Bug 537826

Summary:	sys-devel/gcc-apple-4.2.1_p5666-r2: proper fix for __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ macro on OS X 10.10
Product:	Gentoo/Alt	Reporter:	Michael Weiser <michael>
Component:	Prefix Support	Assignee:	Gentoo Prefix <prefix>
Status:	RESOLVED FIXED
Severity:	normal
Priority:	Normal
Version:	unspecified
Hardware:	All
OS:	Linux
URL:	https://gcc.gnu.org/viewcvs/gcc?view=revision&revision=218873
Whiteboard:
Package list:		Runtime testing required:	---
Attachments:	extend encoding of __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ for 10.10

Description Michael Weiser 2015-01-26 00:04:13 UTC

The current workaround for encoding __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ in gcc-apple for OS X 10.10 lets everyone think, they're on 10.9. There's a proper fix in FSF GCC trunk that handles 10.10 but does not encode the patch level. (https://gcc.gnu.org/viewcvs/gcc?view=revision&revision=218873, https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61407). A much more sophisticated patch that also handles the patch level is in FSF GCC bugzilla (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63810) but not yet on trunk because of pending legal paperwork.

I have backported the first patch to gcc-apple-4.2.1_p5666-r2 and extended to also include the patch level.

Example:
michael@osx1010:~ # /usr/bin/clang -E  -mmacosx-version-min=10.10.10 -dM -c t.c | grep OS_X
#define __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ 101010
michael@osx1010:~ # ~/nobak/gentoo/usr/bin/gcc -E  -mmacosx-version-min=10.10.10 -dM -c t.c | grep OS_X
#define __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ 101010

Unpatched gcc-apple would have croaked:

michael@osx1010:~ # gcc -E  -mmacosx-version-min=10.10.10 -dM -c t.c | grep OS_X
<built-in>:0: error: Unknown value '10.10.10' of -mmacosx-version-min
#define __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ 1000

Also, unpatched gcc-apple draws a line at patch level 9:

michael@osx1010 ~ $ gcc -E  -mmacosx-version-min=10.4.10 -dM -c t.c | grep OS_X
<built-in>:0: error: Unknown value '10.4.10' of -mmacosx-version-min
#define __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ 1000

I have opted for the clang way to cap at level 9:

michael@osx1010~ # ~/nobak/gentoo/usr/bin/gcc -E  -mmacosx-version-min=10.4.10 -dM -c t.c | grep OS_X
#define __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ 1049
michael@osx1010~ # /usr/bin/clang -E  -mmacosx-version-min=10.4.10 -dM -c t.c | grep OS_X
#define __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ 1049

Reproducible: Always

Comment 1 Michael Weiser 2015-01-26 00:04:48 UTC

Created attachment 394896 [details, diff]
extend encoding of __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ for 10.10

Comment 2 Fabian Groffen gentoo-dev

2015-01-31 16:16:04 UTC

applied to gcc-apple-4.2.1_p5666-r2, I don't think we need a revbump, since bootstrapping should be broken anyway.