[clang] ccfab8e - [ObjC][DWARF] Emit DW_AT_APPLE_objc_direct for methods marked as __attribute__((objc_direct))
Raphael Isemann via cfe-commits
cfe-commits at lists.llvm.org
Tue Dec 17 00:41:11 PST 2019
Author: Raphael Isemann
Date: 2019-12-17T09:40:36+01:00
New Revision: ccfab8e4596e59c8eea6b3610cd163c5d0312193
URL: https://github.com/llvm/llvm-project/commit/ccfab8e4596e59c8eea6b3610cd163c5d0312193
DIFF: https://github.com/llvm/llvm-project/commit/ccfab8e4596e59c8eea6b3610cd163c5d0312193.diff
LOG: [ObjC][DWARF] Emit DW_AT_APPLE_objc_direct for methods marked as __attribute__((objc_direct))
Summary:
With DWARF5 it is no longer possible to distinguish normal methods and methods with `__attribute__((objc_direct))` by just looking at the debug information
as they are both now children of the of the DW_TAG_structure_type that defines them (before only the `__attribute__((objc_direct))` methods were children).
This means that in LLDB we are no longer able to create a correct Clang AST of a module by just looking at the debug information. Instead we would
need to call the Objective-C runtime to see which of the methods have a `__attribute__((objc_direct))` and then add the attribute to our own Clang AST
depending on what the runtime returns. This would mean that we either let the module AST be dependent on the Objective-C runtime (which doesn't
seem right) or we retroactively add the missing attribute to the imported AST in our expressions.
A third option is to annotate methods with `__attribute__((objc_direct))` as `DW_AT_APPLE_objc_direct` which is what this patch implements. This way
LLDB doesn't have to call the runtime for any `__attribute__((objc_direct))` method and the AST in our module will already be correct when we create it.
Reviewers: aprantl, SouraVX
Reviewed By: aprantl
Subscribers: hiraditya, cfe-commits, llvm-commits
Tags: #clang, #llvm, #debug-info
Differential Revision: https://reviews.llvm.org/D71201
Added:
llvm/test/DebugInfo/X86/objc_direct.ll
Modified:
clang/lib/CodeGen/CGDebugInfo.cpp
clang/test/CodeGenObjC/debug-info-direct-method.m
llvm/include/llvm/BinaryFormat/Dwarf.def
llvm/include/llvm/IR/DebugInfoFlags.def
llvm/include/llvm/IR/DebugInfoMetadata.h
llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
Removed:
################################################################################
diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp
index 06204a860091..675df309e3f0 100644
--- a/clang/lib/CodeGen/CGDebugInfo.cpp
+++ b/clang/lib/CodeGen/CGDebugInfo.cpp
@@ -3495,6 +3495,9 @@ llvm::DISubprogram *CGDebugInfo::getObjCMethodDeclaration(
if (CGM.getCodeGenOpts().DwarfVersion < 5 && !OMD->isDirectMethod())
return nullptr;
+ if (OMD->isDirectMethod())
+ SPFlags |= llvm::DISubprogram::SPFlagObjCDirect;
+
// Starting with DWARF V5 method declarations are emitted as children of
// the interface type.
