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Fix MSVC 1920+ auto NTTP mangling for pointers to members (llvm#97007)
Fixes llvm#70899. This is a continuation of llvm#92477 for pointers to member data and pointers to member functions. The mangled name must be prefixed with `$M <mangled-type>` for the deduced type of the nttp parameter.
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-20
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6 files changed

+204
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lines changed

‎clang/docs/ReleaseNotes.rst

Lines changed: 7 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -106,6 +106,13 @@ ABI Changes in This Version
106106
earlier versions of Clang unless such code is built with the compiler option
107107
`-fms-compatibility-version=19.14` to imitate the MSVC 1914 mangling behavior.
108108

109+
- Fixed Microsoft name mangling for auto non-type template arguments of pointer
110+
to member type for MSVC 1920+. This change resolves incompatibilities with code
111+
compiled by MSVC 1920+ but will introduce incompatibilities with code compiled by
112+
earlier versions of Clang unless such code is built with the compiler option
113+
`-fms-compatibility-version=19.14` to imitate the MSVC 1914 mangling behavior.
114+
(GH#70899).
115+
109116
AST Dumping Potentially Breaking Changes
110117
----------------------------------------
111118

‎clang/lib/AST/MicrosoftMangle.cpp

Lines changed: 56 additions & 17 deletions
Original file line numberDiff line numberDiff line change
@@ -368,11 +368,15 @@ class MicrosoftCXXNameMangler {
368368
void mangleFunctionEncoding(GlobalDecl GD, bool ShouldMangle);
369369
void mangleVariableEncoding(const VarDecl *VD);
370370
void mangleMemberDataPointer(const CXXRecordDecl *RD, const ValueDecl *VD,
371+
const NonTypeTemplateParmDecl *PD,
372+
QualType TemplateArgType,
371373
StringRef Prefix = "$");
372374
void mangleMemberDataPointerInClassNTTP(const CXXRecordDecl *,
373375
const ValueDecl *);
374376
void mangleMemberFunctionPointer(const CXXRecordDecl *RD,
375377
const CXXMethodDecl *MD,
378+
const NonTypeTemplateParmDecl *PD,
379+
QualType TemplateArgType,
376380
StringRef Prefix = "$");
377381
void mangleFunctionPointer(const FunctionDecl *FD,
378382
const NonTypeTemplateParmDecl *PD,
@@ -673,12 +677,17 @@ void MicrosoftCXXNameMangler::mangleVariableEncoding(const VarDecl *VD) {
673677
}
674678
}
675679

676-
void MicrosoftCXXNameMangler::mangleMemberDataPointer(const CXXRecordDecl *RD,
677-
const ValueDecl *VD,
678-
StringRef Prefix) {
680+
void MicrosoftCXXNameMangler::mangleMemberDataPointer(
681+
const CXXRecordDecl *RD, const ValueDecl *VD,
682+
const NonTypeTemplateParmDecl *PD, QualType TemplateArgType,
683+
StringRef Prefix) {
679684
// <member-data-pointer> ::= <integer-literal>
680685
// ::= $F <number> <number>
681686
// ::= $G <number> <number> <number>
687+
//
688+
// <auto-nttp> ::= $ M <type> <integer-literal>
689+
// <auto-nttp> ::= $ M <type> F <name> <number>
690+
// <auto-nttp> ::= $ M <type> G <name> <number> <number>
682691

683692
int64_t FieldOffset;
684693
int64_t VBTableOffset;
@@ -707,7 +716,18 @@ void MicrosoftCXXNameMangler::mangleMemberDataPointer(const CXXRecordDecl *RD,
707716
case MSInheritanceModel::Unspecified: Code = 'G'; break;
708717
}
709718

710-
Out << Prefix << Code;
719+
Out << Prefix;
720+
721+
if (VD &&
722+
getASTContext().getLangOpts().isCompatibleWithMSVC(
723+
LangOptions::MSVC2019) &&
724+
PD && PD->getType()->getTypeClass() == Type::Auto &&
725+
!TemplateArgType.isNull()) {
726+
Out << "M";
727+
mangleType(TemplateArgType, SourceRange(), QMM_Drop);
728+
}
729+
730+
Out << Code;
711731

712732
mangleNumber(FieldOffset);
713733

@@ -728,7 +748,7 @@ void MicrosoftCXXNameMangler::mangleMemberDataPointerInClassNTTP(
728748
// ::= 8 <postfix> @ <unqualified-name> @
729749

730750
if (IM != MSInheritanceModel::Single && IM != MSInheritanceModel::Multiple)
731-
return mangleMemberDataPointer(RD, VD, "");
751+
return mangleMemberDataPointer(RD, VD, nullptr, QualType(), "");
732752

