r313827 - Give external linkage and mangling to lambdas inside inline variables and variable templates.
Richard Smith via cfe-commits
cfe-commits at lists.llvm.org
Wed Sep 20 15:17:55 PDT 2017
Author: rsmith
Date: Wed Sep 20 15:17:55 2017
New Revision: 313827
URL: http://llvm.org/viewvc/llvm-project?rev=313827&view=rev
Log:
Give external linkage and mangling to lambdas inside inline variables and variable templates.
This implements the proposed approach in https://github.com/itanium-cxx-abi/cxx-abi/issues/33
Modified:
cfe/trunk/lib/AST/Decl.cpp
cfe/trunk/lib/AST/ItaniumMangle.cpp
cfe/trunk/lib/AST/Linkage.h
cfe/trunk/lib/Parse/ParseDecl.cpp
cfe/trunk/lib/Sema/SemaDeclCXX.cpp
cfe/trunk/lib/Sema/SemaLambda.cpp
cfe/trunk/lib/Sema/SemaTemplateInstantiateDecl.cpp
cfe/trunk/test/CodeGenCXX/mangle-lambdas.cpp
cfe/trunk/test/SemaCXX/vartemplate-lambda.cpp
cfe/trunk/test/SemaTemplate/instantiate-static-var.cpp
Modified: cfe/trunk/lib/AST/Decl.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/Decl.cpp?rev=313827&r1=313826&r2=313827&view=diff
==============================================================================
--- cfe/trunk/lib/AST/Decl.cpp (original)
+++ cfe/trunk/lib/AST/Decl.cpp Wed Sep 20 15:17:55 2017
@@ -676,10 +676,10 @@ LinkageComputer::getLVForNamespaceScopeD
if (!LV.isVisibilityExplicit()) {
// Use global type/value visibility as appropriate.
Visibility globalVisibility;
- if (computation == LVForValue) {
+ if ((computation & ~IgnoreTypeLinkageBit) == LVForValue) {
globalVisibility = Context.getLangOpts().getValueVisibilityMode();
} else {
- assert(computation == LVForType);
+ assert((computation & ~IgnoreTypeLinkageBit) == LVForType);
globalVisibility = Context.getLangOpts().getTypeVisibilityMode();
}
LV.mergeVisibility(globalVisibility, /*explicit*/ false);
@@ -719,7 +719,8 @@ LinkageComputer::getLVForNamespaceScopeD
//
// Note that we don't want to make the variable non-external
// because of this, but unique-external linkage suits us.
- if (Context.getLangOpts().CPlusPlus && !isFirstInExternCContext(Var)) {
+ if (Context.getLangOpts().CPlusPlus && !isFirstInExternCContext(Var) &&
+ !(computation & IgnoreTypeLinkageBit)) {
LinkageInfo TypeLV = getLVForType(*Var->getType(), computation);
if (!isExternallyVisible(TypeLV.getLinkage()))
return LinkageInfo::uniqueExternal();
@@ -759,8 +760,8 @@ LinkageComputer::getLVForNamespaceScopeD
// unique-external linkage, it's not legally usable from outside
// this translation unit. However, we should use the C linkage
// rules instead for extern "C" declarations.
- if (Context.getLangOpts().CPlusPlus &&
- !Function->isInExternCContext()) {
+ if (Context.getLangOpts().CPlusPlus && !Function->isInExternCContext() &&
+ !(computation & IgnoreTypeLinkageBit)) {
// Only look at the type-as-written. If this function has an auto-deduced
// return type, we can't compute the linkage of that type because it could
// require looking at the linkage of this function, and we don't need this
@@ -1122,8 +1123,18 @@ LinkageInfo LinkageComputer::getLVForClo
// calculation determines the lambda has external linkage, it should be
// downgraded to VisibleNoLinkage.
if (ContextDecl) {
+ auto *VD = dyn_cast<VarDecl>(ContextDecl);
if (isa<ParmVarDecl>(ContextDecl))
DC = ContextDecl->getDeclContext()->getRedeclContext();
+ else if (VD && VD->getType()->getContainedDeducedType())
+ // If the declaration has a deduced type, we need to skip querying the
+ // linkage and visibility of that type, because it might involve this
+ // closure type. The only effect of this is that we might give a lambda
+ // VisibleNoLinkage rather than NoLinkage when we don't strictly need to,
+ // which is benign.
