[clang] [clang-format] Fix a bug in annotating `*` in `#define`s (PR #99433)

[Owen Pan via cfe-commits]

https://github.com/owenca updated https://github.com/llvm/llvm-project/pull/99433

>From ebf25d890ff47be48bd153942d943906943a247b Mon Sep 17 00:00:00 2001
From: Owen Pan <owenpiano at gmail.com>
Date: Wed, 17 Jul 2024 22:30:21 -0700
Subject: [PATCH 1/2] [clang-format] Fix a bug in annotating `*` in `#define`s

Fixes #99271.
---
 clang/lib/Format/TokenAnnotator.cpp           | 3 ++-
 clang/unittests/Format/TokenAnnotatorTest.cpp | 4 ++++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/clang/lib/Format/TokenAnnotator.cpp b/clang/lib/Format/TokenAnnotator.cpp
index b6d6e52ccb8f8..f1125fd35b427 100644
--- a/clang/lib/Format/TokenAnnotator.cpp
+++ b/clang/lib/Format/TokenAnnotator.cpp
@@ -374,7 +374,8 @@ class AnnotatingParser {
       Contexts.back().IsExpression = true;
     } else if (Line.InPPDirective &&
                (!OpeningParen.Previous ||
-                OpeningParen.Previous->isNot(tok::identifier))) {
+                OpeningParen.Previous->isNot(tok::identifier) ||
+                !OpeningParen.Previous->Previous)) {
       Contexts.back().IsExpression = true;
     } else if (Contexts[Contexts.size() - 2].CaretFound) {
       // This is the parameter list of an ObjC block.
diff --git a/clang/unittests/Format/TokenAnnotatorTest.cpp b/clang/unittests/Format/TokenAnnotatorTest.cpp
index c5e8aa72cd2cb..82c9be0f4df71 100644
--- a/clang/unittests/Format/TokenAnnotatorTest.cpp
+++ b/clang/unittests/Format/TokenAnnotatorTest.cpp
@@ -75,6 +75,10 @@ TEST_F(TokenAnnotatorTest, UnderstandsUsesOfStarAndAmp) {
   EXPECT_TOKEN(Tokens[10], tok::r_paren, TT_TypeDeclarationParen);
   EXPECT_TOKEN(Tokens[11], tok::star, TT_PointerOrReference);
 
+  Tokens = annotate("#define FOO bar(a * b)");
+  ASSERT_EQ(Tokens.size(), 10u) << Tokens;
+  EXPECT_TOKEN(Tokens[6], tok::star, TT_BinaryOperator);
+
   Tokens = annotate("void f() {\n"
                     "  while (p < a && *p == 'a')\n"
                     "    p++;\n"

>From 70af6643045a6ded03fe1b3bbb21c55a2c5971b1 Mon Sep 17 00:00:00 2001
From: Owen Pan <owenpiano at gmail.com>
Date: Fri, 19 Jul 2024 08:59:14 -0700
Subject: [PATCH 2/2] Handles tokens before the function name.

---
 clang/lib/Format/TokenAnnotator.cpp           | 20 +++++++++++++------
 clang/unittests/Format/TokenAnnotatorTest.cpp | 16 +++++++++++++++
 2 files changed, 30 insertions(+), 6 deletions(-)

diff --git a/clang/lib/Format/TokenAnnotator.cpp b/clang/lib/Format/TokenAnnotator.cpp
index f1125fd35b427..50201c970ab60 100644
--- a/clang/lib/Format/TokenAnnotator.cpp
+++ b/clang/lib/Format/TokenAnnotator.cpp
@@ -372,11 +372,6 @@ class AnnotatingParser {
                OpeningParen.Previous->is(tok::kw__Generic)) {
       Contexts.back().ContextType = Context::C11GenericSelection;
       Contexts.back().IsExpression = true;
-    } else if (Line.InPPDirective &&
-               (!OpeningParen.Previous ||
-                OpeningParen.Previous->isNot(tok::identifier) ||
-                !OpeningParen.Previous->Previous)) {
-      Contexts.back().IsExpression = true;
     } else if (Contexts[Contexts.size() - 2].CaretFound) {
       // This is the parameter list of an ObjC block.
       Contexts.back().IsExpression = false;
@@ -389,7 +384,20 @@ class AnnotatingParser {
                OpeningParen.Previous->MatchingParen->isOneOf(
                    TT_ObjCBlockLParen, TT_FunctionTypeLParen)) {
       Contexts.back().IsExpression = false;
-    } else if (!Line.MustBeDeclaration && !Line.InPPDirective) {
+    } else if (Line.InPPDirective) {
+      auto IsExpr = [](const FormatToken &LParen) {
+        const auto *Tok = LParen.Previous;
+        if (!Tok || Tok->isNot(tok::identifier))
+          return true;
+        Tok = Tok->Previous;
+        while (Tok && Tok->endsSequence(tok::coloncolon, tok::identifier)) {
+          assert(Tok->Previous);
+          Tok = Tok->Previous->Previous;
+        }
+        return !Tok || !Tok->Tok.getIdentifierInfo();
+      };
+      Contexts.back().IsExpression = IsExpr(OpeningParen);
+    } else if (!Line.MustBeDeclaration) {
       bool IsForOrCatch =
           OpeningParen.Previous &&
           OpeningParen.Previous->isOneOf(tok::kw_for, tok::kw_catch);
diff --git a/clang/unittests/Format/TokenAnnotatorTest.cpp b/clang/unittests/Format/TokenAnnotatorTest.cpp
index 82c9be0f4df71..f70424c3ee060 100644
--- a/clang/unittests/Format/TokenAnnotatorTest.cpp
+++ b/clang/unittests/Format/TokenAnnotatorTest.cpp
@@ -79,6 +79,22 @@ TEST_F(TokenAnnotatorTest, UnderstandsUsesOfStarAndAmp) {
   ASSERT_EQ(Tokens.size(), 10u) << Tokens;
   EXPECT_TOKEN(Tokens[6], tok::star, TT_BinaryOperator);
 
+  Tokens = annotate("#define FOO foo.bar(a & b)");
+  ASSERT_EQ(Tokens.size(), 12u) << Tokens;
+  EXPECT_TOKEN(Tokens[8], tok::amp, TT_BinaryOperator);
+
+  Tokens = annotate("#define FOO foo::bar(a && b)");
+  ASSERT_EQ(Tokens.size(), 12u) << Tokens;
+  EXPECT_TOKEN(Tokens[8], tok::ampamp, TT_BinaryOperator);
+
+  Tokens = annotate("#define FOO foo bar(a *b)");
+  ASSERT_EQ(Tokens.size(), 11u) << Tokens;
+  EXPECT_TOKEN(Tokens[7], tok::star, TT_PointerOrReference);
+
+  Tokens = annotate("#define FOO void foo::bar(a &b)");
+  ASSERT_EQ(Tokens.size(), 13u) << Tokens;
+  EXPECT_TOKEN(Tokens[9], tok::amp, TT_PointerOrReference);
+
   Tokens = annotate("void f() {\n"
                     "  while (p < a && *p == 'a')\n"
                     "    p++;\n"