[PATCH] D64741: [clangd] Added highlighting for tokens that are macro arguments.

[Johan Vikström via Phabricator via cfe-commits]

jvikstrom created this revision.
jvikstrom added reviewers: hokein, sammccall, ilya-biryukov.
Herald added subscribers: cfe-commits, kadircet, arphaman, jkorous, MaskRay.
Herald added a project: clang.

Adds semantic highlighting for tokens that are a macro argument.
Example:

  #define D_V(X) int X = 1230
  D_V(SomeVar);

The "SomeVar" inside the macro is highlighted as a variable now.

Tokens that are in a macro body expansion are ignored in this patch for three reasons.

- The spelling loc is inside the macro "definition" meaning it would highlight inside the macro definition (could probably easily be fixed by using getExpansionLoc instead of getSpellingLoc?)
- If wanting to highlight the macro definition this could create duplicate tokens. And if the tokens are of different types there would be conflicts (tokens in the same range but with different types). Say a macro defines some name and both a variable declaration and a function use this, there would be two tokens in the macro definition but one with Kind "Variable" and the other with Kind "Function".
- Thirdly, macro body expansions could come from a file that is not the main file (easily fixed, just check that the Loc is in the main file and not even a problem if we wanted to highlight the actual macro "invocation")


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D64741

Files:
  clang-tools-extra/clangd/SemanticHighlighting.cpp
  clang-tools-extra/clangd/unittests/SemanticHighlightingTests.cpp


Index: clang-tools-extra/clangd/unittests/SemanticHighlightingTests.cpp
===================================================================
--- clang-tools-extra/clangd/unittests/SemanticHighlightingTests.cpp
+++ clang-tools-extra/clangd/unittests/SemanticHighlightingTests.cpp
@@ -166,6 +166,42 @@
         $Variable[[AA]].$Field[[E]].$Field[[C]];
         $Class[[A]]::$Variable[[S]] = 90;
       }
+    )cpp",
+    R"cpp(
+      #define DEF_CLASS(T) class T {};
+      DEF_CLASS($Class[[A]])
+
+      #define MACRO_CONCAT(X, V, T) T foo##X = V
+      #define DEF_VAR(X, V) int X = V
+      #define DEF_VAR_T(T, X, V) T X = V
+      #define DEF_VAR_REV(V, X) DEF_VAR(X, V)
+      #define CPY(X) X
+      #define DEF_VAR_TYPE(X, Y) X Y
+      #define SOME_NAME variable
+      #define SOME_NAME_SET variable2 = 123
+      #define INC_VAR(X) X += 2
+      void $Function[[foo]]() {
+        DEF_VAR($Variable[[X]],  123);
+        DEF_VAR_REV(908, $Variable[[XY]]);
+        int CPY( $Variable[[XX]] );
+        DEF_VAR_TYPE($Class[[A]], $Variable[[AA]]);
+        double SOME_NAME;
+        int SOME_NAME_SET;
+        $Variable[[variable]] = 20.1;
+        MACRO_CONCAT(var, 2, float);
+        DEF_VAR_T($Class[[A]], CPY(CPY($Variable[[Nested]])),
+              CPY($Class[[A]]()));
+        INC_VAR($Variable[[variable]]);
+      }
+      void SOME_NAME();
+      DEF_VAR($Variable[[XYZ]], 567);
+      DEF_VAR_REV(756, $Variable[[AB]]);
+
+      #define CALL_FN(F) F();
+      #define DEF_FN(F) void F ()
+      DEF_FN($Function[[g]]) {
+        CALL_FN($Function[[foo]]);
+      }
     )cpp"};
   for (const auto &TestCase : TestCases) {
     checkHighlightings(TestCase);
Index: clang-tools-extra/clangd/SemanticHighlighting.cpp
===================================================================
--- clang-tools-extra/clangd/SemanticHighlighting.cpp
+++ clang-tools-extra/clangd/SemanticHighlighting.cpp
@@ -160,9 +160,15 @@
   }
 
   void addToken(SourceLocation Loc, HighlightingKind Kind) {
-    if (Loc.isMacroID())
-      // FIXME: skip tokens inside macros for now.
-      return;
+    if(Loc.isMacroID()) {
+      // If the location is not an argument it might be from a macro of the form
+      // "#define VAR var". In that case this would highlight "var" in the macro
+      // definition and if VAR is used for functions and variables there would
+      // be conflicts and duplicates. So skip those for now.
+      if (!SM.isMacroArgExpansion(Loc))
+        return;
+      Loc = SM.getSpellingLoc(Loc);
+    }
 
     auto R = getTokenRange(SM, Ctx.getLangOpts(), Loc);
     if (!R) {


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