v.g.vassilev updated this revision to Diff 97098.
v.g.vassilev added a comment.
This revision is now accepted and ready to land.
Implement a special diagnostic switch for the warning.
https://reviews.llvm.org/D29877
Files:
include/clang/Basic/DiagnosticGroups.td
include/clang/Basic/DiagnosticSemaKinds.td
lib/Sema/Sema.cpp
lib/Sema/SemaDecl.cpp
test/SemaCXX/warn-unused-filescoped.cpp
Index: test/SemaCXX/warn-unused-filescoped.cpp
===================================================================
--- test/SemaCXX/warn-unused-filescoped.cpp
+++ test/SemaCXX/warn-unused-filescoped.cpp
@@ -1,5 +1,5 @@
-// RUN: %clang_cc1 -fsyntax-only -verify -Wunused -Wunused-member-function -Wno-unused-local-typedefs -Wno-c++11-extensions -std=c++98 %s
-// RUN: %clang_cc1 -fsyntax-only -verify -Wunused -Wunused-member-function -Wno-unused-local-typedefs -std=c++11 %s
+// RUN: %clang_cc1 -fsyntax-only -verify -Wunused -Wunused-template -Wunused-member-function -Wno-unused-local-typedefs -Wno-c++11-extensions -std=c++98 %s
+// RUN: %clang_cc1 -fsyntax-only -verify -Wunused -Wunused-template -Wunused-member-function -Wno-unused-local-typedefs -std=c++14 %s
#ifdef HEADER
@@ -65,7 +65,7 @@
template <> void TS<int>::m() { } // expected-warning{{unused}}
template <typename T>
- void tf() { }
+ void tf() { } // expected-warning{{unused}}
template <> void tf<int>() { } // expected-warning{{unused}}
struct VS {
@@ -200,6 +200,18 @@
static void func() {}
}
+namespace test9 {
+template<typename T>
+static void completeRedeclChainForTemplateSpecialization() { } // expected-warning {{unused}}
+}
+
+namespace test10 {
+#if __cplusplus >= 201103L
+template<class T>
+constexpr T pi = T(3.14); // expected-warning {{unused}}
+#endif
+}
+
namespace pr19713 {
#if __cplusplus >= 201103L
// FIXME: We should warn on both of these.
Index: lib/Sema/SemaDecl.cpp
===================================================================
--- lib/Sema/SemaDecl.cpp
+++ lib/Sema/SemaDecl.cpp
@@ -8904,6 +8904,7 @@
if (FunctionTemplate) {
if (NewFD->isInvalidDecl())
FunctionTemplate->setInvalidDecl();
+ MarkUnusedFileScopedDecl(NewFD);
return FunctionTemplate;
}
}
@@ -11004,8 +11005,7 @@
/// FinalizeDeclaration - called by ParseDeclarationAfterDeclarator to perform
/// any semantic actions necessary after any initializer has been attached.
-void
-Sema::FinalizeDeclaration(Decl *ThisDecl) {
+void Sema::FinalizeDeclaration(Decl *ThisDecl) {
// Note that we are no longer parsing the initializer for this declaration.
ParsingInitForAutoVars.erase(ThisDecl);
@@ -11170,9 +11170,8 @@
if (DC->getRedeclContext()->isFileContext() && VD->isExternallyVisible())
AddPushedVisibilityAttribute(VD);
- // FIXME: Warn on unused templates.
- if (VD->isFileVarDecl() && !VD->getDescribedVarTemplate() &&
- !isa<VarTemplatePartialSpecializationDecl>(VD))
+ // FIXME: Warn on unused var template partial specializations.
+ if (VD->isFileVarDecl() && !isa<VarTemplatePartialSpecializationDecl>(VD))
MarkUnusedFileScopedDecl(VD);
// Now we have parsed the initializer and can update the table of magic
Index: lib/Sema/Sema.cpp
===================================================================
--- lib/Sema/Sema.cpp
+++ lib/Sema/Sema.cpp
@@ -463,6 +463,13 @@
return true;
if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
+ // If this is a function template and none of its specializations is used,
+ // we should warn.