733753
if (!VD) {
734754
Out << 'N';
@@ -742,14 +762,19 @@ void MicrosoftCXXNameMangler::mangleMemberDataPointerInClassNTTP(
742762
Out << '@';
743763
}
744764

745-
void
746-
MicrosoftCXXNameMangler::mangleMemberFunctionPointer(const CXXRecordDecl *RD,
747-
const CXXMethodDecl *MD,
748-
StringRef Prefix) {
765+
void MicrosoftCXXNameMangler::mangleMemberFunctionPointer(
766+
const CXXRecordDecl *RD, const CXXMethodDecl *MD,
767+
const NonTypeTemplateParmDecl *PD, QualType TemplateArgType,
768+
StringRef Prefix) {
749769
// <member-function-pointer> ::= $1? <name>
750770
// ::= $H? <name> <number>
751771
// ::= $I? <name> <number> <number>
752772
// ::= $J? <name> <number> <number> <number>
773+
//
774+
// <auto-nttp> ::= $ M <type> 1? <name>
775+
// <auto-nttp> ::= $ M <type> H? <name> <number>
776+
// <auto-nttp> ::= $ M <type> I? <name> <number> <number>
777+
// <auto-nttp> ::= $ M <type> J? <name> <number> <number> <number>
753778

754779
MSInheritanceModel IM = RD->getMSInheritanceModel();
755780

@@ -767,7 +792,17 @@ MicrosoftCXXNameMangler::mangleMemberFunctionPointer(const CXXRecordDecl *RD,
767792
uint64_t VBTableOffset = 0;
768793
uint64_t VBPtrOffset = 0;
769794
if (MD) {
770-
Out << Prefix << Code << '?';
795+
Out << Prefix;
796+
797+
if (getASTContext().getLangOpts().isCompatibleWithMSVC(
798+
LangOptions::MSVC2019) &&
799+
PD && PD->getType()->getTypeClass() == Type::Auto &&
800+
!TemplateArgType.isNull()) {
801+
Out << "M";
802+
mangleType(TemplateArgType, SourceRange(), QMM_Drop);
803+
}
804+
805+
Out << Code << '?';
771806
if (MD->isVirtual()) {
772807
MicrosoftVTableContext *VTContext =
773808
cast<MicrosoftVTableContext>(getASTContext().getVTableContext());
@@ -859,7 +894,7 @@ void MicrosoftCXXNameMangler::mangleMemberFunctionPointerInClassNTTP(
859894

860895
if (!MD) {
861896
if (RD->getMSInheritanceModel() != MSInheritanceModel::Single)
862-
return mangleMemberFunctionPointer(RD, MD, "");
897+
return mangleMemberFunctionPointer(RD, MD, nullptr, QualType(), "");
863898

864899
Out << 'N';
865900
return;
@@ -1732,12 +1767,15 @@ void MicrosoftCXXNameMangler::mangleTemplateArg(const TemplateDecl *TD,
17321767
if (isa<FieldDecl>(ND) || isa<IndirectFieldDecl>(ND)) {
17331768
mangleMemberDataPointer(cast<CXXRecordDecl>(ND->getDeclContext())
17341769
->getMostRecentNonInjectedDecl(),
1735-
cast<ValueDecl>(ND));
1770+
cast<ValueDecl>(ND),
1771+
cast<NonTypeTemplateParmDecl>(Parm),
1772+
TA.getParamTypeForDecl());
17361773
} else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND)) {
17371774
const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD);
17381775
if (MD && MD->isInstance()) {
17391776
mangleMemberFunctionPointer(
1740-
MD->getParent()->getMostRecentNonInjectedDecl(), MD);
1777+
MD->getParent()->getMostRecentNonInjectedDecl(), MD,
1778+
cast<NonTypeTemplateParmDecl>(Parm), TA.getParamTypeForDecl());
17411779
} else {
17421780
mangleFunctionPointer(FD, cast<NonTypeTemplateParmDecl>(Parm),
17431781
TA.getParamTypeForDecl());
@@ -1767,12 +1805,12 @@ void MicrosoftCXXNameMangler::mangleTemplateArg(const TemplateDecl *TD,
17671805
const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
17681806
if (MPT->isMemberFunctionPointerType() &&
17691807
!isa<FunctionTemplateDecl>(TD)) {
1770-
mangleMemberFunctionPointer(RD, nullptr);
1808+
mangleMemberFunctionPointer(RD, nullptr, nullptr, QualType());
17711809
return;
17721810
}
17731811
if (MPT->isMemberDataPointer()) {
17741812
if (!isa<FunctionTemplateDecl>(TD)) {
1775-
mangleMemberDataPointer(RD, nullptr);
1813+
mangleMemberDataPointer(RD, nullptr, nullptr, QualType());
17761814
return;
17771815
}
17781816
// nullptr data pointers are always represented with a single field
@@ -1979,9 +2017,10 @@ void MicrosoftCXXNameMangler::mangleTemplateArgValue(QualType T,
19792017
cast_or_null<CXXMethodDecl>(D));
19802018
} else {
19812019
if (T->isMemberDataPointerType())
1982-
mangleMemberDataPointer(RD, D, "");
2020+
mangleMemberDataPointer(RD, D, nullptr, QualType(), "");
19832021
else
1984-
mangleMemberFunctionPointer(RD, cast_or_null<CXXMethodDecl>(D), "");
2022+
mangleMemberFunctionPointer(RD, cast_or_null<CXXMethodDecl>(D), nullptr,
2023+
QualType(), "");
19852024
}
19862025
return;
19872026
}

