[Driver] Add support for -finline-functions and /Ob2 flags

-finline-functions and /Ob2 are currently ignored by Clang. The only way to
enable inlining is to use the global O flags, which also enable other options,
or to emit LLVM bitcode using Clang, then running opt by hand with the inline
pass.

This patch allows to simply use the -finline-functions flag (same as GCC) or
/Ob2 in clang-cl mode to enable inlining without other optimizations.

This is the first patch of a serie to improve support for the /Ob flags.

Patch by Rudy Pons <rudy.pons@ilod.org>!

Differential Revision: http://reviews.llvm.org/D20576

llvm-svn: 270609

1 files changed, 6 insertions, 2 deletions

diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index 852801ab240..aa1c5a04f5b 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -441,8 +441,12 @@ static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK,
                                  : CodeGenOptions::OnlyAlwaysInlining);
   // -fno-inline-functions overrides OptimizationLevel > 1.
   Opts.NoInline = Args.hasArg(OPT_fno_inline);
-  Opts.setInlining(Args.hasArg(OPT_fno_inline_functions) ?
-                     CodeGenOptions::OnlyAlwaysInlining : Opts.getInlining());
+  if (Arg* InlineArg = Args.getLastArg(options::OPT_finline_functions,
+                                       options::OPT_fno_inline_functions)) {
+    Opts.setInlining(
+      InlineArg->getOption().matches(options::OPT_finline_functions) ?
+        CodeGenOptions::NormalInlining : CodeGenOptions::OnlyAlwaysInlining);
+  }
 
   if (Arg *A = Args.getLastArg(OPT_fveclib)) {
     StringRef Name = A->getValue();