Make predefined FLT16 macros conditional on support for the type

[nemanjai]

Summary

We unconditionally predefine these macros. However, they may be used to determine if the type is supported. In that case, there are unnecessary failures to compile the code.
This is the proposed fix for https://bugs.llvm.org/show_bug.cgi?id=40559

[nemanjai]

lib/Basic/Targets/WebAssembly.h

55 ↗

(On Diff #184716)

There are test cases that check for the macros for WebAssembly so I assumed they probably want the type to be valid on the target. If that's not the case, I can change the test case.

[sunfish]

I think WebAssembly is in the same situation as most other architectures, as discussed here:

http://llvm.org/viewvc/llvm-project?view=revision&revision=352221

and should not enable _Float16 yet. The test/Preprocessor/init.c tests were semi-automatically generated, so it wasn't specifically intended to include tests for FLT16 macros for WebAssembly.

[nemanjai]

As mentioned in a comment, the WASM tests weren't really meant to indicate that WASM supports the type. Removed the changes to the WASM target.

[nemanjai]

Does anyone have any further comments or objections to this patch? I would like to commit this and close the PR.

[SjoerdMeijer]

Looks okay to me, with one nit inline.

test/Preprocessor/init.c

9169 ↗

(On Diff #185088)

Perhaps change this in WEBASSEMBLY-NOT so that we also have one negative test for this?

[nemanjai]

Since I haven't seen any further objections to this, I'll commit this later today.

test/Preprocessor/init.c

9169 ↗

(On Diff #185088)

I will do this on the commit.

cfe/trunk/lib/Frontend/InitPreprocessor.cpp

#undef TOSTR2
   DefineType("__CHAR16_TYPE__", TI.getChar16Type(), Builder);
   DefineType("__CHAR32_TYPE__", TI.getChar32Type(), Builder);
 
   DefineTypeWidth("__UINTMAX_WIDTH__",  TI.getUIntMaxType(), TI, Builder);
   DefineType("__UINTPTR_TYPE__", TI.getUIntPtrType(), Builder);
   DefineFmt("__UINTPTR", TI.getUIntPtrType(), TI, Builder);
   DefineTypeWidth("__UINTPTR_WIDTH__", TI.getUIntPtrType(), TI, Builder);
 
+  if (TI.hasFloat16Type())
     DefineFloatMacros(Builder, "FLT16", &TI.getHalfFormat(), "F16");
   DefineFloatMacros(Builder, "FLT", &TI.getFloatFormat(), "F");
   DefineFloatMacros(Builder, "DBL", &TI.getDoubleFormat(), "");
   DefineFloatMacros(Builder, "LDBL", &TI.getLongDoubleFormat(), "L");
 
   // Define a __POINTER_WIDTH__ macro for stdint.h.
   Builder.defineMacro("__POINTER_WIDTH__",
                       Twine((int)TI.getPointerWidth(0)));
 

cfe/trunk/test/Headers/float16.c

-// RUN: %clang_cc1 -fsyntax-only -verify -std=c89 -ffreestanding %s
-// RUN: %clang_cc1 -fsyntax-only -verify -std=c99 -ffreestanding %s
-// RUN: %clang_cc1 -fsyntax-only -verify -std=c11 -ffreestanding %s
-// RUN: %clang_cc1 -fsyntax-only -verify -std=c++11 -x c++ -ffreestanding %s
+// RUN: %clang_cc1 -triple=aarch64-none-none -fsyntax-only -verify -std=c89 \
+// RUN:   -ffreestanding %s
+// RUN: %clang_cc1 -triple=aarch64-none-none -fsyntax-only -verify \
+// RUN:   -std=c99 -ffreestanding %s
+// RUN: %clang_cc1 -triple=aarch64-none-none -fsyntax-only -verify -std=c11 \
+// RUN:   -ffreestanding %s
+// RUN: %clang_cc1 -triple=aarch64-none-none -fsyntax-only -verify \
+// RUN:   -std=c++11 -x c++ -ffreestanding %s
 // expected-no-diagnostics
 
