[Lldb-commits] [clang] [lldb] [clang][DebugInfo][gmodules] Set runtimeLang on ObjC forward declarations (PR #120154)
Michael Buch via lldb-commits
lldb-commits at lists.llvm.org
Tue Dec 17 05:55:32 PST 2024
https://github.com/Michael137 updated https://github.com/llvm/llvm-project/pull/120154
>From b4c56cb11feb10a153edfd1aff8d53e43f7bb7db Mon Sep 17 00:00:00 2001
From: Michael Buch <michaelbuch12 at gmail.com>
Date: Mon, 16 Dec 2024 22:27:08 +0000
Subject: [PATCH 1/2] [clang][DebugInfo][gmodules] Set runtimeLang on ObjC
forward declarations
In Objective-C, forward declarations are currently represented as:
```
DW_TAG_structure_type
DW_AT_name ("Foo")
DW_AT_declaration (true)
DW_AT_APPLE_runtime_class (DW_LANG_ObjC)
```
However, when compiling with `-gmodules`, when a class definition
is turned into a forward declaration within a `DW_TAG_module`, the
DIE for the forward declaration looks as follows:
```
DW_TAG_structure_type
DW_AT_name ("Foo")
DW_AT_declaration (true)
```
Note the absence of `DW_AT_APPLE_runtime_class`. With recent changes in
LLDB, not being able to differentiate between C++ and Objective-C
forward declarations has become problematic (see attached test-case
and explanation in https://github.com/llvm/llvm-project/pull/119860).
---
clang/lib/CodeGen/CGDebugInfo.cpp | 11 +++---
clang/test/Modules/ExtDebugInfo.m | 3 +-
clang/test/Modules/ModuleDebugInfo.m | 1 +
.../DWARF/objc-gmodules-class-extension.test | 34 +++++++++++++++++++
4 files changed, 43 insertions(+), 6 deletions(-)
create mode 100644 lldb/test/Shell/SymbolFile/DWARF/objc-gmodules-class-extension.test
diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp
index 60f32f76109e9a..ff27690d47b080 100644
--- a/clang/lib/CodeGen/CGDebugInfo.cpp
+++ b/clang/lib/CodeGen/CGDebugInfo.cpp
@@ -2995,20 +2995,21 @@ llvm::DIType *CGDebugInfo::CreateType(const ObjCInterfaceType *Ty,
if (!ID)
return nullptr;
+ auto RuntimeLang =
+ static_cast<llvm::dwarf::SourceLanguage>(TheCU->getSourceLanguage());
+
// Return a forward declaration if this type was imported from a clang module,
// and this is not the compile unit with the implementation of the type (which
// may contain hidden ivars).
if (DebugTypeExtRefs && ID->isFromASTFile() && ID->getDefinition() &&
!ID->getImplementation())
- return DBuilder.createForwardDecl(llvm::dwarf::DW_TAG_structure_type,
- ID->getName(),
- getDeclContextDescriptor(ID), Unit, 0);
+ return DBuilder.createForwardDecl(
+ llvm::dwarf::DW_TAG_structure_type, ID->getName(),
+ getDeclContextDescriptor(ID), Unit, 0, RuntimeLang);
// Get overall information about the record type for the debug info.
llvm::DIFile *DefUnit = getOrCreateFile(ID->getLocation());
unsigned Line = getLineNumber(ID->getLocation());
- auto RuntimeLang =
- static_cast<llvm::dwarf::SourceLanguage>(TheCU->getSourceLanguage());
// If this is just a forward declaration return a special forward-declaration
// debug type since we won't be able to lay out the entire type.
