Glibc assumes that ENTRY_POINT is the lowest address for which we need
to keep profiling records and BFD linker uses a linker script to place
the input sections.
Starting from GCC 4.6, the main function is placed in .text.startup
section and starting from binutils 2.22, BFD linker with
commit add44f8d5c5c05e08b11e033127a744d61c26aee
Author: Alan Modra <amodra@gmail.com>
Date: Thu Nov 25 03:03:02 2010 +0000
* scripttempl/elf.sc: Group .text.exit, text.startup and .text.hot
sections.
places .text.startup section before .text section, which leave the main
function out of profiling records.
Starting from binutils 2.15, linker provides __executable_start to mark
the lowest address of the executable. Use __executable_start as the
lowest address to keep the main function in profiling records. This fixes
[BZ #28153].
Tested on Linux/x86-64, Linux/x32 and Linux/i686 as well as with
build-many-glibcs.py.
I used these shell commands:
../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")
and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 6694 files FOO.
I then removed trailing white space from benchtests/bench-pthread-locks.c
and iconvdata/tst-iconv-big5-hkscs-to-2ucs4.c, to work around this
diagnostic from Savannah:
remote: *** pre-commit check failed ...
remote: *** error: lines with trailing whitespace found
remote: error: hook declined to update refs/heads/master
The function, main, is added to profiling output of static executable
which must link against gcrt1.o.
* Makeconfig (+link-static-before-libc): Use the first of
$(CRT-$(@F)) and $(csu-objpfx)$(static-start-installed-name).
* gmon/Makefile (tests): Add tst-gmon-static.
(tests-static): Likewise.
(CFLAGS-tst-gmon-static.c): New.
(CRT-tst-gmon-static): Likewise.
(DEFAULT-LDFLAGS-tst-gmon-static): Likewise.
(tst-gmon-static-ENV): Likewise.
(tests-special): Likewise.
($(objpfx)tst-gmon-static.out): Likewise.
(clean-tst-gmon-static-data): Likewise.
($(objpfx)tst-gmon-static-gprof.out): Likewise.
* gmon/tst-gmon-static-gprof.sh: New file.
* gmon/tst-gmon-static.c: Likewise.