[clang-tools-extra] e1271dd - [clangd] Index reserved symbols from `*intrin.h` system headers (#119735)

[via cfe-commits]

Author: Joseph Huber
Date: 2024-12-15T08:04:47-06:00
New Revision: e1271dd5a7ecf5cee59c8e2684b93501a1aab82d

URL: https://github.com/llvm/llvm-project/commit/e1271dd5a7ecf5cee59c8e2684b93501a1aab82d
DIFF: https://github.com/llvm/llvm-project/commit/e1271dd5a7ecf5cee59c8e2684b93501a1aab82d.diff

LOG: [clangd] Index reserved symbols from `*intrin.h` system headers (#119735)

Summary:
`clangd` intentionally suppresses indexing symbols from system headers
as these are likely implementation details the user does not want.
Howver, there are plenty of system headers that provide extensions that
we want to index, such as vector intrinsic headers. This patch adds an
extra check for these commonly-named '*intrin.h' headers. This is not
fully inclusive for all symbols the user might want, but it's a good
start.

Fixes: https://github.com/llvm/llvm-project/issues/118684

---------

Co-authored-by: Nathan Ridge <zeratul976 at hotmail.com>

Added: 
    

Modified: 
    clang-tools-extra/clangd/index/SymbolCollector.cpp
    clang-tools-extra/clangd/unittests/SymbolCollectorTests.cpp

Removed: 
    


################################################################################
diff  --git a/clang-tools-extra/clangd/index/SymbolCollector.cpp b/clang-tools-extra/clangd/index/SymbolCollector.cpp
index 81125dbb1aeafc..6d0af20e31260c 100644
--- a/clang-tools-extra/clangd/index/SymbolCollector.cpp
+++ b/clang-tools-extra/clangd/index/SymbolCollector.cpp
@@ -550,9 +550,14 @@ bool SymbolCollector::shouldCollectSymbol(const NamedDecl &ND,
   // Avoid indexing internal symbols in protobuf generated headers.
   if (isPrivateProtoDecl(ND))
     return false;
+
+  // System headers that end with `intrin.h` likely contain useful symbols.
   if (!Opts.CollectReserved &&
       (hasReservedName(ND) || hasReservedScope(*ND.getDeclContext())) &&
-      ASTCtx.getSourceManager().isInSystemHeader(ND.getLocation()))
+      ASTCtx.getSourceManager().isInSystemHeader(ND.getLocation()) &&
+      !ASTCtx.getSourceManager()
+           .getFilename(ND.getLocation())
+           .ends_with("intrin.h"))
     return false;
 
   return true;

diff  --git a/clang-tools-extra/clangd/unittests/SymbolCollectorTests.cpp b/clang-tools-extra/clangd/unittests/SymbolCollectorTests.cpp
index e8088cb37fa51c..7a9703c744e93f 100644
--- a/clang-tools-extra/clangd/unittests/SymbolCollectorTests.cpp
+++ b/clang-tools-extra/clangd/unittests/SymbolCollectorTests.cpp
@@ -2111,6 +2111,20 @@ TEST_F(SymbolCollectorTest, Reserved) {
   EXPECT_THAT(Symbols, IsEmpty());
 }
 
+TEST_F(SymbolCollectorTest, ReservedSymbolInIntrinsicHeader) {
+  const char *Header = R"cpp(
+    #pragma once
+    void __foo();
+  )cpp";
+
+  TestHeaderName = "xintrin.h";
+  TestHeaderURI = URI::create(testPath(TestHeaderName)).toString();
+  InMemoryFileSystem = new llvm::vfs::InMemoryFileSystem;
+  CollectorOpts.FallbackDir = testRoot();
+  runSymbolCollector("#pragma GCC system_header\n" + std::string(Header), "");
+  EXPECT_THAT(Symbols, UnorderedElementsAre(qName("__foo")));
+}
+
 TEST_F(SymbolCollectorTest, Concepts) {
   const char *Header = R"cpp(
     template <class T>