Add support for '-fgnu-keywords' and '-fasm' to Clang's driver. They are not

implemented precisely the same as GCC, but the distinction GCC makes isn't
useful to represent. This allows parsing code which uses GCC-specific keywords
('asm', etc.) without parsing in a fully GNU mode.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@101667 91177308-0d34-0410-b5e6-96231b3b80d8

9 files changed, 45 insertions, 4 deletions

diff --git a/include/clang/Basic/DiagnosticFrontendKinds.td b/include/clang/Basic/DiagnosticFrontendKinds.td
index 00bf2f0b84..3b55a77d4c 100644
--- a/include/clang/Basic/DiagnosticFrontendKinds.td
+++ b/include/clang/Basic/DiagnosticFrontendKinds.td
@@ -129,6 +129,9 @@ def warn_pch_extensions : Error<
 def warn_pch_gnu_extensions : Error<
     "GNU extensions were %select{disabled|enabled}0 in PCH file but are "
     "currently %select{disabled|enabled}1">;
+def warn_pch_gnu_keywords : Error<
+    "GNU keywords were %select{disabled|enabled}0 in PCH file but are "
+    "currently %select{disabled|enabled}1">;
 def warn_pch_microsoft_extensions : Error<
     "Microsoft extensions were %select{disabled|enabled}0 in PCH file but are "
     "currently %select{disabled|enabled}1">;
diff --git a/include/clang/Basic/LangOptions.h b/include/clang/Basic/LangOptions.h
index aff867599a..ba98a087f7 100644
--- a/include/clang/Basic/LangOptions.h
+++ b/include/clang/Basic/LangOptions.h
@@ -28,6 +28,7 @@ public:
   unsigned DollarIdents      : 1;  // '$' allowed in identifiers.
   unsigned AsmPreprocessor   : 1;  // Preprocessor in asm mode.
   unsigned GNUMode           : 1;  // True in gnu99 mode false in c99 mode (etc)
+  unsigned GNUKeywords       : 1;  // True if GNU-only keywords are allowed
   unsigned ImplicitInt       : 1;  // C89 implicit 'int'.
   unsigned Digraphs          : 1;  // C94, C99 and C++
   unsigned HexFloats         : 1;  // C99 Hexadecimal float constants.
@@ -130,7 +131,7 @@ public:
 