‎clang/test/CodeGenCXX/mangle-ms-auto-templates-memptrs.cpp

Lines changed: 71 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,71 @@
1+
// RUN: %clang_cc1 -std=c++17 -fms-compatibility-version=19.20 -emit-llvm %s -o - -fms-extensions -fdelayed-template-parsing -triple=x86_64-pc-windows-msvc | FileCheck --check-prefix=AFTER %s
2+
// RUN: %clang_cc1 -std=c++17 -fms-compatibility-version=19.14 -emit-llvm %s -o - -fms-extensions -fdelayed-template-parsing -triple=x86_64-pc-windows-msvc | FileCheck --check-prefix=BEFORE %s
3+
4+
template <auto a>
5+
class AutoParmTemplate {
6+
public:
7+
AutoParmTemplate() {}
8+
};
9+
10+
template <auto a>
11+
auto AutoFunc() {
12+
return a;
13+
}
14+
15+
struct A {};
16+
struct B {};
17+
18+
struct S { int a; void f(); virtual void g(); };
19+
struct M : A, B { int a; void f(); virtual void g(); };
20+
struct V : virtual A { int a; void f(); virtual void g(); };
21+
22+
void template_mangling() {
23+
24+
AutoParmTemplate<&S::f> auto_method_single_inheritance;
25+
// AFTER: call {{.*}} @"??0?$AutoParmTemplate@$MP8S@@EAAXXZ1?f@1@QEAAXXZ@@QEAA@XZ"
26+
// BEFORE: call {{.*}} @"??0?$AutoParmTemplate@$1?f@S@@QEAAXXZ@@QEAA@XZ"
27+
28+
AutoParmTemplate<&M::f> auto_method_multiple_inheritance;
29+
// AFTER: call {{.*}} @"??0?$AutoParmTemplate@$MP8M@@EAAXXZH?f@1@QEAAXXZA@@@QEAA@XZ"
30+
// BEFORE: call {{.*}} @"??0?$AutoParmTemplate@$H?f@M@@QEAAXXZA@@@QEAA@XZ"
31+
32+
AutoParmTemplate<&V::f> auto_method_virtual_inheritance;
33+
// AFTER: call {{.*}} @"??0?$AutoParmTemplate@$MP8V@@EAAXXZI?f@1@QEAAXXZA@A@@@QEAA@XZ"
34+
// BEFORE: call {{.*}} @"??0?$AutoParmTemplate@$I?f@V@@QEAAXXZA@A@@@QEAA@XZ"
35+
36+
AutoFunc<&S::f>();
37+
// AFTER: call {{.*}} @"??$AutoFunc@$MP8S@@EAAXXZ1?f@1@QEAAXXZ@@YA?A?<auto>@@XZ"
38+
// BEFORE: call {{.*}} @"??$AutoFunc@$1?f@S@@QEAAXXZ@@YA?A?<auto>@@XZ"
39+
40+
AutoFunc<&M::f>();
41+
// AFTER: call {{.*}} @"??$AutoFunc@$MP8M@@EAAXXZH?f@1@QEAAXXZA@@@YA?A?<auto>@@XZ"
42+
// BEFORE: call {{.*}} @"??$AutoFunc@$H?f@M@@QEAAXXZA@@@YA?A?<auto>@@XZ"
43+
44+
AutoFunc<&V::f>();
45+
// AFTER: call {{.*}} @"??$AutoFunc@$MP8V@@EAAXXZI?f@1@QEAAXXZA@A@@@YA?A?<auto>@@XZ"
46+
// BEFORE: call {{.*}} @"??$AutoFunc@$I?f@V@@QEAAXXZA@A@@@YA?A?<auto>@@XZ"
47+
48+
AutoParmTemplate<&S::a> auto_data_single_inheritance;
49+
// AFTER: call {{.*}} @"??0?$AutoParmTemplate@$MPEQS@@H07@@QEAA@XZ"
50+
// BEFORE: call {{.*}} @"??0?$AutoParmTemplate@$07@@QEAA@XZ"
51+
52+
AutoParmTemplate<&M::a> auto_data_multiple_inheritance;
53+
// AFTER: call {{.*}} @"??0?$AutoParmTemplate@$MPEQM@@H0M@@@QEAA@XZ"
54+
// BEFORE: call {{.*}} @"??0?$AutoParmTemplate@$0M@@@QEAA@XZ"
55+
56+
AutoParmTemplate<&V::a> auto_data_virtual_inheritance;
57+
// AFTER: call {{.*}} @"??0?$AutoParmTemplate@$MPEQV@@HFBA@A@@@QEAA@XZ"
58+
// BEFORE: call {{.*}} @"??0?$AutoParmTemplate@$FBA@A@@@QEAA@XZ"
59+
60+
AutoFunc<&S::a>();
61+
// AFTER: call {{.*}} @"??$AutoFunc@$MPEQS@@H07@@YA?A?<auto>@@XZ"
62+
// BEFORE: call {{.*}} @"??$AutoFunc@$07@@YA?A?<auto>@@XZ"
63+
64+
AutoFunc<&M::a>();
65+
// AFTER: call {{.*}} @"??$AutoFunc@$MPEQM@@H0M@@@YA?A?<auto>@@XZ"
66+
// BEFORE: call {{.*}} @"??$AutoFunc@$0M@@@YA?A?<auto>@@XZ"
67+
68+
AutoFunc<&V::a>();
69+
// AFTER: call {{.*}} @"??$AutoFunc@$MPEQV@@HFBA@A@@@YA?A?<auto>@@XZ"
70+
// BEFORE: call {{.*}} @"??$AutoFunc@$FBA@A@@@YA?A?<auto>@@XZ"
71+
}

