2 files changed, 18 insertions, 5 deletions

diff --git a/clang-tools-extra/clangd/GlobalCompilationDatabase.cpp b/clang-tools-extra/clangd/GlobalCompilationDatabase.cpp
index 055f92c4734..e7cbc7bcc86 100644
--- a/clang-tools-extra/clangd/GlobalCompilationDatabase.cpp
+++ b/clang-tools-extra/clangd/GlobalCompilationDatabase.cpp
@@ -17,9 +17,19 @@ using namespace llvm;
 namespace clang {
 namespace clangd {
 
+static std::string getFallbackClangPath() {
+  static int Dummy;
+  std::string ClangdExecutable =
+      llvm::sys::fs::getMainExecutable("clangd", (void *)&Dummy);
+  SmallString<128> ClangPath;
+  ClangPath = llvm::sys::path::parent_path(ClangdExecutable);
+  llvm::sys::path::append(ClangPath, "clang");
+  return ClangPath.str();
+}
+
 tooling::CompileCommand
 GlobalCompilationDatabase::getFallbackCommand(PathRef File) const {
-  std::vector<std::string> Argv = {"clang"};
+  std::vector<std::string> Argv = {getFallbackClangPath()};
   // Clang treats .h files as C by default, resulting in unhelpful diagnostics.
   // Parsing as Objective C++ is friendly to more cases.
   if (sys::path::extension(File) == ".h")
diff --git a/clang-tools-extra/unittests/clangd/GlobalCompilationDatabaseTests.cpp b/clang-tools-extra/unittests/clangd/GlobalCompilationDatabaseTests.cpp
index f3916108c63..d5c0e6452b0 100644
--- a/clang-tools-extra/unittests/clangd/GlobalCompilationDatabaseTests.cpp
+++ b/clang-tools-extra/unittests/clangd/GlobalCompilationDatabaseTests.cpp
@@ -19,18 +19,21 @@ namespace clang {
 namespace clangd {
 namespace {
 using ::testing::ElementsAre;
+using ::testing::EndsWith;
 
 TEST(GlobalCompilationDatabaseTest, FallbackCommand) {
   DirectoryBasedGlobalCompilationDatabase DB(None);
   auto Cmd = DB.getFallbackCommand(testPath("foo/bar.cc"));
   EXPECT_EQ(Cmd.Directory, testPath("foo"));
-  EXPECT_THAT(Cmd.CommandLine, ElementsAre("clang", testPath("foo/bar.cc")));
+  EXPECT_THAT(Cmd.CommandLine, ElementsAre(
+    EndsWith("clang"), testPath("foo/bar.cc")));
   EXPECT_EQ(Cmd.Output, "");
 
   // .h files have unknown language, so they are parsed liberally as obj-c++.
   Cmd = DB.getFallbackCommand(testPath("foo/bar.h"));
-  EXPECT_THAT(Cmd.CommandLine, ElementsAre("clang", "-xobjective-c++-header",
-                                           testPath("foo/bar.h")));
+  EXPECT_THAT(Cmd.CommandLine,
+              ElementsAre(EndsWith("clang"), "-xobjective-c++-header",
+                          testPath("foo/bar.h")));
 }
 
 static tooling::CompileCommand cmd(StringRef File, StringRef Arg) {
@@ -88,7 +91,7 @@ TEST_F(OverlayCDBTest, NoBase) {
   EXPECT_EQ(CDB.getCompileCommand(testPath("bar.cc")), Override);
 
   EXPECT_THAT(CDB.getFallbackCommand(testPath("foo.cc")).CommandLine,
-              ElementsAre("clang", testPath("foo.cc"), "-DA=6"));
+              ElementsAre(EndsWith("clang"), testPath("foo.cc"), "-DA=6"));
 }
 
 TEST_F(OverlayCDBTest, Watch) {