[clang] [AST] Dump argument types for TypeTraitExpr. (PR #89370)

[Haojian Wu via cfe-commits]

https://github.com/hokein created https://github.com/llvm/llvm-project/pull/89370

The argument types are not modeled as children of TypeTraitExpr, therefore they are not dumped with the default implementation.

Dumping them is really useful for ad-hoc debugging, context #89358 

>From e8a9fcfa4210b6bf5ca342df5a055012b0fe8e88 Mon Sep 17 00:00:00 2001
From: Haojian Wu <hokein.wu at gmail.com>
Date: Thu, 18 Apr 2024 15:42:56 +0200
Subject: [PATCH] [AST] Dump argument types for TypeTraitExpr.

The argument types are not modeled as children of TypeTraitExpr,
therefore they are not dumped with the default implementation.

Dumping them is really useful for ad-hoc debugging.
---
 clang/include/clang/AST/ASTNodeTraverser.h    |  6 +++
 ...dump-template-json-win32-mangler-crash.cpp | 40 ++++++++++++++++++-
 clang/test/AST/ast-dump-traits.cpp            |  9 +++++
 3 files changed, 53 insertions(+), 2 deletions(-)

diff --git a/clang/include/clang/AST/ASTNodeTraverser.h b/clang/include/clang/AST/ASTNodeTraverser.h
index f5c47d8a7c2113..216dc9eef08b62 100644
--- a/clang/include/clang/AST/ASTNodeTraverser.h
+++ b/clang/include/clang/AST/ASTNodeTraverser.h
@@ -851,6 +851,12 @@ class ASTNodeTraverser
       Visit(R);
   }
 
