[clang] [clang][ast]: Add DynamicAllocLValue and TypeInfoLValue support to APValue::dump(). (PR #135178)

[via cfe-commits]

https://github.com/YLChenZ created https://github.com/llvm/llvm-project/pull/135178

Closes #134996.

The crash about `TypeInfoLValue` is https://godbolt.org/z/73WY31s55. The crash about `DynamicAllocLValue` I don't know how to reproduce it yet.

Before the patch:
```
......
`-VarDecl 0x118857f0 <<source>:3:1, col:50> col:33 val 'const std::type_info *const' constexpr cinit
  |-value: LValue Base=
clang++: /root/llvm-project/llvm/include/llvm/Support/Casting.h:566: decltype(auto) llvm::cast(const From&) [with To = const clang::ValueDecl*; From = llvm::PointerUnion<const clang::ValueDecl*, const clang::Expr*, clang::TypeInfoLValue, clang::DynamicAllocLValue>]: Assertion `isa<To>(Val) && "cast<Ty>() argument of incompatible type!"' failed.
``` 

After the patch:
```
......
`-VarDecl 0x55b81259b750 <test.cpp:3:1, col:50> col:33 val 'const std::type_info *const' constexpr cinit
  |-value: LValue Base=TypeInfoLValue, Null=0, Offset=0, HasPath=1, PathLength=0, Path=()
  `-UnaryOperator 0x55b81259b7f0 <col:39, col:50> 'const std::type_info *' prefix '&' cannot overflow
    `-CXXTypeidExpr 0x55b81259b7d0 <col:40, col:50> 'const std::type_info' lvalue
```



>From 6368e470bbefc66369128c13b41c33e75c8b31a1 Mon Sep 17 00:00:00 2001
From: YLChenZ <chentongyongcz at gmail.com>
Date: Thu, 10 Apr 2025 21:20:58 +0800
Subject: [PATCH] [clang][ast]: Add DynamicAllocLValue and TypeInfoLValue
 support to APValue::dump()

---
 clang/lib/AST/TextNodeDumper.cpp           |  4 ++++
 clang/test/AST/ast-dump-APValue-lvalue.cpp | 12 ++++++++++--
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/clang/lib/AST/TextNodeDumper.cpp b/clang/lib/AST/TextNodeDumper.cpp
index be8d609974d81..0849e5642f006 100644
--- a/clang/lib/AST/TextNodeDumper.cpp
+++ b/clang/lib/AST/TextNodeDumper.cpp
@@ -738,6 +738,10 @@ void TextNodeDumper::Visit(const APValue &Value, QualType Ty) {
     else if (const auto *BE = B.dyn_cast<const Expr *>()) {
       OS << BE->getStmtClassName() << ' ';
       dumpPointer(BE);
+    } else if (B.is<TypeInfoLValue>()) {
+      OS << "TypeInfoLValue";
+    } else if (B.is<DynamicAllocLValue>()) {
+      OS << "DynamicAllocLValue";
     } else {
       const auto *VDB = B.get<const ValueDecl *>();
       OS << VDB->getDeclKindName() << "Decl";
diff --git a/clang/test/AST/ast-dump-APValue-lvalue.cpp b/clang/test/AST/ast-dump-APValue-lvalue.cpp
index 224caddb3eabe..7e520254da41a 100644
--- a/clang/test/AST/ast-dump-APValue-lvalue.cpp
+++ b/clang/test/AST/ast-dump-APValue-lvalue.cpp
@@ -23,6 +23,10 @@ struct F {
 };
 F f;
 
+namespace std {
+  class type_info;
+}
+
 void Test(int (&arr)[10]) {
   constexpr int *pi = &i;
   // CHECK:  | `-VarDecl {{.*}} <col:{{.*}}, col:{{.*}}> col:{{.*}} pi 'int *const' constexpr cinit
@@ -45,6 +49,10 @@ void Test(int (&arr)[10]) {
   // CHECK-NEXT:  |   |-value: LValue Base=VarDecl {{.*}}, Null=0, Offset=2, HasPath=1, PathLength=2, Path=({{.*}}, 2)
 
   constexpr const int *n = nullptr;
-  // CHECK:    `-VarDecl {{.*}} <col:{{.*}}, col:{{.*}}> col:{{.*}} n 'const int *const' constexpr cinit
-  // CHECK-NEXT:      |-value: LValue Base=null, Null=1, Offset=0, HasPath=1, PathLength=0, Path=()
+  // CHECK:  | `-VarDecl {{.*}} <col:{{.*}}, col:{{.*}}> col:{{.*}} n 'const int *const' constexpr cinit
+  // CHECK-NEXT:  |   |-value: LValue Base=null, Null=1, Offset=0, HasPath=1, PathLength=0, Path=()
+
+  constexpr const std::type_info* pti = &typeid(int);
+  // CHECK:    `-VarDecl {{.*}} <col:{{.*}}, col:{{.*}}> col:{{.*}} pti 'const std::type_info *const' constexpr cinit
+  // CHECK-NEXT:      |-value: LValue Base=TypeInfoLValue, Null=0, Offset=0, HasPath=1, PathLength=0, Path=()
 }