FLT_EVAL_METHOD should always be set

[zahiraam]

Summary

This is a fix for a bug that showed up in the (reverted for now) patch https://reviews.llvm.org/D109239
The bug entry for it is here: https://github.com/llvm/llvm-project/issues/53931
This will not be pushed to the repo, that's why I am not adding any repo to this entry. It will eventually be added to the bigger patch above.

[aaron.ballman]

This looks about like what I'd expect to see in terms of the code changes.

clang/test/Preprocessor/flt_eval_macro.cpp

46

Why did we drop this? Seems like we're losing test coverage now?

[zahiraam]

Thanks @aaron.ballman

clang/test/Preprocessor/flt_eval_macro.cpp

46

Added it back.

[MaskRay]

clang/test/Preprocessor/flt_eval_macro.cpp

2

It is customary to indent continuation lines with 2 spaces.

3

Drop // (uncommon and making { } jumping difficult)

[zahiraam]

@MaskRay Thanks. Will do that.

clang/include/clang/Lex/Preprocessor.h

assert(Val != LangOptions::FEM_UnsetOnCommandLine &&
            "FPEvalMethod should never be set to FEM_UnsetOnCommandLine");
     // This is the location of the '#pragma float_control" where the
     // execution state is modifed.
     LastFPEvalPragmaLocation = PragmaLoc;
     CurrentFPEvalMethod = Val;
     TUFPEvalMethod = Val;
   }
 
+  void setTUFPEvalMethod(LangOptions::FPEvalMethodKind Val) {
+    assert(Val != LangOptions::FEM_UnsetOnCommandLine &&
+           "TUPEvalMethod should never be set to FEM_UnsetOnCommandLine");
+    TUFPEvalMethod = Val;
+  }
+
   /// Retrieves the module that we're currently building, if any.
   Module *getCurrentModule();
 
   /// Allocate a new MacroInfo object with the provided SourceLocation.
   MacroInfo *AllocateMacroInfo(SourceLocation L);
 
   /// Turn the specified lexer token into a fully checked and spelled
   /// filename, e.g. as an operand of \#include.

clang/lib/Lex/Preprocessor.cpp

void Preprocessor::Initialize(const TargetInfo &Target,
   this->AuxTarget = AuxTarget;
 
   // Initialize information about built-ins.
   BuiltinInfo->InitializeTarget(Target, AuxTarget);
   HeaderInfo.setTarget(Target);
 
   // Populate the identifier table with info about keywords for the current language.
   Identifiers.AddKeywords(LangOpts);
+
+  // Initialize the __FTL_EVAL_METHOD__ macro to the TargetInfo.
+  setTUFPEvalMethod(getTargetInfo().getFPEvalMethod());
 }
 
 void Preprocessor::InitializeForModelFile() {
   NumEnteredSourceFiles = 0;
 
   // Reset pragmas
   PragmaHandlersBackup = std::move(PragmaHandlers);
   PragmaHandlers = std::make_unique<PragmaNamespace>(StringRef());

clang/test/Preprocessor/flt_eval_macro.cpp

-// RUN: %clang_cc1 -E -dM %s -o - | FileCheck %s -strict-whitespace
+// RUN: %clang_cc1 -E -dM -triple=x86_64-none-none  %s -o - \
+// RUN: | FileCheck %s -strict-whitespace
+//
+// RUN: %clang_cc1 -E -dM -triple=x86_64-none-none -target-feature -sse \
+// RUN: %s -o - | FileCheck %s -check-prefix=EXT -strict-whitespace
+//
+// RUN: %clang_cc1 -E -dM -triple=arm64e-apple-ios -target-feature -sse \
+// RUN: %s -o - | FileCheck %s  -strict-whitespace
+//
+// RUN: %clang_cc1 -E -dM -triple=arm64e-apple-ios -target-feature +sse \
+// RUN: %s -o - | FileCheck %s  -strict-whitespace
+//
+// RUN: %clang_cc1 -E -dM -triple=arm64_32-apple-ios  %s -o - \
+// RUN: | FileCheck %s  -strict-whitespace
+//
+// RUN: %clang_cc1 -E -dM -triple=arm64_32-apple-ios -target-feature -sse \
+// RUN: %s -o - | FileCheck %s  -strict-whitespace
+//
+// RUN: %clang_cc1 -E -dM -triple i386-pc-windows -target-cpu pentium4 %s -o - \
+// RUN: | FileCheck %s  -strict-whitespace
+//
+// RUN: %clang_cc1 -E -dM -triple i386-pc-windows -target-cpu pentium4 \
+// RUN: -target-feature -sse %s -o - | FileCheck -check-prefix=EXT %s \
+// RUN: -strict-whitespace
 
 #ifdef __FLT_EVAL_METHOD__
 #if __FLT_EVAL_METHOD__ == 3
 #define __GLIBC_FLT_EVAL_METHOD 2
 #else
 #define __GLIBC_FLT_EVAL_METHOD __FLT_EVAL_METHOD__
 #endif
 #elif defined __x86_64__
 #define __GLIBC_FLT_EVAL_METHOD 0
 #else
 #define __GLIBC_FLT_EVAL_METHOD 2
 #endif
 
 #if __GLIBC_FLT_EVAL_METHOD == 0 || __GLIBC_FLT_EVAL_METHOD == 16
 #define Name "One"
 #elif __GLIBC_FLT_EVAL_METHOD == 1
 #define Name "Two"
 #elif __GLIBC_FLT_EVAL_METHOD == 2
-#define Name "Unset on command line"
+#define Name "Three"
 #elif __GLIBC_FLT_EVAL_METHOD == 32
 #define Name "Four"
 #elif __GLIBC_FLT_EVAL_METHOD == 33
 #define Name "Five"
 #elif __GLIBC_FLT_EVAL_METHOD == 64
 #define Name "Six"
 #elif __GLIBC_FLT_EVAL_METHOD == 65
 #define Name "Seven"
 #elif __GLIBC_FLT_EVAL_METHOD == 128
 #define Name "Eight"
 #elif __GLIBC_FLT_EVAL_METHOD == 129
 #define Name "Nine"
 #else
 #error "Unknown __GLIBC_FLT_EVAL_METHOD"
 #endif
 
 int foo() {
-  // CHECK: #define Name "Unset on command line"
+  // CHECK: #define Name "One"
+  // EXT: #define Name "Three"
   return Name;
 }
 
 #if __FLT_EVAL_METHOD__ == 3
+#define Val "Unset"
+#elif __FLT_EVAL_METHOD__ == 0
 #define Val "val0"
-#endif
-
-#pragma fp eval_method(double)
-
-#if __FLT_EVAL_METHOD__ == 0
-#define Val "val1"
 #elif __FLT_EVAL_METHOD__ == 1
-#define Val "val2"
+#define Val "val1"
 #elif __FLT_EVAL_METHOD__ == 2
-#define Val "val3"
+#define Val "val2"
 #endif
 
 int goo() {
   // CHECK: #define Val "val0"
-  return Name;
+  // EXT: #define Val "val2"
+  return Val;
 }