[Lldb-commits] [PATCH] D130213: [LLDB][ClangExpression] Fix evaluation of types with constant initialized enum typedefs

[Michael Buch via Phabricator via lldb-commits]

Michael137 created this revision.
Michael137 added reviewers: aprantl, jingham, werat, labath.
Herald added a project: All.
Michael137 requested review of this revision.
Herald added a project: LLDB.
Herald added a subscriber: lldb-commits.

`IntegerLiteral::Create` expects integer types. For that reason
when we parse DWARF into an AST, when we encounter a constant
initialized enum member variable, we try to determine the underlying
integer type before creating the `IntegerLiteral`. However, we
currently don't desugar the type and the `dyn_cast<EnumType>`
fails. In debug builds this triggers following assert:

  Assertion failed: (type->isIntegerType() && "Illegal type in
  IntegerLiteral"), function IntegerLiteral, file Expr.cpp, line 892

This patch turns the `dyn_cast<EnumType>` into a `getAs<EnumType>`
which desguars the enum if necessary, allowing us to get to the
underlying integer type.

**Testing**

- API test
- Manual repro is fixed


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D130213

Files:
  lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp
  lldb/test/API/lang/cpp/const_static_integral_member/TestConstStaticIntegralMember.py
  lldb/test/API/lang/cpp/const_static_integral_member/main.cpp


Index: lldb/test/API/lang/cpp/const_static_integral_member/main.cpp
===================================================================
--- lldb/test/API/lang/cpp/const_static_integral_member/main.cpp
+++ lldb/test/API/lang/cpp/const_static_integral_member/main.cpp
@@ -1,3 +1,4 @@
+#include <cstdint>
 #include <limits>
 
 enum Enum {
@@ -69,6 +70,11 @@
   constexpr static ScopedEnum scoped_enum_val = ScopedEnum::scoped_enum_case2;
 } cwc;
 
+struct ClassWithEnumAlias {
+  using EnumAlias = ScopedEnum;
+  static constexpr EnumAlias enum_alias = ScopedEnum::scoped_enum_case2;
+};
+
 int main() {
   A a;
 
@@ -98,5 +104,8 @@
   se = A::invalid_scoped_enum_val;
   ScopedCharEnum sce = A::scoped_char_enum_val;
   ScopedLongLongEnum sle = A::scoped_ll_enum_val;
+
+  auto enum_alias_val = ClassWithEnumAlias::enum_alias;
+
   return 0; // break here
 }
Index: lldb/test/API/lang/cpp/const_static_integral_member/TestConstStaticIntegralMember.py
===================================================================
--- lldb/test/API/lang/cpp/const_static_integral_member/TestConstStaticIntegralMember.py
+++ lldb/test/API/lang/cpp/const_static_integral_member/TestConstStaticIntegralMember.py
@@ -66,6 +66,9 @@
         self.expect_expr("A::scoped_ll_enum_val_neg", result_value="case0")
         self.expect_expr("A::scoped_ll_enum_val", result_value="case2")
 
+        # Test an aliased enum with fixed underlying type.
+        self.expect_expr("ClassWithEnumAlias::enum_alias", result_value="scoped_enum_case2")
+
         # Test taking address.
         if lldbplatformutil.getPlatform() == "windows":
             # On Windows data members without the out-of-class definitions still have
Index: lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp
===================================================================
--- lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp
+++ lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp
@@ -7538,10 +7538,11 @@
          "only integer or enum types supported");
   // If the variable is an enum type, take the underlying integer type as
   // the type of the integer literal.
-  if (const EnumType *enum_type = llvm::dyn_cast<EnumType>(qt.getTypePtr())) {
+  if (const EnumType *enum_type = qt->getAs<EnumType>()) {
     const EnumDecl *enum_decl = enum_type->getDecl();
     qt = enum_decl->getIntegerType();
   }
+
   var->setInit(IntegerLiteral::Create(ast, init_value, qt.getUnqualifiedType(),
                                       SourceLocation()));
 }


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D130213.446304.patch
Type: text/x-patch
Size: 2524 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/lldb-commits/attachments/20220721/9e0317f8/attachment.bin>