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Pedro Alves a376e11d84 Fix calling ifunc functions when resolver has debug info and different name
Currently, on Fedora 27 (glibc 2.26), if you try to call strlen in the
inferior you get:

 (gdb) p strlen ("hello")
 $1 = (size_t (*)(const char *)) 0x7ffff554aac0 <__strlen_avx2>

strlen is an ifunc function, and what we see above is the result of
calling the ifunc resolver in the inferior.  That returns a pointer to
the actual target function that implements strlen on my machine.  GDB
should have turned around and called the resolver automatically
without the user noticing.

This is was caused by commit:

  commit bf223d3e80
  Date: Mon Aug 21 11:34:32 2017 +0100

      Handle function aliases better (PR gdb/19487, errno printing)

which added the find_function_alias_target call to c-exp.y, to try to
find an alias with debug info for a minsym.  For ifunc symbols, that
finds the ifunc's resolver if it has debug info (in the example it's
called "strlen_ifunc"), with the result that GDB calls that as a
regular function.

After this commit, we get now get:

  (top-gdb) p strlen ("hello")
  '__strlen_avx2' has unknown return type; cast the call to its declared return type

Which is correct, because __strlen_avx2 is written in assembly.
That'll be improved in a following patch, though.

gdb/ChangeLog:
2018-04-26  Pedro Alves  <palves@redhat.com>

	* c-exp.y (variable production): Skip finding an alias for ifunc
	symbols.
2018-04-26 13:04:09 +01:00
bfd Automatic date update in version.in 2018-04-26 00:00:46 +00:00
binutils [ARM] FDPIC: Update testsuite so that many tests pass with arm*-uclinuxfdpiceabi. 2018-04-25 21:13:14 +00:00
config config: Sync with GCC 2018-04-05 15:22:13 -07:00
cpu opcodes error messages 2018-03-03 11:34:26 +10:30
elfcpp PowerPC inline PLT call support 2018-04-09 17:25:20 +09:30
etc Update year range in copyright notice of binutils files 2018-01-03 17:49:56 +10:30
gas x86: fold various non-memory operand AVX512VL templates 2018-04-26 08:55:02 +02:00
gdb Fix calling ifunc functions when resolver has debug info and different name 2018-04-26 13:04:09 +01:00
gold Fix bug with relocation addends and merge sections with --icf. 2018-04-24 22:13:56 -07:00
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include [ARM] Add TLS relocations for FDPIC. 2018-04-25 20:57:02 +00:00
intl Require ngettext in test of system gettext implementation 2017-11-07 15:56:44 +10:30
ld [ARM] FDPIC: Update testsuite so that many tests pass with arm*-uclinuxfdpiceabi. 2018-04-25 21:13:14 +00:00
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ChangeLog WebAssembly: Disable subdirectory configuration for unsupported LD 2018-02-13 12:56:29 +00:00
compile Update from upstream Automake 2014-11-16 13:43:48 +01:00
config-ml.in Update top level configure files by synchronizing them with gcc. 2018-01-10 15:29:21 +00:00
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config.rpath
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configure WebAssembly: Disable subdirectory configuration for unsupported LD 2018-02-13 12:56:29 +00:00
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libtool.m4 Sync top-level btool.m4 with GCC 2016-01-12 08:44:52 -08:00
lt~obsolete.m4
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MAINTAINERS Update description of ownership of files in include/ 2014-11-04 16:14:14 -08:00
Makefile.def Sync top-level make and configure files with FSF GCC mainline versions. 2017-01-23 11:55:48 +00:00
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