[cfe-commits] r167783 - in /cfe/trunk: include/clang/Basic/Attr.td include/clang/Basic/DiagnosticSemaKinds.td lib/Sema/SemaDecl.cpp lib/Sema/SemaDeclAttr.cpp test/SemaCXX/warn-unused-result.cpp

[Richard Smith]

On Mon, Nov 12, 2012 at 3:48 PM, Kaelyn Uhrain <rikka at google.com> wrote:
> Author: rikka
> Date: Mon Nov 12 17:48:05 2012
> New Revision: 167783
>
> URL: http://llvm.org/viewvc/llvm-project?rev=167783&view=rev
> Log:
> Enable C++11 attribute syntax for warn_unused_result and allow it to be
> applied to CXXRecordDecls, where functions with that return type will
> inherit the warn_unused_result attribute.
>
> Also includes a tiny fix (with no discernable behavior change for
> existing code) to re-sync AttributeDeclKind enum and
> err_attribute_wrong_decl_type with warn_attribute_wrong_decl_type since
> the enum is used with both diagnostic messages to chose the correct
> description.
>
> Modified:
>     cfe/trunk/include/clang/Basic/Attr.td
>     cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
>     cfe/trunk/lib/Sema/SemaDecl.cpp
>     cfe/trunk/lib/Sema/SemaDeclAttr.cpp
>     cfe/trunk/test/SemaCXX/warn-unused-result.cpp
>
> Modified: cfe/trunk/include/clang/Basic/Attr.td
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/Attr.td?rev=167783&r1=167782&r2=167783&view=diff
> ==============================================================================
> --- cfe/trunk/include/clang/Basic/Attr.td (original)
> +++ cfe/trunk/include/clang/Basic/Attr.td Mon Nov 12 17:48:05 2012
> @@ -699,7 +699,7 @@
>  }
>
>  def WarnUnusedResult : InheritableAttr {
> -  let Spellings = [GNU<"warn_unused_result">];
> +  let Spellings = [GNU<"warn_unused_result">, CXX11<"","warn_unused_result">];

Please use CXX11<"clang", "warn_unused_result">.

>  }
>
>  def Weak : InheritableAttr {
>
> Modified: cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td?rev=167783&r1=167782&r2=167783&view=diff
> ==============================================================================
> --- cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td (original)
> +++ cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td Mon Nov 12 17:48:05 2012
> @@ -1773,17 +1773,18 @@
>  def warn_attribute_wrong_decl_type : Warning<
>    "%0 attribute only applies to %select{functions|unions|"
>    "variables and functions|functions and methods|parameters|"
> -  "functions, methods and blocks|functions, methods, and parameters|"
> -  "classes|variables|methods|variables, functions and labels|"
> -  "fields and global variables|structs|"
> +  "functions, methods and blocks|functions, methods, and classes|"
> +  "functions, methods, and parameters|classes|variables|methods|"
> +  "variables, functions and labels|fields and global variables|structs|"
>    "variables, functions and tag types|thread-local variables}1">,
>    InGroup<IgnoredAttributes>;
>  def err_attribute_wrong_decl_type : Error<
>    "%0 attribute only applies to %select{functions|unions|"
>    "variables and functions|functions and methods|parameters|"
> -  "functions, methods and blocks|functions, methods, and parameters|"
> -  "classes|variables|methods|variables, functions and labels|"
> -  "fields and global variables|structs|thread-local variables}1">;
> +  "functions, methods and blocks|functions, methods, and classes|"
> +  "functions, methods, and parameters|classes|variables|methods|"
> +  "variables, functions and labels|fields and global variables|structs|"
> +  "variables, functions and tag types|thread-local variables}1">;
>  def warn_function_attribute_wrong_type : Warning<
>    "'%0' only applies to function types; type here is %1">,
>    InGroup<IgnoredAttributes>;
>
> Modified: cfe/trunk/lib/Sema/SemaDecl.cpp
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDecl.cpp?rev=167783&r1=167782&r2=167783&view=diff
> ==============================================================================
> --- cfe/trunk/lib/Sema/SemaDecl.cpp (original)
> +++ cfe/trunk/lib/Sema/SemaDecl.cpp Mon Nov 12 17:48:05 2012
> @@ -5691,6 +5691,14 @@
>    ProcessDeclAttributes(S, NewFD, D,
>                          /*NonInheritable=*/false, /*Inheritable=*/true);
>
> +  QualType RetType = NewFD->getResultType();
> +  const CXXRecordDecl *Ret = RetType->isRecordType() ?
> +      RetType->getAsCXXRecordDecl() : RetType->getPointeeCXXRecordDecl();
> +  if (!NewFD->isInvalidDecl() && !NewFD->hasAttr<WarnUnusedResultAttr>() &&
> +      Ret && Ret->hasAttr<WarnUnusedResultAttr>()) {
> +    NewFD->addAttr(new (Context) WarnUnusedResultAttr(SourceRange(), Context));
> +  }
> +
>    if (!getLangOpts().CPlusPlus) {
>      // Perform semantic checking on the function declaration.
>      bool isExplicitSpecialization=false;
>
> Modified: cfe/trunk/lib/Sema/SemaDeclAttr.cpp
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDeclAttr.cpp?rev=167783&r1=167782&r2=167783&view=diff
> ==============================================================================
> --- cfe/trunk/lib/Sema/SemaDeclAttr.cpp (original)
> +++ cfe/trunk/lib/Sema/SemaDeclAttr.cpp Mon Nov 12 17:48:05 2012
> @@ -37,6 +37,7 @@
>    ExpectedFunctionOrMethod,
>    ExpectedParameter,
>    ExpectedFunctionMethodOrBlock,
> +  ExpectedFunctionMethodOrClass,
>    ExpectedFunctionMethodOrParameter,
>    ExpectedClass,
>    ExpectedVariable,
> @@ -44,6 +45,7 @@
>    ExpectedVariableFunctionOrLabel,
>    ExpectedFieldOrGlobalVar,
>    ExpectedStruct,
> +  ExpectedVariableFunctionOrTag,

