[Modules] Emit the module file paths as dependencies of the PCH when we are building one.

This is because the PCH is tied to the module files, if one of the module files changes or gets removed
the build system should re-build the PCH file.

rdar://16321245

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@203885 91177308-0d34-0410-b5e6-96231b3b80d8

include/clang/Driver/CC1Options.td

@@ -223,6 +223,8 @@ def dependent_lib : Joined<["--"], "dependent-lib=">,
 
 def sys_header_deps : Flag<["-"], "sys-header-deps">,
   HelpText<"Include system headers in dependency output">;
+def module_file_deps : Flag<["-"], "module-file-deps">,
+  HelpText<"Include module files in dependency output">;
 def header_include_file : Separate<["-"], "header-include-file">,
   HelpText<"Filename (or -) to write header include output to">;
 def show_includes : Flag<["--"], "show-includes">,

include/clang/Frontend/DependencyOutputOptions.h

@@ -26,6 +26,7 @@ public:
                                      /// problems.
   unsigned AddMissingHeaderDeps : 1; ///< Add missing headers to dependency list
   unsigned PrintShowIncludes : 1; ///< Print cl.exe style /showIncludes info.
+  unsigned IncludeModuleFiles : 1; ///< Include module file dependencies.
   
   /// The file to write dependency output to.
   std::string OutputFile;
@@ -50,6 +51,7 @@ public:
     UsePhonyTargets = 0;
     AddMissingHeaderDeps = 0;
     PrintShowIncludes = 0;
+    IncludeModuleFiles = 0;
   }
 };
 

include/clang/Serialization/ASTReader.h

@@ -171,6 +171,9 @@ public:
   virtual void ReadCounter(const serialization::ModuleFile &M,
                            unsigned Value) {}
 
+  /// This is called for each AST file loaded.
+  virtual void visitModuleFile(StringRef Filename) {}
+
   /// \brief Returns true if this \c ASTReaderListener wants to receive the
   /// input files of the AST file via \c visitInputFile, false otherwise.
   virtual bool needsInputFileVisitation() { return false; }
@@ -217,6 +220,7 @@ public:
   void ReadCounter(const serialization::ModuleFile &M, unsigned Value) override;
   bool needsInputFileVisitation() override;
   bool needsSystemInputFileVisitation() override;
+  void visitModuleFile(StringRef Filename) override;
   bool visitInputFile(StringRef Filename, bool isSystem,
                       bool isOverridden) override;
 };

lib/Driver/Tools.cpp

@@ -295,6 +295,9 @@ void Clang::AddPreprocessingOptions(Compilation &C,
     if (A->getOption().matches(options::OPT_M) ||
         A->getOption().matches(options::OPT_MD))
       CmdArgs.push_back("-sys-header-deps");
+
+    if (isa<PrecompileJobAction>(JA))
+      CmdArgs.push_back("-module-file-deps");
   }
 
   if (Args.hasArg(options::OPT_MG)) {

lib/Frontend/CompilerInvocation.cpp

@@ -528,6 +528,7 @@ static void ParseDependencyOutputArgs(DependencyOutputOptions &Opts,
   Opts.OutputFile = Args.getLastArgValue(OPT_dependency_file);
   Opts.Targets = Args.getAllArgValues(OPT_MT);
   Opts.IncludeSystemHeaders = Args.hasArg(OPT_sys_header_deps);
+  Opts.IncludeModuleFiles = Args.hasArg(OPT_module_file_deps);
   Opts.UsePhonyTargets = Args.hasArg(OPT_MP);
   Opts.ShowHeaderIncludes = Args.hasArg(OPT_H);
   Opts.HeaderIncludeOutputFile = Args.getLastArgValue(OPT_header_include_file);

