[clang-cl] Print /showIncludes to stderr, if used in combination with /E, /EP or /P
This replicates 'cl.exe' behavior and allows for both preprocessor output and
dependency information to be extraced with a single compiler invocation.
This is especially useful for compiler caching with tools like Mozilla's sccache.
See: https://github.com/mozilla/sccache/issues/246
Patch By: fxb
Differential Revision: https://reviews.llvm.org/D46394
llvm-svn: 331533
diff --git a/clang/lib/Frontend/HeaderIncludeGen.cpp b/clang/lib/Frontend/HeaderIncludeGen.cpp
index 5bff4ec..9dc107c 100644
--- a/clang/lib/Frontend/HeaderIncludeGen.cpp
+++ b/clang/lib/Frontend/HeaderIncludeGen.cpp
@@ -80,9 +80,23 @@
const DependencyOutputOptions &DepOpts,
bool ShowAllHeaders, StringRef OutputPath,
bool ShowDepth, bool MSStyle) {
- raw_ostream *OutputFile = MSStyle ? &llvm::outs() : &llvm::errs();
+ raw_ostream *OutputFile = &llvm::errs();
bool OwnsOutputFile = false;
+ // Choose output stream, when printing in cl.exe /showIncludes style.
+ if (MSStyle) {
+ switch (DepOpts.ShowIncludesDest) {
+ default:
+ llvm_unreachable("Invalid destination for /showIncludes output!");
+ case ShowIncludesDestination::Stderr:
+ OutputFile = &llvm::errs();
+ break;
+ case ShowIncludesDestination::Stdout:
+ OutputFile = &llvm::outs();
+ break;
+ }
+ }
+
// Open the output file, if used.
if (!OutputPath.empty()) {
std::error_code EC;