MS ABI: Implement driver-level support for thread-safe statics

Decide whether or not to use thread-safe statics depending on whether or
not we have an explicit request from the driver.  If we don't have an
explicit request, infer which behavior to use depending on the
compatibility version we are targeting.

N.B. CodeGen support is still ongoing.

llvm-svn: 232906

1 files changed, 31 insertions, 27 deletions

diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
index 0f44ce7..bcab1bb 100644
--- a/clang/lib/Driver/Tools.cpp
+++ b/clang/lib/Driver/Tools.cpp
@@ -2483,24 +2483,17 @@ static void addDashXForInput(const ArgList &Args, const InputInfo &Input,
     CmdArgs.push_back(types::getTypeName(Input.getType()));
 }
 
-static std::string getMSCompatibilityVersion(const char *VersionStr) {
-  unsigned Version;
-  if (StringRef(VersionStr).getAsInteger(10, Version))
-    return "0";
-
+static VersionTuple getMSCompatibilityVersion(unsigned Version) {
   if (Version < 100)
-    return llvm::utostr_32(Version) + ".0";
+    return VersionTuple(Version);
 
   if (Version < 10000)
-    return llvm::utostr_32(Version / 100) + "." +
-        llvm::utostr_32(Version % 100);
+    return VersionTuple(Version / 100, Version % 100);
 
   unsigned Build = 0, Factor = 1;
   for ( ; Version > 10000; Version = Version / 10, Factor = Factor * 10)
     Build = Build + (Version % 10) * Factor;
-  return llvm::utostr_32(Version / 100) + "." +
-      llvm::utostr_32(Version % 100) + "." +
-      llvm::utostr_32(Build);
+  return VersionTuple(Version / 100, Version % 100, Build);
 }
 
 // Claim options we don't want to warn if they are unused. We do this for
@@ -4067,11 +4060,6 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
                     isSignedCharDefault(getToolChain().getTriple())))
     CmdArgs.push_back("-fno-signed-char");
 
-  // -fthreadsafe-static is default.
-  if (!Args.hasFlag(options::OPT_fthreadsafe_statics,
-                    options::OPT_fno_threadsafe_statics))
-    CmdArgs.push_back("-fno-threadsafe-statics");
-
   // -fuse-cxa-atexit is default.
   if (!Args.hasFlag(options::OPT_fuse_cxa_atexit,
                     options::OPT_fno_use_cxa_atexit,
@@ -4099,9 +4087,11 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
                                                   true))))
     CmdArgs.push_back("-fms-compatibility");
 
-  // -fms-compatibility-version=17.00 is default.
+  // -fms-compatibility-version=18.00 is default.
+  VersionTuple MSVT;
   if (Args.hasFlag(options::OPT_fms_extensions, options::OPT_fno_ms_extensions,
-                   IsWindowsMSVC) || Args.hasArg(options::OPT_fmsc_version) ||
+                   IsWindowsMSVC) ||
+      Args.hasArg(options::OPT_fmsc_version) ||
       Args.hasArg(options::OPT_fms_compatibility_version)) {
     const Arg *MSCVersion = Args.getLastArg(options::OPT_fmsc_version);
     const Arg *MSCompatibilityVersion =
@@ -4112,16 +4102,23 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
           << MSCVersion->getAsString(Args)
           << MSCompatibilityVersion->getAsString(Args);
 
-    std::string Ver;
-    if (MSCompatibilityVersion)
-      Ver = Args.getLastArgValue(options::OPT_fms_compatibility_version);
-    else if (MSCVersion)
-      Ver = getMSCompatibilityVersion(MSCVersion->getValue());
+    if (MSCompatibilityVersion) {
+      if (MSVT.tryParse(MSCompatibilityVersion->getValue()))
+        D.Diag(diag::err_drv_invalid_value)
+            << MSCompatibilityVersion->getAsString(Args)
+            << MSCompatibilityVersion->getValue();
+    } else if (MSCVersion) {
+      unsigned Version = 0;
+      if (StringRef(MSCVersion->getValue()).getAsInteger(10, Version))
+        D.Diag(diag::err_drv_invalid_value) << MSCVersion->getAsString(Args)
+                                            << MSCVersion->getValue();
+      MSVT = getMSCompatibilityVersion(Version);
+    } else {
+      MSVT = VersionTuple(18);
+    }
 
-    if (Ver.empty())
-      CmdArgs.push_back("-fms-compatibility-version=18.00");
-    else
-      CmdArgs.push_back(Args.MakeArgString("-fms-compatibility-version=" + Ver));
+    CmdArgs.push_back(
+        Args.MakeArgString("-fms-compatibility-version=" + MSVT.getAsString()));
   }
 
   // -fno-borland-extensions is default.
@@ -4129,6 +4126,13 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
                    options::OPT_fno_borland_extensions, false))
     CmdArgs.push_back("-fborland-extensions");
 
+  // -fthreadsafe-static is default, except for MSVC compatibility versions less
+  // than 19.
+  if (!Args.hasFlag(options::OPT_fthreadsafe_statics,
+                    options::OPT_fno_threadsafe_statics,
+                    !IsWindowsMSVC || MSVT.getMajor() >= 19))
+    CmdArgs.push_back("-fno-threadsafe-statics");
+
   // -fno-delayed-template-parsing is default, except for Windows where MSVC STL
   // needs it.
   if (Args.hasFlag(options::OPT_fdelayed_template_parsing,