On 09/12/14 11:49, Hans-Peter Nilsson wrote:
Ping! <http://gcc.gnu.org/ml/gcc-patches/2014-09/msg00402.html>
From: Hans-Peter Nilsson <h...@axis.com>
Date: Thu, 4 Sep 2014 23:40:40 +0200
The directory at $target_header_dir is already inspected in
gcc/configure, for e.g. glibc version and stack protector
support, but not for setting inhibit_libc. This is just
inconsistent and the obvious resolution to me is to inhibit
inhibit_libc when a target *does* "have its own set of headers",
to quote the comment above the inhibit_libc setting. There is
nothing in the build log for "make all-gcc" that shows a
difference with/without --with-headers, if headers are actually
present anyway!
It may seem that libgcc/configure.ac would be the appropriate
place to patch and test, but it is gcc/configure.ac which tests
various things about target headers and makes the inhibit_libc
decision, exporting it through the generated obj/gcc/libgcc.mvars
that is included in libgcc/Makefile.
Tested before/after by "make all-gcc" on native x86_64-linux (*a) and
seeing it still set (for the peace of most users) in
gcc/Makefile, and cross to mipsel-linux "make all-gcc" with/without (*b,c) a
pre-installed set of headers just implied by --prefix and --target to
observe the intended difference and the same with (*d)
--with-sysroot (but no headers at the sysroot) and (*e)
--with-build-sysroot and both (*f) (note that
--with-build-sysroot=... without --with-sysroot also got
inhibit_libc) to observe no change for the --with-sysroot one
(still no inhibit_libc). The same with --with-headers
(*g). Also, I checked that nothing other than the inhibit_libc code
uses target_header_dir or sets the used variables in the block
of code involved in the move.
Ok to commit?
gcc:
* configure.ac (target_header_dir): Move block defining
this to before the block setting inhibit_libc.
(inhibit_libc): When considering $with_headers, just
check it it's explicitly "no". If not, also check if
$target_header_dir/stdio.h is present. If not, set
inhibit_libc=true.
* configure: Regenerate.
OK.
jeff
