[llvm] f919be3 - [DWARF5] Added support for deleted C++ special member functions.
Adrian Prantl via llvm-commits
llvm-commits at lists.llvm.org
Tue Oct 29 13:44:45 PDT 2019
Author: Adrian Prantl
Date: 2019-10-29T13:44:06-07:00
New Revision: f919be336583349d883ba0dfdb3b2479a190b67c
URL: https://github.com/llvm/llvm-project/commit/f919be336583349d883ba0dfdb3b2479a190b67c
DIFF: https://github.com/llvm/llvm-project/commit/f919be336583349d883ba0dfdb3b2479a190b67c.diff
LOG: [DWARF5] Added support for deleted C++ special member functions.
This patch adds support for deleted C++ special member functions in
clang and llvm. Also added Defaulted member encodings for future
support for defaulted member functions.
Patch by Sourabh Singh Tomar!
Differential Revision: https://reviews.llvm.org/D69215
Added:
clang/test/CodeGenCXX/debug-info-deleted.cpp
llvm/test/DebugInfo/X86/DW_AT_deleted.ll
Modified:
clang/lib/CodeGen/CGDebugInfo.cpp
llvm/docs/SourceLevelDebugging.rst
llvm/include/llvm/BinaryFormat/Dwarf.h
llvm/include/llvm/IR/DebugInfoFlags.def
llvm/include/llvm/IR/DebugInfoMetadata.h
llvm/lib/BinaryFormat/Dwarf.cpp
llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
Removed:
################################################################################
diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp
index 7c63743f3b43..292d13e62bd4 100644
--- a/clang/lib/CodeGen/CGDebugInfo.cpp
+++ b/clang/lib/CodeGen/CGDebugInfo.cpp
@@ -1607,8 +1607,31 @@ llvm::DISubprogram *CGDebugInfo::CreateCXXMemberFunction(
ContainingType = RecordTy;
}
+ // We're checking for deleted C++ special member functions
+ // [Ctors,Dtors, Copy/Move]
+ auto checkAttrDeleted = [&SPFlags](const auto *Method) {
+ if (Method->getCanonicalDecl()->isDeleted())
+ SPFlags |= llvm::DISubprogram::SPFlagDeleted;
+ };
+
+ switch (Method->getKind()) {
+
+ case Decl::CXXConstructor:
+ case Decl::CXXDestructor:
+ checkAttrDeleted(Method);
+ break;
+ case Decl::CXXMethod:
+ if (Method->isCopyAssignmentOperator() ||
+ Method->isMoveAssignmentOperator())
+ checkAttrDeleted(Method);
+ break;
+ default:
+ break;
+ }
+
if (Method->isNoReturn())
Flags |= llvm::DINode::FlagNoReturn;
+
if (Method->isStatic())
Flags |= llvm::DINode::FlagStaticMember;
if (Method->isImplicit())
diff --git a/clang/test/CodeGenCXX/debug-info-deleted.cpp b/clang/test/CodeGenCXX/debug-info-deleted.cpp
new file mode 100644
index 000000000000..d7d0b6dba49e
--- /dev/null
+++ b/clang/test/CodeGenCXX/debug-info-deleted.cpp
@@ -0,0 +1,31 @@
+// Test for debug info for C++11 deleted member functions
+
+//Supported: -O0, standalone DI
+// RUN: %clang_cc1 -emit-llvm -triple x86_64-linux-gnu %s -o - \
+// RUN: -O0 -disable-llvm-passes \
+// RUN: -debug-info-kind=standalone \
+// RUN: | FileCheck %s -check-prefix=ATTR
+
+// ATTR: DISubprogram(name: "deleted", {{.*}}, flags: DIFlagPublic | DIFlagPrototyped,
+// ATTR: DISubprogram(name: "deleted", {{.*}}, flags: DIFlagPublic | DIFlagPrototyped, spFlags: DISPFlagDeleted
+// ATTR: DISubprogram(name: "operator=", linkageName: "_ZN7deletedaSERKS_", {{.*}}, flags: DIFlagPublic | DIFlagPrototyped, spFlags: DISPFlagDeleted
+// ATTR: DISubprogram(name: "deleted", {{.*}}, flags: DIFlagPublic | DIFlagPrototyped, spFlags: DISPFlagDeleted
+// ATTR: DISubprogram(name: "operator=", linkageName: "_ZN7deletedaSEOS_", {{.*}}, flags: DIFlagPublic | DIFlagPrototyped, spFlags: DISPFlagDeleted
+// ATTR: DISubprogram(name: "~deleted", {{.*}}, flags: DIFlagPublic | DIFlagPrototyped,
+class deleted {
+public:
+ // Defaulted on purpose, so as to facilitate object creation
+ deleted() = default;
+
+ deleted(const deleted &) = delete;
+ deleted &operator=(const deleted &) = delete;
+
+ deleted(deleted &&) = delete;
+ deleted &operator=(deleted &&) = delete;
+
+ ~deleted() = default;
+};
+
+void foo() {
+ deleted obj1;
+}
diff --git a/llvm/docs/SourceLevelDebugging.rst b/llvm/docs/SourceLevelDebugging.rst
index a887810db4d8..978184743314 100644
--- a/llvm/docs/SourceLevelDebugging.rst
+++ b/llvm/docs/SourceLevelDebugging.rst
@@ -989,6 +989,39 @@ a C/C++ front-end would generate the following descriptors:
...
