[clang-cl] Expose the /volatile:{iso,ms} choice via _ISO_VOLATILE

MSVC allows interpreting volatile loads and stores, when combined with
/volatile:iso, as having acquire/release semantics. MSVC also exposes a
define, _ISO_VOLATILE, which allows users to enquire if this feature is
enabled or disabled.

diff --git a/clang/include/clang/Basic/CodeGenOptions.def b/clang/include/clang/Basic/CodeGenOptions.def
index 0f35420..87c75bb 100644 (file)
--- a/clang/include/clang/Basic/CodeGenOptions.def
+++ b/clang/include/clang/Basic/CodeGenOptions.def
@@ -173,7 +173,6 @@ CODEGENOPT(IncrementalLinkerCompatible, 1, 0) ///< Emit an object file which can
                                               ///< linker.
 CODEGENOPT(MergeAllConstants , 1, 1) ///< Merge identical constants.
 CODEGENOPT(MergeFunctions    , 1, 0) ///< Set when -fmerge-functions is enabled.
-CODEGENOPT(MSVolatile        , 1, 0) ///< Set when /volatile:ms is enabled.
 CODEGENOPT(NoCommon          , 1, 0) ///< Set when -fno-common or C++ is enabled.
 CODEGENOPT(NoDwarfDirectoryAsm , 1, 0) ///< Set when -fno-dwarf-directory-asm is
                                        ///< enabled.

diff --git a/clang/include/clang/Basic/LangOptions.def b/clang/include/clang/Basic/LangOptions.def
index ad36682..4f3f6fc 100644 (file)
--- a/clang/include/clang/Basic/LangOptions.def
+++ b/clang/include/clang/Basic/LangOptions.def
@@ -148,6 +148,7 @@ LANGOPT(TraditionalCPP    , 1, 0, "traditional CPP emulation")
 LANGOPT(RTTI              , 1, 1, "run-time type information")
 LANGOPT(RTTIData          , 1, 1, "emit run-time type information data")
 LANGOPT(MSBitfields       , 1, 0, "Microsoft-compatible structure layout")
+LANGOPT(MSVolatile        , 1, 0, "Microsoft-compatible volatile loads and stores")
 LANGOPT(Freestanding, 1, 0, "freestanding implementation")
 LANGOPT(NoBuiltin         , 1, 0, "disable builtin functions")
 LANGOPT(NoMathBuiltin     , 1, 0, "disable math builtin functions")

diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index aadd516..ec5f553 100644 (file)
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -2204,7 +2204,7 @@ defm asm_blocks : BoolFOption<"asm-blocks",
   LangOpts<"AsmBlocks">, Default<fms_extensions.KeyPath>,
   PosFlag<SetTrue, [CC1Option]>, NegFlag<SetFalse>>;
 def fms_volatile : Flag<["-"], "fms-volatile">, Group<f_Group>, Flags<[CC1Option]>,
-  MarshallingInfoFlag<CodeGenOpts<"MSVolatile">>;
+  MarshallingInfoFlag<LangOpts<"MSVolatile">>;
 def fmsc_version : Joined<["-"], "fmsc-version=">, Group<f_Group>, Flags<[NoXarchOption, CoreOption]>,
   HelpText<"Microsoft compiler version number to report in _MSC_VER (0 = don't define it (default))">;
 def fms_compatibility_version

diff --git a/clang/lib/Basic/Targets/OSTargets.cpp b/clang/lib/Basic/Targets/OSTargets.cpp
index 5c73402..d11b9f5 100644 (file)
--- a/clang/lib/Basic/Targets/OSTargets.cpp
+++ b/clang/lib/Basic/Targets/OSTargets.cpp
@@ -263,6 +263,9 @@ static void addVisualCDefines(const LangOptions &Opts, MacroBuilder &Builder) {
     }
   }
 
+  if (!Opts.MSVolatile)
+    Builder.defineMacro("_ISO_VOLATILE");
+
   if (Opts.Kernel)
     Builder.defineMacro("_KERNEL_MODE");
 

diff --git a/clang/lib/CodeGen/CGAtomic.cpp b/clang/lib/CodeGen/CGAtomic.cpp
index ccc66bc..8ef95bb 100644 (file)
--- a/clang/lib/CodeGen/CGAtomic.cpp
+++ b/clang/lib/CodeGen/CGAtomic.cpp
@@ -1594,7 +1594,7 @@ llvm::Value *AtomicInfo::EmitAtomicLoadOp(llvm::AtomicOrdering AO,
 /// we are operating under /volatile:ms *and* the LValue itself is volatile and
 /// performing such an operation can be performed without a libcall.
 bool CodeGenFunction::LValueIsSuitableForInlineAtomic(LValue LV) {
-  if (!CGM.getCodeGenOpts().MSVolatile) return false;
+  if (!CGM.getLangOpts().MSVolatile) return false;
   AtomicInfo AI(*this, LV);
   bool IsVolatile = LV.isVolatile() || hasVolatileMember(LV.getType());
   // An atomic is inline if we don't need to use a libcall.

diff --git a/clang/test/Preprocessor/predefined-win-macros.c b/clang/test/Preprocessor/predefined-win-macros.c
index df43ae5..f402ce9 100644 (file)
--- a/clang/test/Preprocessor/predefined-win-macros.c
+++ b/clang/test/Preprocessor/predefined-win-macros.c
@@ -5,6 +5,7 @@
 // RUN: %clang_cc1 %s -x c++ -E -dM -triple x86_64-pc-win32 -fms-extensions -fms-compatibility \
 // RUN:     -fms-compatibility-version=19.00 -std=c++14 -o - | grep GCC | count 5
 // CHECK-MS64: #define _INTEGRAL_MAX_BITS 64
+// CHECK-MS64: #define _ISO_VOLATILE 1
 // CHECK-MS64: #define _MSC_EXTENSIONS 1
 // CHECK-MS64: #define _MSC_VER 1900
 // CHECK-MS64: #define _MSVC_LANG 201402L
@@ -27,6 +28,7 @@
 // RUN: %clang_cc1 %s -x c++ -E -dM -triple i686-pc-win32 -fms-extensions -fms-compatibility \
 // RUN:     -fms-compatibility-version=19.00 -std=c++17 -o - | grep GCC | count 5
 // CHECK-MS: #define _INTEGRAL_MAX_BITS 64
+// CHECK-MS: #define _ISO_VOLATILE 1
 // CHECK-MS: #define _MSC_EXTENSIONS 1
 // CHECK-MS: #define _MSC_VER 1900
 // CHECK-MS: #define _MSVC_LANG 201703L