add infrastructure for warning if redef'd macro bodies differ, but don't

fully implement it.

Fix warning on #define __LINE__ to warn about redefinition, not #undef.

llvm-svn: 38679

6 files changed, 33 insertions, 10 deletions

diff --git a/clang/Lex/MacroInfo.cpp b/clang/Lex/MacroInfo.cpp
index 9cd46dbdaec..28579a46bc0 100644
--- a/clang/Lex/MacroInfo.cpp
+++ b/clang/Lex/MacroInfo.cpp
@@ -15,3 +15,10 @@
 #include <iostream>
 using namespace llvm;
 using namespace clang;
+
+/// isEqualTo - Return true if the specified macro definition is equal to this
+/// macro in spelling, arguments, and whitespace.  This is used to emit
+/// duplicate definition warnings.
+bool MacroInfo::isEqualTo(const MacroInfo &Other) const {
+  return true;
+}
diff --git a/clang/Lex/Preprocessor.cpp b/clang/Lex/Preprocessor.cpp
index 86b9d9c1bdc..66acd6c7bd5 100644
--- a/clang/Lex/Preprocessor.cpp
+++ b/clang/Lex/Preprocessor.cpp
@@ -839,10 +839,10 @@ void Preprocessor::DiscardUntilEndOfDirective() {
 
 /// ReadMacroName - Lex and validate a macro name, which occurs after a
 /// #define or #undef.  This sets the token kind to eom and discards the rest
-/// of the macro line if the macro name is invalid.  isDefineUndef is true if
-/// this is due to a a #define or #undef directive, false if it is something
+/// of the macro line if the macro name is invalid.  isDefineUndef is 1 if
+/// this is due to a a #define, 2 if #undef directive, 0 if it is something
 /// else (e.g. #ifdef).
-void Preprocessor::ReadMacroName(LexerToken &MacroNameTok, bool isDefineUndef) {
+void Preprocessor::ReadMacroName(LexerToken &MacroNameTok, char isDefineUndef) {
   // Read the token, don't allow macro expansion on it.
   LexUnexpandedToken(MacroNameTok);
   
@@ -864,7 +864,10 @@ void Preprocessor::ReadMacroName(LexerToken &MacroNameTok, bool isDefineUndef) {
   } else if (isDefineUndef && II->getMacroInfo() &&
              II->getMacroInfo()->isBuiltinMacro()) {
     // Error if defining "__LINE__" and other builtins: C99 6.10.8.4.
-    Diag(MacroNameTok, diag::pp_undef_builtin_macro);
+    if (isDefineUndef == 1)
+      Diag(MacroNameTok, diag::pp_redef_builtin_macro);
+    else
+      Diag(MacroNameTok, diag::pp_undef_builtin_macro);
   } else {
     // Okay, we got a good identifier node.  Return it.
     return;
@@ -1322,7 +1325,7 @@ void Preprocessor::HandleDefineDirective(LexerToken &DefineTok) {
   ++NumDefined;
 
   LexerToken MacroNameTok;
-  ReadMacroName(MacroNameTok, true);
+  ReadMacroName(MacroNameTok, 1);
   
   // Error reading macro name?  If so, diagnostic already issued.
   if (MacroNameTok.getKind() == tok::eom)
@@ -1396,9 +1399,13 @@ void Preprocessor::HandleDefineDirective(LexerToken &DefineTok) {
     if (!OtherMI->isUsed())
       Diag(OtherMI->getDefinitionLoc(), diag::pp_macro_not_used);
 
-    // FIXME: Verify the definition is the same.
     // Macros must be identical.  This means all tokes and whitespace separation
     // must be the same.
+    if (!MI->isEqualTo(*OtherMI)) {
+      Diag(MI->getDefinitionLoc(), diag::ext_pp_macro_redef,
+           MacroNameTok.getIdentifierInfo()->getName());
+      Diag(OtherMI->getDefinitionLoc(), diag::ext_pp_macro_redef2);
+    }
     delete OtherMI;
   }
   
@@ -1412,7 +1419,7 @@ void Preprocessor::HandleUndefDirective(LexerToken &UndefTok) {
   ++NumUndefined;
 
   LexerToken MacroNameTok;
-  ReadMacroName(MacroNameTok, true);
+  ReadMacroName(MacroNameTok, 2);
   