+ return computeLVForDecl(
+ cast<NamedDecl>(ContextDecl),
+ LVComputationKind(computation | IgnoreTypeLinkageBit));
else
return getLVForDecl(cast<NamedDecl>(ContextDecl), computation);
}
Modified: cfe/trunk/lib/AST/ItaniumMangle.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/ItaniumMangle.cpp?rev=313827&r1=313826&r2=313827&view=diff
==============================================================================
--- cfe/trunk/lib/AST/ItaniumMangle.cpp (original)
+++ cfe/trunk/lib/AST/ItaniumMangle.cpp Wed Sep 20 15:17:55 2017
@@ -1691,10 +1691,16 @@ void CXXNameMangler::mangleLambda(const
// to emit that last part of the prefix here.
if (Decl *Context = Lambda->getLambdaContextDecl()) {
if ((isa<VarDecl>(Context) || isa<FieldDecl>(Context)) &&
- Context->getDeclContext()->isRecord()) {
+ !isa<ParmVarDecl>(Context)) {
+ // FIXME: 'inline auto [a, b] = []{ return ... };' does not get a
+ // reasonable mangling here.
if (const IdentifierInfo *Name
= cast<NamedDecl>(Context)->getIdentifier()) {
mangleSourceName(Name);
+ const TemplateArgumentList *TemplateArgs = nullptr;
+ if (const TemplateDecl *TD =
+ isTemplate(cast<NamedDecl>(Context), TemplateArgs))
+ mangleTemplateArgs(*TemplateArgs);
Out << 'M';
}
}
Modified: cfe/trunk/lib/AST/Linkage.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/Linkage.h?rev=313827&r1=313826&r2=313827&view=diff
==============================================================================
--- cfe/trunk/lib/AST/Linkage.h (original)
+++ cfe/trunk/lib/AST/Linkage.h Wed Sep 20 15:17:55 2017
@@ -24,7 +24,8 @@
namespace clang {
enum : unsigned {
IgnoreExplicitVisibilityBit = 2,
- IgnoreAllVisibilityBit = 4
+ IgnoreAllVisibilityBit = 4,
+ IgnoreTypeLinkageBit = 8,
};
/// Kinds of LV computation. The linkage side of the computation is
Modified: cfe/trunk/lib/Parse/ParseDecl.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Parse/ParseDecl.cpp?rev=313827&r1=313826&r2=313827&view=diff
==============================================================================
--- cfe/trunk/lib/Parse/ParseDecl.cpp (original)
+++ cfe/trunk/lib/Parse/ParseDecl.cpp Wed Sep 20 15:17:55 2017
@@ -2131,6 +2131,37 @@ Decl *Parser::ParseDeclarationAfterDecla
Decl *Parser::ParseDeclarationAfterDeclaratorAndAttributes(
Declarator &D, const ParsedTemplateInfo &TemplateInfo, ForRangeInit *FRI) {
+ // RAII type used to track whether we're inside an initializer.
+ struct InitializerScopeRAII {
+ Parser &P;
+ Declarator &D;
+ Decl *ThisDecl;
+
+ InitializerScopeRAII(Parser &P, Declarator &D, Decl *ThisDecl)
+ : P(P), D(D), ThisDecl(ThisDecl) {
+ if (ThisDecl && P.getLangOpts().CPlusPlus) {
+ Scope *S = nullptr;
+ if (D.getCXXScopeSpec().isSet()) {
+ P.EnterScope(0);
+ S = P.getCurScope();
+ }
+ P.Actions.ActOnCXXEnterDeclInitializer(S, ThisDecl);
+ }
+ }
+ ~InitializerScopeRAII() { pop(); }
+ void pop() {
+ if (ThisDecl && P.getLangOpts().CPlusPlus) {
+ Scope *S = nullptr;
+ if (D.getCXXScopeSpec().isSet())
+ S = P.getCurScope();
+ P.Actions.ActOnCXXExitDeclInitializer(S, ThisDecl);
+ if (S)
+ P.ExitScope();
+ }
+ ThisDecl = nullptr;
+ }
+ };
+
// Inform the current actions module that we just parsed this declarator.