Is this enum value used anywhere?

>    ExpectedTLSVar
>  };
>
> @@ -2445,7 +2447,7 @@
>    if (!checkAttributeNumArgs(S, Attr, 0))
>      return;
>
> -  if (!isFunction(D) && !isa<ObjCMethodDecl>(D)) {
> +  if (!isFunction(D) && !isa<ObjCMethodDecl>(D) && !isa<CXXRecordDecl>(D)) {
>      S.Diag(Attr.getLoc(), diag::warn_attribute_wrong_decl_type)
>        << Attr.getName() << ExpectedFunctionOrMethod;

Should this be updated to ExpectedFunctionMethodOrClass?

>      return;
>
> Modified: cfe/trunk/test/SemaCXX/warn-unused-result.cpp
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/warn-unused-result.cpp?rev=167783&r1=167782&r2=167783&view=diff
> ==============================================================================
> --- cfe/trunk/test/SemaCXX/warn-unused-result.cpp (original)
> +++ cfe/trunk/test/SemaCXX/warn-unused-result.cpp Mon Nov 12 17:48:05 2012
> @@ -1,4 +1,4 @@
> -// RUN: %clang_cc1 -fsyntax-only -verify %s
> +// RUN: %clang_cc1 -fsyntax-only -verify -std=c++11 %s
>
>  int f() __attribute__((warn_unused_result));
>
> @@ -42,3 +42,33 @@
>    x.foo(); // expected-warning {{ignoring return value}}
>    x2->foo(); // expected-warning {{ignoring return value}}
>  }
> +
> +namespace warn_unused_CXX11 {
> +struct [[warn_unused_result]] Status {
> +  bool ok() const;
> +};
> +Status DoSomething();
> +Status& DoSomethingElse();
> +Status* DoAnotherThing();
> +Status** DoYetAnotherThing();
> +void lazy() {
> +  Status s = DoSomething();
> +  if (!s.ok()) return;
> +  Status &rs = DoSomethingElse();
> +  if (!rs.ok()) return;
> +  Status *ps = DoAnotherThing();
> +  if (!ps->ok()) return;
> +  Status **pps = DoYetAnotherThing();
> +  if (!(*pps)->ok()) return;
> +
> +  (void)DoSomething();
> +  (void)DoSomethingElse();
> +  (void)DoAnotherThing();
> +  (void)DoYetAnotherThing();
> +
> +  DoSomething(); // expected-warning {{ignoring return value}}
> +  DoSomethingElse(); // expected-warning {{ignoring return value}}
> +  DoAnotherThing(); // expected-warning {{ignoring return value}}
> +  DoYetAnotherThing();
> +}
> +}