   LangOptions() {
     Trigraphs = BCPLComment = Bool = DollarIdents = AsmPreprocessor = 0;
-    GNUMode = ImplicitInt = Digraphs = 0;
+    GNUMode = GNUKeywords = ImplicitInt = Digraphs = 0;
     HexFloats = 0;
     GC = ObjC1 = ObjC2 = ObjCNonFragileABI = ObjCNonFragileABI2 = 0;
     C99 = Microsoft = CPlusPlus = CPlusPlus0x = 0;
diff --git a/include/clang/Driver/CC1Options.td b/include/clang/Driver/CC1Options.td
index 27b13929ef..f910a8edc0 100644
--- a/include/clang/Driver/CC1Options.td
+++ b/include/clang/Driver/CC1Options.td
@@ -341,6 +341,10 @@ def fno_access_control : Flag<"-fno-access-control">,
   HelpText<"Disable C++ access control">;
 def fno_assume_sane_operator_new : Flag<"-fno-assume-sane-operator-new">,
   HelpText<"Don't assume that C++'s global operator new can't alias any pointer">;
+def fgnu_keywords : Flag<"-fgnu-keywords">,
+  HelpText<"Allow GNU-extension keywords regardless of language standard">;
+def fno_gnu_keywords : Flag<"-fno-gnu-keywords">,
+  HelpText<"Disallow GNU-extension keywords regardless of language standard">;
 def fdollars_in_identifiers : Flag<"-fdollars-in-identifiers">,
   HelpText<"Allow '$' in identifiers">;
 def fno_dollars_in_identifiers : Flag<"-fno-dollars-in-identifiers">,
diff --git a/include/clang/Driver/Options.td b/include/clang/Driver/Options.td
index dd4586e619..41c06fe886 100644
--- a/include/clang/Driver/Options.td
+++ b/include/clang/Driver/Options.td
@@ -265,6 +265,10 @@ def fexceptions : Flag<"-fexceptions">, Group<f_Group>;
 def fextdirs_EQ : Joined<"-fextdirs=">, Group<f_Group>;
 def fhosted : Flag<"-fhosted">, Group<f_Group>;
 def ffreestanding : Flag<"-ffreestanding">, Group<f_Group>;
+
+def fgnu_keywords : Flag<"-fgnu-keywords">, Group<f_Group>;
+def fasm : Flag<"-fasm">, Alias<fgnu_keywords>;
+
 def fgnu_runtime : Flag<"-fgnu-runtime">, Group<f_Group>;
 def fheinous_gnu_extensions : Flag<"-fheinous-gnu-extensions">;
 def filelist : Separate<"-filelist">, Flags<[LinkerInput]>;
@@ -300,6 +304,10 @@ def fno_diagnostics_show_option : Flag<"-fno-diagnostics-show-option">, Group<f_
 def fno_dollars_in_identifiers : Flag<"-fno-dollars-in-identifiers">, Group<f_Group>;
 def fno_eliminate_unused_debug_symbols : Flag<"-fno-eliminate-unused-debug-symbols">, Group<f_Group>;
 def fno_exceptions : Flag<"-fno-exceptions">, Group<f_Group>;
+
+def fno_gnu_keywords : Flag<"-fno-gnu-keywords">, Group<f_Group>;
+def fno_asm : Flag<"-fno-asm">, Alias<fno_gnu_keywords>;
+
 def fno_inline_functions : Flag<"-fno-inline-functions">, Group<clang_ignored_f_Group>;
 def fno_inline : Flag<"-fno-inline">, Group<clang_ignored_f_Group>;
 def fno_keep_inline_functions : Flag<"-fno-keep-inline-functions">, Group<clang_ignored_f_Group>;
diff --git a/lib/Basic/IdentifierTable.cpp b/lib/Basic/IdentifierTable.cpp
index 3da19ca16d..ed0de8c4af 100644
--- a/lib/Basic/IdentifierTable.cpp
+++ b/lib/Basic/IdentifierTable.cpp
@@ -78,9 +78,9 @@ namespace {
 /// identifiers because they are language keywords.  This causes the lexer to
 /// automatically map matching identifiers to specialized token codes.
 ///
-/// The C90/C99/CPP/CPP0x flags are set to 0 if the token should be
+/// The C90/C99/CPP/CPP0x flags are set to 2 if the token should be
 /// enabled in the specified langauge, set to 1 if it is an extension
-/// in the specified language, and set to 2 if disabled in the
+/// in the specified language, and set to 0 if disabled in the
 /// specified language.
 static void AddKeyword(llvm::StringRef Keyword,
                        tok::TokenKind TokenCode, unsigned Flags,
@@ -90,7 +90,7 @@ static void AddKeyword(llvm::StringRef Keyword,
   else if (LangOpts.CPlusPlus && (Flags & KEYCXX)) AddResult = 2;
   else if (LangOpts.CPlusPlus0x && (Flags & KEYCXX0X)) AddResult = 2;
   else if (LangOpts.C99 && (Flags & KEYC99)) AddResult = 2;
-  else if (LangOpts.GNUMode && (Flags & KEYGNU)) AddResult = 1;
+  else if (LangOpts.GNUKeywords && (Flags & KEYGNU)) AddResult = 1;
   else if (LangOpts.Microsoft && (Flags & KEYMS)) AddResult = 1;
   else if (LangOpts.Bool && (Flags & BOOLSUPPORT)) AddResult = 2;
   else if (LangOpts.AltiVec && (Flags & KEYALTIVEC)) AddResult = 2;
diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index 899eb4841a..d9df471714 100644
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -1208,6 +1208,16 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
                    getToolChain().getTriple().getOS() == llvm::Triple::Win32))
     CmdArgs.push_back("-fms-extensions");
 