lib/Frontend/DependencyFile.cpp

@@ -40,6 +40,7 @@ class DFGImpl : public PPCallbacks {
   bool PhonyTarget;
   bool AddMissingHeaderDeps;
   bool SeenMissingHeader;
+  bool IncludeModuleFiles;
 private:
   bool FileMatchesDepCriteria(const char *Filename,
                               SrcMgr::CharacteristicKind FileType);
@@ -51,7 +52,8 @@ public:
       IncludeSystemHeaders(Opts.IncludeSystemHeaders),
       PhonyTarget(Opts.UsePhonyTargets),
       AddMissingHeaderDeps(Opts.AddMissingHeaderDeps),
-      SeenMissingHeader(false) {}
+      SeenMissingHeader(false),
+      IncludeModuleFiles(Opts.IncludeModuleFiles) {}
 
   void FileChanged(SourceLocation Loc, FileChangeReason Reason,
                    SrcMgr::CharacteristicKind FileType,
@@ -68,6 +70,7 @@ public:
 
   void AddFilename(StringRef Filename);
   bool includeSystemHeaders() const { return IncludeSystemHeaders; }
+  bool includeModuleFiles() const { return IncludeModuleFiles; }
 };
 
 class DFGASTReaderListener : public ASTReaderListener {
@@ -79,6 +82,7 @@ public:
   bool needsSystemInputFileVisitation() override {
     return Parent.includeSystemHeaders();
   }
+  void visitModuleFile(StringRef Filename) override;
   bool visitInputFile(StringRef Filename, bool isSystem,
                       bool isOverridden) override;
 };
@@ -268,3 +272,7 @@ bool DFGASTReaderListener::visitInputFile(llvm::StringRef Filename,
   return true;
 }
 
+void DFGASTReaderListener::visitModuleFile(llvm::StringRef Filename) {
+  if (Parent.includeModuleFiles())
+    Parent.AddFilename(Filename);
+}

lib/Serialization/ASTReader.cpp

@@ -118,6 +118,10 @@ bool ChainedASTReaderListener::needsSystemInputFileVisitation() {
   return First->needsSystemInputFileVisitation() ||
   Second->needsSystemInputFileVisitation();
 }
+void ChainedASTReaderListener::visitModuleFile(StringRef Filename) {
+  First->visitModuleFile(Filename);
+  Second->visitModuleFile(Filename);
+}
 bool ChainedASTReaderListener::visitInputFile(StringRef Filename,
                                               bool isSystem,
                                               bool isOverridden) {
@@ -2118,6 +2122,9 @@ ASTReader::ReadControlBlock(ModuleFile &F,
         }
       }
 
+      if (Listener)
+        Listener->visitModuleFile(F.FileName);
+
       if (Listener && Listener->needsInputFileVisitation()) {
         unsigned N = Listener->needsSystemInputFileVisitation() ? NumInputs
                                                                 : NumUserInputs;

test/Driver/pch-deps.c

@@ -0,0 +1,10 @@
+// RUN: %clang -x c-header %s -o %t.pch -MMD -MT dependencies -MF %t.d -### 2> %t
+// RUN: FileCheck %s -input-file=%t
+// CHECK: -emit-pch
+// CHECK: -dependency-file
+// CHECK: -module-file-deps
+
+// RUN: %clang -c %s -o %t -MMD -MT dependencies -MF %t.d -### 2> %t
+// RUN: FileCheck %s -check-prefix=CHECK-NOPCH -input-file=%t
+// CHECK-NOPCH: -dependency-file
+// CHECK-NOPCH-NOT: -module-file-deps

test/Modules/dependency-gen-pch.m

@@ -0,0 +1,12 @@
+// RUN: rm -rf %t-mcp
+// RUN: mkdir -p %t-mcp
+
+// RUN: %clang_cc1 -isysroot %S/Inputs/System -triple x86_64-apple-darwin10 -module-file-deps -dependency-file %t.d -MT %s.o -I %S/Inputs -fmodules -fmodules-cache-path=%t-mcp -emit-pch -o %t.pch %s
+// RUN: FileCheck %s < %t.d
+// CHECK: dependency-gen-pch.m.o
+// CHECK-NEXT: dependency-gen-pch.m
+// CHECK-NEXT: diamond_top.pcm
+// CHECK-NEXT: Inputs{{.}}diamond_top.h
+// CHECK-NEXT: Inputs{{.}}module.map
+
+#import "diamond_top.h"