Added support for expanding response files in clang_Driver_getExternalActionsForCommand_v0

clang/tools/libclang/Driver.cpp

@@ -40,15 +40,29 @@ clang_Driver_getExternalActionsForCommand_v0(int ArgC, const char **ArgV,
   if (ArgC < 1)
     return nullptr;
 
-  CXDiagnosticSetDiagnosticConsumer DiagConsumer;
-  auto DiagOpts = CreateAndPopulateDiagOpts(ArrayRef(ArgV, ArgC));
-
   // Use createPhysicalFileSystem instead of getRealFileSystem so that
   // setCurrentWorkingDirectory doesn't change the working directory of the
   // process.
   std::unique_ptr<llvm::vfs::FileSystem> VFS =
       llvm::vfs::createPhysicalFileSystem();
 
+  CXDiagnosticSetDiagnosticConsumer DiagConsumer;
+
+  SmallVector<const char *, 256> Args(ArgV, ArgV + ArgC);
+  llvm::BumpPtrAllocator Alloc;
+  if (llvm::Error E =
+      driver::expandResponseFiles(Args, /*CLMode=*/false, Alloc)) {
+    // Construct a default DiagnosticOptions to use to emit the failure.
+    DiagnosticOptions DiagOpts;
+    auto Diags = CompilerInstance::createDiagnostics(*VFS, &DiagOpts,
+                                                     &DiagConsumer, false);
+
+    Diags->Report(diag::err_drv_expand_response_file)
+        << llvm::toString(std::move(E));
+    return nullptr;
+  }
+
+  auto DiagOpts = CreateAndPopulateDiagOpts(Args);
   auto Diags = CompilerInstance::createDiagnostics(*VFS, DiagOpts.release(),
                                                    &DiagConsumer, false);
   if (WorkingDirectory)
@@ -65,7 +79,7 @@ clang_Driver_getExternalActionsForCommand_v0(int ArgC, const char **ArgV,
                            VFS.release());
   TheDriver.setCheckInputsExist(false);
   std::unique_ptr<driver::Compilation> C(
-      TheDriver.BuildCompilation(ArrayRef(ArgV, ArgC)));
+      TheDriver.BuildCompilation(Args));
   if (!C || Diags->hasErrorOccurred()) {
     if (OutDiags)
       *OutDiags = DiagConsumer.getDiagnosticSet();

clang/unittests/libclang/DriverTest.cpp

@@ -11,6 +11,8 @@
 #include "llvm/Support/Debug.h"
 #include "gtest/gtest.h"
 
+#include "TestUtils.h"
+
 #define DEBUG_TYPE "driver-test"
 
 TEST(DriverTests, Basic) {
@@ -129,3 +131,44 @@ TEST(DriverTests, DriverParsesDiagnosticsOptions) {
   clang_disposeDiagnosticSet(Diags);
   clang_Driver_ExternalActionList_dispose(EAL);
 }
+
+class LibclangDriverResponseFileTest : public LibclangParseTest {};
+
+TEST_F(LibclangDriverResponseFileTest, DriverResponseFile) {
+  // Enable -Weverything (a flag not set by default) via a response file.
+  std::string ResponseFilename = "AdditionalOptions.resp";
+  WriteFile(ResponseFilename, "-Weverything\n");
+
+  llvm::SmallString<256> ResponseArg("@");
+  ResponseArg.append(ResponseFilename);
+
+  const char *ArgV[] = {"clang",
+                        ResponseArg.c_str(),
+                        "-c",
+                        "t.cpp",
+                        "-o",
+                        "t.o"};
+
+  CXDiagnosticSet Diags;
+  CXExternalActionList *EAL = clang_Driver_getExternalActionsForCommand_v0(
+      std::extent_v<decltype(ArgV)>, ArgV, nullptr, "/", &Diags);
+
+  ASSERT_NE(EAL, nullptr);
+  ASSERT_EQ(EAL->Count, 1);
+  ASSERT_EQ(nullptr, Diags);
+
+  auto *CompileAction = EAL->Actions[0];
+  ASSERT_GE(CompileAction->ArgC, 2);
+  EXPECT_STREQ(CompileAction->ArgV[0], "clang");
+  EXPECT_STREQ(CompileAction->ArgV[1], "-cc1");
+
+  const char **WFlag = std::find(CompileAction->ArgV,
+      CompileAction->ArgV + CompileAction->ArgC,
+       llvm::StringRef("-Weverything"));
+
+  ASSERT_NE(WFlag, CompileAction->ArgV + CompileAction->ArgC);
+  EXPECT_STREQ(*WFlag, "-Weverything");
+
+  clang_disposeDiagnosticSet(Diags);
+  clang_Driver_ExternalActionList_dispose(EAL);
+}