Decl *ThisDecl = nullptr;
switch (TemplateInfo.Kind) {
@@ -2208,10 +2239,7 @@ Decl *Parser::ParseDeclarationAfterDecla
else
Diag(ConsumeToken(), diag::err_default_special_members);
} else {
- if (getLangOpts().CPlusPlus && D.getCXXScopeSpec().isSet()) {
- EnterScope(0);
- Actions.ActOnCXXEnterDeclInitializer(getCurScope(), ThisDecl);
- }
+ InitializerScopeRAII InitScope(*this, D, ThisDecl);
if (Tok.is(tok::code_completion)) {
Actions.CodeCompleteInitializer(getCurScope(), ThisDecl);
@@ -2234,10 +2262,7 @@ Decl *Parser::ParseDeclarationAfterDecla
FRI->RangeExpr = Init;
}
- if (getLangOpts().CPlusPlus && D.getCXXScopeSpec().isSet()) {
- Actions.ActOnCXXExitDeclInitializer(getCurScope(), ThisDecl);
- ExitScope();
- }
+ InitScope.pop();
if (Init.isInvalid()) {
SmallVector<tok::TokenKind, 2> StopTokens;
@@ -2259,10 +2284,7 @@ Decl *Parser::ParseDeclarationAfterDecla
ExprVector Exprs;
CommaLocsTy CommaLocs;
- if (getLangOpts().CPlusPlus && D.getCXXScopeSpec().isSet()) {
- EnterScope(0);
- Actions.ActOnCXXEnterDeclInitializer(getCurScope(), ThisDecl);
- }
+ InitializerScopeRAII InitScope(*this, D, ThisDecl);
llvm::function_ref<void()> ExprListCompleter;
auto ThisVarDecl = dyn_cast_or_null<VarDecl>(ThisDecl);
@@ -2283,11 +2305,6 @@ Decl *Parser::ParseDeclarationAfterDecla
if (ParseExpressionList(Exprs, CommaLocs, ExprListCompleter)) {
Actions.ActOnInitializerError(ThisDecl);
SkipUntil(tok::r_paren, StopAtSemi);
-
- if (getLangOpts().CPlusPlus && D.getCXXScopeSpec().isSet()) {
- Actions.ActOnCXXExitDeclInitializer(getCurScope(), ThisDecl);
- ExitScope();
- }
} else {
// Match the ')'.
T.consumeClose();
@@ -2295,10 +2312,7 @@ Decl *Parser::ParseDeclarationAfterDecla
assert(!Exprs.empty() && Exprs.size()-1 == CommaLocs.size() &&
"Unexpected number of commas!");
- if (getLangOpts().CPlusPlus && D.getCXXScopeSpec().isSet()) {
- Actions.ActOnCXXExitDeclInitializer(getCurScope(), ThisDecl);
- ExitScope();
- }
+ InitScope.pop();
ExprResult Initializer = Actions.ActOnParenListExpr(T.getOpenLocation(),
T.getCloseLocation(),
@@ -2311,17 +2325,11 @@ Decl *Parser::ParseDeclarationAfterDecla
// Parse C++0x braced-init-list.
