> -----Original Message-----
> From: cfe-commits <cfe-commits-boun...@lists.llvm.org> On Behalf Of Aaron
> Ballman via cfe-commits
> Sent: Wednesday, September 23, 2020 3:27 PM
> To: cfe-commits@lists.llvm.org
> Subject: [clang] af1d3e6 - Allow init_priority values <= 100 and > 65535
> within system headers.
>
>
> Author: Aaron Ballman
> Date: 2020-09-23T15:26:50-04:00
> New Revision: af1d3e655991e5f0c86df372b8583a60d20268e0
>
> URL: https://urldefense.com/v3/__https://github.com/llvm/llvm-
> project/commit/af1d3e655991e5f0c86df372b8583a60d20268e0__;!!JmoZiZGBv3RvKR
> Sx!uCGMaNBytzj1FhG349bRMYFleWUAIQwiwZLW4mUe1SfbBjKnJvDM4dGzlplaS-cftQ$
> DIFF: https://urldefense.com/v3/__https://github.com/llvm/llvm-
> project/commit/af1d3e655991e5f0c86df372b8583a60d20268e0.diff__;!!JmoZiZGBv
> 3RvKRSx!uCGMaNBytzj1FhG349bRMYFleWUAIQwiwZLW4mUe1SfbBjKnJvDM4dGzlpn6UUxJFg
> $
>
> LOG: Allow init_priority values <= 100 and > 65535 within system headers.
>
> This also adds some bare-bones documentation for the attribute rather
> than leaving it undocumented.
>
> Added:
>
>
> Modified:
> clang/include/clang/Basic/Attr.td
> clang/include/clang/Basic/AttrDocs.td
> clang/lib/Sema/SemaDeclAttr.cpp
> clang/test/SemaCXX/init-priority-attr.cpp
>
> Removed:
>
>
>
> ##########################################################################
> ######
> diff --git a/clang/include/clang/Basic/Attr.td
> b/clang/include/clang/Basic/Attr.td
> index e8ac819c8b556..7222f396089e0 100644
> --- a/clang/include/clang/Basic/Attr.td
> +++ b/clang/include/clang/Basic/Attr.td
> @@ -2196,7 +2196,7 @@ def InitPriority : InheritableAttr {
> let Spellings = [GCC<"init_priority", /*AllowInC*/0>];
> let Args = [UnsignedArgument<"Priority">];
> let Subjects = SubjectList<[Var], ErrorDiag>;
> - let Documentation = [Undocumented];
> + let Documentation = [InitPriorityDocs];
> }
>
> def Section : InheritableAttr {
>
> diff --git a/clang/include/clang/Basic/AttrDocs.td
> b/clang/include/clang/Basic/AttrDocs.td
> index 9c119218656d8..3e27924589e4a 100644
> --- a/clang/include/clang/Basic/AttrDocs.td
> +++ b/clang/include/clang/Basic/AttrDocs.td
> @@ -57,6 +57,32 @@ global variable or function should be in after
> translation.
> let Heading = "section, __declspec(allocate)";
> }
>
> +def InitPriorityDocs : Documentation {
> + let Category = DocCatVariable;
> + let Content = [{
> +In C++, the order in which global variables are initialized across
> translation
> +units is unspecified, unlike the ordering within a single translation
> unit. The
> +``init_priority`` attribute allows you to specify a relative ordering for
> the
> +initialization of objects declared at namespace scope in C++. The
> priority is
> +given as an integer constant expression between 101 and 65535
> (inclusive).
> +Priorities outside of that range are reserved for use by the
> implementation. A
> +lower value indicates a higher priority of initialization. Note that only
> the
> +relative ordering of values is important. For example:
> +
> +.. code-block:: c++
> +
> + struct SomeType { SomeType(); };
> + __attribute__((init_priority(200))) SomeType Obj1;
> + __attribute__((init_priority(101))) SomeType Obj2;
> +
> +``Obj1`` will be initialized *before* ``Obj2`` despite the usual order of
> +initialization being the opposite.
I think here ``Obj2`` will be initialized before ``Obj1``
despite the usual order? (Usual order would be in order of
declaration, and init_priority goes from low to high.)
