On 23/04/21 20:54 -0400, David Edelsohn via Libstdc++ wrote:
Some ports require libatomic for atomic operations, at least for some
data types and widths. The libstdc++ testsuite previously was updated
to link against libatomic, but the search path was hard-coded to
something that is not always correct, and the shared library search
path was not set.
In libstdc++_init we have:
# Locate libatomic.
set v3-libatomic 0
set libatomicdir [lookfor_file $blddir/../libatomic
.libs/libatomic.$shlib_ext]
if {$libatomicdir != ""} {
set v3-libatomic 1
set libatomicdir [file dirname $libatomicdir]
append ld_library_path_tmp ":${libatomicdir}"
verbose -log "libatomic support detected"
}
v3track libatomicdir 3
Which should have added it to the search path unconditionally, so that
it will be found if a test is linked with -latomic and needs it. I
Don't know why that's not working for AIX, I see it doing the right
thing in the logs for x86_64-linux (and the path is right for the
alternative unix/-m32 multilib tests):
libatomic support detected
libgomp support detected
shared library support detected
LD_LIBRARY_PATH=:/home/jwakely/src/gcc/build/gcc:/home/jwakely/src/gcc/build/x86_64-pc-linux-gnu/32/libstdc++-v3/../libatomic/.libs:/home/jwakely/src/gcc/build/x86_64-pc-linux-gnu/32/libstdc++-v3/../libgomp/.libs:/home/jwakely/src/gcc/build/x86_64-pc-linux-gnu/32/libstdc++-v3/src/.libs:/home/jwakely/src/gcc/build/gcc/32
LD_RUN_PATH=:/home/jwakely/src/gcc/build/gcc:/home/jwakely/src/gcc/build/x86_64-pc-linux-gnu/32/libstdc++-v3/../libatomic/.libs:/home/jwakely/src/gcc/build/x86_64-pc-linux-gnu/32/libstdc++-v3/../libgomp/.libs:/home/jwakely/src/gcc/build/x86_64-pc-linux-gnu/32/libstdc++-v3/src/.libs:/home/jwakely/src/gcc/build/gcc/32
SHLIB_PATH=:/home/jwakely/src/gcc/build/gcc:/home/jwakely/src/gcc/build/x86_64-pc-linux-gnu/32/libstdc++-v3/../libatomic/.libs:/home/jwakely/src/gcc/build/x86_64-pc-linux-gnu/32/libstdc++-v3/../libgomp/.libs:/home/jwakely/src/gcc/build/x86_64-pc-linux-gnu/32/libstdc++-v3/src/.libs:/home/jwakely/src/gcc/build/gcc/32
LD_LIBRARY_PATH_32=:/home/jwakely/src/gcc/build/gcc:/home/jwakely/src/gcc/build/x86_64-pc-linux-gnu/32/libstdc++-v3/../libatomic/.libs:/home/jwakely/src/gcc/build/x86_64-pc-linux-gnu/32/libstdc++-v3/../libgomp/.libs:/home/jwakely/src/gcc/build/x86_64-pc-linux-gnu/32/libstdc++-v3/src/.libs:/home/jwakely/src/gcc/build/gcc/32
LD_LIBRARY_PATH_64=:/home/jwakely/src/gcc/build/gcc:/home/jwakely/src/gcc/build/x86_64-pc-linux-gnu/32/libstdc++-v3/../libatomic/.libs:/home/jwakely/src/gcc/build/x86_64-pc-linux-gnu/32/libstdc++-v3/../libgomp/.libs:/home/jwakely/src/gcc/build/x86_64-pc-linux-gnu/32/libstdc++-v3/src/.libs:/home/jwakely/src/gcc/build/gcc/32
DYLD_LIBRARY_PATH=:/home/jwakely/src/gcc/build/gcc:/home/jwakely/src/gcc/build/x86_64-pc-linux-gnu/32/libstdc++-v3/../libatomic/.libs:/home/jwakely/src/gcc/build/x86_64-pc-linux-gnu/32/libstdc++-v3/../libgomp/.libs:/home/jwakely/src/gcc/build/x86_64-pc-linux-gnu/32/libstdc++-v3/src/.libs:/home/jwakely/src/gcc/build/gcc/32
LD_LIBRARY_PATH =
:/home/jwakely/src/gcc/build/gcc:/home/jwakely/src/gcc/build/x86_64-pc-linux-gnu/32/libstdc++-v3/../libatomic/.libs:/home/jwakely/src/gcc/build/x86_64-pc-linux-gnu/32/libstdc++-v3/../libgomp/.libs:/home/jwakely/src/gcc/build/x86_64-pc-linux-gnu/32/libstdc++-v3/src/.libs:/home/jwakely/src/gcc/build/gcc/32
The search path was hard-coded to the expected location of the
libatomic build directory relative to the libstdc++ testsuite
directory, but if one uses parallelism when invoking the libstdc++
testsuite, the tests are run in the "normalXX" sub-directories, for
which the hard-coded search path is incorrect.
