Allow CompilerInvocations to generate .d files.

Summary:
Most clang tools should ignore the -M
family of options because one wouldn't want them
to generate a new dependency (.d) file. However,
some tools may want this dependency file. This
patch creates a mechanism for them to do this.

This implementation just plumbs a boolean down
several layers of calls. Each of the modified calls
has several call sites, and so a single member
variable or new API entry point won't work.

An alternative would be to write a function to filter
the -M family of arguments out of CC1Args, and have
each caller call that function by hand before calling
newInvocation, Invocation::run, or buildAstFromCodeWithArgs.
This is a more complicated and error-prone solution.
Why burden all the callers to remember to use
this function?

But I could rewrite this patch to use that method if
that is deemed more appropriate.

Reviewers: klimek

Reviewed By: klimek

Subscribers: klimek, cfe-commits

Differential Revision: https://reviews.llvm.org/D34304

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@307315 91177308-0d34-0410-b5e6-96231b3b80d8

include/clang/Tooling/ArgumentsAdjusters.h

@@ -44,6 +44,10 @@ ArgumentsAdjuster getClangSyntaxOnlyAdjuster();
 /// arguments.
 ArgumentsAdjuster getClangStripOutputAdjuster();
 
+/// \brief Gets an argument adjuster which removes dependency-file
+/// related command line arguments.
+ArgumentsAdjuster getClangStripDependencyFileAdjuster();
+
 enum class ArgumentInsertPosition { BEGIN, END };
 
 /// \brief Gets an argument adjuster which inserts \p Extra arguments in the

include/clang/Tooling/Tooling.h

@@ -202,12 +202,15 @@ buildASTFromCode(const Twine &Code, const Twine &FileName = "input.cc",
 /// \param PCHContainerOps The PCHContainerOperations for loading and creating
 /// clang modules.
 ///
+/// \param Adjuster A function to filter the command line arguments as specified.
+///
 /// \return The resulting AST or null if an error occurred.
 std::unique_ptr<ASTUnit> buildASTFromCodeWithArgs(
     const Twine &Code, const std::vector<std::string> &Args,
     const Twine &FileName = "input.cc", const Twine &ToolName = "clang-tool",
     std::shared_ptr<PCHContainerOperations> PCHContainerOps =
-        std::make_shared<PCHContainerOperations>());
+      std::make_shared<PCHContainerOperations>(),
+    ArgumentsAdjuster Adjuster = getClangStripDependencyFileAdjuster());
 
 /// \brief Utility to run a FrontendAction in a single clang invocation.
 class ToolInvocation {

lib/Tooling/ArgumentsAdjusters.cpp

@@ -42,7 +42,7 @@ ArgumentsAdjuster getClangStripOutputAdjuster() {
         AdjustedArgs.push_back(Args[i]);
 
       if (Arg == "-o") {
-        // Output is specified as -o foo. Skip the next argument also.
+        // Output is specified as -o foo. Skip the next argument too.
         ++i;
       }
       // Else, the output is specified as -ofoo. Just do nothing.
@@ -51,6 +51,26 @@ ArgumentsAdjuster getClangStripOutputAdjuster() {
   };
 }
 
+ArgumentsAdjuster getClangStripDependencyFileAdjuster() {
+  return [](const CommandLineArguments &Args, StringRef /*unused*/) {
+    CommandLineArguments AdjustedArgs;
+    for (size_t i = 0, e = Args.size(); i < e; ++i) {
+      StringRef Arg = Args[i];
+      // All dependency-file options begin with -M. These include -MM,
+      // -MF, -MG, -MP, -MT, -MQ, -MD, and -MMD.
+      if (!Arg.startswith("-M"))
+        AdjustedArgs.push_back(Args[i]);
+
+      if ((Arg == "-MF") || (Arg == "-MT") || (Arg == "-MQ") ||
+          (Arg == "-MD") || (Arg == "-MMD")) {
+        // Output is specified as -MX foo. Skip the next argument also.
+        ++i;
+      }
+    }
+    return AdjustedArgs;
+  };
+}
+
 ArgumentsAdjuster getInsertArgumentAdjuster(const CommandLineArguments &Extra,
                                             ArgumentInsertPosition Pos) {
   return [Extra, Pos](const CommandLineArguments &Args, StringRef /*unused*/) {
@@ -83,4 +103,3 @@ ArgumentsAdjuster combineAdjusters(ArgumentsAdjuster First,
 
 } // end namespace tooling
 } // end namespace clang
-

lib/Tooling/Tooling.cpp

@@ -100,7 +100,6 @@ clang::CompilerInvocation *newInvocation(
       *Diagnostics);
   Invocation->getFrontendOpts().DisableFree = false;
   Invocation->getCodeGenOpts().DisableFree = false;
-  Invocation->getDependencyOutputOpts() = DependencyOutputOptions();
   return Invocation;
 }
 
@@ -510,7 +509,8 @@ buildASTFromCode(const Twine &Code, const Twine &FileName,
 std::unique_ptr<ASTUnit> buildASTFromCodeWithArgs(
     const Twine &Code, const std::vector<std::string> &Args,
     const Twine &FileName, const Twine &ToolName,
-    std::shared_ptr<PCHContainerOperations> PCHContainerOps) {
+    std::shared_ptr<PCHContainerOperations> PCHContainerOps,
+    ArgumentsAdjuster Adjuster) {
   SmallString<16> FileNameStorage;
   StringRef FileNameRef = FileName.toNullTerminatedStringRef(FileNameStorage);
 
@@ -523,8 +523,10 @@ std::unique_ptr<ASTUnit> buildASTFromCodeWithArgs(
   OverlayFileSystem->pushOverlay(InMemoryFileSystem);
   llvm::IntrusiveRefCntPtr<FileManager> Files(
       new FileManager(FileSystemOptions(), OverlayFileSystem));
-  ToolInvocation Invocation(getSyntaxOnlyToolArgs(ToolName, Args, FileNameRef),
-                            &Action, Files.get(), std::move(PCHContainerOps));
+
+  ToolInvocation Invocation(
+      getSyntaxOnlyToolArgs(ToolName, Adjuster(Args, FileNameRef), FileNameRef),
+      &Action, Files.get(), std::move(PCHContainerOps));
 
   SmallString<1024> CodeStorage;
   InMemoryFileSystem->addFile(FileNameRef, 0,