[MSVC Compat] Add support for /GX, /GX-

These are legacy flags which map to /EHsc and /EHs-c- respectively.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@261424 91177308-0d34-0410-b5e6-96231b3b80d8

include/clang/Driver/CLCompatOptions.td

@@ -205,6 +205,10 @@ def _SLASH_Fi : CLCompileJoined<"Fi">,
 def _SLASH_Fo : CLCompileJoined<"Fo">,
   HelpText<"Set output object file, or directory (ends in / or \\) (with /c)">,
   MetaVarName<"<file or directory>">;
+def _SLASH_GX : CLFlag<"GX">,
+  HelpText<"Enable exception handling">;
+def _SLASH_GX_ : CLFlag<"GX-">,
+  HelpText<"Enable exception handling">;
 def _SLASH_LD : CLFlag<"LD">, HelpText<"Create DLL">;
 def _SLASH_LDd : CLFlag<"LDd">, HelpText<"Create debug DLL">;
 def _SLASH_link : CLRemainingArgs<"link">,
@@ -308,7 +312,6 @@ def _SLASH_Gr : CLFlag<"Gr">;
 def _SLASH_GS : CLFlag<"GS">;
 def _SLASH_GT : CLFlag<"GT">;
 def _SLASH_Guard : CLJoined<"guard:">;
-def _SLASH_GX : CLFlag<"GX">;
 def _SLASH_Gv : CLFlag<"Gv">;
 def _SLASH_Gz : CLFlag<"Gz">;
 def _SLASH_GZ : CLFlag<"GZ">;

lib/Driver/Tools.cpp

@@ -5775,10 +5775,9 @@ static bool maybeConsumeDash(const std::string &EH, size_t &I) {
 
 namespace {
 struct EHFlags {
-  EHFlags() : Synch(false), Asynch(false), NoExceptC(false) {}
-  bool Synch;
-  bool Asynch;
-  bool NoExceptC;
+  bool Synch = false;
+  bool Asynch = false;
+  bool NoUnwindC = false;
 };
 } // end anonymous namespace
 
@@ -5802,7 +5801,7 @@ static EHFlags parseClangCLEHFlags(const Driver &D, const ArgList &Args) {
         EH.Asynch = maybeConsumeDash(EHVal, I);
         continue;
       case 'c':
-        EH.NoExceptC = maybeConsumeDash(EHVal, I);
+        EH.NoUnwindC = maybeConsumeDash(EHVal, I);
         continue;
       case 's':
         EH.Synch = maybeConsumeDash(EHVal, I);
@@ -5814,6 +5813,12 @@ static EHFlags parseClangCLEHFlags(const Driver &D, const ArgList &Args) {
       break;
     }
   }
+  // The /GX, /GX- flags are only processed if there are not /EH flags.
+  if (EHArgs.empty() &&
+      Args.hasFlag(options::OPT__SLASH_GX, options::OPT__SLASH_GX_)) {
+    EH.Synch = true;
+    EH.NoUnwindC = true;
+  }
 
   return EH;
 }
@@ -9704,6 +9709,8 @@ std::unique_ptr<Command> visualstudio::Compiler::GetCommand(
   // Flags that can simply be passed through.
   Args.AddAllArgs(CmdArgs, options::OPT__SLASH_LD);
   Args.AddAllArgs(CmdArgs, options::OPT__SLASH_LDd);
+  Args.AddAllArgs(CmdArgs, options::OPT__SLASH_GX);
+  Args.AddAllArgs(CmdArgs, options::OPT__SLASH_GX_);
   Args.AddAllArgs(CmdArgs, options::OPT__SLASH_EH);
   Args.AddAllArgs(CmdArgs, options::OPT__SLASH_Zl);
 

test/Driver/cl-options.c

@@ -211,6 +211,12 @@
 // RUN: %clang_cl /FI asdf.h -### -- %s 2>&1 | FileCheck -check-prefix=FI_ %s
 // FI_: "-include" "asdf.h"
 
+// RUN: %clang_cl /c /GX -### -- %s 2>&1 | FileCheck -check-prefix=GX %s
+// GX: "-fcxx-exceptions" "-fexceptions"
+
+// RUN: %clang_cl /c /GX /GX- -### -- %s 2>&1 | FileCheck -check-prefix=GX_ %s
+// GX_-NOT: "-fcxx-exceptions" "-fexceptions"
+
 // We forward any unrecognized -W diagnostic options to cc1.
 // RUN: %clang_cl -Wunused-pragmas -### -- %s 2>&1 | FileCheck -check-prefix=WJoined %s
 // WJoined: "-cc1"