[llvm] [Demangle] demangle builtin type transformations (PR #65902)

[Congcong Cai via llvm-commits]

https://github.com/HerrCai0907 created https://github.com/llvm/llvm-project/pull/65902:

Fixed: https://github.com/llvm/llvm-project/issues/62127 https://reviews.llvm.org/D116203 introduced several compiler builtin equivalents of the unary type traits. In some cases (e.g. template) those builtin will be dependent and need to be mangle.
This patch add the check for `u{builtin}I{type}E` to demangle it.

Reviewed By: rjmccall

Differential Revision: https://reviews.llvm.org/D148465

>From 8efd20185735a2009e7d6698007af3a3cf3a8c54 Mon Sep 17 00:00:00 2001
From: Congcong Cai <congcongcai0907 at 163.com>
Date: Sun, 10 Sep 2023 23:55:42 +0800
Subject: [PATCH] [Demangle] demangle builtin type transformations

Fixed: https://github.com/llvm/llvm-project/issues/62127
https://reviews.llvm.org/D116203 introduced several compiler builtin
equivalents of the unary type traits. In some cases (e.g. template) those
builtin will be dependent and need to be mangle.
This patch add the check for `u{builtin}I{type}E` to demangle it.

Reviewed By: rjmccall

Differential Revision: https://reviews.llvm.org/D148465
---
 libcxxabi/src/demangle/ItaniumDemangle.h     | 27 +++++++++++++++++++-
 libcxxabi/src/demangle/ItaniumNodes.def      |  1 +
 libcxxabi/test/test_demangle.pass.cpp        |  3 +++
 llvm/include/llvm/Demangle/ItaniumDemangle.h | 27 +++++++++++++++++++-
 llvm/include/llvm/Demangle/ItaniumNodes.def  |  1 +
 5 files changed, 57 insertions(+), 2 deletions(-)

diff --git a/libcxxabi/src/demangle/ItaniumDemangle.h b/libcxxabi/src/demangle/ItaniumDemangle.h
index c80f343cc876e99..92573a26e3f1d30 100644
--- a/libcxxabi/src/demangle/ItaniumDemangle.h
+++ b/libcxxabi/src/demangle/ItaniumDemangle.h
@@ -534,6 +534,23 @@ class ElaboratedTypeSpefType : public Node {
   }
 };
 
+class TransformedType : public Node {
+  std::string_view Transform;
+  Node *BaseType;
+public:
+  TransformedType(std::string_view Transform_, Node *BaseType_)
+      : Node(KTransformedType), Transform(Transform_), BaseType(BaseType_) {}
+
+  template<typename Fn> void match(Fn F) const { F(Transform, BaseType); }
+
+  void printLeft(OutputBuffer &OB) const override {
+    OB += Transform;
+    OB += '(';
+    BaseType->print(OB);
+    OB += ')';
+  }
+};
+
 struct AbiTagAttr : Node {
   Node *Base;
   std::string_view Tag;
@@ -3894,7 +3911,15 @@ Node *AbstractManglingParser<Derived, Alloc>::parseType() {
     // Typically, <builtin-type>s are not considered substitution candidates,
     // but the exception to that exception is vendor extended types (Itanium C++
     // ABI 5.9.1).
-    Result = make<NameType>(Res);
+    if (consumeIf('I')) {
+      Node *BaseType = parseType();
+      if (BaseType == nullptr)
+        return nullptr;
+      if (!consumeIf('E'))
+        return nullptr;
+      Result = make<TransformedType>(Res, BaseType);
+    } else
+      Result = make<NameType>(Res);
     break;
   }
   case 'D':
diff --git a/libcxxabi/src/demangle/ItaniumNodes.def b/libcxxabi/src/demangle/ItaniumNodes.def
index f615cb9fadb05e8..a54ee370a935b7a 100644
--- a/libcxxabi/src/demangle/ItaniumNodes.def
+++ b/libcxxabi/src/demangle/ItaniumNodes.def
@@ -19,6 +19,7 @@ NODE(QualType)
 NODE(ConversionOperatorType)
 NODE(PostfixQualifiedType)
 NODE(ElaboratedTypeSpefType)
+NODE(TransformedType)
 NODE(NameType)
 NODE(AbiTagAttr)
 NODE(EnableIfAttr)
diff --git a/libcxxabi/test/test_demangle.pass.cpp b/libcxxabi/test/test_demangle.pass.cpp
index 471808db5d5b8fc..891bc8b43d1bd47 100644
--- a/libcxxabi/test/test_demangle.pass.cpp
+++ b/libcxxabi/test/test_demangle.pass.cpp
@@ -30114,6 +30114,9 @@ const char* cases[][2] =
      " std::allocator<char>>::basic_string()"},
     {"_ZN1SB8ctor_tagC2Ev", "S[abi:ctor_tag]::S()"},
     {"_ZN1SB8ctor_tagD2Ev", "S[abi:ctor_tag]::~S()"},
+
+    // clang builtin type transform
+    {"_Z2f5IiEvu7__decayIT_E", "void f5<int>(__decay(int))"},
 };
 
 const unsigned N = sizeof(cases) / sizeof(cases[0]);
diff --git a/llvm/include/llvm/Demangle/ItaniumDemangle.h b/llvm/include/llvm/Demangle/ItaniumDemangle.h
index 26acd38f8ae8476..4fe203d0adab52c 100644
--- a/llvm/include/llvm/Demangle/ItaniumDemangle.h
+++ b/llvm/include/llvm/Demangle/ItaniumDemangle.h
@@ -528,6 +528,23 @@ class ElaboratedTypeSpefType : public Node {
   }
 };
 
+class TransformedType : public Node {
+  std::string_view Transform;
+  Node *BaseType;
+public:
+  TransformedType(std::string_view Transform_, Node *BaseType_)
+      : Node(KTransformedType), Transform(Transform_), BaseType(BaseType_) {}
+
+  template<typename Fn> void match(Fn F) const { F(Transform, BaseType); }
+
+  void printLeft(OutputBuffer &OB) const override {
+    OB += Transform;
+    OB += '(';
+    BaseType->print(OB);
+    OB += ')';
+  }
+};
+
 struct AbiTagAttr : Node {
   Node *Base;
   std::string_view Tag;
@@ -3889,7 +3906,15 @@ Node *AbstractManglingParser<Derived, Alloc>::parseType() {
     // Typically, <builtin-type>s are not considered substitution candidates,
     // but the exception to that exception is vendor extended types (Itanium C++
     // ABI 5.9.1).
-    Result = make<NameType>(Res);
+    if (consumeIf('I')) {
+      Node *BaseType = parseType();
+      if (BaseType == nullptr)
+        return nullptr;
+      if (!consumeIf('E'))
+        return nullptr;
+      Result = make<TransformedType>(Res, BaseType);
+    } else
+      Result = make<NameType>(Res);
     break;
   }
   case 'D':
diff --git a/llvm/include/llvm/Demangle/ItaniumNodes.def b/llvm/include/llvm/Demangle/ItaniumNodes.def
index c0e277d554ccfad..dafce502ce9e900 100644
--- a/llvm/include/llvm/Demangle/ItaniumNodes.def
+++ b/llvm/include/llvm/Demangle/ItaniumNodes.def
@@ -19,6 +19,7 @@ NODE(QualType)
 NODE(ConversionOperatorType)
 NODE(PostfixQualifiedType)
 NODE(ElaboratedTypeSpefType)
+NODE(TransformedType)
 NODE(NameType)
 NODE(AbiTagAttr)
 NODE(EnableIfAttr)