Fix improper microsoft-pure-definition warning on template class

[Ilod]

Summary

Clang emits a warning when using pure specifier =0 in function definition at class scope, which is a MS-specific construct, when using -fms-extensions.
However, to detect this, it was using FD->isCanonicalDecl() on function declaration, which was also detecting out-of-class definition of member functions of template class.
This fix it by instead of !FD->isOutOfLine() to detect the places where we must emit the warning.
This will fix https://llvm.org/bugs/show_bug.cgi?id=21334

[adrianh.bsc]

Just wondering if this will be fixed soon. It's kinda annoying.

[riccibruno]

This looks reasonable to me (although I think that the test should be in SemaCXX/ and not in Parser/, but the test for the non-template case is already in Parser/ so ok).

cfe/trunk/lib/Sema/SemaDecl.cpp

if (FD) {
 
     // If the function implicitly returns zero (like 'main') or is naked,
     // don't complain about missing return statements.
     if (FD->hasImplicitReturnZero() || FD->hasAttr<NakedAttr>())
       WP.disableCheckFallThrough();
 
     // MSVC permits the use of pure specifier (=0) on function definition,
     // defined at class scope, warn about this non-standard construct.
-    if (getLangOpts().MicrosoftExt && FD->isPure() && FD->isCanonicalDecl())
+    if (getLangOpts().MicrosoftExt && FD->isPure() && !FD->isOutOfLine())
       Diag(FD->getLocation(), diag::ext_pure_function_definition);
 
     if (!FD->isInvalidDecl()) {
       // Don't diagnose unused parameters of defaulted or deleted functions.
       if (!FD->isDeleted() && !FD->isDefaulted() && !FD->hasSkippedBody())
         DiagnoseUnusedParameters(FD->parameters());
       DiagnoseSizeOfParametersAndReturnValue(FD->parameters(),
                                              FD->getReturnType(), FD);

cfe/trunk/test/Parser/MicrosoftExtensions.cpp

struct pure_virtual_dtor {
   virtual ~pure_virtual_dtor() = 0;
 };
 pure_virtual_dtor::~pure_virtual_dtor() { }
 
 struct pure_virtual_dtor_inline {
   virtual ~pure_virtual_dtor_inline() = 0 { }// expected-warning {{function definition with pure-specifier is a Microsoft extension}}
 };
 
+template<typename T> struct pure_virtual_dtor_template {
+  virtual ~pure_virtual_dtor_template() = 0;
+};
+template<typename T> pure_virtual_dtor_template<T>::~pure_virtual_dtor_template() {}
+template struct pure_virtual_dtor_template<int>;
+
+template<typename T> struct pure_virtual_dtor_template_inline {
+    virtual ~pure_virtual_dtor_template_inline() = 0 {}
+    // expected-warning@-1 2{{function definition with pure-specifier is a Microsoft extension}}
+};
+template struct pure_virtual_dtor_template_inline<int>;
+// expected-note@-1 {{in instantiation of member function}}
 
 int main () {
   // Necessary to force instantiation in -fdelayed-template-parsing mode.
   test_late_defined_uuid<int>();
   redundant_typename<int>();
   missing_template_keyword<int>();
 }