split macro expansion support out of Preprocessor.cpp into PPMacroExpansion.cpp
Rename Directives.cpp -> PPDirectives.cpp since it implements part of the
Preprocessor class.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@48078 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/Lex/PPMacroExpansion.cpp b/Lex/PPMacroExpansion.cpp
new file mode 100644
index 0000000..8218d0a
--- /dev/null
+++ b/Lex/PPMacroExpansion.cpp
@@ -0,0 +1,523 @@
+//===--- MacroExpansion.cpp - Top level Macro Expansion -------------------===//
+//
+// 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 top level handling of macro expasion for the
+// preprocessor.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Lex/Preprocessor.h"
+#include "MacroArgs.h"
+#include "clang/Lex/MacroInfo.h"
+#include "clang/Basic/SourceManager.h"
+#include "clang/Basic/FileManager.h"
+#include "clang/Basic/Diagnostic.h"
+using namespace clang;
+
+/// setMacroInfo - Specify a macro for this identifier.
+///
+void Preprocessor::setMacroInfo(IdentifierInfo *II, MacroInfo *MI) {
+ if (MI == 0) {
+ if (II->hasMacroDefinition()) {
+ Macros.erase(II);
+ II->setHasMacroDefinition(false);
+ }
+ } else {
+ Macros[II] = MI;
+ II->setHasMacroDefinition(true);
+ }
+}
+
+/// RegisterBuiltinMacro - Register the specified identifier in the identifier
+/// table and mark it as a builtin macro to be expanded.
+IdentifierInfo *Preprocessor::RegisterBuiltinMacro(const char *Name) {
+ // Get the identifier.
+ IdentifierInfo *Id = getIdentifierInfo(Name);
+
+ // Mark it as being a macro that is builtin.
+ MacroInfo *MI = new MacroInfo(SourceLocation());
+ MI->setIsBuiltinMacro();
+ setMacroInfo(Id, MI);
+ return Id;
+}
+
+
+/// RegisterBuiltinMacros - Register builtin macros, such as __LINE__ with the
+/// identifier table.
+void Preprocessor::RegisterBuiltinMacros() {
+ Ident__LINE__ = RegisterBuiltinMacro("__LINE__");
+ Ident__FILE__ = RegisterBuiltinMacro("__FILE__");
+ Ident__DATE__ = RegisterBuiltinMacro("__DATE__");
+ Ident__TIME__ = RegisterBuiltinMacro("__TIME__");
+ Ident_Pragma = RegisterBuiltinMacro("_Pragma");
+
+ // GCC Extensions.
+ Ident__BASE_FILE__ = RegisterBuiltinMacro("__BASE_FILE__");
+ Ident__INCLUDE_LEVEL__ = RegisterBuiltinMacro("__INCLUDE_LEVEL__");
+ Ident__TIMESTAMP__ = RegisterBuiltinMacro("__TIMESTAMP__");
+}
+
+/// isTrivialSingleTokenExpansion - Return true if MI, which has a single token
+/// in its expansion, currently expands to that token literally.
+static bool isTrivialSingleTokenExpansion(const MacroInfo *MI,
+ const IdentifierInfo *MacroIdent,
+ Preprocessor &PP) {
+ IdentifierInfo *II = MI->getReplacementToken(0).getIdentifierInfo();
+
+ // If the token isn't an identifier, it's always literally expanded.
+ if (II == 0) return true;
+
+ // If the identifier is a macro, and if that macro is enabled, it may be
+ // expanded so it's not a trivial expansion.
+ if (II->hasMacroDefinition() && PP.getMacroInfo(II)->isEnabled() &&
+ // Fast expanding "#define X X" is ok, because X would be disabled.
+ II != MacroIdent)
+ return false;
+
+ // If this is an object-like macro invocation, it is safe to trivially expand
+ // it.
+ if (MI->isObjectLike()) return true;
+
+ // If this is a function-like macro invocation, it's safe to trivially expand
+ // as long as the identifier is not a macro argument.
+ for (MacroInfo::arg_iterator I = MI->arg_begin(), E = MI->arg_end();
+ I != E; ++I)
+ if (*I == II)
+ return false; // Identifier is a macro argument.
+
+ return true;
+}
+
+
+/// isNextPPTokenLParen - Determine whether the next preprocessor token to be
+/// lexed is a '('. If so, consume the token and return true, if not, this
+/// method should have no observable side-effect on the lexed tokens.
+bool Preprocessor::isNextPPTokenLParen() {
+ // Do some quick tests for rejection cases.
+ unsigned Val;
+ if (CurLexer)
+ Val = CurLexer->isNextPPTokenLParen();
+ else
+ Val = CurTokenLexer->isNextTokenLParen();
+
+ if (Val == 2) {
+ // We have run off the end. If it's a source file we don't
+ // examine enclosing ones (C99 5.1.1.2p4). Otherwise walk up the
+ // macro stack.
+ if (CurLexer)
+ return false;
+ for (unsigned i = IncludeMacroStack.size(); i != 0; --i) {
+ IncludeStackInfo &Entry = IncludeMacroStack[i-1];
+ if (Entry.TheLexer)
+ Val = Entry.TheLexer->isNextPPTokenLParen();
+ else
+ Val = Entry.TheTokenLexer->isNextTokenLParen();
+
+ if (Val != 2)
+ break;
+
+ // Ran off the end of a source file?
+ if (Entry.TheLexer)
+ return false;
+ }
+ }
+
+ // Okay, if we know that the token is a '(', lex it and return. Otherwise we
+ // have found something that isn't a '(' or we found the end of the
+ // translation unit. In either case, return false.
+ if (Val != 1)
+ return false;
+
+ Token Tok;
+ LexUnexpandedToken(Tok);
+ assert(Tok.is(tok::l_paren) && "Error computing l-paren-ness?");
+ return true;
+}
+
+/// HandleMacroExpandedIdentifier - If an identifier token is read that is to be
+/// expanded as a macro, handle it and return the next token as 'Identifier'.
+bool Preprocessor::HandleMacroExpandedIdentifier(Token &Identifier,
+ MacroInfo *MI) {
+ // If this is a macro exapnsion in the "#if !defined(x)" line for the file,
+ // then the macro could expand to different things in other contexts, we need
+ // to disable the optimization in this case.
+ if (CurLexer) CurLexer->MIOpt.ExpandedMacro();
+
+ // If this is a builtin macro, like __LINE__ or _Pragma, handle it specially.
+ if (MI->isBuiltinMacro()) {
+ ExpandBuiltinMacro(Identifier);
+ return false;
+ }
+
+ /// Args - If this is a function-like macro expansion, this contains,
+ /// for each macro argument, the list of tokens that were provided to the
+ /// invocation.
+ MacroArgs *Args = 0;
+
+ // If this is a function-like macro, read the arguments.
+ if (MI->isFunctionLike()) {
+ // C99 6.10.3p10: If the preprocessing token immediately after the the macro
+ // name isn't a '(', this macro should not be expanded. Otherwise, consume
+ // it.
+ if (!isNextPPTokenLParen())
+ return true;
+
+ // Remember that we are now parsing the arguments to a macro invocation.
+ // Preprocessor directives used inside macro arguments are not portable, and
+ // this enables the warning.
+ InMacroArgs = true;
+ Args = ReadFunctionLikeMacroArgs(Identifier, MI);
+
+ // Finished parsing args.
+ InMacroArgs = false;
+
+ // If there was an error parsing the arguments, bail out.
+ if (Args == 0) return false;
+
+ ++NumFnMacroExpanded;
+ } else {
+ ++NumMacroExpanded;
+ }
+
+ // Notice that this macro has been used.
+ MI->setIsUsed(true);
+
+ // If we started lexing a macro, enter the macro expansion body.
+
+ // If this macro expands to no tokens, don't bother to push it onto the
+ // expansion stack, only to take it right back off.
+ if (MI->getNumTokens() == 0) {
+ // No need for arg info.
+ if (Args) Args->destroy();
+
+ // Ignore this macro use, just return the next token in the current
+ // buffer.
+ bool HadLeadingSpace = Identifier.hasLeadingSpace();
+ bool IsAtStartOfLine = Identifier.isAtStartOfLine();
+
+ Lex(Identifier);
+
+ // If the identifier isn't on some OTHER line, inherit the leading
+ // whitespace/first-on-a-line property of this token. This handles
+ // stuff like "! XX," -> "! ," and " XX," -> " ,", when XX is
+ // empty.
+ if (!Identifier.isAtStartOfLine()) {
+ if (IsAtStartOfLine) Identifier.setFlag(Token::StartOfLine);
+ if (HadLeadingSpace) Identifier.setFlag(Token::LeadingSpace);
+ }
+ ++NumFastMacroExpanded;
+ return false;
+
+ } else if (MI->getNumTokens() == 1 &&
+ isTrivialSingleTokenExpansion(MI, Identifier.getIdentifierInfo(),
+ *this)){
+ // Otherwise, if this macro expands into a single trivially-expanded
+ // token: expand it now. This handles common cases like
+ // "#define VAL 42".
+
+ // Propagate the isAtStartOfLine/hasLeadingSpace markers of the macro
+ // identifier to the expanded token.
+ bool isAtStartOfLine = Identifier.isAtStartOfLine();
+ bool hasLeadingSpace = Identifier.hasLeadingSpace();
+
+ // Remember where the token is instantiated.
+ SourceLocation InstantiateLoc = Identifier.getLocation();
+
+ // Replace the result token.
+ Identifier = MI->getReplacementToken(0);
+
+ // Restore the StartOfLine/LeadingSpace markers.
+ Identifier.setFlagValue(Token::StartOfLine , isAtStartOfLine);
+ Identifier.setFlagValue(Token::LeadingSpace, hasLeadingSpace);
+
+ // Update the tokens location to include both its logical and physical
+ // locations.
+ SourceLocation Loc =
+ SourceMgr.getInstantiationLoc(Identifier.getLocation(), InstantiateLoc);
+ Identifier.setLocation(Loc);
+
+ // If this is #define X X, we must mark the result as unexpandible.
+ if (IdentifierInfo *NewII = Identifier.getIdentifierInfo())
+ if (getMacroInfo(NewII) == MI)
+ Identifier.setFlag(Token::DisableExpand);
+
+ // Since this is not an identifier token, it can't be macro expanded, so
+ // we're done.
+ ++NumFastMacroExpanded;
+ return false;
+ }
+
+ // Start expanding the macro.
+ EnterMacro(Identifier, Args);
+
+ // Now that the macro is at the top of the include stack, ask the
+ // preprocessor to read the next token from it.
+ Lex(Identifier);
+ return false;
+}
+
+/// ReadFunctionLikeMacroArgs - After reading "MACRO(", this method is
+/// invoked to read all of the actual arguments specified for the macro
+/// invocation. This returns null on error.
+MacroArgs *Preprocessor::ReadFunctionLikeMacroArgs(Token &MacroName,
+ MacroInfo *MI) {
+ // The number of fixed arguments to parse.
+ unsigned NumFixedArgsLeft = MI->getNumArgs();
+ bool isVariadic = MI->isVariadic();
+
+ // Outer loop, while there are more arguments, keep reading them.
+ Token Tok;
+ Tok.setKind(tok::comma);
+ --NumFixedArgsLeft; // Start reading the first arg.
+
+ // ArgTokens - Build up a list of tokens that make up each argument. Each
+ // argument is separated by an EOF token. Use a SmallVector so we can avoid
+ // heap allocations in the common case.
+ llvm::SmallVector<Token, 64> ArgTokens;
+
+ unsigned NumActuals = 0;
+ while (Tok.is(tok::comma)) {
+ // C99 6.10.3p11: Keep track of the number of l_parens we have seen. Note
+ // that we already consumed the first one.
+ unsigned NumParens = 0;
+
+ while (1) {
+ // Read arguments as unexpanded tokens. This avoids issues, e.g., where
+ // an argument value in a macro could expand to ',' or '(' or ')'.
+ LexUnexpandedToken(Tok);
+
+ if (Tok.is(tok::eof) || Tok.is(tok::eom)) { // "#if f(<eof>" & "#if f(\n"
+ Diag(MacroName, diag::err_unterm_macro_invoc);
+ // Do not lose the EOF/EOM. Return it to the client.
+ MacroName = Tok;
+ return 0;
+ } else if (Tok.is(tok::r_paren)) {
+ // If we found the ) token, the macro arg list is done.
+ if (NumParens-- == 0)
+ break;
+ } else if (Tok.is(tok::l_paren)) {
+ ++NumParens;
+ } else if (Tok.is(tok::comma) && NumParens == 0) {
+ // Comma ends this argument if there are more fixed arguments expected.
+ if (NumFixedArgsLeft)
+ break;
+
+ // If this is not a variadic macro, too many args were specified.
+ if (!isVariadic) {
+ // Emit the diagnostic at the macro name in case there is a missing ).
+ // Emitting it at the , could be far away from the macro name.
+ Diag(MacroName, diag::err_too_many_args_in_macro_invoc);
+ return 0;
+ }
+ // Otherwise, continue to add the tokens to this variable argument.
+ } else if (Tok.is(tok::comment) && !KeepMacroComments) {
+ // If this is a comment token in the argument list and we're just in
+ // -C mode (not -CC mode), discard the comment.
+ continue;
+ } else if (Tok.is(tok::identifier)) {
+ // Reading macro arguments can cause macros that we are currently
+ // expanding from to be popped off the expansion stack. Doing so causes
+ // them to be reenabled for expansion. Here we record whether any
+ // identifiers we lex as macro arguments correspond to disabled macros.