 #define __STDC_WANT_IEC_60559_TYPES_EXT__
 #include <float.h>
 
 #ifndef FLT16_MIN_10_EXP
     #error "Macro FLT16_MIN_10_EXP is missing."
 #elif   FLT16_MIN_10_EXP > -13

cfe/trunk/test/Preprocessor/init.c

 // WEBASSEMBLY-NEXT:#define __DBL_MAX__ 1.7976931348623157e+308
 // WEBASSEMBLY-NEXT:#define __DBL_MIN_10_EXP__ (-307)
 // WEBASSEMBLY-NEXT:#define __DBL_MIN_EXP__ (-1021)
 // WEBASSEMBLY-NEXT:#define __DBL_MIN__ 2.2250738585072014e-308
 // WEBASSEMBLY-NEXT:#define __DECIMAL_DIG__ __LDBL_DECIMAL_DIG__
 // WEBASSEMBLY-NOT:#define __ELF__
 // WEBASSEMBLY-NEXT:#define __FINITE_MATH_ONLY__ 0
 // WEBASSEMBLY-NEXT:#define __FLOAT128__ 1
-// WEBASSEMBLY-NEXT:#define __FLT16_DECIMAL_DIG__ 5
-// WEBASSEMBLY-NEXT:#define __FLT16_DENORM_MIN__ 5.9604644775390625e-8F16
-// WEBASSEMBLY-NEXT:#define __FLT16_DIG__ 3
-// WEBASSEMBLY-NEXT:#define __FLT16_EPSILON__ 9.765625e-4F16
-// WEBASSEMBLY-NEXT:#define __FLT16_HAS_DENORM__ 1
-// WEBASSEMBLY-NEXT:#define __FLT16_HAS_INFINITY__ 1
-// WEBASSEMBLY-NEXT:#define __FLT16_HAS_QUIET_NAN__ 1
-// WEBASSEMBLY-NEXT:#define __FLT16_MANT_DIG__ 11
-// WEBASSEMBLY-NEXT:#define __FLT16_MAX_10_EXP__ 4
-// WEBASSEMBLY-NEXT:#define __FLT16_MAX_EXP__ 15
-// WEBASSEMBLY-NEXT:#define __FLT16_MAX__ 6.5504e+4F16
-// WEBASSEMBLY-NEXT:#define __FLT16_MIN_10_EXP__ (-13)
-// WEBASSEMBLY-NEXT:#define __FLT16_MIN_EXP__ (-14)
-// WEBASSEMBLY-NEXT:#define __FLT16_MIN__ 6.103515625e-5F16
+// WEBASSEMBLY-NOT:#define __FLT16_DECIMAL_DIG__
+// WEBASSEMBLY-NOT:#define __FLT16_DENORM_MIN__
+// WEBASSEMBLY-NOT:#define __FLT16_DIG__
+// WEBASSEMBLY-NOT:#define __FLT16_EPSILON__
+// WEBASSEMBLY-NOT:#define __FLT16_HAS_DENORM__
+// WEBASSEMBLY-NOT:#define __FLT16_HAS_INFINITY__
+// WEBASSEMBLY-NOT:#define __FLT16_HAS_QUIET_NAN__
+// WEBASSEMBLY-NOT:#define __FLT16_MANT_DIG__
+// WEBASSEMBLY-NOT:#define __FLT16_MAX_10_EXP__
+// WEBASSEMBLY-NOT:#define __FLT16_MAX_EXP__
+// WEBASSEMBLY-NOT:#define __FLT16_MAX__
+// WEBASSEMBLY-NOT:#define __FLT16_MIN_10_EXP__
+// WEBASSEMBLY-NOT:#define __FLT16_MIN_EXP__
+// WEBASSEMBLY-NOT:#define __FLT16_MIN__
 // WEBASSEMBLY-NEXT:#define __FLT_DECIMAL_DIG__ 9
 // WEBASSEMBLY-NEXT:#define __FLT_DENORM_MIN__ 1.40129846e-45F
 // WEBASSEMBLY-NEXT:#define __FLT_DIG__ 6
 // WEBASSEMBLY-NEXT:#define __FLT_EPSILON__ 1.19209290e-7F
 // WEBASSEMBLY-NEXT:#define __FLT_EVAL_METHOD__ 0
 // WEBASSEMBLY-NEXT:#define __FLT_HAS_DENORM__ 1
 // WEBASSEMBLY-NEXT:#define __FLT_HAS_INFINITY__ 1
 // WEBASSEMBLY-NEXT:#define __FLT_HAS_QUIET_NAN__ 1