r239213 - clang-cl: Implement /GL in terms of -flto.

[Peter Collingbourne]

We are planning to create bitcode-compatible replacements for link.exe and
lib.exe, so it doesn't seem entirely unreasonable for /GL to map to -flto,
at least once those tools are ready.

In the meantime, there's probably no way at the moment to pass /GL on its own
and get something that works, so it does make sense to make /GL a no-op again.
I don't know if we should expose -flto as a core flag though. I'll see if
there is some combination of -Xclang flags I can use as a workalike for -flto,
if so I can probably just use that for now until we're ready to implement /GL.

Feel free to revert or I'll do it when I get a chance.

Peter

On Fri, Jun 12, 2015 at 06:59:59PM -0700, Nico Weber wrote:
> This breaks building with /GL (e.g. in an official chrome build). Clang
> will think "hey, I'll emit bitcode" and then link.exe or lib.exe will fall
> over. Mapping /GL to -flto guarantees that every build that uses /GL won't
> work, which doesn't seem that great. (Linker and static library archiver
> are called directly on Windows, not through the driver.)
> 
> Maybe -flto should be a core flag so that it can be passed to clang-cl
> explicitly, but mapping /GL to -flto seems wrong to me.
> 
> On Fri, Jun 5, 2015 at 7:09 PM, Peter Collingbourne <peter at pcc.me.uk> wrote:
> 
> > Author: pcc
> > Date: Fri Jun  5 21:09:34 2015
> > New Revision: 239213
> >
> > URL: http://llvm.org/viewvc/llvm-project?rev=239213&view=rev
> > Log:
> > clang-cl: Implement /GL in terms of -flto.
> >
> > No documentation yet; the linker needs more work.
> >
> > Differential Revision: http://reviews.llvm.org/D10270
> >
> > Modified:
> >     cfe/trunk/include/clang/Driver/CLCompatOptions.td
> >     cfe/trunk/lib/Driver/Driver.cpp
> >     cfe/trunk/lib/Driver/Types.cpp
> >     cfe/trunk/test/Driver/cl-outputs.c
> >
> > Modified: cfe/trunk/include/clang/Driver/CLCompatOptions.td
> > URL:
> > http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Driver/CLCompatOptions.td?rev=239213&r1=239212&r2=239213&view=diff
> >
> > ==============================================================================
> > --- cfe/trunk/include/clang/Driver/CLCompatOptions.td (original)
> > +++ cfe/trunk/include/clang/Driver/CLCompatOptions.td Fri Jun  5 21:09:34
> > 2015
> > @@ -202,6 +202,7 @@ def _SLASH_Fi : CLCompileJoined<"Fi">,
> >  def _SLASH_Fo : CLCompileJoined<"Fo">,
> >    HelpText<"Set output object file, or directory (ends in / or \\)">,
> >    MetaVarName<"<file or directory>">;
> > +def _SLASH_GL : CLFlag<"GL">, Alias<flto>;
> >  def _SLASH_LD : CLFlag<"LD">, HelpText<"Create DLL">;
> >  def _SLASH_LDd : CLFlag<"LDd">, HelpText<"Create debug DLL">;
> >  def _SLASH_link : CLRemainingArgs<"link">,
> > @@ -286,7 +287,6 @@ def _SLASH_G2 : CLFlag<"G2">;
> >  def _SLASH_Ge : CLFlag<"Ge">;
> >  def _SLASH_Gh : CLFlag<"Gh">;
> >  def _SLASH_GH : CLFlag<"GH">;
> > -def _SLASH_GL : CLFlag<"GL">;
> >  def _SLASH_GL_ : CLFlag<"GL-">;
> >  def _SLASH_Gm : CLFlag<"Gm">;
> >  def _SLASH_Gm_ : CLFlag<"Gm-">;
> >
> > Modified: cfe/trunk/lib/Driver/Driver.cpp
> > URL:
> > http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Driver/Driver.cpp?rev=239213&r1=239212&r2=239213&view=diff
> >
> > ==============================================================================
> > --- cfe/trunk/lib/Driver/Driver.cpp (original)
> > +++ cfe/trunk/lib/Driver/Driver.cpp Fri Jun  5 21:09:34 2015
> > @@ -1744,7 +1744,7 @@ const char *Driver::GetNamedOutputPath(C
> >    // Determine what the derived output name should be.
> >    const char *NamedOutput;
> >
> > -  if (JA.getType() == types::TY_Object &&
> > +  if ((JA.getType() == types::TY_Object || JA.getType() ==
> > types::TY_LTO_BC) &&
> >        C.getArgs().hasArg(options::OPT__SLASH_Fo, options::OPT__SLASH_o)) {
> >      // The /Fo or /o flag decides the object filename.
> >      StringRef Val = C.getArgs().getLastArg(options::OPT__SLASH_Fo,
> >
> > Modified: cfe/trunk/lib/Driver/Types.cpp
> > URL:
> > http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Driver/Types.cpp?rev=239213&r1=239212&r2=239213&view=diff
> >
> > ==============================================================================
> > --- cfe/trunk/lib/Driver/Types.cpp (original)
> > +++ cfe/trunk/lib/Driver/Types.cpp Fri Jun  5 21:09:34 2015
> > @@ -45,7 +45,7 @@ types::ID types::getPreprocessedType(ID
> >  }
> >
> >  const char *types::getTypeTempSuffix(ID Id, bool CLMode) {
> > -  if (Id == TY_Object && CLMode)
> > +  if ((Id == TY_Object || Id == TY_LTO_BC) && CLMode)
> >      return "obj";
> >    if (Id == TY_Image && CLMode)
> >      return "exe";
> >
> > Modified: cfe/trunk/test/Driver/cl-outputs.c
> > URL:
> > http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Driver/cl-outputs.c?rev=239213&r1=239212&r2=239213&view=diff
> >
> > ==============================================================================
> > --- cfe/trunk/test/Driver/cl-outputs.c (original)
> > +++ cfe/trunk/test/Driver/cl-outputs.c Fri Jun  5 21:09:34 2015
> > @@ -273,3 +273,9 @@
> >  // RUN: %clang_cl /P /Fifoo.x /obar.x -### -- %s 2>&1 | FileCheck
> > -check-prefix=FioRACE2 %s
> >  // FioRACE2: "-E"
> >  // FioRACE2: "-o" "bar.x"
> > +
> > +// RUN: %clang_cl /c /GL -### -- %s 2>&1 | FileCheck
> > -check-prefix=LTO-DEFAULT %s
> > +// LTO-DEFAULT: "-emit-llvm-bc"{{.*}}"-o" "cl-outputs.obj"
> > +
> > +// RUN: %clang_cl /c /GL /Fofoo -### -- %s 2>&1 | FileCheck
> > -check-prefix=LTO-FO %s
> > +// LTO-FO: "-emit-llvm-bc"{{.*}}"-o" "foo.obj"
> >
> >
> > _______________________________________________
> > cfe-commits mailing list
> > cfe-commits at cs.uiuc.edu
> > http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
> >

-- 
Peter