+  // -fgnu-keywords default varies depending on language; only pass if
+  // specified.
+  if (Arg *A = Args.getLastArg(options::OPT_fgnu_keywords,
+                               options::OPT_fno_gnu_keywords)) {
+    if (A->getOption().matches(options::OPT_fgnu_keywords))
+      CmdArgs.push_back("-fgnu-keywords");
+    else
+      CmdArgs.push_back("-fno-gnu-keywords");
+  }
+
   // -fnext-runtime is default.
   if (!Args.hasFlag(options::OPT_fnext_runtime, options::OPT_fgnu_runtime,
                     getToolChain().getTriple().getOS() == llvm::Triple::Darwin))
diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp
index cb227b7bf7..932481f87f 100644
--- a/lib/Frontend/CompilerInvocation.cpp
+++ b/lib/Frontend/CompilerInvocation.cpp
@@ -473,6 +473,10 @@ static void LangOptsToArgs(const LangOptions &Opts,
   //   BCPLComment, C99, CPlusPlus0x, Digraphs, GNUInline, ImplicitInt, GNUMode
   if (Opts.DollarIdents)
     Res.push_back("-fdollars-in-identifiers");
+  if (Opts.GNUMode && !Opts.GNUKeywords)
+    Res.push_back("-fno-gnu-keywords");
+  if (!Opts.GNUMode && Opts.GNUKeywords)
+    Res.push_back("-fgnu-keywords");
   if (Opts.Microsoft)
     Res.push_back("-fms-extensions");
   if (Opts.ObjCNonFragileABI)
@@ -1151,6 +1155,14 @@ static void ParseLangArgs(LangOptions &Opts, ArgList &Args,
   // OpenCL and C++ both have bool, true, false keywords.
   Opts.Bool = Opts.OpenCL || Opts.CPlusPlus;
 
+  // We abuse '-f[no-]gnu-keywords' to force overriding all GNU-extension
+  // keywords. This behavior is provided by GCC's poorly named '-fasm' flag,
+  // while a subset (the non-C++ GNU keywords) is provided by GCC's
+  // '-fgnu-keywords'. Clang conflates the two for simplicity under the single
+  // name, as it doesn't seem a useful distinction.
+  Opts.GNUKeywords = Args.hasFlag(OPT_fgnu_keywords, OPT_fno_gnu_keywords,
+                                  Opts.GNUMode);
+
   if (Opts.CPlusPlus)
     Opts.CXXOperatorNames = !Args.hasArg(OPT_fno_operator_names);
 
diff --git a/lib/Frontend/PCHReader.cpp b/lib/Frontend/PCHReader.cpp
index 578c047b00..bed9403706 100644
--- a/lib/Frontend/PCHReader.cpp
+++ b/lib/Frontend/PCHReader.cpp
@@ -62,6 +62,7 @@ PCHValidator::ReadLanguageOptions(const LangOptions &LangOpts) {
   PARSE_LANGOPT_BENIGN(DollarIdents);
   PARSE_LANGOPT_BENIGN(AsmPreprocessor);
   PARSE_LANGOPT_IMPORTANT(GNUMode, diag::warn_pch_gnu_extensions);
+  PARSE_LANGOPT_IMPORTANT(GNUKeywords, diag::warn_pch_gnu_keywords);
   PARSE_LANGOPT_BENIGN(ImplicitInt);
   PARSE_LANGOPT_BENIGN(Digraphs);
   PARSE_LANGOPT_BENIGN(HexFloats);
@@ -1885,6 +1886,7 @@ bool PCHReader::ParseLanguageOptions(
     PARSE_LANGOPT(DollarIdents);
     PARSE_LANGOPT(AsmPreprocessor);
     PARSE_LANGOPT(GNUMode);
+    PARSE_LANGOPT(GNUKeywords);
     PARSE_LANGOPT(ImplicitInt);
     PARSE_LANGOPT(Digraphs);
     PARSE_LANGOPT(HexFloats);
diff --git a/lib/Frontend/PCHWriter.cpp b/lib/Frontend/PCHWriter.cpp
index 4dd8dc36b7..a6faf9ba99 100644
--- a/lib/Frontend/PCHWriter.cpp
+++ b/lib/Frontend/PCHWriter.cpp
@@ -745,6 +745,7 @@ void PCHWriter::WriteLanguageOptions(const LangOptions &LangOpts) {
   Record.push_back(LangOpts.DollarIdents);  // '$' allowed in identifiers.
   Record.push_back(LangOpts.AsmPreprocessor);  // Preprocessor in asm mode.
   Record.push_back(LangOpts.GNUMode);  // True in gnu99 mode false in c99 mode (etc)
+  Record.push_back(LangOpts.GNUKeywords);  // Allow GNU-extension keywords
   Record.push_back(LangOpts.ImplicitInt);  // C89 implicit 'int'.
   Record.push_back(LangOpts.Digraphs);  // C94, C99 and C++
   Record.push_back(LangOpts.HexFloats);  // C99 Hexadecimal float constants.