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MS ABI: Implement the MSVC 2015 scheme for scope disambiguation 

consider C++ that looks like:
  inline int &f(bool b) {
    if (b) {
      static int i;
      return i;
    }
    static int i;
    return i;
  }

Both 'i' variables must have distinct (and stable) names for linkage
purposes.  The MSVC 2013 ABI would number the variables using a count of
the number of scopes that have been created.  However, the final 'i'
returns to a scope that has already been created leading to a mangling
collision.

MSVC 2015 fixes this by giving the second 'i' the name it would have if
it were declared before the 'if'.  However, this results in ABI breakage
because the mangled name, in cases where there was no ambiguity, would
now be different.

We implement the new behavior and only enable it if we are targeting the
MSVC 2015 ABI, otherwise the old behavior will be used.

This fixes PR18131.

llvm-svn: 232766
This commit is contained in:
David Majnemer 2015-03-19 21:54:30 +00:00
parent 0a93e2db9c
commit a7f8c46439
9 changed files with 79 additions and 45 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
clang/include/clang/Parse/Parser.h
View File

@ -245,8 +245,8 @@ public:
const Token &getCurToken() const { return Tok; }
Scope *getCurScope() const { return Actions.getCurScope(); }
void incrementMSLocalManglingNumber() const {
return Actions.incrementMSLocalManglingNumber();
void incrementMSManglingNumber() const {
return Actions.incrementMSManglingNumber();
}
Decl *getObjCDeclContext() const { return Actions.getObjCDeclContext(); }
@ -759,7 +759,7 @@ public:
Self->EnterScope(ScopeFlags);
else {
if (BeforeCompoundStmt)
Self->incrementMSLocalManglingNumber();
Self->incrementMSManglingNumber();
this->Self = nullptr;
}

38
clang/include/clang/Sema/Scope.h
View File

@ -139,7 +139,9 @@ private:
/// \brief Declarations with static linkage are mangled with the number of
/// scopes seen as a component.
unsigned short MSLocalManglingNumber;
unsigned short MSLastManglingNumber;
unsigned short MSCurManglingNumber;
/// PrototypeDepth - This is the number of function prototype scopes
/// enclosing this scope, including this scope.
@ -152,7 +154,7 @@ private:
/// FnParent - If this scope has a parent scope that is a function body, this
/// pointer is non-null and points to it. This is used for label processing.
Scope *FnParent;
Scope *MSLocalManglingParent;
Scope *MSLastManglingParent;
/// BreakParent/ContinueParent - This is a direct link to the innermost
/// BreakScope/ContinueScope which contains the contents of this scope
@ -218,10 +220,10 @@ public:
const Scope *getFnParent() const { return FnParent; }
Scope *getFnParent() { return FnParent; }
const Scope *getMSLocalManglingParent() const {
return MSLocalManglingParent;
const Scope *getMSLastManglingParent() const {
return MSLastManglingParent;
}
Scope *getMSLocalManglingParent() { return MSLocalManglingParent; }
Scope *getMSLastManglingParent() { return MSLastManglingParent; }
/// getContinueParent - Return the closest scope that a continue statement
/// would be affected by.
@ -275,22 +277,30 @@ public:
DeclsInScope.erase(D);
}
void incrementMSLocalManglingNumber() {
if (Scope *MSLMP = getMSLocalManglingParent())
MSLMP->MSLocalManglingNumber += 1;
void incrementMSManglingNumber() {
if (Scope *MSLMP = getMSLastManglingParent()) {
MSLMP->MSLastManglingNumber += 1;
MSCurManglingNumber += 1;
}
}
void decrementMSLocalManglingNumber() {
if (Scope *MSLMP = getMSLocalManglingParent())
MSLMP->MSLocalManglingNumber -= 1;
void decrementMSManglingNumber() {
if (Scope *MSLMP = getMSLastManglingParent()) {
MSLMP->MSLastManglingNumber -= 1;
MSCurManglingNumber -= 1;
}
}
unsigned getMSLocalManglingNumber() const {
if (const Scope *MSLMP = getMSLocalManglingParent())
return MSLMP->MSLocalManglingNumber;
unsigned getMSLastManglingNumber() const {
if (const Scope *MSLMP = getMSLastManglingParent())
return MSLMP->MSLastManglingNumber;
return 1;
}
unsigned getMSCurManglingNumber() const {
return MSCurManglingNumber;
}
/// isDeclScope - Return true if this is the scope that the specified decl is
/// declared in.
bool isDeclScope(Decl *D) {

