[PATCH] D65694: Properly instantiate a decltype in argument's default initializer
Mordante added a comment. Friendly ping. CHANGES SINCE LAST ACTION https://reviews.llvm.org/D65694/new/ https://reviews.llvm.org/D65694 ___ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
[PATCH] D65694: Properly instantiate a decltype in argument's default initializer
comex added a comment. Ping. I'm not qualified to review this myself but I'd like to see the bug fixed. :) CHANGES SINCE LAST ACTION https://reviews.llvm.org/D65694/new/ https://reviews.llvm.org/D65694 ___ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
[PATCH] D65694: Properly instantiate a decltype in argument's default initializer
Mordante updated this revision to Diff 218256.
Mordante added a comment.
Changed the approach to use `addInstantiatedParametersToScope` as suggested by
@rsmith. Since the function was `static` in another file I made it a member of
`LocalInstantiationScope` and adjusted all callers.
Minor changes:
- Unit test remove link to Bugzilla
- MutiLevelArgList -> Mu__l__tiLevelArgList
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D65694/new/
https://reviews.llvm.org/D65694
Files:
clang/include/clang/Sema/Template.h
clang/lib/Sema/SemaExpr.cpp
clang/lib/Sema/SemaTemplateInstantiate.cpp
clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
clang/test/SemaTemplate/default-arguments-cxx0x.cpp
Index: clang/test/SemaTemplate/default-arguments-cxx0x.cpp
===
--- clang/test/SemaTemplate/default-arguments-cxx0x.cpp
+++ clang/test/SemaTemplate/default-arguments-cxx0x.cpp
@@ -114,3 +114,33 @@
S _a{};
};
}
+
+// Failure to resolve the decltype part during instantiation caused an
+// assertion failure
+namespace PR28500 {
+namespace original {
+template
+void bar(T t = [](decltype(t) i) { return 0; }(0)) {}
+void foo() {
+ bar();
+}
+} // namespace original
+
+namespace cast {
+template
+void bar(T t = decltype(t)(0)) {}
+void foo() {
+ bar();
+ bar();
+}
+} // namespace cast
+
+namespace value {
+template
+void bar(T t = decltype(t)()) {}
+void foo() {
+ bar();
+ bar();
+}
+} // namespace value
+} // namespace PR28500
Index: clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
===
--- clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -3823,70 +3823,6 @@
return NewTInfo;
}
-/// Introduce the instantiated function parameters into the local
-/// instantiation scope, and set the parameter names to those used
-/// in the template.
-static bool addInstantiatedParametersToScope(Sema , FunctionDecl *Function,
- const FunctionDecl *PatternDecl,
- LocalInstantiationScope ,
- const MultiLevelTemplateArgumentList ) {
- unsigned FParamIdx = 0;
- for (unsigned I = 0, N = PatternDecl->getNumParams(); I != N; ++I) {
-const ParmVarDecl *PatternParam = PatternDecl->getParamDecl(I);
-if (!PatternParam->isParameterPack()) {
- // Simple case: not a parameter pack.
- assert(FParamIdx < Function->getNumParams());
- ParmVarDecl *FunctionParam = Function->getParamDecl(FParamIdx);
- FunctionParam->setDeclName(PatternParam->getDeclName());
- // If the parameter's type is not dependent, update it to match the type
- // in the pattern. They can differ in top-level cv-qualifiers, and we want
- // the pattern's type here. If the type is dependent, they can't differ,
- // per core issue 1668. Substitute into the type from the pattern, in case
- // it's instantiation-dependent.
- // FIXME: Updating the type to work around this is at best fragile.
- if (!PatternDecl->getType()->isDependentType()) {
-QualType T = S.SubstType(PatternParam->getType(), TemplateArgs,
- FunctionParam->getLocation(),
- FunctionParam->getDeclName());
-if (T.isNull())
- return true;
-FunctionParam->setType(T);
- }
-
- Scope.InstantiatedLocal(PatternParam, FunctionParam);
- ++FParamIdx;
- continue;
-}
-
-// Expand the parameter pack.
