[clang] [clang-tools-extra] [clang-query] Allow for trailing comma in matchers (PR #148018)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: Remy Farley (one-d-wide)

<details>
<summary>Changes</summary>

Allow AST matches in clang-query to have a trailing comma at the end of matcher arguments. Makes it nicer to work with queries that span multiple lines.

So, for example, the following is possible:

```clang-query
match namedDecl(
  isExpansionInMainFile(),
  anyOf(
    varDecl().bind("var"),
    functionDecl().bind("func"),
    # enumDecl().bind("enum"),
  ),
)
```

CC: @<!-- -->AaronBallman

---
Full diff: https://github.com/llvm/llvm-project/pull/148018.diff


2 Files Affected:

- (added) clang-tools-extra/test/clang-query/trailing-comma.c (+10) 
- (modified) clang/lib/ASTMatchers/Dynamic/Parser.cpp (+10) 


``````````diff
diff --git a/clang-tools-extra/test/clang-query/trailing-comma.c b/clang-tools-extra/test/clang-query/trailing-comma.c
new file mode 100644
index 0000000000000..ecdfd3b8ab6fd
--- /dev/null
+++ b/clang-tools-extra/test/clang-query/trailing-comma.c
@@ -0,0 +1,10 @@
+// RUN: clang-query -c "match \
+// RUN:   functionDecl( \
+// RUN:       hasName( \
+// RUN:           \"foo\", \
+// RUN:       ), \
+// RUN:   ) \
+// RUN: " %s -- | FileCheck %s
+
+// CHECK: trailing-comma.c:10:1: note: "root" binds here
+void foo(void) {}
diff --git a/clang/lib/ASTMatchers/Dynamic/Parser.cpp b/clang/lib/ASTMatchers/Dynamic/Parser.cpp
index 8a5ac4d0f9d0c..baac797f09ec3 100644
--- a/clang/lib/ASTMatchers/Dynamic/Parser.cpp
+++ b/clang/lib/ASTMatchers/Dynamic/Parser.cpp
@@ -490,6 +490,11 @@ bool Parser::parseMatcherBuilder(MatcherCtor Ctor, const TokenInfo &NameToken,
               << CommaToken.Text;
           return false;
         }
+        // Allow for a trailing , token and possibly a new line.
+        Tokenizer->SkipNewlines();
+        if (Tokenizer->nextTokenKind() == TokenInfo::TK_CloseParen) {
+          continue;
+        }
       }
 
       Diagnostics::Context Ctx(Diagnostics::Context::MatcherArg, Error,
@@ -658,6 +663,11 @@ bool Parser::parseMatcherExpressionImpl(const TokenInfo &NameToken,
               << CommaToken.Text;
           return false;
         }
+        // Allow for a trailing , token and possibly a new line.
+        Tokenizer->SkipNewlines();
+        if (Tokenizer->nextTokenKind() == TokenInfo::TK_CloseParen) {
+          continue;
+        }
       }
 
       Diagnostics::Context Ctx(Diagnostics::Context::MatcherArg, Error,

``````````

</details>


https://github.com/llvm/llvm-project/pull/148018