[X86] Make `x86intrin.h`, `immintrin.h` includable with `-fno-gnu-inline-asm`.

Currently `immintrin.h` includes `pconfigintrin.h` and `sgxintrin.h`
which contain inline assembly. It causes failures when building with the
flag `-fno-gnu-inline-asm`.

Fix by excluding functions with inline assembly when this extension is
disabled. So far there was no need to support `_pconfig_u32`,
`_enclu_u32`, `_encls_u32`, `_enclv_u32` on platforms that require
`-fno-gnu-inline-asm`. But if developers start using these functions,
they'll have compile-time undeclared identifier errors which is
preferrable to runtime errors.

rdar://problem/49540880

Reviewers: craig.topper, GBuella, rnk, echristo

Reviewed By: rnk

Subscribers: jkorous, dexonsmith, cfe-commits

Differential Revision: https://reviews.llvm.org/D61621

llvm-svn: 360630

4 files changed, 12 insertions, 2 deletions

diff --git a/clang/lib/Headers/immintrin.h b/clang/lib/Headers/immintrin.h
index 2bd79bd88f3..ea009bd88b1 100644
--- a/clang/lib/Headers/immintrin.h
+++ b/clang/lib/Headers/immintrin.h
@@ -421,7 +421,7 @@ _storebe_i64(void * __P, long long __D) {
 #include <invpcidintrin.h>
 #endif
 
-#ifdef _MSC_VER
+#if defined(_MSC_VER) && __has_extension(gnu_asm)
 /* Define the default attributes for these intrinsics */
 #define __DEFAULT_FN_ATTRS __attribute__((__always_inline__, __nodebug__))
 #ifdef __cplusplus
@@ -503,6 +503,6 @@ _InterlockedCompareExchange64_HLERelease(__int64 volatile *_Destination,
 
 #undef __DEFAULT_FN_ATTRS
 
-#endif /* _MSC_VER */
+#endif /* defined(_MSC_VER) && __has_extension(gnu_asm) */
 
 #endif /* __IMMINTRIN_H */
diff --git a/clang/lib/Headers/pconfigintrin.h b/clang/lib/Headers/pconfigintrin.h
index d2b39cd5832..d2014b026f3 100644
--- a/clang/lib/Headers/pconfigintrin.h
+++ b/clang/lib/Headers/pconfigintrin.h
@@ -16,6 +16,8 @@
 
 #define __PCONFIG_KEY_PROGRAM 0x00000001
 
+#if __has_extension(gnu_asm)
+
 /* Define the default attributes for the functions in this file. */
 #define __DEFAULT_FN_ATTRS \
   __attribute__((__always_inline__, __nodebug__,  __target__("pconfig")))
@@ -33,4 +35,6 @@ _pconfig_u32(unsigned int __leaf, __SIZE_TYPE__ __d[])
 
 #undef __DEFAULT_FN_ATTRS
 
+#endif /* __has_extension(gnu_asm) */
+
 #endif
diff --git a/clang/lib/Headers/sgxintrin.h b/clang/lib/Headers/sgxintrin.h
index 55805e3954d..303a21f6b2e 100644
--- a/clang/lib/Headers/sgxintrin.h
+++ b/clang/lib/Headers/sgxintrin.h
@@ -14,6 +14,8 @@
 #ifndef __SGXINTRIN_H
 #define __SGXINTRIN_H
 
+#if __has_extension(gnu_asm)
+
 /* Define the default attributes for the functions in this file. */
 #define __DEFAULT_FN_ATTRS \
   __attribute__((__always_inline__, __nodebug__,  __target__("sgx")))
@@ -53,4 +55,6 @@ _enclv_u32(unsigned int __leaf, __SIZE_TYPE__ __d[])
 
 #undef __DEFAULT_FN_ATTRS
 
+#endif /* __has_extension(gnu_asm) */
+
 #endif
diff --git a/clang/test/Modules/compiler_builtins_x86.c b/clang/test/Modules/compiler_builtins_x86.c
index 1b4d42177ab..43e2283dfbe 100644
--- a/clang/test/Modules/compiler_builtins_x86.c
+++ b/clang/test/Modules/compiler_builtins_x86.c
@@ -1,6 +1,8 @@
 // RUN: rm -rf %t
 // RUN: %clang_cc1 -triple i686-unknown-unknown -fsyntax-only -fmodules -fimplicit-module-maps -fmodules-cache-path=%t %s -verify -ffreestanding
 // RUN: %clang_cc1 -triple i686-unknown-unknown -fsyntax-only -fmodules -fmodule-map-file=%resource_dir/module.modulemap -fmodules-cache-path=%t %s -verify -ffreestanding
+// RUN: %clang_cc1 -triple i686-unknown-unknown -fsyntax-only -fmodules -fimplicit-module-maps -fmodules-cache-path=%t %s -verify -ffreestanding -fno-gnu-inline-asm
+// RUN: %clang_cc1 -triple i686--windows -fsyntax-only -fmodules -fimplicit-module-maps -fmodules-cache-path=%t %s -verify -ffreestanding -fno-gnu-inline-asm -fms-extensions -fms-compatibility-version=17.00
 // expected-no-diagnostics
 
 #include<x86intrin.h>