arphaman created this revision.
This patch fixes an an assertion that previously occurred for the following
sample:
template <typename InputT, typename OutputT>
struct SourceSelectionRequirement {
template<typename T>
OutputT evaluateSelectionRequirement(InputT &&Value) {
}
};
template <typename InputT, typename OutputT>
OutputT SourceSelectionRequirement<InputT,
OutputT>::evaluateSelectionRequirement<void>(InputT &&Value) {
return Value;
}
Clang asserted when it was trying to deduce the function template
specialisation for `evaluateSelectionRequirement`, because it was trying to do
deduction with the template specialisation `<void>` and `template <typename
InputT, typename OutputT>` which have different template depth.
I initially fixed the issue by setting the right depth, during the deduction,
but wasn't happy with the results (we produced two errors, the second one
complained about failed deduction). Thus I changed my approach to the one
that's presented in this patch - we can detect if the template parameters are
fabricated and then avoid the deduction. This approach avoids the second error
while fixing the assertion. It also fixed a redundant error `FIXME` in
`SemaTemplate/explicit-specialization-member.cpp` (Basically removed a
redundant deduction error).
Thanks for taking a look
Repository:
rL LLVM
https://reviews.llvm.org/D37341
Files:
lib/Sema/SemaDecl.cpp
test/SemaTemplate/deduction-crash.cpp
test/SemaTemplate/explicit-specialization-member.cpp
Index: test/SemaTemplate/explicit-specialization-member.cpp
===================================================================
--- test/SemaTemplate/explicit-specialization-member.cpp
+++ test/SemaTemplate/explicit-specialization-member.cpp
@@ -38,24 +38,20 @@
template<typename T>
template<int N>
- void Baz<T>::bar() { // expected-note {{couldn't infer template argument
'N'}}
+ void Baz<T>::bar() {
}
- // FIXME: We shouldn't try to match this against a prior declaration if
- // template parameter matching failed.
template<typename T>
- void Baz<T>::bar<0>() { // expected-error {{cannot specialize a member of an
unspecialized template}} \
- // expected-error {{no function template matches}}
+ void Baz<T>::bar<0>() { // expected-error {{cannot specialize a member of an
unspecialized template}}
}
}
namespace PR19340 {
template<typename T> struct Helper {
- template<int N> static void func(const T *m) {} // expected-note {{failed
template argument deduction}}
+ template<int N> static void func(const T *m) {}
};
-template<typename T> void Helper<T>::func<2>() {} // expected-error {{cannot
specialize a member}} \
- // expected-error {{no
function template matches}}
+template<typename T> void Helper<T>::func<2>() {} // expected-error {{cannot
specialize a member}}
}
namespace SpecLoc {
Index: test/SemaTemplate/deduction-crash.cpp
===================================================================
--- test/SemaTemplate/deduction-crash.cpp
+++ test/SemaTemplate/deduction-crash.cpp
@@ -144,3 +144,20 @@
template<typename T, typename U = void> int n<T *>; // expected-error +{{}}
expected-note {{}}
int k = n<void *>;
}
+
+namespace deduceFunctionSpecializationForInvalidOutOfLineFunction {
+
+template <typename InputT, typename OutputT>
+struct SourceSelectionRequirement {
+ template<typename T>
+ OutputT evaluateSelectionRequirement(InputT &&Value) {
+ }
+};
+
+template <typename InputT, typename OutputT>
+OutputT SourceSelectionRequirement<InputT, OutputT>::
+evaluateSelectionRequirement<void>(InputT &&Value) { // expected-error
{{cannot specialize a member of an unspecialized template}}
+ return Value;
+}
+
+}
Index: lib/Sema/SemaDecl.cpp
===================================================================
--- lib/Sema/SemaDecl.cpp
+++ lib/Sema/SemaDecl.cpp
@@ -8195,6 +8195,7 @@
FunctionTemplateDecl *FunctionTemplate = nullptr;
bool isMemberSpecialization = false;
bool isFunctionTemplateSpecialization = false;
+ bool HasFabricatedTemplateSpecializationTemplateParams = false;
bool isDependentClassScopeExplicitSpecialization = false;
bool HasExplicitTemplateArgs = false;
@@ -8303,6 +8304,8 @@
} else {
// This is a function template specialization.
isFunctionTemplateSpecialization = true;
+ if (Invalid && TemplateParams->getLAngleLoc().isInvalid())
+ HasFabricatedTemplateSpecializationTemplateParams = true;
// For source fidelity, store all the template param lists.
