[CLANG] Fix INF/NAN warning.

clang/include/clang/Basic/DiagnosticCommonKinds.td

@@ -72,7 +72,9 @@ def warn_pragma_debug_unexpected_argument : Warning<
 
 def warn_fp_nan_inf_when_disabled : Warning<
   "use of %select{infinity|NaN}0%select{| via a macro}1 is undefined behavior "
-  "due to the currently enabled floating-point options">,
+  "due to the currently enabled floating-point options%select{|; mix of safe "
+  "and unsafe math options are used. Check the order of you command line "
+  "arguments}2">,
   InGroup<DiagGroup<"nan-infinity-disabled">>;
 }
 

clang/include/clang/Lex/Preprocessor.h

@@ -2838,7 +2838,8 @@ class Preprocessor {
     return AnnotationInfos.find(II)->second;
   }
 
-  void emitMacroExpansionWarnings(const Token &Identifier) const {
+  void emitMacroExpansionWarnings(const Token &Identifier,
+                                  bool IsIfnDef = false) const {
     IdentifierInfo *Info = Identifier.getIdentifierInfo();
     if (Info->isDeprecatedMacro())
       emitMacroDeprecationWarning(Identifier);
@@ -2847,12 +2848,15 @@ class Preprocessor {
         !SourceMgr.isInMainFile(Identifier.getLocation()))
       emitRestrictExpansionWarning(Identifier);
 
-    if (Info->getName() == "INFINITY")
-      if (getLangOpts().NoHonorInfs)
-        emitRestrictInfNaNWarning(Identifier, 0);
-    if (Info->getName() == "NAN")
-      if (getLangOpts().NoHonorNaNs)
-        emitRestrictInfNaNWarning(Identifier, 1);
+    if (!IsIfnDef) {
+      bool UnsafeMath = getLangOpts().UnsafeFPMath;
+      if (Info->getName() == "INFINITY")
+        if (getLangOpts().NoHonorInfs)
+          emitRestrictInfNaNWarning(Identifier, 0, UnsafeMath);
+      if (Info->getName() == "NAN")
+        if (getLangOpts().NoHonorNaNs)
+          emitRestrictInfNaNWarning(Identifier, 1, UnsafeMath);
+    }
   }
 
   static void processPathForFileMacro(SmallVectorImpl<char> &Path,
@@ -2869,7 +2873,7 @@ class Preprocessor {
   void emitRestrictExpansionWarning(const Token &Identifier) const;
   void emitFinalMacroWarning(const Token &Identifier, bool IsUndef) const;
   void emitRestrictInfNaNWarning(const Token &Identifier,
-                                 unsigned DiagSelection) const;
+                                 unsigned DiagSelection, bool UnsafeMath) const;
 
   /// This boolean state keeps track if the current scanned token (by this PP)
   /// is in an "-Wunsafe-buffer-usage" opt-out region. Assuming PP scans a

clang/lib/Lex/PPDirectives.cpp

@@ -3288,7 +3288,7 @@ void Preprocessor::HandleIfdefDirective(Token &Result,
     return;
   }
 
-  emitMacroExpansionWarnings(MacroNameTok);
+  emitMacroExpansionWarnings(MacroNameTok, true);
 
   // Check to see if this is the last token on the #if[n]def line.
   CheckEndOfDirective(isIfndef ? "ifndef" : "ifdef");

clang/lib/Lex/Preprocessor.cpp

@@ -1466,8 +1466,10 @@ void Preprocessor::emitRestrictExpansionWarning(const Token &Identifier) const {
 }
 
 void Preprocessor::emitRestrictInfNaNWarning(const Token &Identifier,
-                                             unsigned DiagSelection) const {
-  Diag(Identifier, diag::warn_fp_nan_inf_when_disabled) << DiagSelection << 1;
+                                             unsigned DiagSelection,
+                                             bool UnsafeMath) const {
+  Diag(Identifier, diag::warn_fp_nan_inf_when_disabled)
+      << DiagSelection << 1 << UnsafeMath;
 }
 
 void Preprocessor::emitFinalMacroWarning(const Token &Identifier,

clang/lib/Sema/SemaChecking.cpp

@@ -9132,7 +9132,7 @@ bool Sema::SemaBuiltinUnorderedCompare(CallExpr *TheCall, unsigned BuiltinID) {
   if (BuiltinID == Builtin::BI__builtin_isunordered &&
       TheCall->getFPFeaturesInEffect(getLangOpts()).getNoHonorNaNs())
     Diag(TheCall->getBeginLoc(), diag::warn_fp_nan_inf_when_disabled)
-        << 1 << 0 << TheCall->getSourceRange();
+        << 1 << 0 << 0;
 
   ExprResult OrigArg0 = TheCall->getArg(0);
   ExprResult OrigArg1 = TheCall->getArg(1);
@@ -9178,12 +9178,12 @@ bool Sema::SemaBuiltinFPClassification(CallExpr *TheCall, unsigned NumArgs,
                                BuiltinID == Builtin::BI__builtin_isinf ||
                                BuiltinID == Builtin::BI__builtin_isinf_sign))
     Diag(TheCall->getBeginLoc(), diag::warn_fp_nan_inf_when_disabled)
-        << 0 << 0 << TheCall->getSourceRange();
+        << 0 << 0 << 0;
 
   if (FPO.getNoHonorNaNs() && (BuiltinID == Builtin::BI__builtin_isnan ||
                                BuiltinID == Builtin::BI__builtin_isunordered))
     Diag(TheCall->getBeginLoc(), diag::warn_fp_nan_inf_when_disabled)
-        << 1 << 0 << TheCall->getSourceRange();
+        << 1 << 0 << 0;
 
   bool IsFPClass = NumArgs == 2;
 
@@ -12938,13 +12938,13 @@ void Sema::CheckInfNaNFunction(const CallExpr *Call,
        (Call->getBuiltinCallee() == Builtin::BI__builtin_nanf)) &&
       FPO.getNoHonorNaNs())
     Diag(Call->getBeginLoc(), diag::warn_fp_nan_inf_when_disabled)
-        << 1 << 0 << Call->getSourceRange();
+        << 1 << 0 << 0;
   else if ((IsStdFunction(FDecl, "isinf") ||
             (IsStdFunction(FDecl, "isfinite") ||
              (FDecl->getIdentifier() && FDecl->getName() == "infinity"))) &&
            FPO.getNoHonorInfs())
     Diag(Call->getBeginLoc(), diag::warn_fp_nan_inf_when_disabled)
-        << 0 << 0 << Call->getSourceRange();
+        << 0 << 0 << 0;
 }
 
 // Warn when using the wrong abs() function.