--paulr
> +
> +This attribute is only supported for C++ and Objective-C++ and is ignored
> in
> +other language modes.
> + }];
> +}
> +
> def InitSegDocs : Documentation {
> let Category = DocCatVariable;
> let Content = [{
>
> diff --git a/clang/lib/Sema/SemaDeclAttr.cpp
> b/clang/lib/Sema/SemaDeclAttr.cpp
> index 6edeb79396296..3babbe05ca8f9 100644
> --- a/clang/lib/Sema/SemaDeclAttr.cpp
> +++ b/clang/lib/Sema/SemaDeclAttr.cpp
> @@ -3313,7 +3313,11 @@ static void handleInitPriorityAttr(Sema &S, Decl
> *D, const ParsedAttr &AL) {
> return;
> }
>
> - if (prioritynum < 101 || prioritynum > 65535) {
> + // Only perform the priority check if the attribute is outside of a
> system
> + // header. Values <= 100 are reserved for the implementation, and
> libc++
> + // benefits from being able to specify values in that range.
> + if ((prioritynum < 101 || prioritynum > 65535) &&
> + !S.getSourceManager().isInSystemHeader(AL.getLoc())) {
> S.Diag(AL.getLoc(), diag::err_attribute_argument_out_of_range)
> << E->getSourceRange() << AL << 101 << 65535;
> AL.setInvalid();
>
> diff --git a/clang/test/SemaCXX/init-priority-attr.cpp
> b/clang/test/SemaCXX/init-priority-attr.cpp
> index 8f31e2fd62d00..5b5e3b9eb940e 100644
> --- a/clang/test/SemaCXX/init-priority-attr.cpp
> +++ b/clang/test/SemaCXX/init-priority-attr.cpp
> @@ -1,4 +1,9 @@
> // RUN: %clang_cc1 -fsyntax-only -verify %s
> +// RUN: %clang_cc1 -fsyntax-only -DSYSTEM -verify %s
> +
> +#if defined(SYSTEM)
> +#5 "init-priority-attr.cpp" 3 // system header
> +#endif
>
> class Two {
> private:
> @@ -21,7 +26,15 @@ Two foo __attribute__((init_priority(101))) ( 5, 6 );
>
> Two goo __attribute__((init_priority(2,3))) ( 5, 6 ); // expected-error
> {{'init_priority' attribute takes one argument}}
>
> -Two coo[2] __attribute__((init_priority(3))); // expected-error
> {{'init_priority' attribute requires integer constant between 101 and
> 65535 inclusive}}
> +Two coo[2] __attribute__((init_priority(100)));
> +#if !defined(SYSTEM)
> +// expected-error@-2 {{'init_priority' attribute requires integer
> constant between 101 and 65535 inclusive}}
> +#endif
> +
> +Two boo[2] __attribute__((init_priority(65536)));
> +#if !defined(SYSTEM)
> +// expected-error@-2 {{'init_priority' attribute requires integer
> constant between 101 and 65535 inclusive}}
> +#endif
>
> Two koo[4] __attribute__((init_priority(1.13))); // expected-error
> {{'init_priority' attribute requires an integer constant}}
>
> @@ -30,6 +43,5 @@ Two func() __attribute__((init_priority(1001))); //
> expected-error {{'init_prio
> int i __attribute__((init_priority(1001))); // expected-error {{can only
> use 'init_priority' attribute on file-scope definitions of objects of
> class type}}
>
> int main() {
> - Two foo __attribute__((init_priority(1001))); // expected-error
> {{can only use 'init_priority' attribute on file-scope definitions of
> objects of class type}}
> + Two foo __attribute__((init_priority(1001))); // expected-error {{can
> only use 'init_priority' attribute on file-scope definitions of objects of
> class type}}
> }
> -
>
>
>
> _______________________________________________
> cfe-commits mailing list
> cfe-commits@lists.llvm.org
> https://urldefense.com/v3/__https://lists.llvm.org/cgi-
> bin/mailman/listinfo/cfe-
> commits__;!!JmoZiZGBv3RvKRSx!uCGMaNBytzj1FhG349bRMYFleWUAIQwiwZLW4mUe1SfbB
> jKnJvDM4dGzlplvreK7og$
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