if (TemplateParamLists.size() > 0)
NewFD->setTemplateParameterListsInfo(Context, TemplateParamLists);
@@ -8874,7 +8877,8 @@
diag::ext_function_specialization_in_class :
diag::err_function_specialization_in_class)
<< NewFD->getDeclName();
- } else if (CheckFunctionTemplateSpecialization(NewFD,
+ } else if (!HasFabricatedTemplateSpecializationTemplateParams &&
+ CheckFunctionTemplateSpecialization(NewFD,
(HasExplicitTemplateArgs ? &TemplateArgs
: nullptr),
Previous))
Index: test/SemaTemplate/explicit-specialization-member.cpp
===================================================================
--- test/SemaTemplate/explicit-specialization-member.cpp
+++ test/SemaTemplate/explicit-specialization-member.cpp
@@ -38,24 +38,20 @@
template<typename T>
template<int N>
- void Baz<T>::bar() { // expected-note {{couldn't infer template argument 'N'}}
+ void Baz<T>::bar() {
}
- // FIXME: We shouldn't try to match this against a prior declaration if
- // template parameter matching failed.
template<typename T>
- void Baz<T>::bar<0>() { // expected-error {{cannot specialize a member of an unspecialized template}} \
- // expected-error {{no function template matches}}
+ void Baz<T>::bar<0>() { // expected-error {{cannot specialize a member of an unspecialized template}}
}
}
namespace PR19340 {
template<typename T> struct Helper {
- template<int N> static void func(const T *m) {} // expected-note {{failed template argument deduction}}
+ template<int N> static void func(const T *m) {}
};
-template<typename T> void Helper<T>::func<2>() {} // expected-error {{cannot specialize a member}} \
- // expected-error {{no function template matches}}
+template<typename T> void Helper<T>::func<2>() {} // expected-error {{cannot specialize a member}}
}
namespace SpecLoc {
Index: test/SemaTemplate/deduction-crash.cpp
===================================================================
--- test/SemaTemplate/deduction-crash.cpp
+++ test/SemaTemplate/deduction-crash.cpp
@@ -144,3 +144,20 @@
template<typename T, typename U = void> int n<T *>; // expected-error +{{}} expected-note {{}}
int k = n<void *>;
}
+
+namespace deduceFunctionSpecializationForInvalidOutOfLineFunction {
+
+template <typename InputT, typename OutputT>
+struct SourceSelectionRequirement {
+ template<typename T>
+ OutputT evaluateSelectionRequirement(InputT &&Value) {
+ }
+};
+
+template <typename InputT, typename OutputT>
+OutputT SourceSelectionRequirement<InputT, OutputT>::
+evaluateSelectionRequirement<void>(InputT &&Value) { // expected-error {{cannot specialize a member of an unspecialized template}}
+ return Value;
+}
+
+}
Index: lib/Sema/SemaDecl.cpp
===================================================================
--- lib/Sema/SemaDecl.cpp
+++ lib/Sema/SemaDecl.cpp
@@ -8195,6 +8195,7 @@
FunctionTemplateDecl *FunctionTemplate = nullptr;
bool isMemberSpecialization = false;
bool isFunctionTemplateSpecialization = false;
+ bool HasFabricatedTemplateSpecializationTemplateParams = false;
bool isDependentClassScopeExplicitSpecialization = false;
bool HasExplicitTemplateArgs = false;
@@ -8303,6 +8304,8 @@
} else {
// This is a function template specialization.
isFunctionTemplateSpecialization = true;
+ if (Invalid && TemplateParams->getLAngleLoc().isInvalid())
+ HasFabricatedTemplateSpecializationTemplateParams = true;
// For source fidelity, store all the template param lists.
if (TemplateParamLists.size() > 0)
NewFD->setTemplateParameterListsInfo(Context, TemplateParamLists);
@@ -8874,7 +8877,8 @@
diag::ext_function_specialization_in_class :
diag::err_function_specialization_in_class)
<< NewFD->getDeclName();
- } else if (CheckFunctionTemplateSpecialization(NewFD,
+ } else if (!HasFabricatedTemplateSpecializationTemplateParams &&
+ CheckFunctionTemplateSpecialization(NewFD,
(HasExplicitTemplateArgs ? &TemplateArgs
: nullptr),
Previous))
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