Diag(Tok, diag::warn_cxx98_compat_generalized_initializer_lists);
- if (D.getCXXScopeSpec().isSet()) {
- EnterScope(0);
- Actions.ActOnCXXEnterDeclInitializer(getCurScope(), ThisDecl);
- }
+ InitializerScopeRAII InitScope(*this, D, ThisDecl);
ExprResult Init(ParseBraceInitializer());
- if (D.getCXXScopeSpec().isSet()) {
- Actions.ActOnCXXExitDeclInitializer(getCurScope(), ThisDecl);
- ExitScope();
- }
+ InitScope.pop();
if (Init.isInvalid()) {
Actions.ActOnInitializerError(ThisDecl);
Modified: cfe/trunk/lib/Sema/SemaDeclCXX.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDeclCXX.cpp?rev=313827&r1=313826&r2=313827&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaDeclCXX.cpp (original)
+++ cfe/trunk/lib/Sema/SemaDeclCXX.cpp Wed Sep 20 15:17:55 2017
@@ -14240,21 +14240,22 @@ void Sema::ActOnPureSpecifier(Decl *D, S
Diag(D->getLocation(), diag::err_illegal_initializer);
}
-/// \brief Determine whether the given declaration is a static data member.
-static bool isStaticDataMember(const Decl *D) {
+/// \brief Determine whether the given declaration is a global variable or
+/// static data member.
+static bool isNonlocalVariable(const Decl *D) {
if (const VarDecl *Var = dyn_cast_or_null<VarDecl>(D))
- return Var->isStaticDataMember();
+ return Var->hasGlobalStorage();
return false;
}
-/// ActOnCXXEnterDeclInitializer - Invoked when we are about to parse
-/// an initializer for the out-of-line declaration 'Dcl'. The scope
-/// is a fresh scope pushed for just this purpose.
+/// Invoked when we are about to parse an initializer for the declaration
+/// 'Dcl'.
///
/// After this method is called, according to [C++ 3.4.1p13], if 'Dcl' is a
/// static data member of class X, names should be looked up in the scope of
-/// class X.
+/// class X. If the declaration had a scope specifier, a scope will have
+/// been created and passed in for this purpose. Otherwise, S will be null.
void Sema::ActOnCXXEnterDeclInitializer(Scope *S, Decl *D) {
// If there is no declaration, there was an error parsing it.
if (!D || D->isInvalidDecl())
@@ -14264,28 +14265,27 @@ void Sema::ActOnCXXEnterDeclInitializer(
// might not be out of line if the specifier names the current namespace:
// extern int n;
// int ::n = 0;
- if (D->isOutOfLine())
+ if (S && D->isOutOfLine())
EnterDeclaratorContext(S, D->getDeclContext());
// If we are parsing the initializer for a static data member, push a
// new expression evaluation context that is associated with this static
// data member.
- if (isStaticDataMember(D))
+ if (isNonlocalVariable(D))
PushExpressionEvaluationContext(
ExpressionEvaluationContext::PotentiallyEvaluated, D);
}
-/// ActOnCXXExitDeclInitializer - Invoked after we are finished parsing an
-/// initializer for the out-of-line declaration 'D'.
+/// Invoked after we are finished parsing an initializer for the declaration D.
void Sema::ActOnCXXExitDeclInitializer(Scope *S, Decl *D) {
// If there is no declaration, there was an error parsing it.
