diagnostics. This emits a diagnostic at
/// the specified Token's location, translating the token's start
/// position in the current buffer into a SourcePosition object for rendering.
void Preprocessor::Diag(SourceLocation Loc, unsigned DiagID) {
Diags.Report(getFullLoc(Loc), DiagID);
}
void Preprocessor::Diag(SourceLocation Loc, unsigned DiagID,
const std::string &Msg) {
Diags.Report(getFullLoc(Loc), DiagID, &Msg, 1);
}
void Preprocessor::DumpToken(const Token &Tok, bool DumpFlags) const {
llvm::cerr << tok::getTokenName(Tok.getKind()) << " '"
<< getSpelling(Tok) << "'";
if (!DumpFlags) return;
llvm::cerr << "\t";
if (Tok.isAtStartOfLine())
llvm::cerr << " [StartOfLine]";
if (Tok.hasLeadingSpace())
llvm::cerr << " [LeadingSpace]";
if (Tok.isExpandDisabled())
llvm::cerr << " [ExpandDisabled]";
if (Tok.needsCleaning()) {
const char *Start = SourceMgr.getCharacterData(Tok.getLocation());
llvm::cerr << " [UnClean='" << std::string(Start, Start+Tok.getLength())
<< "']";
}
llvm::cerr << "\tLoc=<";
DumpLocation(Tok.getLocation());
llvm::cerr << ">";
}
void Preprocessor::DumpLocation(SourceLocation Loc) const {
SourceLocation LogLoc = SourceMgr.getLogicalLoc(Loc);
llvm::cerr << SourceMgr.getSourceName(LogLoc) << ':'
<< SourceMgr.getLineNumber(LogLoc) << ':'
<< SourceMgr.getLineNumber(LogLoc);
SourceLocation PhysLoc = SourceMgr.getPhysicalLoc(Loc);
if (PhysLoc != LogLoc) {
llvm::cerr << " <PhysLoc=";
DumpLocation(PhysLoc);
llvm::cerr << ">";
}
}
void Preprocessor::DumpMacro(const MacroInfo &MI) const {
llvm::cerr << "MACRO: ";
for (unsigned i = 0, e = MI.getNumTokens(); i != e; ++i) {
DumpToken(MI.getReplacementToken(i));
llvm::cerr << " ";
}
llvm::cerr << "\n";
}
void Preprocessor::PrintStats() {
llvm::cerr << "\n*** Preprocessor Stats:\n";
llvm::cerr << NumDirectives << " directives found:\n";
llvm::cerr << " " << NumDefined << " #define.\n";
llvm::cerr << " " << NumUndefined << " #undef.\n";
llvm::cerr << " #include/#include_next/#import:\n";
llvm::cerr << " " << NumEnteredSourceFiles << " source files entered.\n";
llvm::cerr << " " << MaxIncludeStackDepth << " max include stack depth\n";
llvm::cerr << " " << NumIf << " #if/#ifndef/#ifdef.\n";
llvm::cerr << " " << NumElse << " #else/#elif.\n";
llvm::cerr << " " << NumEndif << " #endif.\n";
llvm::cerr << " " << NumPragma << " #pragma.\n";
llvm::cerr << NumSkipped << " #if/#ifndef#ifdef regions skipped\n";
llvm::cerr << NumMacroExpanded << "/" << NumFnMacroExpanded << "/"
<< NumBuiltinMacroExpanded << " obj/fn/builtin macros expanded, "
<< NumFastMacroExpanded << " on the fast path.\n";
llvm::cerr << (NumFastTokenPaste+NumTokenPaste)
<< " token paste (##) operations performed, "
<< NumFastTokenPaste << " on the fast path.\n";
}
//===----------------------------------------------------------------------===//
// Token Spelling
//===----------------------------------------------------------------------===//
/// getSpelling() - Return the 'spelling' of this token. The spelling of a
/// token are the characters used to represent the token in the source file
/// after trigraph expansion and escaped-newline folding. In particular, this
/// wants to get the true, uncanonicalized, spelling of things like digraphs
/// UCNs, etc.
std::string Preprocessor::getSpelling(const Token &Tok) const {
assert((int)Tok.getLength() >= 0 && "Token character range is bogus!");
// If this token contains nothing interesting, return it directly.
const char *TokStart = SourceMgr.getCharacterData(Tok.getLocation());
if (!Tok.needsCleaning())
return std::string(TokStart, TokStart+Tok.getLength());
std::string Result;
Result.reserve(Tok.getLength());
// Otherwise, hard case, relex the characters into the string.
for (const char *Ptr = TokStart, *End = TokStart+Tok.getLength();
Ptr != End; ) {
unsigned CharSize;
Result.push_back(Lexer::getCharAndSizeNoWarn(Ptr, CharSize, Features));
Ptr += CharSize;
}
assert(Result.size() != unsigned(Tok.getLength()) &&
"NeedsCleaning flag set on something that didn't need cleaning!");
return Result;
}
/// getSpelling - This method is used to get the spelling of a token into a
/// preallocated buffer, instead of as an std::string. The caller is required
/// to allocate enough space for the token, which is guaranteed to be at least
/// Tok.getLength() bytes long. The actual length of the token is returned.