}
+C++ specific debug information
+==============================
+
+C++ special member functions information
+----------------------------------------
+
+DWARF v5 introduces attributes defined to enhance debugging information of C++ programs. LLVM can generate (or omit) these appropriate DWARF attributes. In C++ a special member function Ctors, Dtors, Copy/Move Ctors, assignment operators can be declared with C++11 keyword deleted. This is represented in LLVM using spFlags value DISPFlagDeleted.
+
+Given a class declaration with copy constructor declared as deleted:
+
+.. code-block:: c
+
+ class foo {
+ public:
+ foo(const foo&) = deleted;
+ };
+
+A C++ frontend would generate follwing:
+
+.. code-block:: text
+
+ !17 = !DISubprogram(name: "foo", scope: !11, file: !1, line: 5, type: !18, scopeLine: 5, flags: DIFlagPublic | DIFlagPrototyped, spFlags: DISPFlagDeleted)
+
+and this will produce an additional DWARF attibute as:
+
+.. code-block:: text
+
+ DW_TAG_subprogram [7] *
+ DW_AT_name [DW_FORM_strx1] (indexed (00000006) string = "foo")
+ DW_AT_decl_line [DW_FORM_data1] (5)
+ ...
+ DW_AT_deleted [DW_FORM_flag_present] (true)
+
Fortran specific debug information
==================================
diff --git a/llvm/include/llvm/BinaryFormat/Dwarf.h b/llvm/include/llvm/BinaryFormat/Dwarf.h
index 1c6aee48661c..93eaf368033a 100644
--- a/llvm/include/llvm/BinaryFormat/Dwarf.h
+++ b/llvm/include/llvm/BinaryFormat/Dwarf.h
@@ -458,6 +458,7 @@ StringRef AttributeEncodingString(unsigned Encoding);
StringRef DecimalSignString(unsigned Sign);
StringRef EndianityString(unsigned Endian);
StringRef AccessibilityString(unsigned Access);
+StringRef DefaultedMemberString(unsigned DefaultedEncodings);
StringRef VisibilityString(unsigned Visibility);
StringRef VirtualityString(unsigned Virtuality);
StringRef LanguageString(unsigned Language);
diff --git a/llvm/include/llvm/IR/DebugInfoFlags.def b/llvm/include/llvm/IR/DebugInfoFlags.def
index f90c580f10ef..91179299eb6c 100644
--- a/llvm/include/llvm/IR/DebugInfoFlags.def
+++ b/llvm/include/llvm/IR/DebugInfoFlags.def
@@ -88,11 +88,14 @@ HANDLE_DISP_FLAG((1u << 5), Pure)
HANDLE_DISP_FLAG((1u << 6), Elemental)
HANDLE_DISP_FLAG((1u << 7), Recursive)
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)
#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 << 8), Largest)
+HANDLE_DISP_FLAG((1 << 9), Largest)
#undef DISP_FLAG_LARGEST_NEEDED
#endif
diff --git a/llvm/include/llvm/IR/DebugInfoMetadata.h b/llvm/include/llvm/IR/DebugInfoMetadata.h
index 28a59576b7c6..6ebd05ba03cd 100644
--- a/llvm/include/llvm/IR/DebugInfoMetadata.h
+++ b/llvm/include/llvm/IR/DebugInfoMetadata.h
@@ -1759,6 +1759,12 @@ class DISubprogram : public DILocalScope {
bool isElemental() const { return getSPFlags() & SPFlagElemental; }
bool isRecursive() const { return getSPFlags() & SPFlagRecursive; }
+ /// Check if this is deleted member function.
+ ///
+ /// Return true if this subprogram is a C++11 special
+ /// member function declared deleted.
+ bool isDeleted() const { return getSPFlags() & SPFlagDeleted; }
+
/// Check if this is reference-qualified.