+ // If so, we mark the token as noexpand. This is a subtle aspect of
+ // C99 6.10.3.4p2.
+ if (MacroInfo *MI = getMacroInfo(Tok.getIdentifierInfo()))
+ if (!MI->isEnabled())
+ Tok.setFlag(Token::DisableExpand);
+ }
+
+ ArgTokens.push_back(Tok);
+ }
+
+ // Empty arguments are standard in C99 and supported as an extension in
+ // other modes.
+ if (ArgTokens.empty() && !Features.C99)
+ Diag(Tok, diag::ext_empty_fnmacro_arg);
+
+ // Add a marker EOF token to the end of the token list for this argument.
+ Token EOFTok;
+ EOFTok.startToken();
+ EOFTok.setKind(tok::eof);
+ EOFTok.setLocation(Tok.getLocation());
+ EOFTok.setLength(0);
+ ArgTokens.push_back(EOFTok);
+ ++NumActuals;
+ --NumFixedArgsLeft;
+ };
+
+ // Okay, we either found the r_paren. Check to see if we parsed too few
+ // arguments.
+ unsigned MinArgsExpected = MI->getNumArgs();
+
+ // See MacroArgs instance var for description of this.
+ bool isVarargsElided = false;
+
+ if (NumActuals < MinArgsExpected) {
+ // There are several cases where too few arguments is ok, handle them now.
+ if (NumActuals+1 == MinArgsExpected && MI->isVariadic()) {
+ // Varargs where the named vararg parameter is missing: ok as extension.
+ // #define A(x, ...)
+ // A("blah")
+ Diag(Tok, diag::ext_missing_varargs_arg);
+
+ // Remember this occurred if this is a C99 macro invocation with at least
+ // one actual argument.
+ isVarargsElided = MI->isC99Varargs() && MI->getNumArgs() > 1;
+ } else if (MI->getNumArgs() == 1) {
+ // #define A(x)
+ // A()
+ // is ok because it is an empty argument.
+
+ // Empty arguments are standard in C99 and supported as an extension in
+ // other modes.
+ if (ArgTokens.empty() && !Features.C99)
+ Diag(Tok, diag::ext_empty_fnmacro_arg);
+ } else {
+ // Otherwise, emit the error.
+ Diag(Tok, diag::err_too_few_args_in_macro_invoc);
+ return 0;
+ }
+
+ // Add a marker EOF token to the end of the token list for this argument.
+ SourceLocation EndLoc = Tok.getLocation();
+ Tok.startToken();
+ Tok.setKind(tok::eof);
+ Tok.setLocation(EndLoc);
+ Tok.setLength(0);
+ ArgTokens.push_back(Tok);
+ }
+
+ return MacroArgs::create(MI, &ArgTokens[0], ArgTokens.size(),isVarargsElided);
+}
+
+/// ComputeDATE_TIME - Compute the current time, enter it into the specified
+/// scratch buffer, then return DATELoc/TIMELoc locations with the position of
+/// the identifier tokens inserted.
+static void ComputeDATE_TIME(SourceLocation &DATELoc, SourceLocation &TIMELoc,
+ Preprocessor &PP) {
+ time_t TT = time(0);
+ struct tm *TM = localtime(&TT);
+
+ static const char * const Months[] = {
+ "Jan","Feb","Mar","Apr","May","Jun","Jul","Aug","Sep","Oct","Nov","Dec"
+ };
+
+ char TmpBuffer[100];
+ sprintf(TmpBuffer, "\"%s %2d %4d\"", Months[TM->tm_mon], TM->tm_mday,
+ TM->tm_year+1900);
+ DATELoc = PP.CreateString(TmpBuffer, strlen(TmpBuffer));
+
+ sprintf(TmpBuffer, "\"%02d:%02d:%02d\"", TM->tm_hour, TM->tm_min, TM->tm_sec);
+ TIMELoc = PP.CreateString(TmpBuffer, strlen(TmpBuffer));
+}
+
+/// ExpandBuiltinMacro - If an identifier token is read that is to be expanded
+/// as a builtin macro, handle it and return the next token as 'Tok'.
+void Preprocessor::ExpandBuiltinMacro(Token &Tok) {
+ // Figure out which token this is.
+ IdentifierInfo *II = Tok.getIdentifierInfo();
+ assert(II && "Can't be a macro without id info!");
+
+ // If this is an _Pragma directive, expand it, invoke the pragma handler, then
+ // lex the token after it.
+ if (II == Ident_Pragma)
+ return Handle_Pragma(Tok);
+
+ ++NumBuiltinMacroExpanded;
+
+ char TmpBuffer[100];
+
+ // Set up the return result.