if (!D || D->isInvalidDecl())
return;
- if (isStaticDataMember(D))
+ if (isNonlocalVariable(D))
PopExpressionEvaluationContext();
- if (D->isOutOfLine())
+ if (S && D->isOutOfLine())
ExitDeclaratorContext(S);
}
Modified: cfe/trunk/lib/Sema/SemaLambda.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaLambda.cpp?rev=313827&r1=313826&r2=313827&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaLambda.cpp (original)
+++ cfe/trunk/lib/Sema/SemaLambda.cpp Wed Sep 20 15:17:55 2017
@@ -288,7 +288,9 @@ Sema::getCurrentMangleNumberContext(cons
Normal,
DefaultArgument,
DataMember,
- StaticDataMember
+ StaticDataMember,
+ InlineVariable,
+ VariableTemplate
} Kind = Normal;
// Default arguments of member function parameters that appear in a class
@@ -303,6 +305,14 @@ Sema::getCurrentMangleNumberContext(cons
} else if (VarDecl *Var = dyn_cast<VarDecl>(ManglingContextDecl)) {
if (Var->getDeclContext()->isRecord())
Kind = StaticDataMember;
+ else if (Var->getMostRecentDecl()->isInline())
+ Kind = InlineVariable;
+ else if (Var->getDescribedVarTemplate())
+ Kind = VariableTemplate;
+ else if (auto *VTS = dyn_cast<VarTemplateSpecializationDecl>(Var)) {
+ if (!VTS->isExplicitSpecialization())
+ Kind = VariableTemplate;
+ }
} else if (isa<FieldDecl>(ManglingContextDecl)) {
Kind = DataMember;
}
@@ -343,6 +353,10 @@ Sema::getCurrentMangleNumberContext(cons
// -- the in-class initializers of class members
case DefaultArgument:
// -- default arguments appearing in class definitions
+ case InlineVariable:
+ // -- the initializers of inline variables
+ case VariableTemplate:
+ // -- the initializers of templated variables
return &ExprEvalContexts.back().getMangleNumberingContext(Context);
}
Modified: cfe/trunk/lib/Sema/SemaTemplateInstantiateDecl.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaTemplateInstantiateDecl.cpp?rev=313827&r1=313826&r2=313827&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaTemplateInstantiateDecl.cpp (original)
+++ cfe/trunk/lib/Sema/SemaTemplateInstantiateDecl.cpp Wed Sep 20 15:17:55 2017
@@ -4140,12 +4140,8 @@ void Sema::InstantiateVariableInitialize
Var->setImplicitlyInline();
if (OldVar->getInit()) {
- if (Var->isStaticDataMember() && !OldVar->isOutOfLine())
- PushExpressionEvaluationContext(
- Sema::ExpressionEvaluationContext::ConstantEvaluated, OldVar);
- else
- PushExpressionEvaluationContext(
- Sema::ExpressionEvaluationContext::PotentiallyEvaluated, OldVar);
+ EnterExpressionEvaluationContext Evaluated(
+ *this, Sema::ExpressionEvaluationContext::PotentiallyEvaluated, Var);
// Instantiate the initializer.
ExprResult Init;
@@ -4173,8 +4169,6 @@ void Sema::InstantiateVariableInitialize
// because of a bogus initializer.
Var->setInvalidDecl();
}
-
- PopExpressionEvaluationContext();
} else {
if (Var->isStaticDataMember()) {
if (!Var->isOutOfLine())
Modified: cfe/trunk/test/CodeGenCXX/mangle-lambdas.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/mangle-lambdas.cpp?rev=313827&r1=313826&r2=313827&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenCXX/mangle-lambdas.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/mangle-lambdas.cpp Wed Sep 20 15:17:55 2017
@@ -26,6 +26,24 @@ void call_inline_func() {
inline_func(17);
}
+// CHECK-LABEL: define linkonce_odr i32* @_ZNK10inline_varMUlvE_clEv(
+// CHECK: @_ZZNK10inline_varMUlvE_clEvE1n
+inline auto inline_var = [] {
+ static int n = 5;
+ return &n;
+};
+
+int *use_inline_var = inline_var();
+
+// CHECK-LABEL: define linkonce_odr i32* @_ZNK12var_templateIiEMUlvE_clEv(
+// CHECK: @_ZZNK12var_templateIiEMUlvE_clEvE1n
+template<typename T> auto var_template = [] {
+ static int n = 9;
+ return &n;
+};
+