4
clang/include/clang/Sema/Sema.h
View File

@ -8610,8 +8610,8 @@ public:
/// template substitution or instantiation.
Scope *getCurScope() const { return CurScope; }
void incrementMSLocalManglingNumber() const {
return CurScope->incrementMSLocalManglingNumber();
void incrementMSManglingNumber() const {
return CurScope->incrementMSManglingNumber();
}
IdentifierInfo *getSuperIdentifier() const;

4
clang/lib/Parse/ParseStmt.cpp
View File

@ -1268,7 +1268,7 @@ StmtResult Parser::ParseSwitchStatement(SourceLocation *TrailingElseLoc) {
// We have incremented the mangling number for the SwitchScope and the
// InnerScope, which is one too many.
if (C99orCXX)
getCurScope()->decrementMSLocalManglingNumber();
getCurScope()->decrementMSManglingNumber();
// Read the body statement.
StmtResult Body(ParseStatement(TrailingElseLoc));
@ -1710,7 +1710,7 @@ StmtResult Parser::ParseForStatement(SourceLocation *TrailingElseLoc) {
// It will only be incremented if the body contains other things that would
// normally increment the mangling number (like a compound statement).
if (C99orCXXorObjC)
getCurScope()->decrementMSLocalManglingNumber();
getCurScope()->decrementMSManglingNumber();
// Read the body statement.
StmtResult Body(ParseStatement(TrailingElseLoc));

20
clang/lib/Sema/Scope.cpp
View File

@ -38,7 +38,8 @@ void Scope::Init(Scope *parent, unsigned flags) {
FnParent = parent->FnParent;
BlockParent = parent->BlockParent;
TemplateParamParent = parent->TemplateParamParent;
MSLocalManglingParent = parent->MSLocalManglingParent;
MSLastManglingParent = parent->MSLastManglingParent;
MSCurManglingNumber = getMSLastManglingNumber();
if ((Flags & (FnScope | ClassScope | BlockScope | TemplateParamScope |
FunctionPrototypeScope | AtCatchScope | ObjCMethodScope)) ==
0)
@ -47,9 +48,10 @@ void Scope::Init(Scope *parent, unsigned flags) {
Depth = 0;
PrototypeDepth = 0;
PrototypeIndex = 0;
MSLocalManglingParent = FnParent = BlockParent = nullptr;
MSLastManglingParent = FnParent = BlockParent = nullptr;
TemplateParamParent = nullptr;
MSLocalManglingNumber = 1;
MSLastManglingNumber = 1;
MSCurManglingNumber = 1;
}
// If this scope is a function or contains breaks/continues, remember it.
@ -57,8 +59,9 @@ void Scope::Init(Scope *parent, unsigned flags) {
// The MS mangler uses the number of scopes that can hold declarations as
// part of an external name.
if (Flags & (ClassScope | FnScope)) {
MSLocalManglingNumber = getMSLocalManglingNumber();
MSLocalManglingParent = this;
MSLastManglingNumber = getMSLastManglingNumber();
MSLastManglingParent = this;
MSCurManglingNumber = 1;
}
if (flags & BreakScope) BreakParent = this;
if (flags & ContinueScope) ContinueParent = this;
@ -78,7 +81,7 @@ void Scope::Init(Scope *parent, unsigned flags) {
else if ((flags & EnumScope))
; // Don't increment for enum scopes.
else
incrementMSLocalManglingNumber();
incrementMSManglingNumber();
}
DeclsInScope.clear();
@ -209,12 +212,13 @@ void Scope::dumpImpl(raw_ostream &OS) const {
OS << "Parent: (clang::Scope*)" << Parent << '\n';
OS << "Depth: " << Depth << '\n';
OS << "MSLocalManglingNumber: " << getMSLocalManglingNumber() << '\n';
OS << "MSLastManglingNumber: " << getMSLastManglingNumber() << '\n';
OS << "MSCurManglingNumber: " << getMSCurManglingNumber() << '\n';
if (const DeclContext *DC = getEntity())
OS << "Entity : (clang::DeclContext*)" << DC << '\n';
if (NRVO.getInt())
OS << "NRVO not allowed";
OS << "NRVO not allowed\n";
else if (NRVO.getPointer())
OS << "NRVO candidate : (clang::VarDecl*)" << NRVO.getPointer() << '\n';
}

