From e2039da5d99dc8fe4255069ef8ab14459766bf2d Mon Sep 17 00:00:00 2001
From: Dylan Baker <dylan@pnwbakers.com>
Date: Mon, 24 Jun 2019 14:02:26 -0700
Subject: Split attribute visibility

* c_function_attributes: remove 'protected' from 'visibility'

This doesn't exist on macos with the apple compiler, which always causes
failures.

Fixes #5530

* compilers: Add split visibility checks to has_function_attribute

These check for a single visibility at a time, rather than all four at
once. This allows for finer grained searches, and should make using
these checks safer across operating systems.
---
 docs/markdown/Reference-tables.md                     | 12 +++++++++++-
 docs/markdown/snippets/split-visibility-attributes.md | 14 ++++++++++++++
 2 files changed, 25 insertions(+), 1 deletion(-)
 create mode 100644 docs/markdown/snippets/split-visibility-attributes.md

(limited to 'docs/markdown')

diff --git a/docs/markdown/Reference-tables.md b/docs/markdown/Reference-tables.md
index 682e508..84ce06f 100644
--- a/docs/markdown/Reference-tables.md
+++ b/docs/markdown/Reference-tables.md
@@ -182,12 +182,22 @@ which are supported by GCC, Clang, and other compilers.
 | returns_nonnull      |
 | unused               |
 | used                 |
-| visibility           |
+| visibility*          |
+| visibility:default†  |
+| visibility:hidden†   |
+| visibility:internal† |
+| visibility:protected†|
 | warning              |
 | warn_unused_result   |
 | weak                 |
 | weakreaf             |
 
+\* *Changed in 0.52.0* the "visibility" target no longer includes
+"protected", which is not present in Apple's clang.
+
+† *New in 0.52.0* These split visibility attributes are preferred to the plain
+"visibility" as they provide narrower checks.
+
 ### MSVC __declspec
 
 These values are supported using the MSVC style `__declspec` annotation,
diff --git a/docs/markdown/snippets/split-visibility-attributes.md b/docs/markdown/snippets/split-visibility-attributes.md
new file mode 100644
index 0000000..e8cd152
--- /dev/null
+++ b/docs/markdown/snippets/split-visibility-attributes.md
@@ -0,0 +1,14 @@
+## Splitting of Compiler.get_function_attribute('visibility')
+
+On macOS there is no `protected` visibility, which results in the visbility
+check always failing. 0.52.0 introduces two changes to improve this situation:
+
+1. the "visibility" check no longer includes "protected"
+2. a new set of "split" checks are introduced which check for a single
+   attribute instead of all attributes.
+
+These new attributes are:
+* visibility:default
+* visibility:hidden
+* visibility:internal
+* visibility:protected
\ No newline at end of file
-- 
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