[clang] 2168dbf - getClangStripDependencyFileAdjuster(): Do not remove -M args when using MSVC cl driver

[Hans Wennborg via cfe-commits]

Author: Shivanshu Goyal
Date: 2020-09-08T10:21:18+02:00
New Revision: 2168dbf4cc766dfb552076d9b1e84b00122b7993

URL: https://github.com/llvm/llvm-project/commit/2168dbf4cc766dfb552076d9b1e84b00122b7993
DIFF: https://github.com/llvm/llvm-project/commit/2168dbf4cc766dfb552076d9b1e84b00122b7993.diff

LOG: getClangStripDependencyFileAdjuster(): Do not remove -M args when using MSVC cl driver

MSVC's cl.exe has a few command line arguments which start with -M such
as "-MD", "-MDd", "-MT", "-MTd", "-MP".
These arguments are not dependency file generation related, and these
arguments were being removed by getClangStripDependencyFileAdjuster()
which was wrong.

Differential revision: https://reviews.llvm.org/D86999

Added: 
    

Modified: 
    clang/lib/Tooling/ArgumentsAdjusters.cpp
    clang/unittests/Tooling/ToolingTest.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/Tooling/ArgumentsAdjusters.cpp b/clang/lib/Tooling/ArgumentsAdjusters.cpp
index a857b57fbf7b..bcfb5b39a077 100644
--- a/clang/lib/Tooling/ArgumentsAdjusters.cpp
+++ b/clang/lib/Tooling/ArgumentsAdjusters.cpp
@@ -21,6 +21,16 @@
 namespace clang {
 namespace tooling {
 
+static StringRef getDriverMode(const CommandLineArguments &Args) {
+  for (const auto &Arg : Args) {
+    StringRef ArgRef = Arg;
+    if (ArgRef.consume_front("--driver-mode=")) {
+      return ArgRef;
+    }
+  }
+  return StringRef();
+}
+
 /// Add -fsyntax-only option and drop options that triggers output generation.
 ArgumentsAdjuster getClangSyntaxOnlyAdjuster() {
   return [](const CommandLineArguments &Args, StringRef /*unused*/) {
@@ -93,20 +103,28 @@ ArgumentsAdjuster getClangStripSerializeDiagnosticAdjuster() {
 
 ArgumentsAdjuster getClangStripDependencyFileAdjuster() {
   return [](const CommandLineArguments &Args, StringRef /*unused*/) {
+    auto UsingClDriver = (getDriverMode(Args) == "cl");
+
     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") && !Arg.startswith("/showIncludes") &&
-          !Arg.startswith("-showIncludes")) {
-        AdjustedArgs.push_back(Args[i]);
+
+      // These flags take an argument: -MX foo. Skip the next argument also.
+      if (!UsingClDriver && (Arg == "-MF" || Arg == "-MT" || Arg == "-MQ")) {
+        ++i;
         continue;
       }
+      // When not using the cl driver mode, dependency file generation options
+      // begin with -M. These include -MM, -MF, -MG, -MP, -MT, -MQ, -MD, and
+      // -MMD.
+      if (!UsingClDriver && Arg.startswith("-M"))
+        continue;
+      // Under MSVC's cl driver mode, dependency file generation is controlled
+      // using /showIncludes
+      if (Arg.startswith("/showIncludes") || Arg.startswith("-showIncludes"))
+        continue;
 
-      if (Arg == "-MF" || Arg == "-MT" || Arg == "-MQ")
-        // These flags take an argument: -MX foo. Skip the next argument also.
-        ++i;
+      AdjustedArgs.push_back(Args[i]);
     }
     return AdjustedArgs;
   };

diff  --git a/clang/unittests/Tooling/ToolingTest.cpp b/clang/unittests/Tooling/ToolingTest.cpp
index cc6f453284d7..691a847d5a71 100644
--- a/clang/unittests/Tooling/ToolingTest.cpp
+++ b/clang/unittests/Tooling/ToolingTest.cpp
@@ -563,6 +563,40 @@ TEST(ClangToolTest, StripDependencyFileAdjusterShowIncludes) {
   EXPECT_TRUE(HasFlag("-c"));
 }
 
+// Check getClangStripDependencyFileAdjuster doesn't strip args when using the
+// MSVC cl.exe driver
+TEST(ClangToolTest, StripDependencyFileAdjusterMsvc) {
+  FixedCompilationDatabase Compilations(
+      "/", {"--driver-mode=cl", "-MD", "-MDd", "-MT", "-O1", "-MTd", "-MP"});
+
+  ClangTool Tool(Compilations, std::vector<std::string>(1, "/a.cc"));
+  Tool.mapVirtualFile("/a.cc", "void a() {}");
+
+  std::unique_ptr<FrontendActionFactory> Action(
+      newFrontendActionFactory<SyntaxOnlyAction>());
+
+  CommandLineArguments FinalArgs;
+  ArgumentsAdjuster CheckFlagsAdjuster =
+      [&FinalArgs](const CommandLineArguments &Args, StringRef /*unused*/) {
+        FinalArgs = Args;
+        return Args;
+      };
+  Tool.clearArgumentsAdjusters();
+  Tool.appendArgumentsAdjuster(getClangStripDependencyFileAdjuster());
+  Tool.appendArgumentsAdjuster(CheckFlagsAdjuster);
+  Tool.run(Action.get());
+
+  auto HasFlag = [&FinalArgs](const std::string &Flag) {
+    return llvm::find(FinalArgs, Flag) != FinalArgs.end();
+  };
+  EXPECT_TRUE(HasFlag("-MD"));
+  EXPECT_TRUE(HasFlag("-MDd"));
+  EXPECT_TRUE(HasFlag("-MT"));
+  EXPECT_TRUE(HasFlag("-O1"));
+  EXPECT_TRUE(HasFlag("-MTd"));
+  EXPECT_TRUE(HasFlag("-MP"));
+}
+
 // Check getClangStripPluginsAdjuster strips plugin related args.
 TEST(ClangToolTest, StripPluginsAdjuster) {
   FixedCompilationDatabase Compilations(