+ Tok.setIdentifierInfo(0);
+ Tok.clearFlag(Token::NeedsCleaning);
+
+ if (II == Ident__LINE__) {
+ // __LINE__ expands to a simple numeric value.
+ sprintf(TmpBuffer, "%u", SourceMgr.getLogicalLineNumber(Tok.getLocation()));
+ unsigned Length = strlen(TmpBuffer);
+ Tok.setKind(tok::numeric_constant);
+ Tok.setLength(Length);
+ Tok.setLocation(CreateString(TmpBuffer, Length, Tok.getLocation()));
+ } else if (II == Ident__FILE__ || II == Ident__BASE_FILE__) {
+ SourceLocation Loc = Tok.getLocation();
+ if (II == Ident__BASE_FILE__) {
+ Diag(Tok, diag::ext_pp_base_file);
+ SourceLocation NextLoc = SourceMgr.getIncludeLoc(Loc);
+ while (NextLoc.isValid()) {
+ Loc = NextLoc;
+ NextLoc = SourceMgr.getIncludeLoc(Loc);
+ }
+ }
+
+ // Escape this filename. Turn '\' -> '\\' '"' -> '\"'
+ std::string FN = SourceMgr.getSourceName(SourceMgr.getLogicalLoc(Loc));
+ FN = '"' + Lexer::Stringify(FN) + '"';
+ Tok.setKind(tok::string_literal);
+ Tok.setLength(FN.size());
+ Tok.setLocation(CreateString(&FN[0], FN.size(), Tok.getLocation()));
+ } else if (II == Ident__DATE__) {
+ if (!DATELoc.isValid())
+ ComputeDATE_TIME(DATELoc, TIMELoc, *this);
+ Tok.setKind(tok::string_literal);
+ Tok.setLength(strlen("\"Mmm dd yyyy\""));
+ Tok.setLocation(SourceMgr.getInstantiationLoc(DATELoc, Tok.getLocation()));
+ } else if (II == Ident__TIME__) {
+ if (!TIMELoc.isValid())
+ ComputeDATE_TIME(DATELoc, TIMELoc, *this);
+ Tok.setKind(tok::string_literal);
+ Tok.setLength(strlen("\"hh:mm:ss\""));
+ Tok.setLocation(SourceMgr.getInstantiationLoc(TIMELoc, Tok.getLocation()));
+ } else if (II == Ident__INCLUDE_LEVEL__) {
+ Diag(Tok, diag::ext_pp_include_level);
+
+ // Compute the include depth of this token.
+ unsigned Depth = 0;
+ SourceLocation Loc = SourceMgr.getIncludeLoc(Tok.getLocation());
+ for (; Loc.isValid(); ++Depth)
+ Loc = SourceMgr.getIncludeLoc(Loc);
+
+ // __INCLUDE_LEVEL__ expands to a simple numeric value.
+ sprintf(TmpBuffer, "%u", Depth);
+ unsigned Length = strlen(TmpBuffer);
+ Tok.setKind(tok::numeric_constant);
+ Tok.setLength(Length);
+ Tok.setLocation(CreateString(TmpBuffer, Length, Tok.getLocation()));
+ } else if (II == Ident__TIMESTAMP__) {
+ // MSVC, ICC, GCC, VisualAge C++ extension. The generated string should be
+ // of the form "Ddd Mmm dd hh::mm::ss yyyy", which is returned by asctime.
+ Diag(Tok, diag::ext_pp_timestamp);
+
+ // Get the file that we are lexing out of. If we're currently lexing from
+ // a macro, dig into the include stack.
+ const FileEntry *CurFile = 0;
+ Lexer *TheLexer = getCurrentFileLexer();
+
+ if (TheLexer)
+ CurFile = SourceMgr.getFileEntryForLoc(TheLexer->getFileLoc());
+
+ // If this file is older than the file it depends on, emit a diagnostic.
+ const char *Result;
+ if (CurFile) {
+ time_t TT = CurFile->getModificationTime();
+ struct tm *TM = localtime(&TT);
+ Result = asctime(TM);
+ } else {
+ Result = "??? ??? ?? ??:??:?? ????\n";
+ }
+ TmpBuffer[0] = '"';
+ strcpy(TmpBuffer+1, Result);
+ unsigned Len = strlen(TmpBuffer);
+ TmpBuffer[Len-1] = '"'; // Replace the newline with a quote.
+ Tok.setKind(tok::string_literal);
+ Tok.setLength(Len);
+ Tok.setLocation(CreateString(TmpBuffer, Len, Tok.getLocation()));
+ } else {
+ assert(0 && "Unknown identifier!");
+ }
+}