[PATCH] D29877: Warn about unused static file scope function template declarations.

[Vassil Vassilev via Phabricator via cfe-commits]

v.g.vassilev updated this revision to Diff 94350.
v.g.vassilev added a comment.

Found out which is the right place to avoid the linkage computation issues.


https://reviews.llvm.org/D29877

Files:
  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-member-function -Wno-unused-local-typedefs -std=c++14 %s
 
 #ifdef HEADER
 
@@ -32,6 +32,14 @@
   inline void bar(int, int) { }
 };
 
+namespace test8 {
+// Should ignore overloaded operators.
+template <typename PT1, typename PT2>
+struct S {};
+template <typename PT1, typename PT2>
+static bool operator==(S<PT1, PT2> lhs, S<PT1, PT2> rhs) { }
+}
+
 namespace pr19713 {
 #if __cplusplus >= 201103L
   static constexpr int constexpr1() { return 1; }
@@ -65,7 +73,7 @@
   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 +208,18 @@
 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
@@ -1493,6 +1493,10 @@
       // 'static inline' functions are defined in headers; don't warn.
       if (FD->isInlined() && !isMainFileLoc(*this, FD->getLocation()))
         return false;
+      // 'static operator' functions are defined in headers; don't warn.
+      if (FD->isOverloadedOperator() &&
+          !isMainFileLoc(*this, FD->getLocation()))
+        return false;
     }
 
     if (FD->doesThisDeclarationHaveABody() &&
@@ -8887,6 +8891,7 @@
     if (FunctionTemplate) {
       if (NewFD->isInvalidDecl())
         FunctionTemplate->setInvalidDecl();
+      MarkUnusedFileScopedDecl(NewFD);
       return FunctionTemplate;
     }
   }
@@ -10991,8 +10996,7 @@
 
 /// 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);
 
@@ -11157,9 +11161,8 @@
   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
@@ -470,6 +470,13 @@
     return true;
 
   if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
+    // If this is a function template and neither of its specs is unused 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;
@@ -493,6 +500,11 @@
         VD->isUsableInConstantExpressions(SemaRef->Context))
       return true;
 
+    if (VarTemplateDecl *Template = VD->getDescribedVarTemplate())
+      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();

_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits