[clang-tools-extra] 25682c3 - [clangd] highlight import and export keywords for C++20 modules (#204511)

[via cfe-commits]

Author: Access
Date: 2026-07-15T16:44:02+03:00
New Revision: 25682c3470410534c59708d7d3e2c9248802485f

URL: https://github.com/llvm/llvm-project/commit/25682c3470410534c59708d7d3e2c9248802485f
DIFF: https://github.com/llvm/llvm-project/commit/25682c3470410534c59708d7d3e2c9248802485f.diff

LOG: [clangd] highlight import and export keywords for C++20 modules (#204511)

Add syntax highlighting for C++20 module `import` and `export` keywords.

Note: Highlighting of the `export` keyword in a module export statement is not possible, because such statements don't appear in the AST

Added: 
    

Modified: 
    clang-tools-extra/clangd/SemanticHighlighting.cpp
    clang-tools-extra/clangd/unittests/PrerequisiteModulesTest.cpp

Removed: 
    


################################################################################
diff  --git a/clang-tools-extra/clangd/SemanticHighlighting.cpp b/clang-tools-extra/clangd/SemanticHighlighting.cpp
index 5d9336fa6e53d..d2d110b72011b 100644
--- a/clang-tools-extra/clangd/SemanticHighlighting.cpp
+++ b/clang-tools-extra/clangd/SemanticHighlighting.cpp
@@ -582,6 +582,18 @@ class CollectExtraHighlightings
     return true;
   }
 
+  bool VisitImportDecl(const ImportDecl *D) {
+    H.addToken(D->getLocation(), HighlightingKind::Modifier);
+    for (const auto ModuleLoc : D->getIdentifierLocs()) {
+      H.addToken(ModuleLoc, HighlightingKind::Namespace);
+    }
+    return true;
+  }
+  bool VisitExportDecl(const ExportDecl *D) {
+    H.addToken(D->getLocation(), HighlightingKind::Modifier);
+    return true;
+  }
+
   bool VisitTagDecl(TagDecl *D) {
     for (TemplateParameterList *TPL : D->getTemplateParameterLists())
       H.addAngleBracketTokens(TPL->getLAngleLoc(), TPL->getRAngleLoc());

diff  --git a/clang-tools-extra/clangd/unittests/PrerequisiteModulesTest.cpp b/clang-tools-extra/clangd/unittests/PrerequisiteModulesTest.cpp
index f163e248c383a..f10f3e4976cf9 100644
--- a/clang-tools-extra/clangd/unittests/PrerequisiteModulesTest.cpp
+++ b/clang-tools-extra/clangd/unittests/PrerequisiteModulesTest.cpp
@@ -17,6 +17,7 @@
 #include "ModulesBuilder.h"
 #include "Preamble.h"
 #include "ProjectModules.h"
+#include "SemanticHighlighting.h"
 #include "TestTU.h"
 #include "support/Path.h"
 #include "support/ThreadsafeFS.h"
@@ -575,7 +576,8 @@ int use() { return a; }
 
   ModulesBuilder Builder(CDB);
 
-  auto UseInfo = Builder.buildPrerequisiteModulesFor(getFullPath("Use.cpp"), FS);
+  auto UseInfo =
+      Builder.buildPrerequisiteModulesFor(getFullPath("Use.cpp"), FS);
   ASSERT_TRUE(UseInfo);
 
   HeaderSearchOptions HSOpts;
@@ -1669,6 +1671,55 @@ void use() {}
                                     getFullPath("Consumer.cpp"), *NewCI));
 }
 
+TEST_F(PrerequisiteModulesTests, ModuleSemanticHighlighting) {
+  MockDirectoryCompilationDatabase CDB(TestDir, FS);
+
+  llvm::StringRef AnnotatedCode = R"cpp(
+      module;
+      $import[[import]] M;
+      export module highlight;
+      $export[[export]] void foo() {
+      }
+)cpp";
+  Annotations UseCpp(AnnotatedCode);
+
+  CDB.addFile("M.cppm", R"cpp(
+export module M;
+export struct TypeFromModule {};
+)cpp");
+
+  CDB.addFile("Use.cpp", UseCpp.code());
+
+  ModulesBuilder Builder(CDB);
+
+  auto Inputs = getInputs("Use.cpp", CDB);
+  Inputs.ModulesManager = &Builder;
+  Inputs.Opts.SkipPreambleBuild = true;
+
+  auto CI = buildCompilerInvocation(Inputs, DiagConsumer);
+  ASSERT_TRUE(CI);
+
+  auto Preamble =
+      buildPreamble(getFullPath("Use.cpp"), *CI, Inputs, /*StoreInMemory=*/true,
+                    /*PeambleCallback=*/nullptr);
+  ASSERT_TRUE(Preamble);
+
+  auto AST = ParsedAST::build(getFullPath("Use.cpp"), Inputs, std::move(CI), {},
+                              Preamble);
+
+  ASSERT_TRUE(AST);
+
+  auto Actual = getSemanticHighlightings(AST.value(),
+                                         /*IncludeInactiveRegionTokens=*/true);
+  auto HasToken = [&](llvm::StringRef Name, HighlightingKind Kind) {
+    return llvm::any_of(Actual, [&](const HighlightingToken &T) {
+      return T.Kind == Kind && T.R == UseCpp.range(Name);
+    });
+  };
+  EXPECT_TRUE(HasToken("import", HighlightingKind::Modifier));
+  EXPECT_TRUE(HasToken("export", HighlightingKind::Modifier));
+}
+
 } // namespace
 } // namespace clang::clangd