This has occurred to me previously, and I checked it, and it works
fine for parallel test runs. I must be running the tests differently
from you, as I can't reproruce the problem.
For example, in r11-8285 I added the libatomic options to
30_threads/semaphore/try_acquire_posix.cc because it was failing on
AIX (on gcc119 specifically). With the { dg-add-options libatomic } in
place it no longer fails. That is true for parallel and non-parallel
test runs, and whether I run "make check" in the $target/libstdc++-v3
directory, or $target/libstdc++-v3/testsuite, or run make
check-target-libstdc++-v3 in the top-level build dir.
The path also is
incorrect for alternative multilib and tool options.
Is it? For alternative multilibs we have something like:
./libstdc++/testsuite
./libatomic/.libs
ppc64/libstdc++-v3/testsuite
ppc64/libatomic/.libs
pthread/libstdc++-v3/testsuite
pthread/libatomic/.libs
In each case, the relative path from the v3/testsuite directory to
libatomic.a ia the same, ../../libatomic/.src
The patch seems like an improvement, but I don't see the problem it
was fixing.
This patch adopts the logic from gcc/testsuite/lib/atomic-dg.exp to
search for the library and adds the logic to the libstdc++ testsuite
libatomic seatch path code. Previously the libstdc++ testsuite atomic
tests failed depending on the build configuration and if a build of
libatomic was installed in the default search path.
Bootstrapped on powerpc-ibm-aix7.2.3.0.
Okay to install?
Thanks, David
* testsuite/lib/dg-options.exp (atomic_link_flags): New.
(add_options_for_libatomic): Use atomic_link_flags.
--- a/libstdc++-v3/testsuite/lib/dg-options.exp
+++ b/libstdc++-v3/testsuite/lib/dg-options.exp
@@ -260,13 +260,58 @@ proc add_options_for_net_ts { flags } {
# Add to FLAGS all the target-specific flags to link to libatomic,
# if required for atomics on pointers and 64-bit types.
+proc atomic_link_flags { paths } {
+ global srcdir
+ global ld_library_path
+ global shlib_ext
+
+ set gccpath ${paths}
+ set flags ""
+
+ set shlib_ext [get_shlib_extension]
+
+ if { $gccpath != "" } {
+ if { [file exists "${gccpath}/libatomic/.libs/libatomic.a"]
+ || [file exists "${gccpath}/libatomic/.libs/libatomic.${shlib_ext}"]
} {
+ append flags " -B${gccpath}/libatomic/ "
+ append flags " -L${gccpath}/libatomic/.libs"
+ append ld_library_path ":${gccpath}/libatomic/.libs"
+ }
+ } else {
+ global tool_root_dir
+
+ set libatomic [lookfor_file ${tool_root_dir} libatomic]
+ if { $libatomic != "" } {
+ append flags "-L${libatomic} "
+ append ld_library_path ":${libatomic}"
+ }
+ }
+
+ set_ld_library_path_env_vars
+
+ return "$flags"
+}
+
proc add_options_for_libatomic { flags } {
if { [istarget hppa*-*-hpux*]
|| ([istarget powerpc*-*-*] && [check_effective_target_ilp32])
|| [istarget riscv*-*-*]
|| ([istarget sparc*-*-linux-gnu] && [check_effective_target_ilp32])
} {
- return "$flags -L../../libatomic/.libs -latomic"
+ global TOOL_OPTIONS
+
+ set link_flags ""
+ if ![is_remote host] {
+ if [info exists TOOL_OPTIONS] {
+ set link_flags "[atomic_link_flags [get_multilibs
${TOOL_OPTIONS}]]"
+ } else {
+ set link_flags "[atomic_link_flags [get_multilibs]]"
+ }
+ }
+
+ append link_flags " -latomic "
+
+ return "$flags $link_flags"
}
return $flags
}
