Do not warn on keyword undef

#undef a keyword is generally harmless but used often in configuration scripts.
Also added tests that I forgot to include to commit in r223114.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@224100 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/clang/Basic/DiagnosticLexKinds.td b/include/clang/Basic/DiagnosticLexKinds.td
index 5eb9e65953d7025add22bc2ca9ddba46744f5ad8..325ab0e4333477117b4271811818e491c0073ddb 100644 (file)
--- a/include/clang/Basic/DiagnosticLexKinds.td
+++ b/include/clang/Basic/DiagnosticLexKinds.td
@@ -291,12 +291,10 @@ def note_pp_ambiguous_macro_chosen : Note<
 def note_pp_ambiguous_macro_other : Note<
   "other definition of %0">;
 def warn_pp_macro_hides_keyword : Warning<
-  "keyword or reserved identifier is hidden by macro definition">,
+  "keyword is hidden by macro definition">,
   InGroup<KeywordAsMacro>;
 def warn_pp_macro_is_reserved_id : Warning<
-  "macro name is a keyword or reserved identifier">, InGroup<KeywordAsMacro>;
-def warn_pp_defundef_reserved_ident : Warning<
-  "reserved identifier is used as macro name">, DefaultIgnore,
+  "macro name is a reserved identifier">, DefaultIgnore,
   InGroup<ReservedIdAsMacro>;
 
 def pp_invalid_string_literal : Warning<

diff --git a/lib/Lex/PPDirectives.cpp b/lib/Lex/PPDirectives.cpp
index 16b86b7a305a8fc26206c9c5241bb023333d3519..e359ea5ec39a2992ee48f9520daf355aebf5c17a 100644 (file)
--- a/lib/Lex/PPDirectives.cpp
+++ b/lib/Lex/PPDirectives.cpp
@@ -104,8 +104,7 @@ void Preprocessor::DiscardUntilEndOfDirective() {
 enum MacroDiag {
   MD_NoWarn,        //> Not a reserved identifier
   MD_KeywordDef,    //> Macro hides keyword, enabled by default
-  MD_KeywordUndef,  //> #undef keyword, enabled by default
-  MD_WarnStrict     //> Other reserved id, disabled by default
+  MD_ReservedMacro  //> #define of #undef reserved id, disabled by default
 };
 
 /// \brief Checks if the specified identifier is reserved in the specified
@@ -132,7 +131,8 @@ static MacroDiag shouldWarnOnMacroDef(Preprocessor &PP, IdentifierInfo *II) {
   const LangOptions &Lang = PP.getLangOpts();
   StringRef Text = II->getName();
   if (isReservedId(Text, Lang))
-    return MD_WarnStrict;
+    return MD_ReservedMacro;
+  // Do not warn on keyword undef.  It is generally harmless and widely used.
   if (II->isKeyword(Lang))
     return MD_KeywordDef;
   if (Lang.CPlusPlus && (Text.equals("override") || Text.equals("final")))
@@ -142,13 +142,10 @@ static MacroDiag shouldWarnOnMacroDef(Preprocessor &PP, IdentifierInfo *II) {
 
 static MacroDiag shouldWarnOnMacroUndef(Preprocessor &PP, IdentifierInfo *II) {
   const LangOptions &Lang = PP.getLangOpts();
-  if (II->isKeyword(Lang))
-    return MD_KeywordUndef;
   StringRef Text = II->getName();
-  if (Lang.CPlusPlus && (Text.equals("override") || Text.equals("final")))
-    return MD_KeywordUndef;
+  // Do not warn on keyword undef.  It is generally harmless and widely used.
   if (isReservedId(Text, Lang))
-    return MD_WarnStrict;
+    return MD_ReservedMacro;
   return MD_NoWarn;
 }
 
@@ -203,10 +200,8 @@ bool Preprocessor::CheckMacroName(Token &MacroNameTok, MacroUse isDefineUndef) {
       D = shouldWarnOnMacroUndef(*this, II);
     if (D == MD_KeywordDef)
       Diag(MacroNameTok, diag::warn_pp_macro_hides_keyword);
-    if (D == MD_KeywordUndef)
+    if (D == MD_ReservedMacro)
       Diag(MacroNameTok, diag::warn_pp_macro_is_reserved_id);
-    else if (D == MD_WarnStrict)
-      Diag(MacroNameTok, diag::warn_pp_defundef_reserved_ident);
   }
 
