r304964 - Improve diagnostics if friend function redefines file-level function.
Serge Pavlov via cfe-commits
cfe-commits at lists.llvm.org
Wed Jun 7 23:07:07 PDT 2017
Author: sepavloff
Date: Thu Jun 8 01:07:07 2017
New Revision: 304964
URL: http://llvm.org/viewvc/llvm-project?rev=304964&view=rev
Log:
Improve diagnostics if friend function redefines file-level function.
Clang makes check for function redefinition after it merged the new
declaration with the existing one. As a result, it produces poor
diagnostics in the case of a friend function defined inline, as in
the code:
```
void func() {}
class C { friend void func() {} };
```
Error message in this case states that `inline declaration of 'func'
follows non-inline definition`, which is misleading, as `func` does
not have explicit `inline` specifier.
With this changes compiler reports function redefinition if the new
function is a friend defined inline and it does not have explicit
`inline` specifier.
Differential Revision: https://reviews.llvm.org/D26065
Modified:
cfe/trunk/lib/Sema/SemaDeclCXX.cpp
cfe/trunk/test/CXX/dcl.dcl/dcl.spec/dcl.fct.spec/p4.cpp
Modified: cfe/trunk/lib/Sema/SemaDeclCXX.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDeclCXX.cpp?rev=304964&r1=304963&r2=304964&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaDeclCXX.cpp (original)
+++ cfe/trunk/lib/Sema/SemaDeclCXX.cpp Thu Jun 8 01:07:07 2017
@@ -638,7 +638,12 @@ bool Sema::MergeCXXFunctionDecl(Function
Diag(Old->getLocation(), diag::note_previous_declaration);
Invalid = true;
} else if (!Old->getMostRecentDecl()->isInlined() && New->isInlined() &&
- Old->isDefined(Def)) {
+ Old->isDefined(Def) &&
+ // If a friend function is inlined but does not have 'inline'
+ // specifier, it is a definition. Do not report attribute conflict
+ // in this case, redefinition will be diagnosed later.
+ (New->isInlineSpecified() ||
+ New->getFriendObjectKind() == Decl::FOK_None)) {
// C++11 [dcl.fcn.spec]p4:
// If the definition of a function appears in a translation unit before its
// first declaration as inline, the program is ill-formed.
Modified: cfe/trunk/test/CXX/dcl.dcl/dcl.spec/dcl.fct.spec/p4.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CXX/dcl.dcl/dcl.spec/dcl.fct.spec/p4.cpp?rev=304964&r1=304963&r2=304964&view=diff
==============================================================================
--- cfe/trunk/test/CXX/dcl.dcl/dcl.spec/dcl.fct.spec/p4.cpp (original)
+++ cfe/trunk/test/CXX/dcl.dcl/dcl.spec/dcl.fct.spec/p4.cpp Thu Jun 8 01:07:07 2017
@@ -4,3 +4,31 @@ void f0() { // expected-note {{previous
}
inline void f0(); // expected-error {{inline declaration of 'f0' follows non-inline definition}}
+
+void func_01() {} // expected-note{{previous definition is here}}
+struct C01 {
+ friend void func_01() {} // expected-error{{redefinition of 'func_01'}}
+};
+
+void func_02() {} // expected-note{{previous definition is here}}
+struct C02 {
+ friend inline void func_02(); // expected-error{{inline declaration of 'func_02' follows non-inline definition}}
+};
+
+void func_03() {} // expected-note{{previous definition is here}}
+struct C03 {
+ friend inline void func_03() {} // expected-error{{inline declaration of 'func_03' follows non-inline definition}}
+};
+
+void func_04() {} // expected-note{{previous definition is here}}
+inline void func_04() {} // expected-error{{inline declaration of 'func_04' follows non-inline definition}}
+
+void func_06() {} // expected-note{{previous definition is here}}
+template<typename T> struct C06 {
+ friend inline void func_06() {} // expected-error{{inline declaration of 'func_06' follows non-inline definition}}
+};
+
+void func_07() {} // expected-note{{previous definition is here}}
+template<typename T> struct C07 {
+ friend inline void func_07(); // expected-error{{inline declaration of 'func_07' follows non-inline definition}}
+};
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