‎clang/test/CodeGenCXX/mangle-ms-auto-templates-nullptr.cpp

Lines changed: 24 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,24 @@
1+
// RUN: %clang_cc1 -std=c++17 -fms-compatibility-version=19.20 -emit-llvm %s -o - -fms-extensions -fdelayed-template-parsing -triple=x86_64-pc-windows-msvc | FileCheck --check-prefix=AFTER %s
2+
// RUN: %clang_cc1 -std=c++17 -fms-compatibility-version=19.14 -emit-llvm %s -o - -fms-extensions -fdelayed-template-parsing -triple=x86_64-pc-windows-msvc | FileCheck --check-prefix=BEFORE %s
3+
4+
template <auto a>
5+
class AutoParmTemplate {
6+
public:
7+
AutoParmTemplate() {}
8+
};
9+
10+
template <auto a>
11+
auto AutoFunc() {
12+
return a;
13+
}
14+
15+
void template_mangling() {
16+
17+
AutoParmTemplate<nullptr> auto_nullptr;
18+
// AFTER: call {{.*}} @"??0?$AutoParmTemplate@$M$$T0A@@@QEAA@XZ"
19+
// BEFORE: call {{.*}} @"??0?$AutoParmTemplate@$0A@@@QEAA@XZ"
20+
21+
AutoFunc<nullptr>();
22+
// AFTER: call {{.*}} @"??$AutoFunc@$M$$T0A@@@YA?A?<auto>@@XZ"
23+
// BEFORE: call {{.*}} @"??$AutoFunc@$0A@@@YA?A?<auto>@@XZ"
24+
}

‎llvm/lib/Demangle/MicrosoftDemangle.cpp

Lines changed: 4 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -2343,12 +2343,13 @@ Demangler::demangleTemplateParameterList(std::string_view &MangledName) {
23432343
TP.N = TPRN = Arena.alloc<TemplateParameterReferenceNode>();
23442344
TPRN->Symbol = parse(MangledName);
23452345
TPRN->Affinity = PointerAffinity::Reference;
2346-
} else if (llvm::itanium_demangle::starts_with(MangledName, "$F") ||
2347-
llvm::itanium_demangle::starts_with(MangledName, "$G")) {
2346+
} else if (startsWith(MangledName, "$F", "F", !IsAutoNTTP) ||
2347+
startsWith(MangledName, "$G", "G", !IsAutoNTTP)) {
23482348
TP.N = TPRN = Arena.alloc<TemplateParameterReferenceNode>();
23492349