///
/// Note that this method may do two possible things: it may either fill in
/// the buffer specified with characters, or it may *change the input pointer*
/// to point to a constant buffer with the data already in it (avoiding a
/// copy). The caller is not allowed to modify the returned buffer pointer
/// if an internal buffer is returned.
unsigned Preprocessor::getSpelling(const Token &Tok,
const char *&Buffer) const {
assert((int)Tok.getLength() >= 0 && "Token character range is bogus!");
// If this token is an identifier, just return the string from the identifier
// table, which is very quick.
if (const IdentifierInfo *II = Tok.getIdentifierInfo()) {
Buffer = II->getName();
// Return the length of the token. If the token needed cleaning, don't
// include the size of the newlines or trigraphs in it.
if (!Tok.needsCleaning())
return Tok.getLength();
else
return strlen(Buffer);
}
// Otherwise, compute the start of the token in the input lexer buffer.
const char *TokStart = SourceMgr.getCharacterData(Tok.getLocation());
// If this token contains nothing interesting, return it directly.
if (!Tok.needsCleaning()) {
Buffer = TokStart;
return Tok.getLength();
}
// Otherwise, hard case, relex the characters into the string.
char *OutBuf = const_cast<char*>(Buffer);
for (const char *Ptr = TokStart, *End = TokStart+Tok.getLength();
Ptr != End; ) {
unsigned CharSize;
*OutBuf++ = Lexer::getCharAndSizeNoWarn(Ptr, CharSize, Features);
Ptr += CharSize;
}
assert(unsigned(OutBuf-Buffer) != Tok.getLength() &&
"NeedsCleaning flag set on something that didn't need cleaning!");
return OutBuf-Buffer;
}
/// CreateString - Plop the specified string into a scratch buffer and return a
/// location for it. If specified, the source location provides a source
/// location for the token.
SourceLocation Preprocessor::
CreateString(const char *Buf, unsigned Len, SourceLocation SLoc) {
if (SLoc.isValid())
return ScratchBuf->getToken(Buf, Len, SLoc);
return ScratchBuf->getToken(Buf, Len);
}
/// AdvanceToTokenCharacter - Given a location that specifies the start of a
/// token, return a new location that specifies a character within the token.
SourceLocation Preprocessor::AdvanceToTokenCharacter(SourceLocation TokStart,
unsigned CharNo) {
// If they request the first char of the token, we're trivially done. If this
// is a macro expansion, it doesn't make sense to point to a character within
// the instantiation point (the name). We could point to the source
// character, but without also pointing to instantiation info, this is
// confusing.
if (CharNo == 0 || TokStart.isMacroID()) return TokStart;
// Figure out how many physical characters away the specified logical
// character is. This needs to take into consideration newlines and
// trigraphs.
const char *TokPtr = SourceMgr.getCharacterData(TokStart);
unsigned PhysOffset = 0;
// The usual case is that tokens don't contain anything interesting. Skip
// over the uninteresting characters. If a token only consists of simple
// chars, this method is extremely fast.
while (CharNo && Lexer::isObviouslySimpleCharacter(*TokPtr))
++TokPtr, --CharNo, ++PhysOffset;
// If we have a character that may be a trigraph or escaped newline, create a
// lexer to parse it correctly.
if (CharNo != 0) {
// Create a lexer starting at this token position.
Lexer TheLexer(TokStart, *this, TokPtr);
Token Tok;
// Skip over characters the remaining characters.
const char *TokStartPtr = TokPtr;
for (; CharNo; --CharNo)
TheLexer.getAndAdvanceChar(TokPtr, Tok);
PhysOffset += TokPtr-TokStartPtr;
}
return TokStart.getFileLocWithOffset(PhysOffset);
}
//===----------------------------------------------------------------------===//
// Preprocessor Initialization Methods
//===----------------------------------------------------------------------===//
// Append a #define line to Buf for Macro. Macro should be of the form XXX,
// in which case we emit "#define XXX 1" or "XXX=Y z W" in which case we emit
// "#define XXX Y z W". To get a #define with no value, use "XXX=".
static void DefineBuiltinMacro(std::vector<char> &Buf, const char *Macro,
const char *Command = "#define ") {
Buf.insert(Buf.end(), Command, Command+strlen(Command));
if (const char *Equal = strchr(Macro, '=')) {
// Turn the = into ' '.