///
/// Return true if this subprogram is a C++11 reference-qualified non-static
diff --git a/llvm/lib/BinaryFormat/Dwarf.cpp b/llvm/lib/BinaryFormat/Dwarf.cpp
index d06cccdf0dfd..9ca3317418ce 100644
--- a/llvm/lib/BinaryFormat/Dwarf.cpp
+++ b/llvm/lib/BinaryFormat/Dwarf.cpp
@@ -274,6 +274,19 @@ StringRef llvm::dwarf::AccessibilityString(unsigned Access) {
return StringRef();
}
+StringRef llvm::dwarf::DefaultedMemberString(unsigned DefaultedEncodings) {
+ switch (DefaultedEncodings) {
+ // Defaulted Member Encodings codes
+ case DW_DEFAULTED_no:
+ return "DW_DEFAULTED_no";
+ case DW_DEFAULTED_in_class:
+ return "DW_DEFAULTED_in_class";
+ case DW_DEFAULTED_out_of_class:
+ return "DW_DEFAULTED_out_of_class";
+ }
+ return StringRef();
+}
+
StringRef llvm::dwarf::VisibilityString(unsigned Visibility) {
switch (Visibility) {
case DW_VIS_local:
@@ -615,6 +628,8 @@ StringRef llvm::dwarf::AttributeValueString(uint16_t Attr, unsigned Val) {
return ArrayOrderString(Val);
case DW_AT_APPLE_runtime_class:
return LanguageString(Val);
+ case DW_AT_defaulted:
+ return DefaultedMemberString(Val);
}
return StringRef();
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
index 37c68c085792..9d7fee1d5b38 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
@@ -1307,6 +1307,9 @@ void DwarfUnit::applySubprogramAttributes(const DISubprogram *SP, DIE &SPDie,
addFlag(SPDie, dwarf::DW_AT_elemental);
if (SP->isRecursive())
addFlag(SPDie, dwarf::DW_AT_recursive);
+
+ if (DD->getDwarfVersion() >= 5 && SP->isDeleted())
+ addFlag(SPDie, dwarf::DW_AT_deleted);
}
void DwarfUnit::constructSubrangeDIE(DIE &Buffer, const DISubrange *SR,
diff --git a/llvm/test/DebugInfo/X86/DW_AT_deleted.ll b/llvm/test/DebugInfo/X86/DW_AT_deleted.ll
new file mode 100644
index 000000000000..80774d696b73
--- /dev/null
+++ b/llvm/test/DebugInfo/X86/DW_AT_deleted.ll
@@ -0,0 +1,110 @@
+; RUN: llc < %s -filetype=obj -o %t
+; RUN: llvm-dwarfdump -v %t | FileCheck %s
+
+; C++ source to regenerate:
+; class deleted {
+; public:
+; // Defaulted on purpose, so as to facilitate object creation
+; deleted() = default;
+;
+; deleted(const deleted &) = delete;
+; deleted &operator=(const deleted &) = delete;
+;
+; deleted(deleted &&) = delete;
+; deleted &operator=(deleted &&) = delete;
+;
+; ~deleted() = default;
+; };
+;
+; void foo() {
+; deleted obj1;
+; }
+; $ clang++ -O0 -g -gdwarf-5 debug-info-deleted.cpp -c
+
+
+; CHECK: .debug_abbrev contents:
+
+; CHECK: [7] DW_TAG_subprogram DW_CHILDREN_yes
+; CHECK: DW_AT_deleted DW_FORM_flag_present
+; CHECK: [9] DW_TAG_subprogram DW_CHILDREN_yes
+; CHECK: DW_AT_deleted DW_FORM_flag_present
+
+; CHECK: .debug_info contents:
+
+; CHECK: DW_TAG_subprogram [7]
+; CHECK-NEXT: DW_AT_name [DW_FORM_strx1] (indexed (00000006) string = "deleted")
+; CHECK: DW_AT_deleted [DW_FORM_flag_present] (true)
+
+; CHECK: DW_TAG_subprogram [9]
+; CHECK-NEXT: DW_AT_linkage_name [DW_FORM_strx1] (indexed (00000007) string = "_ZN7deletedaSERKS_")
+; CHECK: DW_AT_deleted [DW_FORM_flag_present] (true)
+
+; CHECK: DW_TAG_subprogram [7]
+; CHECK-NEXT: DW_AT_name [DW_FORM_strx1] (indexed (00000006) string = "deleted")
+; CHECK: DW_AT_deleted [DW_FORM_flag_present] (true)
+
+; CHECK: DW_TAG_subprogram [9]
+; CHECK-NEXT: DW_AT_linkage_name [DW_FORM_strx1] (indexed (00000009) string = "_ZN7deletedaSEOS_")
+; CHECK-NEXT: DW_AT_name [DW_FORM_strx1] (indexed (00000008) string = "operator=")
+; CHECK: DW_AT_deleted [DW_FORM_flag_present] (true)
+
+; ModuleID = 'debug-info-deleted.cpp'
+source_filename = "debug-info-deleted.cpp"
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+%class.deleted = type { i8 }
+
