COFF: Create an empty file for /pdb.

Most build system depends on existence or time stamp of a file.
This patch is to create an empty file for /pdb:<filename> option
just to satisfy some build rules.

llvm-svn: 240948

3 files changed, 13 insertions, 0 deletions

diff --git a/lld/COFF/Driver.cpp b/lld/COFF/Driver.cpp
index 8f34d1f98c1d..bde1a6c56001 100644
--- a/lld/COFF/Driver.cpp
+++ b/lld/COFF/Driver.cpp
@@ -630,6 +630,10 @@ bool LinkerDriver::link(llvm::ArrayRef<const char *> ArgsArr) {
     if (createSideBySideManifest())
       return false;
 
+  // Create a dummy PDB file to satisfy build sytem rules.
+  if (auto *Arg = Args.getLastArg(OPT_pdb))
+    touchFile(Arg->getValue());
+
   // Write the result.
   Writer Out(&Symtab);
   if (auto EC = Out.write(Config->OutputFile)) {
diff --git a/lld/COFF/Driver.h b/lld/COFF/Driver.h
index e861dead817f..c3e2186d5318 100644
--- a/lld/COFF/Driver.h
+++ b/lld/COFF/Driver.h
@@ -158,6 +158,8 @@ std::error_code checkFailIfMismatch(StringRef Arg);
 ErrorOr<std::unique_ptr<MemoryBuffer>>
 convertResToCOFF(const std::vector<MemoryBufferRef> &MBs);
 
+void touchFile(StringRef Path);
+
 // Create enum with OPT_xxx values for each option in Options.td
 enum {
   OPT_INVALID = 0,
diff --git a/lld/COFF/DriverUtils.cpp b/lld/COFF/DriverUtils.cpp
index 6859e40e710b..598228550014 100644
--- a/lld/COFF/DriverUtils.cpp
+++ b/lld/COFF/DriverUtils.cpp
@@ -517,6 +517,13 @@ std::error_code writeImportLibrary() {
   return E.run();
 }
 
+void touchFile(StringRef Path) {
+  int FD;
+  if (sys::fs::openFileForWrite(Path, FD, sys::fs::F_Append))
+    report_fatal_error("failed to create a file");
+  sys::Process::SafelyCloseFileDescriptor(FD);
+}
+
 // Create OptTable
 
 // Create prefix string literals used in Options.td