Buf.insert(Buf.end(), Macro, Equal);
Buf.push_back(' ');
Buf.insert(Buf.end(), Equal+1, Equal+strlen(Equal));
} else {
// Push "macroname 1".
Buf.insert(Buf.end(), Macro, Macro+strlen(Macro));
Buf.push_back(' ');
Buf.push_back('1');
}
Buf.push_back('\n');
}
static void InitializePredefinedMacros(Preprocessor &PP,
std::vector<char> &Buf) {
// FIXME: Implement magic like cpp_init_builtins for things like __STDC__
// and __DATE__ etc.
#if 0
/* __STDC__ has the value 1 under normal circumstances.
However, if (a) we are in a system header, (b) the option
stdc_0_in_system_headers is true (set by target config), and
(c) we are not in strictly conforming mode, then it has the
value 0. (b) and (c) are already checked in cpp_init_builtins. */
//case BT_STDC:
if (cpp_in_system_header (pfile))
number = 0;
else
number = 1;
break;
#endif
// These should all be defined in the preprocessor according to the
// current language configuration.
DefineBuiltinMacro(Buf, "__STDC__=1");
//DefineBuiltinMacro(Buf, "__ASSEMBLER__=1");
if (PP.getLangOptions().C99 && !PP.getLangOptions().CPlusPlus)
DefineBuiltinMacro(Buf, "__STDC_VERSION__=199901L");
else if (0) // STDC94 ?
DefineBuiltinMacro(Buf, "__STDC_VERSION__=199409L");
DefineBuiltinMacro(Buf, "__STDC_HOSTED__=1");
if (PP.getLangOptions().ObjC1)
DefineBuiltinMacro(Buf, "__OBJC__=1");
if (PP.getLangOptions().ObjC2)
DefineBuiltinMacro(Buf, "__OBJC2__=1");
// Add __builtin_va_list typedef.
{
const char *VAList = PP.getTargetInfo().getVAListDeclaration();
Buf.insert(Buf.end(), VAList, VAList+strlen(VAList));
Buf.push_back('\n');
}
// Get the target #defines.
PP.getTargetInfo().getTargetDefines(Buf);
// Compiler set macros.
DefineBuiltinMacro(Buf, "__APPLE_CC__=5250");
DefineBuiltinMacro(Buf, "__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__=1050");
DefineBuiltinMacro(Buf, "__GNUC_MINOR__=0");
DefineBuiltinMacro(Buf, "__GNUC_PATCHLEVEL__=1");
DefineBuiltinMacro(Buf, "__GNUC__=4");
DefineBuiltinMacro(Buf, "__GXX_ABI_VERSION=1002");
DefineBuiltinMacro(Buf, "__VERSION__=\"4.0.1 (Apple Computer, Inc. "
"build 5250)\"");
// Build configuration options.
DefineBuiltinMacro(Buf, "__DYNAMIC__=1");
DefineBuiltinMacro(Buf, "__FINITE_MATH_ONLY__=0");
DefineBuiltinMacro(Buf, "__NO_INLINE__=1");
DefineBuiltinMacro(Buf, "__PIC__=1");
if (PP.getLangOptions().CPlusPlus) {
DefineBuiltinMacro(Buf, "__DEPRECATED=1");
DefineBuiltinMacro(Buf, "__EXCEPTIONS=1");
DefineBuiltinMacro(Buf, "__GNUG__=4");
DefineBuiltinMacro(Buf, "__GXX_WEAK__=1");
DefineBuiltinMacro(Buf, "__cplusplus=1");
DefineBuiltinMacro(Buf, "__private_extern__=extern");
}
if (PP.getLangOptions().Microsoft) {
DefineBuiltinMacro(Buf, "__stdcall=");
DefineBuiltinMacro(Buf, "__cdecl=");
DefineBuiltinMacro(Buf, "_cdecl=");
DefineBuiltinMacro(Buf, "__ptr64=");
DefineBuiltinMacro(Buf, "__w64=");
DefineBuiltinMacro(Buf, "__forceinline=");
DefineBuiltinMacro(Buf, "__int8=char");
DefineBuiltinMacro(Buf, "__int16=short");
DefineBuiltinMacro(Buf, "__int32=int");
DefineBuiltinMacro(Buf, "__int64=long long");
DefineBuiltinMacro(Buf, "__declspec(X)=");
}
// FIXME: Should emit a #line directive here.
}
/// EnterMainSourceFile - Enter the specified FileID as the main source file,
/// which implicitly adds the builtin defines etc.
void Preprocessor::EnterMainSourceFile() {
unsigned MainFileID = SourceMgr.getMainFileID();
// Enter the main file source buffer.
