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From: "iains at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/109877] New: Support for clang-style attributes is needed
 to parse Darwin SDK headers properly
Date: Tue, 16 May 2023 19:35:07 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D109877

            Bug ID: 109877
           Summary: Support for clang-style attributes is needed to parse
                    Darwin SDK headers properly
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: iains at gcc dot gnu.org
  Target Milestone: ---

clang has GNU-style attribute support, but with essentially per-attribute
parsing of the attribute argument list.

This extends to, for example:

__attribute__((availability(macOS, introduced=3D12.3.4)))

and:

__attribute__((availability(macOS, message=3D"partial string" "more string"=
)))

These are examples that GCC rejects;

The issue actually need addressing during lexing since the first is an inva=
lid
token for a number (it's intended to represent a version) and we reject it
before the parser has a chance to treat it specially.

Ergo, we need a way to escape clang-specific attributes so that we can parse
them.=