Preserve unknown STDC pragma through preprocessor

Summary:
#pragma STDC FP_CONTRACT handler is only registered in parser so we
should keep the unknown STDC pragma through preprocessor and we also
should not emit warning for unknown STDC pragma during preprocessor.

rdar://problem/35724351

Reviewers: efriedma, rsmith, arphaman

Reviewed By: efriedma

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D41780

llvm-svn: 321909

1 files changed, 0 insertions, 55 deletions

diff --git a/clang/lib/Lex/Pragma.cpp b/clang/lib/Lex/Pragma.cpp
index b8acd92521f..d2abc5acc09 100644
--- a/clang/lib/Lex/Pragma.cpp
+++ b/clang/lib/Lex/Pragma.cpp
@@ -1601,44 +1601,6 @@ struct PragmaPopMacroHandler : public PragmaHandler {
   }
 };
 
-// Pragma STDC implementations.
-
-/// PragmaSTDC_FENV_ACCESSHandler - "\#pragma STDC FENV_ACCESS ...".
-struct PragmaSTDC_FENV_ACCESSHandler : public PragmaHandler {
-  PragmaSTDC_FENV_ACCESSHandler() : PragmaHandler("FENV_ACCESS") {}
-
-  void HandlePragma(Preprocessor &PP, PragmaIntroducerKind Introducer,
-                    Token &Tok) override {
-    tok::OnOffSwitch OOS;
-    if (PP.LexOnOffSwitch(OOS))
-     return;
-    if (OOS == tok::OOS_ON)
-      PP.Diag(Tok, diag::warn_stdc_fenv_access_not_supported);
-  }
-};
-
-/// PragmaSTDC_CX_LIMITED_RANGEHandler - "\#pragma STDC CX_LIMITED_RANGE ...".
-struct PragmaSTDC_CX_LIMITED_RANGEHandler : public PragmaHandler {
-  PragmaSTDC_CX_LIMITED_RANGEHandler() : PragmaHandler("CX_LIMITED_RANGE") {}
-
-  void HandlePragma(Preprocessor &PP, PragmaIntroducerKind Introducer,
-                    Token &Tok) override {
-    tok::OnOffSwitch OOS;
-    PP.LexOnOffSwitch(OOS);
-  }
-};
-
-/// PragmaSTDC_UnknownHandler - "\#pragma STDC ...".
-struct PragmaSTDC_UnknownHandler : public PragmaHandler {
-  PragmaSTDC_UnknownHandler() = default;
-
-  void HandlePragma(Preprocessor &PP, PragmaIntroducerKind Introducer,
-                    Token &UnknownTok) override {
-    // C99 6.10.6p2, unknown forms are not allowed.
-    PP.Diag(UnknownTok, diag::ext_stdc_pragma_ignored);
-  }
-};
-
 /// PragmaARCCFCodeAuditedHandler - 
 ///   \#pragma clang arc_cf_code_audited begin/end
 struct PragmaARCCFCodeAuditedHandler : public PragmaHandler {
@@ -1815,10 +1777,6 @@ void Preprocessor::RegisterBuiltinPragmas() {
   ModuleHandler->AddPragma(new PragmaModuleBuildHandler());
   ModuleHandler->AddPragma(new PragmaModuleLoadHandler());
 
-  AddPragmaHandler("STDC", new PragmaSTDC_FENV_ACCESSHandler());
-  AddPragmaHandler("STDC", new PragmaSTDC_CX_LIMITED_RANGEHandler());
-  AddPragmaHandler("STDC", new PragmaSTDC_UnknownHandler());
-
   // MS extensions.
   if (LangOpts.MicrosoftExt) {
     AddPragmaHandler(new PragmaWarningHandler());
@@ -1843,17 +1801,4 @@ void Preprocessor::IgnorePragmas() {
   // in Preprocessor::RegisterBuiltinPragmas().
   AddPragmaHandler("GCC", new EmptyPragmaHandler());
   AddPragmaHandler("clang", new EmptyPragmaHandler());
-  if (PragmaHandler *NS = PragmaHandlers->FindHandler("STDC")) {
-    // Preprocessor::RegisterBuiltinPragmas() already registers
-    // PragmaSTDC_UnknownHandler as the empty handler, so remove it first,
-    // otherwise there will be an assert about a duplicate handler.
-    PragmaNamespace *STDCNamespace = NS->getIfNamespace();
-    assert(STDCNamespace &&
-           "Invalid namespace, registered as a regular pragma handler!");
-    if (PragmaHandler *Existing = STDCNamespace->FindHandler("", false)) {
-      RemovePragmaHandler("STDC", Existing);
-      delete Existing;
-    }
-  }
-  AddPragmaHandler("STDC", new EmptyPragmaHandler());
 }