[clang] [ClangTool] Use CC1Option flag resource-dir in injectResourceDir (PR #140870)

[Wenju He via cfe-commits]

https://github.com/wenju-he created https://github.com/llvm/llvm-project/pull/140870

This PR fixes ClangTool error in -cc1 mode:
error: unknown argument: '-resource-dir=

>From f5e675f17ea737b0668e626f34d013153368425e Mon Sep 17 00:00:00 2001
From: Wenju He <wenju.he at intel.com>
Date: Wed, 21 May 2025 02:08:34 -0700
Subject: [PATCH] [ClangTool] Use CC1Option flag resource-dir in
 injectResourceDir

This PR fixes ClangTool error in -cc1 mode:
error: unknown argument: '-resource-dir=
---
 clang/lib/Tooling/Tooling.cpp           |  8 +++++---
 clang/unittests/Tooling/ToolingTest.cpp | 19 +++++++++++++++++++
 2 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/clang/lib/Tooling/Tooling.cpp b/clang/lib/Tooling/Tooling.cpp
index 3c72f52040142..87a984672662b 100644
--- a/clang/lib/Tooling/Tooling.cpp
+++ b/clang/lib/Tooling/Tooling.cpp
@@ -510,9 +510,11 @@ static void injectResourceDir(CommandLineArguments &Args, const char *Argv0,
       return;
 
   // If there's no override in place add our resource dir.
-  Args = getInsertArgumentAdjuster(
-      ("-resource-dir=" + CompilerInvocation::GetResourcesPath(Argv0, MainAddr))
-          .c_str())(Args, "");
+  CommandLineArguments Extra = {
+      "-resource-dir", CompilerInvocation::GetResourcesPath(Argv0, MainAddr)};
+
+  Args =
+      getInsertArgumentAdjuster(Extra, ArgumentInsertPosition::END)(Args, "");
 }
 
 int ClangTool::run(ToolAction *Action) {
diff --git a/clang/unittests/Tooling/ToolingTest.cpp b/clang/unittests/Tooling/ToolingTest.cpp
index 8cdfffb54390e..07104ccf9835f 100644
--- a/clang/unittests/Tooling/ToolingTest.cpp
+++ b/clang/unittests/Tooling/ToolingTest.cpp
@@ -771,6 +771,25 @@ TEST(ClangToolTest, BaseVirtualFileSystemUsage) {
   EXPECT_EQ(0, Tool.run(Action.get()));
 }
 
+// Check -cc1 command doesn't crash.
+TEST(ClangToolTest, CC1Arg) {
+  FixedCompilationDatabase Compilations("/", {"-cc1"});
+  llvm::IntrusiveRefCntPtr<llvm::vfs::OverlayFileSystem> OverlayFileSystem(
+      new llvm::vfs::OverlayFileSystem(llvm::vfs::getRealFileSystem()));
+  llvm::IntrusiveRefCntPtr<llvm::vfs::InMemoryFileSystem> InMemoryFileSystem(
+      new llvm::vfs::InMemoryFileSystem);
+  OverlayFileSystem->pushOverlay(InMemoryFileSystem);
+
+  InMemoryFileSystem->addFile(
+      "a.cpp", 0, llvm::MemoryBuffer::getMemBuffer("int main() {}"));
+
+  ClangTool Tool(Compilations, std::vector<std::string>(1, "a.cpp"),
+                 std::make_shared<PCHContainerOperations>(), OverlayFileSystem);
+  std::unique_ptr<FrontendActionFactory> Action(
+      newFrontendActionFactory<SyntaxOnlyAction>());
+  EXPECT_EQ(0, Tool.run(Action.get()));
+}
+
 // Check getClangStripDependencyFileAdjuster doesn't strip args after -MD/-MMD.
 TEST(ClangToolTest, StripDependencyFileAdjuster) {
   FixedCompilationDatabase Compilations("/", {"-MD", "-c", "-MMD", "-w"});