Block objects [1] are a C-level syntactic and runtime feature. They
are similar to standard C functions, but in addition to executable
code they may also contain variable bindings to automatic (stack)
or managed (heap) memory. A block can therefore maintain a set of
state (data) that it can use to impact behavior when executed.
This port is based on Apple's GCC 5646 with some bugfixes from
Apple GCC 5666.3. It has some small differences with the support
in clang, which remains the recommended compiler.
Perhaps the most notable difference is that in GCC that __block
is not actually a keyword, but a macro. There will be workaround
for this issue in a near future. Other issues can be consulted in
the clang documentation [2]
For better compatiblity with Apple's GCC and llvm-gcc some related
fixes and features from Apple have been included. Support for the
non-standard nested functions in GCC is now off by default.
No effort was made to update the ObjC support since FreeBSD doesn't
carry ObjC in the base system, but some of the code crept in and
was more difficult to remove than to adjust.
Reference:
[1]
https://developer.apple.com/library/mac/documentation/Cocoa/Conceptual/Blocks/Articles/00_Introduction.html
[2]
http://clang.llvm.org/compatibility.html#block-variable-initialization
Obtained from: Apple GCC 4.2
MFC after: 3 weeks
Unfortunately this causes ICE on powerpc and sparc64.
Reducing these differences against upstream is not important
anymore so hopefully I have finished breaking the compiler
occasionally.
Apple GCC has extensions to support for both label attributes and
an "unavailable" attribute. These are critical for objc but are
also useful in regular C/C++.
Apparently at least the label attributes might have found their way to
upstream GCC but the code doesn't seem available on the GPLv2 tree so
we are taking the code directly from Apple. To make this clearer we
are preserving the annoying "APPLE LOCAL" tags and the ChangeLogs
when they are available.
Obtained from: Apple GCC 4.2 - 5531
MFC after: 3 weeks
This solves GCC/32617 and contributes to reduce differences with
Apple's gcc42.
Complete some references in the ChangeLog while here.
Obtained from: gcc 4.3 (rev. 126529, 126588; GPLv2)
MFC after: 3 weeks
1.2 -fformat-extensions.
Remove r1.7 (FORCE_OPTIMIZATION_DOWNGRADE knob for Alpha) as obsolete.
Move r1.14 (-O0 -O1 optimize alignment for time, not size) to opts.c.
From current testsuite results, the optimizer bugs don't appear to exist
anymore. RTH@cygnus.com did a lot of work on the Alpha ELF code generator
for GCC 3.2[.0]. A recent FreeBSD/AXP GCC bootstrap is at
http://gcc.gnu.org/ml/gcc-testresults/2002-09/msg00604.html
In this bootstraps, all gcc libraries are built with -O2 and c-torture
gives -O2 a real workout. None of the remaining failures have anything
to do with -O2 optimizer bugs.
Submitted by: Loren James Rittle <rittle@latour.rsch.comm.mot.com>
value, it forces GCC to not optimize above this level. For intance, GCC
made with "WANT_FORCE_OPTIMIZATION_DOWNGRADE=1" is a good setting for the
Alpha platform when building ports.
This is enabled by the undocumented option -fformat-extensions.
This option should be named better and/or give more control over
the extensions.
Fixed a message - don't warn about the field width when it's the
precision that has the wrong type. Didn't fix excessive checking
for the precision relative to the type - ANSI requires both to be
ints, but gcc permits the field width to be either int or unsigned
int.
non-i386, non-unix, and generatable files have been trimmed, but can easily
be added in later if needed.
gcc-2.7.2.1 will follow shortly, it's a very small delta to this and it's
handy to have both available for reference for such little cost.
The freebsd-specific changes will then be committed, and once the dust has
settled, the bmakefiles will be committed to use this code.
