Add -f[no-]declspec to control recognition of __declspec as a keyword

In versions of clang prior to r238238, __declspec was recognized as a keyword in
all modes.  It was then changed to only be enabled when Microsoft or Borland
extensions were enabled (and for CUDA, as a temporary measure).  There is a
desire to support __declspec in Playstation code, and possibly other
environments.  This commit adds a command-line switch to allow explicit
enabling/disabling of the recognition of __declspec as a keyword.  Recognition
is enabled by default in Microsoft, Borland, CUDA, and PS4 environments, and
disabled in all other environments.

Patch by Warren Ristow!

llvm-svn: 249279

1 files changed, 7 insertions, 0 deletions

diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
index 7cccf09..1b42ff7 100644
--- a/clang/lib/Driver/Tools.cpp
+++ b/clang/lib/Driver/Tools.cpp
@@ -4610,6 +4610,13 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
                    options::OPT_fno_borland_extensions, false))
     CmdArgs.push_back("-fborland-extensions");
 
+  // -fno-declspec is default, except for PS4.
+  if (Args.hasFlag(options::OPT_fdeclspec, options::OPT_fno_declspec,
+                   getToolChain().getTriple().isPS4()))
+    CmdArgs.push_back("-fdeclspec");
+  else if (Args.hasArg(options::OPT_fno_declspec))
+    CmdArgs.push_back("-fno-declspec"); // Explicitly disabling __declspec.
+
   // -fthreadsafe-static is default, except for MSVC compatibility versions less
   // than 19.
   if (!Args.hasFlag(options::OPT_fthreadsafe_statics,