   // Okay, we got a good identifier.

diff --git a/test/PCH/single-token-macro.c b/test/PCH/single-token-macro.c
index b077abaa0365566661d7eff007dac933b22adacf..aa02f65f78b14fb3cb37d7ff3b9044b8aa3ac98d 100644 (file)
--- a/test/PCH/single-token-macro.c
+++ b/test/PCH/single-token-macro.c
@@ -12,8 +12,6 @@
 #ifndef HEADER
 #define HEADER
 
-#pragma clang diagnostic ignored "-Wreserved-id-macro"
-
 #ifdef __stdcall
 // __stdcall is defined as __attribute__((__stdcall__)) for targeting mingw32.
 #undef __stdcall

diff --git a/test/Preprocessor/macro-reserved.c b/test/Preprocessor/macro-reserved.c
new file mode 100644 (file)
index 0000000..2a0e26f
--- /dev/null
+++ b/test/Preprocessor/macro-reserved.c
@@ -0,0 +1,25 @@
+// RUN: %clang_cc1 -fsyntax-only %s -verify
+
+#define for 0    // expected-warning {{keyword is hidden by macro definition}}
+#define final 1
+#define __HAVE_X 0
+#define _HAVE_X 0
+#define X__Y
+
+#undef __cplusplus
+#undef _HAVE_X
+#undef X__Y
+
+#pragma clang diagnostic warning "-Wreserved-id-macro"
+
+#define switch if  // expected-warning {{keyword is hidden by macro definition}}
+#define final 1
+#define __HAVE_X 0 // expected-warning {{macro name is a reserved identifier}}
+#define _HAVE_X 0  // expected-warning {{macro name is a reserved identifier}}
+#define X__Y
+
+#undef __cplusplus // expected-warning {{macro name is a reserved identifier}}
+#undef _HAVE_X     // expected-warning {{macro name is a reserved identifier}}
+#undef X__Y
+
+int x;

diff --git a/test/Preprocessor/macro-reserved.cpp b/test/Preprocessor/macro-reserved.cpp
new file mode 100644 (file)
index 0000000..8529ddf
--- /dev/null
+++ b/test/Preprocessor/macro-reserved.cpp
@@ -0,0 +1,25 @@
+// RUN: %clang_cc1 -fsyntax-only %s -verify
+
+#define for 0    // expected-warning {{keyword is hidden by macro definition}}
+#define final 1  // expected-warning {{keyword is hidden by macro definition}}
+#define __HAVE_X 0
+#define _HAVE_X 0
+#define X__Y
+
+#undef __cplusplus
+#undef _HAVE_X
+#undef X__Y
+
+#pragma clang diagnostic warning "-Wreserved-id-macro"
+
+#define switch if  // expected-warning {{keyword is hidden by macro definition}}
+#define final 1    // expected-warning {{keyword is hidden by macro definition}}
+#define __HAVE_X 0 // expected-warning {{macro name is a reserved identifier}}
+#define _HAVE_X 0  // expected-warning {{macro name is a reserved identifier}}
+#define X__Y       // expected-warning {{macro name is a reserved identifier}}
+
+#undef __cplusplus // expected-warning {{macro name is a reserved identifier}}
+#undef _HAVE_X     // expected-warning {{macro name is a reserved identifier}}
+#undef X__Y        // expected-warning {{macro name is a reserved identifier}}
+
+int x;

diff --git a/test/Sema/thread-specifier.c b/test/Sema/thread-specifier.c
index 71e44c3472691a320d7ce66b9b71aafa7c34d896..3968ae14cf2a2a8f8ab05d703b77ee1a6935235e 100644 (file)
--- a/test/Sema/thread-specifier.c
+++ b/test/Sema/thread-specifier.c
@@ -5,8 +5,6 @@
 // RUN: %clang_cc1 -triple i686-pc-linux-gnu -fsyntax-only -Wno-private-extern -verify -pedantic -x c++ %s -DCXX11 -D__thread=thread_local -std=c++11 -Wno-deprecated
 // RUN: %clang_cc1 -triple i686-pc-linux-gnu -fsyntax-only -Wno-private-extern -verify -pedantic -x c++ %s -DC11 -D__thread=_Thread_local -std=c++11 -Wno-deprecated
 
-#pragma clang diagnostic ignored "-Wkeyword-macro"
-
 #ifdef __cplusplus
 // In C++, we define __private_extern__ to extern.
 #undef __private_extern__