-Scope.MakeInstantiatedLocalArgPack(PatternParam);
-Optional NumArgumentsInExpansion
- = S.getNumArgumentsInExpansion(PatternParam->getType(), TemplateArgs);
-if (NumArgumentsInExpansion) {
- QualType PatternType =
- PatternParam->getType()->castAs()->getPattern();
- for (unsigned Arg = 0; Arg < *NumArgumentsInExpansion; ++Arg) {
-ParmVarDecl *FunctionParam = Function->getParamDecl(FParamIdx);
-FunctionParam->setDeclName(PatternParam->getDeclName());
-if (!PatternDecl->getType()->isDependentType()) {
- Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(S, Arg);
- QualType T = S.SubstType(PatternType, TemplateArgs,
- FunctionParam->getLocation(),
- FunctionParam->getDeclName());
- if (T.isNull())
-return true;
- FunctionParam->setType(T);
-}
-
-Scope.InstantiatedLocalPackArg(PatternParam, FunctionParam);
-++FParamIdx;
- }
-}
- }
-
- return false;
-}
-
void Sema::InstantiateExceptionSpec(SourceLocation PointOfInstantiation,
FunctionDecl *Decl) {
const FunctionProtoType *Proto = Decl->getType()->castAs();
@@ -3918,8 +3854,7 @@
getTemplateInstantiationArgs(Decl, nullptr, /*RelativeToPrimary*/true);
[PATCH] D65694: Properly instantiate a decltype in argument's default initializer
rsmith added a comment. This isn't the right approach: instead of re-instantiating the parameter when we encounter a use of it, we should inject the parameters into the local instantiation scope before trying to instantiate a default argument (`Sema::CheckCXXDefaultArgExpr` should call `addInstantiatedParametersToScope` to populate the `LocalInstantiationScope` before calling `SubstInitializer`). Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D65694/new/ https://reviews.llvm.org/D65694 ___ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
[PATCH] D65694: Properly instantiate a decltype in argument's default initializer
comex added a comment. Ping. Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D65694/new/ https://reviews.llvm.org/D65694 ___ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
[PATCH] D65694: Properly instantiate a decltype in argument's default initializer
Mordante created this revision.
Mordante added reviewers: sepavloff, rsmith.
Mordante added a project: clang.
This fixes https://bugs.llvm.org/show_bug.cgi?id=28500
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D65694
Files:
clang/lib/Sema/SemaTemplateInstantiate.cpp
clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
clang/test/SemaTemplate/default-arguments-cxx0x.cpp
Index: clang/test/SemaTemplate/default-arguments-cxx0x.cpp
===
--- clang/test/SemaTemplate/default-arguments-cxx0x.cpp
+++ clang/test/SemaTemplate/default-arguments-cxx0x.cpp
@@ -114,3 +114,34 @@
S _a{};
};
}
+
+// https://bugs.llvm.org/show_bug.cgi?id=28500
+// Failure to resolve the decltype part during instantiation caused an
+// assertion failure
+namespace PR28500 {
+namespace original {
+template
+void bar(T t = [](decltype(t) i) { return 0; }(0)) {}
+void foo() {
+ bar();
+}
+} // namespace original
+
+namespace cast {
+template
+void bar(T t = decltype(t)(0)) {}
+void foo() {
+ bar();
+ bar();
+}
+} // namespace cast
+
+namespace value {
+template
+void bar(T t = decltype(t)()) {}
+void foo() {
+ bar();
+ bar();
+}
+} // namespace value
+} // namespace PR28500
Index: clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
===
--- clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -5287,29 +5287,33 @@
// }
//
// In this case instantiation of the type of 'g1' requires definition of
-// 'x1', which is defined later. Error recovery may produce an enum used
-// before definition. In these cases we need to instantiate relevant
-// declarations here.
+// 'x1', which is defined later.
+//
+// Error recovery may produce an enum used before definition.
+//
+// Default arguments with a decltype referencing arguments:
+//
+// template void bar(T t = decltype(t)()) {}
+//
+// Else we must have a label decl that hasn't been found yet.
+//
+// In these cases we need to instantiate relevant declarations here.
bool NeedInstantiate = false;
if (CXXRecordDecl *RD = dyn_cast(D))
NeedInstantiate = RD->isLocalClass();
else
- NeedInstantiate = isa(D);
+ NeedInstantiate =
+ isa(D) || isa(D) || isa(D);
if (NeedInstantiate) {
Decl *Inst = SubstDecl(D, CurContext, TemplateArgs);
+ assert(Inst && "Failed to instantiate");
CurrentInstantiationScope->InstantiatedLocal(D, Inst);
- return cast(Inst);
+ return cast(Inst);
}
-// If we didn't find the decl, then we must have a label decl that hasn't
-// been found yet. Lazily instantiate it and return it now.
-assert(isa(D));
-
-Decl *Inst = SubstDecl(D, CurContext, TemplateArgs);
-assert(Inst && "Failed to instantiate label??");
+assert(0 && "Failed to instantiate");
-CurrentInstantiationScope->InstantiatedLocal(D, Inst);
-return cast(Inst);
+return nullptr;
}
if (CXXRecordDecl *Record = dyn_cast(D)) {
Index: clang/lib/Sema/SemaTemplateInstantiate.cpp
===
--- clang/lib/Sema/SemaTemplateInstantiate.cpp
+++ clang/lib/Sema/SemaTemplateInstantiate.cpp
@@ -2974,6 +2974,11 @@
if (isa(D))
return nullptr;
+ // Default arguments with a decltype referencing arguments prior to definition
+ // may require instantiation.
+ if (isa(D))
+return nullptr;
+
// If we didn't find the decl, then we either have a sema bug, or we have a
// forward reference to a label declaration. Return null to indicate that
// we have an uninstantiated label.
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