+  void VisitTypeTraitExpr(const TypeTraitExpr *E) {
+    // Argument types are not children of the TypeTraitExpr.
+    for (auto *A : E->getArgs())
+      Visit(A->getType());
+  }
+
   void VisitLambdaExpr(const LambdaExpr *Node) {
     if (Traversal == TK_IgnoreUnlessSpelledInSource) {
       for (unsigned I = 0, N = Node->capture_size(); I != N; ++I) {
diff --git a/clang/test/AST/ast-dump-template-json-win32-mangler-crash.cpp b/clang/test/AST/ast-dump-template-json-win32-mangler-crash.cpp
index 8c03b58abb0edb..cf740516db6f4b 100644
--- a/clang/test/AST/ast-dump-template-json-win32-mangler-crash.cpp
+++ b/clang/test/AST/ast-dump-template-json-win32-mangler-crash.cpp
@@ -2725,7 +2725,25 @@ int main()
 // CHECK-NEXT:        "type": {
 // CHECK-NEXT:         "qualType": "bool"
 // CHECK-NEXT:        },
-// CHECK-NEXT:        "valueCategory": "prvalue"
+// CHECK-NEXT:        "valueCategory": "prvalue",
+// CHECK-NEXT:        "inner": [
+// CHECK-NEXT:         {
+// CHECK-NEXT:          "id": "0x{{.*}}",
+// CHECK-NEXT:          "kind": "TemplateTypeParmType",
+// CHECK-NEXT:          "type": {
+// CHECK-NEXT:           "qualType": "_Ty"
+// CHECK-NEXT:          },
+// CHECK-NEXT:          "isDependent": true,
+// CHECK-NEXT:          "isInstantiationDependent": true,
+// CHECK-NEXT:          "depth": 0,
+// CHECK-NEXT:          "index": 0,
+// CHECK-NEXT:          "decl": {
+// CHECK-NEXT:           "id": "0x{{.*}}",
+// CHECK-NEXT:           "kind": "TemplateTypeParmDecl",
+// CHECK-NEXT:           "name": "_Ty"
+// CHECK-NEXT:          }
+// CHECK-NEXT:         }
+// CHECK-NEXT:        ]
 // CHECK-NEXT:       }
 // CHECK-NEXT:      ]
 // CHECK-NEXT:     }
@@ -3003,7 +3021,25 @@ int main()
 // CHECK-NEXT:        "type": {
 // CHECK-NEXT:         "qualType": "bool"
 // CHECK-NEXT:        },
-// CHECK-NEXT:        "valueCategory": "prvalue"
+// CHECK-NEXT:        "valueCategory": "prvalue",
+// CHECK-NEXT:        "inner": [
+// CHECK-NEXT:         {
+// CHECK-NEXT:          "id": "0x{{.*}}",
+// CHECK-NEXT:          "kind": "TemplateTypeParmType",
+// CHECK-NEXT:          "type": {
+// CHECK-NEXT:           "qualType": "_Ty"
+// CHECK-NEXT:          },
+// CHECK-NEXT:          "isDependent": true,
+// CHECK-NEXT:          "isInstantiationDependent": true,
+// CHECK-NEXT:          "depth": 0,
+// CHECK-NEXT:          "index": 0,
+// CHECK-NEXT:          "decl": {
+// CHECK-NEXT:           "id": "0x{{.*}}",
+// CHECK-NEXT:           "kind": "TemplateTypeParmDecl",
+// CHECK-NEXT:           "name": "_Ty"
+// CHECK-NEXT:          }
+// CHECK-NEXT:         }
+// CHECK-NEXT:        ]
 // CHECK-NEXT:       }
 // CHECK-NEXT:      ]
 // CHECK-NEXT:     }
diff --git a/clang/test/AST/ast-dump-traits.cpp b/clang/test/AST/ast-dump-traits.cpp
index 99ad50f528eb79..3085e5883fd2e2 100644
--- a/clang/test/AST/ast-dump-traits.cpp
+++ b/clang/test/AST/ast-dump-traits.cpp
@@ -40,10 +40,19 @@ void test_unary_expr_or_type_trait() {
 // CHECK-NEXT: |   | `-EnumDecl {{.*}} <col:3, col:11> col:8{{( imported)?}} referenced E
 // CHECK-NEXT: |   |-CStyleCastExpr {{.*}} <line:13:3, col:21> 'void' <ToVoid>
 // CHECK-NEXT: |   | `-TypeTraitExpr {{.*}} <col:10, col:21> 'bool' __is_enum
+// CHECK-NEXT: |   |   `-ElaboratedType {{.*}} 'E' sugar
+// CHECK-NEXT: |   |     `-EnumType {{.*}} 'E'
+// CHECK-NEXT: |   |       `-Enum {{.*}} 'E'
 // CHECK-NEXT: |   |-CStyleCastExpr {{.*}} <line:15:3, col:30> 'void' <ToVoid>
 // CHECK-NEXT: |   | `-TypeTraitExpr {{.*}} <col:10, col:30> 'bool' __is_same
+// CHECK-NEXT: |   |   |-BuiltinType {{.*}} 'int'
+// CHECK-NEXT: |   |   `-BuiltinType {{.*}} 'float'
 // CHECK-NEXT: |   `-CStyleCastExpr {{.*}} <line:17:3, col:47> 'void' <ToVoid>
 // CHECK-NEXT: |     `-TypeTraitExpr {{.*}} <col:10, col:47> 'bool' __is_constructible
+// CHECK-NEXT:         |-BuiltinType {{.*}} 'int'
+// CHECK-NEXT:         |-BuiltinType {{.*}} 'int'
+// CHECK-NEXT:         |-BuiltinType {{.*}} 'int'
+// CHECK-NEXT:         `-BuiltinType {{.*}} 'int'
 // CHECK-NEXT: |-FunctionDecl {{.*}} <line:20:1, line:23:1> line:20:6{{( imported)?}} test_array_type_trait 'void ()'
 // CHECK-NEXT: | `-CompoundStmt {{.*}} <col:30, line:23:1>
 // CHECK-NEXT: |   `-CStyleCastExpr {{.*}} <line:22:3, col:34> 'void' <ToVoid>