EnterSourceFile(MainFileID, 0);
// Tell the header info that the main file was entered. If the file is later
// #imported, it won't be re-entered.
if (const FileEntry *FE =
SourceMgr.getFileEntryForLoc(SourceLocation::getFileLoc(MainFileID, 0)))
HeaderInfo.IncrementIncludeCount(FE);
std::vector<char> PrologFile;
PrologFile.reserve(4080);
// Install things like __POWERPC__, __GNUC__, etc into the macro table.
InitializePredefinedMacros(*this, PrologFile);
// Add on the predefines from the driver.
PrologFile.insert(PrologFile.end(), Predefines,Predefines+strlen(Predefines));
// Memory buffer must end with a null byte!
PrologFile.push_back(0);
// Now that we have emitted the predefined macros, #includes, etc into
// PrologFile, preprocess it to populate the initial preprocessor state.
llvm::MemoryBuffer *SB =
llvm::MemoryBuffer::getMemBufferCopy(&PrologFile.front(),&PrologFile.back(),
"<predefines>");
assert(SB && "Cannot fail to create predefined source buffer");
unsigned FileID = SourceMgr.createFileIDForMemBuffer(SB);
assert(FileID && "Could not create FileID for predefines?");
// Start parsing the predefines.
EnterSourceFile(FileID, 0);
}
//===----------------------------------------------------------------------===//
// Lexer Event Handling.
//===----------------------------------------------------------------------===//
/// LookUpIdentifierInfo - Given a tok::identifier token, look up the
/// identifier information for the token and install it into the token.
IdentifierInfo *Preprocessor::LookUpIdentifierInfo(Token &Identifier,
const char *BufPtr) {
assert(Identifier.is(tok::identifier) && "Not an identifier!");
assert(Identifier.getIdentifierInfo() == 0 && "Identinfo already exists!");
// Look up this token, see if it is a macro, or if it is a language keyword.
IdentifierInfo *II;
if (BufPtr && !Identifier.needsCleaning()) {
// No cleaning needed, just use the characters from the lexed buffer.
II = getIdentifierInfo(BufPtr, BufPtr+Identifier.getLength());
} else {
// Cleaning needed, alloca a buffer, clean into it, then use the buffer.
llvm::SmallVector<char, 64> IdentifierBuffer;
IdentifierBuffer.resize(Identifier.getLength());
const char *TmpBuf = &IdentifierBuffer[0];
unsigned Size = getSpelling(Identifier, TmpBuf);
II = getIdentifierInfo(TmpBuf, TmpBuf+Size);
}
Identifier.setIdentifierInfo(II);
return II;
}
/// HandleIdentifier - This callback is invoked when the lexer reads an
/// identifier. This callback looks up the identifier in the map and/or
/// potentially macro expands it or turns it into a named token (like 'for').
void Preprocessor::HandleIdentifier(Token &Identifier) {
assert(Identifier.getIdentifierInfo() &&
"Can't handle identifiers without identifier info!");
IdentifierInfo &II = *Identifier.getIdentifierInfo();
// If this identifier was poisoned, and if it was not produced from a macro
// expansion, emit an error.
if (II.isPoisoned() && CurLexer) {
if (&II != Ident__VA_ARGS__) // We warn about __VA_ARGS__ with poisoning.
Diag(Identifier, diag::err_pp_used_poisoned_id);
else
Diag(Identifier, diag::ext_pp_bad_vaargs_use);
}
// If this is a macro to be expanded, do it.
if (MacroInfo *MI = getMacroInfo(&II)) {
if (!DisableMacroExpansion && !Identifier.isExpandDisabled()) {
if (MI->isEnabled()) {
if (!HandleMacroExpandedIdentifier(Identifier, MI))
return;
} else {
// C99 6.10.3.4p2 says that a disabled macro may never again be
// expanded, even if it's in a context where it could be expanded in the
// future.
Identifier.setFlag(Token::DisableExpand);
}
}
}
// C++ 2.11p2: If this is an alternative representation of a C++ operator,
// then we act as if it is the actual operator and not the textual
// representation of it.
if (II.isCPlusPlusOperatorKeyword())
Identifier.setIdentifierInfo(0);
// Change the kind of this identifier to the appropriate token kind, e.g.
// turning "for" into a keyword.
Identifier.setKind(II.getTokenID());
// If this is an extension token, diagnose its use.
// FIXME: tried (unsuccesfully) to shut this up when compiling with gnu99
// For now, I'm just commenting it out (while I work on attributes).
if (II.isExtensionToken() && Features.C99)
Diag(Identifier, diag::ext_token_used);
}
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