+int *use_var_template = var_template<int>();
+
struct S {
void f(int = []{return 1;}()
+ []{return 2;}(),
@@ -118,7 +136,7 @@ T StaticMembers<T>::z = accept_lambda([]
template<typename T>
int (*StaticMembers<T>::f)() = []{return 5;};
-// CHECK-LABEL: define internal void @__cxx_global_var_init()
+// CHECK-LABEL: define internal void @__cxx_global_var_init
// CHECK: call i32 @_ZNK13StaticMembersIfE1xMUlvE_clEv
// CHECK-NEXT: call i32 @_ZNK13StaticMembersIfE1xMUlvE0_clEv
// CHECK-NEXT: add nsw
@@ -128,23 +146,23 @@ int (*StaticMembers<T>::f)() = []{return
// CHECK: ret i32 2
template float StaticMembers<float>::x;
-// CHECK-LABEL: define internal void @__cxx_global_var_init.1()
+// CHECK-LABEL: define internal void @__cxx_global_var_init
// CHECK: call i32 @_ZNK13StaticMembersIfE1yMUlvE_clEv
// CHECK-LABEL: define linkonce_odr i32 @_ZNK13StaticMembersIfE1yMUlvE_clEv
// CHECK: ret i32 3
template float StaticMembers<float>::y;
-// CHECK-LABEL: define internal void @__cxx_global_var_init.2()
+// CHECK-LABEL: define internal void @__cxx_global_var_init
// CHECK: call i32 @_Z13accept_lambdaIN13StaticMembersIfE1zMUlvE_EEiT_
// CHECK: declare i32 @_Z13accept_lambdaIN13StaticMembersIfE1zMUlvE_EEiT_()
template float StaticMembers<float>::z;
-// CHECK-LABEL: define internal void @__cxx_global_var_init.3()
+// CHECK-LABEL: define internal void @__cxx_global_var_init
// CHECK: call {{.*}} @_ZNK13StaticMembersIfE1fMUlvE_cvPFivEEv
// CHECK-LABEL: define linkonce_odr i32 ()* @_ZNK13StaticMembersIfE1fMUlvE_cvPFivEEv
template int (*StaticMembers<float>::f)();
-// CHECK-LABEL: define internal void @__cxx_global_var_init.4
+// CHECK-LABEL: define internal void @__cxx_global_var_init
// CHECK: call i32 @"_ZNK13StaticMembersIdE3$_2clEv"
// CHECK-LABEL: define internal i32 @"_ZNK13StaticMembersIdE3$_2clEv"
// CHECK: ret i32 42
Modified: cfe/trunk/test/SemaCXX/vartemplate-lambda.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/vartemplate-lambda.cpp?rev=313827&r1=313826&r2=313827&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/vartemplate-lambda.cpp (original)
+++ cfe/trunk/test/SemaCXX/vartemplate-lambda.cpp Wed Sep 20 15:17:55 2017
@@ -8,7 +8,7 @@ template<typename T> auto v1 = [](int a
struct S {
template<class T>
- static constexpr T t = [](int f = T(7)){return f;}(); // expected-error{{constexpr variable 't<int>' must be initialized by a constant expression}} expected-error{{a lambda expression may not appear inside of a constant expression}} expected-note{{cannot be used in a constant expression}}
+ static constexpr T t = [](int f = T(7)){return f;}(); // expected-error{{constexpr variable 't<int>' must be initialized by a constant expression}} expected-note{{cannot be used in a constant expression}}
};
template <typename X>
Modified: cfe/trunk/test/SemaTemplate/instantiate-static-var.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaTemplate/instantiate-static-var.cpp?rev=313827&r1=313826&r2=313827&view=diff
==============================================================================
--- cfe/trunk/test/SemaTemplate/instantiate-static-var.cpp (original)
+++ cfe/trunk/test/SemaTemplate/instantiate-static-var.cpp Wed Sep 20 15:17:55 2017
@@ -5,7 +5,7 @@
template<typename T, T Divisor>
class X {
public:
- static const T value = 10 / Divisor; // expected-error{{in-class initializer for static data member is not a constant expression}}
+ static const T value = 10 / Divisor; // expected-error{{in-class initializer for static data member is not a constant expression}} expected-warning {{division by zero}}
};
int array1[X<int, 2>::value == 5? 1 : -1];
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