35
clang/lib/Sema/SemaDecl.cpp
View File

@ -3416,6 +3416,17 @@ Decl *Sema::ParsedFreeStandingDeclSpec(Scope *S, AccessSpecifier AS,
return ParsedFreeStandingDeclSpec(S, AS, DS, MultiTemplateParamsArg());
}
// The MS ABI changed between VS2013 and VS2015 with regard to numbers used to
// disambiguate entities defined in different scopes.
// While the VS2015 ABI fixes potential miscompiles, it is also breaks
// compatibility.
// We will pick our mangling number depending on which version of MSVC is being
// targeted.
static unsigned getMSManglingNumber(const LangOptions &LO, Scope *S) {
return LO.isCompatibleWithMSVC(19) ? S->getMSCurManglingNumber()
: S->getMSLastManglingNumber();
}
void Sema::handleTagNumbering(const TagDecl *Tag, Scope *TagScope) {
if (!Context.getLangOpts().CPlusPlus)
return;
@ -3428,7 +3439,8 @@ void Sema::handleTagNumbering(const TagDecl *Tag, Scope *TagScope) {
MangleNumberingContext &MCtx =
Context.getManglingNumberContext(Tag->getParent());
Context.setManglingNumber(
Tag, MCtx.getManglingNumber(Tag, TagScope->getMSLocalManglingNumber()));
Tag, MCtx.getManglingNumber(
Tag, getMSManglingNumber(getLangOpts(), TagScope)));
return;
}
@ -3437,8 +3449,8 @@ void Sema::handleTagNumbering(const TagDecl *Tag, Scope *TagScope) {
if (MangleNumberingContext *MCtx = getCurrentMangleNumberContext(
Tag->getDeclContext(), ManglingContextDecl)) {
Context.setManglingNumber(
Tag,
MCtx->getManglingNumber(Tag, TagScope->getMSLocalManglingNumber()));
Tag, MCtx->getManglingNumber(
Tag, getMSManglingNumber(getLangOpts(), TagScope)));
}
}
@ -4135,10 +4147,11 @@ Decl *Sema::BuildAnonymousStructOrUnion(Scope *S, DeclSpec &DS,
if (VarDecl *NewVD = dyn_cast<VarDecl>(Anon)) {
if (getLangOpts().CPlusPlus && NewVD->isStaticLocal()) {
Decl *ManglingContextDecl;
if (MangleNumberingContext *MCtx =
getCurrentMangleNumberContext(NewVD->getDeclContext(),
ManglingContextDecl)) {
Context.setManglingNumber(NewVD, MCtx->getManglingNumber(NewVD, S->getMSLocalManglingNumber()));
if (MangleNumberingContext *MCtx = getCurrentMangleNumberContext(
NewVD->getDeclContext(), ManglingContextDecl)) {
Context.setManglingNumber(
NewVD, MCtx->getManglingNumber(
NewVD, getMSManglingNumber(getLangOpts(), S)));
Context.setStaticLocalNumber(NewVD, MCtx->getStaticLocalNumber(NewVD));
}
}
@ -5925,11 +5938,11 @@ Sema::ActOnVariableDeclarator(Scope *S, Declarator &D, DeclContext *DC,
if (getLangOpts().CPlusPlus && NewVD->isStaticLocal()) {
Decl *ManglingContextDecl;
if (MangleNumberingContext *MCtx =
getCurrentMangleNumberContext(NewVD->getDeclContext(),
ManglingContextDecl)) {
if (MangleNumberingContext *MCtx = getCurrentMangleNumberContext(
NewVD->getDeclContext(), ManglingContextDecl)) {
Context.setManglingNumber(
NewVD, MCtx->getManglingNumber(NewVD, S->getMSLocalManglingNumber()));
NewVD, MCtx->getManglingNumber(
NewVD, getMSManglingNumber(getLangOpts(), S)));
Context.setStaticLocalNumber(NewVD, MCtx->getStaticLocalNumber(NewVD));
}
}