+; Function Attrs: noinline nounwind optnone uwtable
+define dso_local void @_Z3foov() #0 !dbg !7 {
+ %1 = alloca %class.deleted, align 1
+ call void @llvm.dbg.declare(metadata %class.deleted* %1, metadata !10, metadata !DIExpression()), !dbg !34
+ ret void, !dbg !35
+}
+
+; Function Attrs: nounwind readnone speculatable willreturn
+declare void @llvm.dbg.declare(metadata, metadata, metadata) #1
+
+attributes #0 = { noinline nounwind optnone uwtable }
+attributes #1 = { nounwind readnone speculatable willreturn }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4, !5}
+!llvm.ident = !{!6}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !1, producer: "clang version 10.0.0 (https://github.com/llvm/llvm-project.git 715c47d5de9aa8860050992a7aaf27dca53f7f4a)", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, nameTableKind: None)
+!1 = !DIFile(filename: "debug-info-deleted.cpp", directory: "/home/sourabh/work/dwarf/c_c++/c++11", checksumkind: CSK_MD5, checksum: "49dc56907586479c64634558b060292d")
+!2 = !{}
+!3 = !{i32 2, !"Dwarf Version", i32 5}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{i32 1, !"wchar_size", i32 4}
+!6 = !{!"clang version 10.0.0 (https://github.com/llvm/llvm-project.git 715c47d5de9aa8860050992a7aaf27dca53f7f4a)"}
+!7 = distinct !DISubprogram(name: "foo", linkageName: "_Z3foov", scope: !1, file: !1, line: 14, type: !8, scopeLine: 14, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !2)
+!8 = !DISubroutineType(types: !9)
+!9 = !{null}
+!10 = !DILocalVariable(name: "obj1", scope: !7, file: !1, line: 15, type: !11)
+!11 = distinct !DICompositeType(tag: DW_TAG_class_type, name: "deleted", file: !1, line: 1, size: 8, flags: DIFlagTypePassByReference, elements: !12, identifier: "_ZTS7deleted")
+!12 = !{!13, !17, !22, !26, !30, !33}
+!13 = !DISubprogram(name: "deleted", scope: !11, file: !1, line: 3, type: !14, scopeLine: 3, flags: DIFlagPublic | DIFlagPrototyped, spFlags: 0)
+!14 = !DISubroutineType(types: !15)
+!15 = !{null, !16}
+!16 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !11, size: 64, flags: DIFlagArtificial | DIFlagObjectPointer)
+!17 = !DISubprogram(name: "deleted", scope: !11, file: !1, line: 5, type: !18, scopeLine: 5, flags: DIFlagPublic | DIFlagPrototyped, spFlags: DISPFlagDeleted)
+!18 = !DISubroutineType(types: !19)
+!19 = !{null, !16, !20}
+!20 = !DIDerivedType(tag: DW_TAG_reference_type, baseType: !21, size: 64)
+!21 = !DIDerivedType(tag: DW_TAG_const_type, baseType: !11)
+!22 = !DISubprogram(name: "operator=", linkageName: "_ZN7deletedaSERKS_", scope: !11, file: !1, line: 6, type: !23, scopeLine: 6, flags: DIFlagPublic | DIFlagPrototyped, spFlags: DISPFlagDeleted)
+!23 = !DISubroutineType(types: !24)
+!24 = !{!25, !16, !20}
+!25 = !DIDerivedType(tag: DW_TAG_reference_type, baseType: !11, size: 64)
+!26 = !DISubprogram(name: "deleted", scope: !11, file: !1, line: 8, type: !27, scopeLine: 8, flags: DIFlagPublic | DIFlagPrototyped, spFlags: DISPFlagDeleted)
+!27 = !DISubroutineType(types: !28)
+!28 = !{null, !16, !29}
+!29 = !DIDerivedType(tag: DW_TAG_rvalue_reference_type, baseType: !11, size: 64)
+!30 = !DISubprogram(name: "operator=", linkageName: "_ZN7deletedaSEOS_", scope: !11, file: !1, line: 9, type: !31, scopeLine: 9, flags: DIFlagPublic | DIFlagPrototyped, spFlags: DISPFlagDeleted)
+!31 = !DISubroutineType(types: !32)
+!32 = !{!25, !16, !29}
+!33 = !DISubprogram(name: "~deleted", scope: !11, file: !1, line: 11, type: !14, scopeLine: 11, flags: DIFlagPublic | DIFlagPrototyped, spFlags: 0)
+!34 = !DILocation(line: 15, column: 13, scope: !7)
+!35 = !DILocation(line: 16, column: 3, scope: !7)
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