auto *ID = dyn_cast_or_null<ObjCInterfaceDecl>(D->getDeclContext());
diff --git a/clang/test/CodeGenObjC/debug-info-direct-method.m b/clang/test/CodeGenObjC/debug-info-direct-method.m
index f822088f946c..e5e2939a8c81 100644
--- a/clang/test/CodeGenObjC/debug-info-direct-method.m
+++ b/clang/test/CodeGenObjC/debug-info-direct-method.m
@@ -1,12 +1,17 @@
// RUN: %clang_cc1 -dwarf-version=5 -emit-llvm -debug-info-kind=limited -w -triple x86_64-apple-darwin10 %s -o - | FileCheck %s
// RUN: %clang_cc1 -dwarf-version=4 -emit-llvm -debug-info-kind=limited -w -triple x86_64-apple-darwin10 %s -o - | FileCheck %s
+// RUN: %clang_cc1 -dwarf-version=5 -emit-llvm -debug-info-kind=limited -w -triple x86_64-apple-darwin10 %s -o - -DDISABLE_DIRECT | FileCheck --check-prefix=CHECK-DISABLED %s
__attribute__((objc_root_class))
@interface Root
@end
@implementation Root
-- (int)getInt __attribute__((objc_direct)) {
+- (int)getInt
+#ifndef DISABLE_DIRECT
+ __attribute__((objc_direct))
+#endif
+{
return 42;
}
@end
@@ -19,3 +24,6 @@ - (int)getInt __attribute__((objc_direct)) {
// CHECK-SAME: runtimeLang: DW_LANG_ObjC)
// CHECK: ![[MEMBERS]] = !{![[GETTER:[0-9]+]]}
// CHECK: ![[GETTER]] = !DISubprogram(name: "-[Root getInt]",
+// CHECK-SAME: spFlags: DISPFlagObjCDirect
+
+// CHECK-DISABLED-NOT: DISPFlagObjCDirect
diff --git a/llvm/include/llvm/BinaryFormat/Dwarf.def b/llvm/include/llvm/BinaryFormat/Dwarf.def
index 34a7410f7474..8b1b14de6f09 100644
--- a/llvm/include/llvm/BinaryFormat/Dwarf.def
+++ b/llvm/include/llvm/BinaryFormat/Dwarf.def
@@ -421,6 +421,7 @@ HANDLE_DW_AT(0x3fea, APPLE_property_setter, 0, APPLE)
HANDLE_DW_AT(0x3feb, APPLE_property_attribute, 0, APPLE)
HANDLE_DW_AT(0x3fec, APPLE_objc_complete_type, 0, APPLE)
HANDLE_DW_AT(0x3fed, APPLE_property, 0, APPLE)
+HANDLE_DW_AT(0x3fee, APPLE_objc_direct, 0, APPLE)
// Attribute form encodings.
HANDLE_DW_FORM(0x01, addr, 2, DWARF)
diff --git a/llvm/include/llvm/IR/DebugInfoFlags.def b/llvm/include/llvm/IR/DebugInfoFlags.def
index 587df8bec79c..df375b6c68e8 100644
--- a/llvm/include/llvm/IR/DebugInfoFlags.def
+++ b/llvm/include/llvm/IR/DebugInfoFlags.def
@@ -90,11 +90,12 @@ HANDLE_DISP_FLAG((1u << 8), MainSubprogram)
// May also utilize this Flag in future, when adding support
// for defaulted functions
HANDLE_DISP_FLAG((1u << 9), Deleted)
+HANDLE_DISP_FLAG((1u << 11), ObjCDirect)
#ifdef DISP_FLAG_LARGEST_NEEDED
// Intended to be used with ADT/BitmaskEnum.h.
// NOTE: Always must be equal to largest flag, check this when adding new flags.
-HANDLE_DISP_FLAG((1 << 9), Largest)
+HANDLE_DISP_FLAG((1 << 11), Largest)
#undef DISP_FLAG_LARGEST_NEEDED
#endif
diff --git a/llvm/include/llvm/IR/DebugInfoMetadata.h b/llvm/include/llvm/IR/DebugInfoMetadata.h
index d690ccece5fa..214003ad9934 100644
--- a/llvm/include/llvm/IR/DebugInfoMetadata.h
+++ b/llvm/include/llvm/IR/DebugInfoMetadata.h
@@ -1758,6 +1758,7 @@ class DISubprogram : public DILocalScope {
bool isPure() const { return getSPFlags() & SPFlagPure; }
bool isElemental() const { return getSPFlags() & SPFlagElemental; }
bool isRecursive() const { return getSPFlags() & SPFlagRecursive; }
+ bool isObjCDirect() const { return getSPFlags() & SPFlagObjCDirect; }
/// Check if this is deleted member function.