+ if (FunctionTemplateDecl *Template = FD->getDescribedFunctionTemplate())
+ for (const auto *Spec : Template->specializations())
+ if (ShouldRemoveFromUnused(SemaRef, Spec))
+ return true;
+
// UnusedFileScopedDecls stores the first declaration.
// The declaration may have become definition so check again.
const FunctionDecl *DeclToCheck;
@@ -486,6 +493,13 @@
VD->isUsableInConstantExpressions(SemaRef->Context))
return true;
+ if (VarTemplateDecl *Template = VD->getDescribedVarTemplate())
+ // If this is a variable template and none of its specializations is used,
+ // we should warn.
+ for (const auto *Spec : Template->specializations())
+ if (ShouldRemoveFromUnused(SemaRef, Spec))
+ return true;
+
// UnusedFileScopedDecls stores the first declaration.
// The declaration may have become definition so check again.
const VarDecl *DeclToCheck = VD->getDefinition();
@@ -891,10 +905,14 @@
<< /*function*/0 << DiagD->getDeclName();
}
} else {
- Diag(DiagD->getLocation(),
- isa<CXXMethodDecl>(DiagD) ? diag::warn_unused_member_function
- : diag::warn_unused_function)
- << DiagD->getDeclName();
+ if (FD->getDescribedFunctionTemplate())
+ Diag(DiagD->getLocation(), diag::warn_unused_template)
+ << /*function*/0 << DiagD->getDeclName();
+ else
+ Diag(DiagD->getLocation(),
+ isa<CXXMethodDecl>(DiagD) ? diag::warn_unused_member_function
+ : diag::warn_unused_function)
+ << DiagD->getDeclName();
}
} else {
const VarDecl *DiagD = cast<VarDecl>(*I)->getDefinition();
@@ -910,7 +928,11 @@
Diag(DiagD->getLocation(), diag::warn_unused_const_variable)
<< DiagD->getDeclName();
} else {
- Diag(DiagD->getLocation(), diag::warn_unused_variable)
+ if (DiagD->getDescribedVarTemplate())
+ Diag(DiagD->getLocation(), diag::warn_unused_template)
+ << /*variable*/1 << DiagD->getDeclName();
+ else
+ Diag(DiagD->getLocation(), diag::warn_unused_variable)
<< DiagD->getDeclName();
}
}
Index: include/clang/Basic/DiagnosticSemaKinds.td
===================================================================
--- include/clang/Basic/DiagnosticSemaKinds.td
+++ include/clang/Basic/DiagnosticSemaKinds.td
@@ -303,6 +303,8 @@
"replace parentheses with an initializer to declare a variable">;
def warn_unused_function : Warning<"unused function %0">,
InGroup<UnusedFunction>, DefaultIgnore;
+def warn_unused_template : Warning<"unused %select{function|variable}0 template %1">,
+ InGroup<UnusedTemplate>, DefaultIgnore;
def warn_unused_member_function : Warning<"unused member function %0">,
InGroup<UnusedMemberFunction>, DefaultIgnore;
def warn_used_but_marked_unused: Warning<"%0 was marked unused but was used">,
Index: include/clang/Basic/DiagnosticGroups.td
===================================================================
--- include/clang/Basic/DiagnosticGroups.td
+++ include/clang/Basic/DiagnosticGroups.td
@@ -486,6 +486,7 @@
def UnneededMemberFunction : DiagGroup<"unneeded-member-function">;
def UnusedPrivateField : DiagGroup<"unused-private-field">;
def UnusedFunction : DiagGroup<"unused-function", [UnneededInternalDecl]>;
+def UnusedTemplate : DiagGroup<"unused-template", [UnneededInternalDecl]>;
def UnusedMemberFunction : DiagGroup<"unused-member-function",
[UnneededMemberFunction]>;
def UnusedLabel : DiagGroup<"unused-label">;
@@ -627,6 +628,7 @@
def Unused : DiagGroup<"unused",
[UnusedArgument, UnusedFunction, UnusedLabel,
// UnusedParameter, (matches GCC's behavior)
+ // UnusedTemplate, (clean-up libc++ before enabling)
// UnusedMemberFunction, (clean-up llvm before enabling)
UnusedPrivateField, UnusedLambdaCapture,
UnusedLocalTypedef, UnusedValue, UnusedVariable,
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