From 78e394b43448ee4113a0b7fa09a33f2726b8a125 Mon Sep 17 00:00:00 2001
From: David Majnemer <david.majnemer@gmail.com>
Date: Mon, 27 Oct 2014 22:31:50 +0000
Subject: [PATCH] Frontend: Don't include stdin in the dependency list for an
 object file

GCC doesn't do this and it semes weird to include a file that we can't
open.

This fixes PR21362.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@220726 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Frontend/DependencyFile.cpp | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/lib/Frontend/DependencyFile.cpp b/lib/Frontend/DependencyFile.cpp
index 22ed38fc12..08d66c7094 100644
--- a/lib/Frontend/DependencyFile.cpp
+++ b/lib/Frontend/DependencyFile.cpp
@@ -22,6 +22,7 @@
 #include "clang/Lex/Preprocessor.h"
 #include "clang/Serialization/ASTReader.h"
 #include "llvm/ADT/StringSet.h"
+#include "llvm/ADT/StringSwitch.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Path.h"
 #include "llvm/Support/raw_ostream.h"
@@ -113,10 +114,18 @@ void DependencyCollector::maybeAddDependency(StringRef Filename, bool FromModule
     Dependencies.push_back(Filename);
 }
 
+static bool isSpecialFilename(StringRef Filename) {
+  return llvm::StringSwitch<bool>(Filename)
+      .Case("<built-in>", true)
+      .Case("<stdin>", true)
+      .Default(false);
+}
+
 bool DependencyCollector::sawDependency(StringRef Filename, bool FromModule,
                                        bool IsSystem, bool IsModuleFile,
                                        bool IsMissing) {
-  return Filename != "<built-in>" && (needSystemDependencies() || !IsSystem);
+  return !isSpecialFilename(Filename) &&
+         (needSystemDependencies() || !IsSystem);
 }
 
 DependencyCollector::~DependencyCollector() { }
@@ -218,7 +227,7 @@ void DependencyFileGenerator::AttachToASTReader(ASTReader &R) {
 /// considered as a dependency.
 bool DFGImpl::FileMatchesDepCriteria(const char *Filename,
                                      SrcMgr::CharacteristicKind FileType) {
-  if (strcmp("<built-in>", Filename) == 0)
+  if (isSpecialFilename(Filename))
     return false;
 
   if (IncludeSystemHeaders)
-- 
2.40.0