[clang-cl] Add support for /Brepro

The /Brepro flag controls whether or not the compiler should embed
timestamps into the object file.  Object files which do not embed
timestamps are not suitable for incremental linking but are suitable for
hermetic build systems and staged self-hosts of clang.

A normal clang spelling of this flag has been added,
-mincremental-linker-compatible.

llvm-svn: 256204

1 files changed, 9 insertions, 0 deletions

diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
index fd299ea695a..54570286779 100644
--- a/clang/lib/Driver/Tools.cpp
+++ b/clang/lib/Driver/Tools.cpp
@@ -2567,6 +2567,15 @@ static void CollectArgsForIntegratedAssembler(Compilation &C,
   if (UseRelaxAll(C, Args))
     CmdArgs.push_back("-mrelax-all");
 
+  // Only default to -mincremental-linker-compatible if we think we are
+  // targeting the MSVC linker.
+  bool DefaultIncrementalLinkerCompatible =
+      C.getDefaultToolChain().getTriple().isWindowsMSVCEnvironment();
+  if (Args.hasFlag(options::OPT_mincremental_linker_compatible,
+                   options::OPT_mno_incremental_linker_compatible,
+                   DefaultIncrementalLinkerCompatible))
+    CmdArgs.push_back("-mincremental-linker-compatible");
+
   // When passing -I arguments to the assembler we sometimes need to
   // unconditionally take the next argument.  For example, when parsing
   // '-Wa,-I -Wa,foo' we need to accept the -Wa,foo arg after seeing the