[clang-cl, PCH] Implement support for MS-style PCH through headers

Implement support for MS-style PCH through headers.

This enables support for /Yc and /Yu where the through header is either
on the command line or included in the source. It replaces the current
support the requires the header also be specified with /FI.

This change adds a -cc1 option -pch-through-header that is used to either
start or stop compilation during PCH create or use.

When creating a PCH, the compilation ends after compilation of the through
header.

When using a PCH, tokens are skipped until after the through header is seen.

Patch By: mikerice
Differential Revision: https://reviews.llvm.org/D46652

llvm-svn: 336379

1 files changed, 1 insertions, 1 deletions

diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index 3335ccb4fce..f57f23a0d4c 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -1546,7 +1546,6 @@ static InputKind ParseFrontendArgs(FrontendOptions &Opts, ArgList &Args,
     = Args.getLastArgValue(OPT_foverride_record_layout_EQ);
   Opts.AuxTriple =
       llvm::Triple::normalize(Args.getLastArgValue(OPT_aux_triple));
-  Opts.FindPchSource = Args.getLastArgValue(OPT_find_pch_source_EQ);
   Opts.StatsFile = Args.getLastArgValue(OPT_stats_file);
 
   if (const Arg *A = Args.getLastArg(OPT_arcmt_check,
@@ -2828,6 +2827,7 @@ static void ParsePreprocessorArgs(PreprocessorOptions &Opts, ArgList &Args,
                                   frontend::ActionKind Action) {
   Opts.ImplicitPCHInclude = Args.getLastArgValue(OPT_include_pch);
   Opts.ImplicitPTHInclude = Args.getLastArgValue(OPT_include_pth);
+  Opts.PCHThroughHeader = Args.getLastArgValue(OPT_pch_through_header_EQ);
   if (const Arg *A = Args.getLastArg(OPT_token_cache))
       Opts.TokenCache = A->getValue();
   else