6
clang/test/CodeGenCXX/mangle-ms-abi-examples.cpp
View File

@ -1,8 +1,10 @@
// RUN: %clang_cc1 -fms-extensions -fno-rtti -emit-llvm %s -o - -triple=i386-pc-win32 | FileCheck %s
// RUN: %clang_cc1 -fms-extensions -fno-rtti -emit-llvm %s -o - -triple=i386-pc-win32 -fms-compatibility-version=19.00 | FileCheck %s --check-prefix=CHECK --check-prefix=MSVC2015
// RUN: %clang_cc1 -fms-extensions -fno-rtti -emit-llvm %s -o - -triple=i386-pc-win32 -fms-compatibility-version=18.00 | FileCheck %s --check-prefix=CHECK --check-prefix=MSVC2013
// CHECK: @"\01??_7B@?1??foo@A@@QAEXH@Z@6B@" =
// CHECK: @"\01??_7D@C@?1??foo@@YAXXZ@6B@" =
// CHECK: define {{.*}} @"\01?baz@E@?3??bar@C@?1??foo@@YAXXZ@QAEXXZ@QAEXXZ"(
// MSVC2013: define {{.*}} @"\01?baz@E@?3??bar@C@?1??foo@@YAXXZ@QAEXXZ@QAEXXZ"(
// MSVC2015: define {{.*}} @"\01?baz@E@?1??bar@C@?1??foo@@YAXXZ@QAEXXZ@QAEXXZ"(
// Microsoft Visual C++ ABI examples.
struct A {

3
clang/test/CodeGenCXX/mangle-ms-cxx11.cpp
View File

@ -172,7 +172,8 @@ inline int define_lambda() {
// CHECK-DAG: @"\01??R<lambda_1>@?define_lambda@@YAHXZ@QBEHXZ"
// Finally, we have the local which is inside of "<lambda_1>" which is inside of
// "define_lambda". Hooray.
// CHECK-DAG: @"\01?local@?2???R<lambda_1>@?define_lambda@@YAHXZ@QBEHXZ@4HA"
// MSVC2013-DAG: @"\01?local@?2???R<lambda_1>@?define_lambda@@YAHXZ@QBEHXZ@4HA"
// MSVC2015-DAG: @"\01?local@?1???R<lambda_1>@?define_lambda@@YAHXZ@QBEHXZ@4HA"
return lambda();
}

8
clang/test/CodeGenCXX/mangle-ms-cxx14.cpp
View File

@ -1,4 +1,5 @@
// RUN: %clang_cc1 -std=c++1y -fms-extensions -emit-llvm %s -o - -triple=i386-pc-win32 | FileCheck %s
// RUN: %clang_cc1 -std=c++1y -fms-extensions -emit-llvm %s -o - -triple=i386-pc-win32 -fms-compatibility-version=19.00 | FileCheck %s --check-prefix=CHECK --check-prefix=MSVC2015
// RUN: %clang_cc1 -std=c++1y -fms-extensions -emit-llvm %s -o - -triple=i386-pc-win32 -fms-compatibility-version=18.00 | FileCheck %s --check-prefix=CHECK --check-prefix=MSVC2013
template <typename> int x = 0;
@ -34,7 +35,10 @@ auto TemplateFuncionWithLocalLambda(T) {
return LocalLambdaWithLocalType();
}
// CHECK: "\01?ValueFromTemplateFuncionWithLocalLambda@@3ULocalType@?2???R<lambda_1>@??$TemplateFuncionWithLocalLambda@H@@YA?A?<auto>@@H@Z@QBA?A?3@XZ@A"
// MSVC2013-DAG: "\01?ValueFromTemplateFuncionWithLocalLambda@@3ULocalType@?2???R<lambda_1>@??$TemplateFuncionWithLocalLambda@H@@YA?A?<auto>@@H@Z@QBA?A?3@XZ@A"
// MSVC2013-DAG: "\01?ValueFromTemplateFuncionWithLocalLambda@@3ULocalType@?2???R<lambda_1>@??$TemplateFuncionWithLocalLambda@H@@YA?A?<auto>@@H@Z@QBA?A?3@XZ@A"
// MSVC2015-DAG: "\01?ValueFromTemplateFuncionWithLocalLambda@@3ULocalType@?1???R<lambda_1>@??$TemplateFuncionWithLocalLambda@H@@YA?A?<auto>@@H@Z@QBA?A?3@XZ@A"
// MSVC2015-DAG: "\01?ValueFromTemplateFuncionWithLocalLambda@@3ULocalType@?1???R<lambda_1>@??$TemplateFuncionWithLocalLambda@H@@YA?A?<auto>@@H@Z@QBA?A?3@XZ@A"
// CHECK: "\01??$TemplateFuncionWithLocalLambda@H@@YA?A?<auto>@@H@Z"
// CHECK: "\01??R<lambda_1>@??$TemplateFuncionWithLocalLambda@H@@YA?A?<auto>@@H@Z@QBA?A?1@XZ"
auto ValueFromTemplateFuncionWithLocalLambda = TemplateFuncionWithLocalLambda(0);