diff --git a/clang/test/Modules/ExtDebugInfo.m b/clang/test/Modules/ExtDebugInfo.m
index b6a8b2676e5ba4..e2611ae5300634 100644
--- a/clang/test/Modules/ExtDebugInfo.m
+++ b/clang/test/Modules/ExtDebugInfo.m
@@ -75,7 +75,8 @@ int foo(ObjCClass *c) {
// CHECK: !DICompositeType(tag: DW_TAG_structure_type, name: "ObjCClass",
// CHECK-SAME: scope: ![[MOD]],
-// CHECK-SAME: flags: DIFlagFwdDecl)
+// CHECK-SAME: flags: DIFlagFwdDecl,
+// CHECK-SAME: runtimeLang: DW_LANG_ObjC)
// CHECK-NOT: !DICompositeType(tag: DW_TAG_structure_type,
// CHECK: !DICompositeType(tag: DW_TAG_enumeration_type,
diff --git a/clang/test/Modules/ModuleDebugInfo.m b/clang/test/Modules/ModuleDebugInfo.m
index 62c6fd68dd8546..c527c43a0f4a2c 100644
--- a/clang/test/Modules/ModuleDebugInfo.m
+++ b/clang/test/Modules/ModuleDebugInfo.m
@@ -39,6 +39,7 @@
// CHECK: !DICompositeType(tag: DW_TAG_structure_type, name: "FwdDecl",
// CHECK-SAME: scope: ![[MODULE]],
+// CHECK-SAME: runtimeLang: DW_LANG_ObjC
// CHECK: !DICompositeType(tag: DW_TAG_structure_type, name: "ObjCClass",
// CHECK-SAME: scope: ![[MODULE]],
diff --git a/lldb/test/Shell/SymbolFile/DWARF/objc-gmodules-class-extension.test b/lldb/test/Shell/SymbolFile/DWARF/objc-gmodules-class-extension.test
new file mode 100644
index 00000000000000..330a6b338c4723
--- /dev/null
+++ b/lldb/test/Shell/SymbolFile/DWARF/objc-gmodules-class-extension.test
@@ -0,0 +1,34 @@
+# REQUIRES: system-darwin
+
+# Test that we can set a breakpoint in a method of a class extension.
+# This requires us to parse the method into an AST type, and the context
+# too (which in DWARF is just a forward declaration).
+#
+# RUN: split-file %s %t
+# RUN: %clangxx_host %t/lib.m -c -g -gmodules -fmodules -o %t/lib.o
+# RUN: %clangxx_host %t/main.m -g -gmodules -fmodules %t/lib.o -o %t/a.out -framework Foundation
+#
+# RUN: %lldb %t/a.out -o "breakpoint set -f lib.m -l 6" -o exit | FileCheck %s
+
+# CHECK: (lldb) breakpoint set -f lib.m -l 6
+# CHECK: Breakpoint 1: where = a.out`-[NSObject(Foo) func]
+
+#--- main.m
+int main() {
+ return 0;
+}
+
+#--- lib.m
+#import <Foundation/Foundation.h>
+
+ at implementation NSObject (Foo)
+- (NSError *)func {
+ NSLog(@"Hello, World!");
+ return 0;
+}
+ at end
+
+NSObject * func() {
+ return 0;
+}
+
>From f4ad4968ff0e1b779d47a76c8a8570c2bf0121cc Mon Sep 17 00:00:00 2001
From: Michael Buch <michaelbuch12 at gmail.com>
Date: Tue, 17 Dec 2024 13:54:59 +0000
Subject: [PATCH 2/2] fixup! reduce test-case further
---
.../SymbolFile/DWARF/objc-gmodules-class-extension.test | 5 -----
1 file changed, 5 deletions(-)
diff --git a/lldb/test/Shell/SymbolFile/DWARF/objc-gmodules-class-extension.test b/lldb/test/Shell/SymbolFile/DWARF/objc-gmodules-class-extension.test
index 330a6b338c4723..b8290395010720 100644
--- a/lldb/test/Shell/SymbolFile/DWARF/objc-gmodules-class-extension.test
+++ b/lldb/test/Shell/SymbolFile/DWARF/objc-gmodules-class-extension.test
@@ -27,8 +27,3 @@ int main() {
return 0;
}
@end
-
-NSObject * func() {
- return 0;
-}
-
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