23502350
// Data member pointer.
2351-
MangledName.remove_prefix(1);
2351+
if (!IsAutoNTTP)
2352+
MangledName.remove_prefix(1); // Remove leading '$'
23522353
char InheritanceSpecifier = MangledName.front();
23532354
MangledName.remove_prefix(1);
23542355

‎llvm/test/Demangle/ms-auto-templates.test

Lines changed: 42 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -55,3 +55,45 @@
5555

5656
??0?$AutoNTTPClass@$MH0A@$M_N0A@$MD0GB@@@QEAA@XZ
5757
; CHECK: public: __cdecl AutoNTTPClass<0, 0, 97>::AutoNTTPClass<0, 0, 97>(void)
58+
59+
??0?$AutoNTTPClass@$M$$T0A@@@QEAA@XZ
60+
; CHECK: public: __cdecl AutoNTTPClass<0>::AutoNTTPClass<0>(void)
61+
62+
??0?$AutoNTTPClass@$0A@@@QEAA@XZ
63+
; CHECK: public: __cdecl AutoNTTPClass<0>::AutoNTTPClass<0>(void)
64+
65+
??0?$AutoNTTPClass@$MP8S@@EAAXXZ1?f@1@QEAAXXZ@@QEAA@XZ
66+
; CHECK: public: __cdecl AutoNTTPClass<&public: void __cdecl S::f(void)>::AutoNTTPClass<&public: void __cdecl S::f(void)>(void)
67+
68+
??0?$AutoNTTPClass@$1?f@S@@QEAAXXZ@@QEAA@XZ
69+
; CHECK: public: __cdecl AutoNTTPClass<&public: void __cdecl S::f(void)>::AutoNTTPClass<&public: void __cdecl S::f(void)>(void)
70+
71+
??0?$AutoNTTPClass@$MP8M@@EAAXXZH?f@1@QEAAXXZA@@@QEAA@XZ
72+
; CHECK: public: __cdecl AutoNTTPClass<{public: void __cdecl M::f(void), 0}>::AutoNTTPClass<{public: void __cdecl M::f(void), 0}>(void)
73+
74+
??0?$AutoNTTPClass@$H?f@M@@QEAAXXZA@@@QEAA@XZ
75+
; CHECK: public: __cdecl AutoNTTPClass<{public: void __cdecl M::f(void), 0}>::AutoNTTPClass<{public: void __cdecl M::f(void), 0}>(void)
76+
77+
??0?$AutoNTTPClass@$MP8V@@EAAXXZI?f@1@QEAAXXZA@A@@@QEAA@XZ
78+
; CHECK: public: __cdecl AutoNTTPClass<{public: void __cdecl V::f(void), 0, 0}>::AutoNTTPClass<{public: void __cdecl V::f(void), 0, 0}>(void)
79+
80+
??0?$AutoNTTPClass@$I?f@V@@QEAAXXZA@A@@@QEAA@XZ
81+
; CHECK: public: __cdecl AutoNTTPClass<{public: void __cdecl V::f(void), 0, 0}>::AutoNTTPClass<{public: void __cdecl V::f(void), 0, 0}>(void)
82+
83+
??0?$AutoNTTPClass@$MPEQS@@H07@@QEAA@XZ
84+
; CHECK: public: __cdecl AutoNTTPClass<8>::AutoNTTPClass<8>(void)
85+
86+
??0?$AutoNTTPClass@$07@@QEAA@XZ
87+
; CHECK: public: __cdecl AutoNTTPClass<8>::AutoNTTPClass<8>(void)
88+
89+
??0?$AutoNTTPClass@$MPEQM@@H0M@@@QEAA@XZ
90+
; CHECK: public: __cdecl AutoNTTPClass<12>::AutoNTTPClass<12>(void)
91+
92+
??0?$AutoNTTPClass@$0M@@@QEAA@XZ
93+
; CHECK: public: __cdecl AutoNTTPClass<12>::AutoNTTPClass<12>(void)
94+
95+
??0?$AutoNTTPClass@$MPEQV@@HFBA@A@@@QEAA@XZ
96+
; CHECK: public: __cdecl AutoNTTPClass<{16, 0}>::AutoNTTPClass<{16, 0}>(void)
97+
98+
??0?$AutoNTTPClass@$FBA@A@@@QEAA@XZ
99+
; CHECK: public: __cdecl AutoNTTPClass<{16, 0}>::AutoNTTPClass<{16, 0}>(void)

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