///
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
index 86522a85427a..e44e432ec6a0 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
@@ -1233,6 +1233,9 @@ void DwarfUnit::applySubprogramAttributes(const DISubprogram *SP, DIE &SPDie,
Language == dwarf::DW_LANG_ObjC))
addFlag(SPDie, dwarf::DW_AT_prototyped);
+ if (SP->isObjCDirect())
+ addFlag(SPDie, dwarf::DW_AT_APPLE_objc_direct);
+
unsigned CC = 0;
DITypeRefArray Args;
if (const DISubroutineType *SPTy = SP->getType()) {
diff --git a/llvm/test/DebugInfo/X86/objc_direct.ll b/llvm/test/DebugInfo/X86/objc_direct.ll
new file mode 100644
index 000000000000..c29dec14a448
--- /dev/null
+++ b/llvm/test/DebugInfo/X86/objc_direct.ll
@@ -0,0 +1,54 @@
+; RUN: llc < %s -filetype=obj -o %t
+; RUN: llvm-dwarfdump -v %t | FileCheck %s
+
+; Source code to regenerate:
+; __attribute__((objc_root_class))
+; @interface Root
+; - (int)direct_method __attribute__((objc_direct));
+; @end
+;
+; @implementation Root
+; - (int)direct_method __attribute__((objc_direct)) {
+; return 42;
+; }
+; @end
+;
+; clang -O0 -g -gdwarf-5 direct.m -c
+
+; CHECK: DW_TAG_subprogram [3]
+; CHECK: DW_AT_APPLE_objc_direct
+; CHECK-SAME: DW_FORM_flag_present
+; CHECK: DW_TAG_formal_parameter [4]
+
+; ModuleID = 'direct.bc'
+source_filename = "direct.m"
+
+%0 = type opaque
+
+define hidden i32 @"\01-[Root direct_method]"(%0* %self, i8* %_cmd) {
+entry:
+ %retval = alloca i32, align 4
+ %0 = load i32, i32* %retval, align 4
+ ret i32 %0
+}
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!19, !20}
+!llvm.ident = !{}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_ObjC, file: !1, producer: "clang version 10.0.0 (https://github.com/llvm/llvm-project d6b2f33e2b6338d24cf756ba220939aecc81210d)", isOptimized: false, runtimeVersion: 2, emissionKind: FullDebug, enums: !2, retainedTypes: !3, nameTableKind: None)
+!1 = !DIFile(filename: "direct.m", directory: "/", checksumkind: CSK_MD5, checksum: "6b49fad130344b0011fc0eef65949390")
+!2 = !{}
+!3 = !{!4}
+!4 = !DICompositeType(tag: DW_TAG_structure_type, name: "Root", scope: !1, file: !1, line: 2, flags: DIFlagObjcClassComplete, elements: !5, runtimeLang: DW_LANG_ObjC)
+!5 = !{!6}
+!6 = !DISubprogram(name: "-[Root direct_method]", scope: !4, file: !1, line: 7, type: !7, scopeLine: 7, flags: DIFlagPrototyped, spFlags: DISPFlagObjCDirect, retainedNodes: !2)
+!7 = !DISubroutineType(types: !8)
+!8 = !{!9, !10, !11}
+!9 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!10 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !4, size: 64, flags: DIFlagArtificial | DIFlagObjectPointer)
+!11 = !DIDerivedType(tag: DW_TAG_typedef, name: "SEL", file: !1, baseType: !12, flags: DIFlagArtificial)
+!12 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !13, size: 64)
+!13 = !DICompositeType(tag: DW_TAG_structure_type, name: "objc_selector", file: !1, flags: DIFlagFwdDecl)
+!19 = !{i32 7, !"Dwarf Version", i32 5}
+!20 = !{i32 2, !"Debug Info Version", i32 3}
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