[clang] [clang][Tooling] Support relative directory in compilation database (PR #127734)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: Keith Smiley (keith)

<details>
<summary>Changes</summary>

This allows you to use `"directory": ".",` in `compile_commands.json`
and have it be understood for file lookup by `clangd`.


---
Full diff: https://github.com/llvm/llvm-project/pull/127734.diff


2 Files Affected:

- (modified) clang/lib/Tooling/JSONCompilationDatabase.cpp (+1) 
- (modified) clang/unittests/Tooling/CompilationDatabaseTest.cpp (+24) 


``````````diff
diff --git a/clang/lib/Tooling/JSONCompilationDatabase.cpp b/clang/lib/Tooling/JSONCompilationDatabase.cpp
index 5ecba5dfece3d..625ac034d639a 100644
--- a/clang/lib/Tooling/JSONCompilationDatabase.cpp
+++ b/clang/lib/Tooling/JSONCompilationDatabase.cpp
@@ -419,6 +419,7 @@ bool JSONCompilationDatabase::parse(std::string &ErrorMessage) {
     if (llvm::sys::path::is_relative(FileName)) {
       SmallString<8> DirectoryStorage;
       SmallString<128> AbsolutePath(Directory->getValue(DirectoryStorage));
+      llvm::sys::fs::make_absolute(AbsolutePath);
       llvm::sys::path::append(AbsolutePath, FileName);
       llvm::sys::path::native(AbsolutePath, NativeFilePath);
     } else {
diff --git a/clang/unittests/Tooling/CompilationDatabaseTest.cpp b/clang/unittests/Tooling/CompilationDatabaseTest.cpp
index 2032b13726c45..c5d3de7fb2384 100644
--- a/clang/unittests/Tooling/CompilationDatabaseTest.cpp
+++ b/clang/unittests/Tooling/CompilationDatabaseTest.cpp
@@ -399,6 +399,30 @@ TEST(findCompileArgsInJsonDatabase, FindsEntry) {
   EXPECT_EQ("command4", FoundCommand.CommandLine[0]) << ErrorMessage;
 }
 
+TEST(findCompileArgsInJsonDatabase, FindsEntryRelativeDirectory) {
+  StringRef Directory(".");
+  StringRef FileName("file");
+  StringRef Command("command");
+  std::string JsonDatabase = "[";
+  JsonDatabase +=
+    ("{\"directory\":\"" + Directory + "\"," +
+      "\"command\":\"" + Command + "\","
+      "\"file\":\"" + FileName + "\"}").str();
+  JsonDatabase += "]";
+
+  SmallString<256> Result;
+  llvm::sys::fs::current_path(Result);
+  llvm::sys::path::append(Result, FileName);
+
+  std::string ErrorMessage;
+  CompileCommand FoundCommand = findCompileArgsInJsonDatabase(
+    Result, JsonDatabase, ErrorMessage);
+
+  EXPECT_EQ(".", FoundCommand.Directory) << ErrorMessage;
+  ASSERT_EQ(1u, FoundCommand.CommandLine.size()) << ErrorMessage;
+  EXPECT_EQ("command", FoundCommand.CommandLine[0]) << ErrorMessage;
+}
+
 TEST(findCompileArgsInJsonDatabase, ParsesCompilerWrappers) {
   std::vector<std::pair<std::string, std::string>> Cases = {
       {"distcc gcc foo.c", "gcc foo.c"},

``````````

</details>


https://github.com/llvm/llvm-project/pull/127734