   // Error reading macro name?  If so, diagnostic already issued.
   if (MacroNameTok.getKind() == tok::eom)
diff --git a/clang/clang.xcodeproj/project.pbxproj b/clang/clang.xcodeproj/project.pbxproj
index 81c366b830f..dbc9d513ac9 100644
--- a/clang/clang.xcodeproj/project.pbxproj
+++ b/clang/clang.xcodeproj/project.pbxproj
@@ -92,7 +92,7 @@
 /* End PBXCopyFilesBuildPhase section */
 
 /* Begin PBXFileReference section */
-		8DD76F6C0486A84900D96B5E /* clang */ = {isa = PBXFileReference; includeInIndex = 0; lastKnownFileType = "compiled.mach-o.executable"; path = clang; sourceTree = BUILT_PRODUCTS_DIR; };
+		8DD76F6C0486A84900D96B5E /* clang */ = {isa = PBXFileReference; explicitFileType = "compiled.mach-o.executable"; includeInIndex = 0; path = clang; sourceTree = BUILT_PRODUCTS_DIR; };
 		DEAEE98A0A5A2B970045101B /* MultipleIncludeOpt.h */ = {isa = PBXFileReference; fileEncoding = 30; lastKnownFileType = sourcecode.c.h; path = MultipleIncludeOpt.h; sourceTree = "<group>"; };
 		DEAEECAC0A5AF0E30045101B /* clang.h */ = {isa = PBXFileReference; fileEncoding = 30; lastKnownFileType = sourcecode.c.h; path = clang.h; sourceTree = "<group>"; };
 		DEAEECD40A5AF1FE0045101B /* PrintPreprocessedOutput.cpp */ = {isa = PBXFileReference; fileEncoding = 30; lastKnownFileType = sourcecode.cpp.cpp; path = PrintPreprocessedOutput.cpp; sourceTree = "<group>"; };
diff --git a/clang/include/clang/Basic/DiagnosticKinds.def b/clang/include/clang/Basic/DiagnosticKinds.def
index fbf2c7c813a..df5c32e1756 100644
--- a/clang/include/clang/Basic/DiagnosticKinds.def
+++ b/clang/include/clang/Basic/DiagnosticKinds.def
@@ -115,7 +115,11 @@ DIAG(ext_pp_comma_expr, EXTENSION,
      "comma operator in operand of #if")
 DIAG(ext_pp_bad_vaargs_use, EXTENSION,
      "__VA_ARGS__ can only appear in the expansion of a C99 variadic macro")
-     
+DIAG(ext_pp_macro_redef, EXTENSION,
+     "\"%s\" macro redefined")
+DIAG(ext_pp_macro_redef2, EXTENSION,
+     "this is previous definition")
+
 DIAG(ext_pp_base_file, EXTENSION,
      "__BASE_FILE__ is a language extension")
 DIAG(ext_pp_include_level, EXTENSION,
diff --git a/clang/include/clang/Lex/MacroInfo.h b/clang/include/clang/Lex/MacroInfo.h
index bb92ec965d9..ca668a5ae6a 100644
--- a/clang/include/clang/Lex/MacroInfo.h
+++ b/clang/include/clang/Lex/MacroInfo.h
@@ -57,6 +57,11 @@ public:
   ///
   SourceLocation getDefinitionLoc() const { return Location; }
   
+  /// isEqualTo - Return true if the specified macro definition is equal to this
+  /// macro in spelling, arguments, and whitespace.  This is used to emit
+  /// duplicate definition warnings.
+  bool isEqualTo(const MacroInfo &Other) const;
+  
   /// setIsBuiltinMacro - Set or clear the isBuiltinMacro flag.
   ///
   void setIsBuiltinMacro(bool Val = true) {
diff --git a/clang/include/clang/Lex/Preprocessor.h b/clang/include/clang/Lex/Preprocessor.h
index 7a65c82cad2..ef2b662c730 100644
--- a/clang/include/clang/Lex/Preprocessor.h
+++ b/clang/include/clang/Lex/Preprocessor.h
@@ -421,7 +421,7 @@ private:
   /// ReadMacroName - Lex and validate a macro name, which occurs after a
   /// #define or #undef.  This emits a diagnostic, sets the token kind to eom,
   /// and discards the rest of the macro line if the macro name is invalid.
-  void ReadMacroName(LexerToken &MacroNameTok, bool isDefineUndef = false);
+  void ReadMacroName(LexerToken &MacroNameTok, char isDefineUndef = 0);
   
   /// SkipExcludedConditionalBlock - We just read a #if or related directive and
   /// decided that the subsequent tokens are in the #if'd out portion of the