#13935: AC_CHECK_FUNC yields incorrect result for pthread functions on NixOS
causing build to fail
-------------------------------------+-------------------------------------
Reporter: mjvoge02 | Owner: (none)
Type: bug | Status: new
Priority: normal | Milestone:
Component: Build System | Version:
Keywords: autoconf, | Operating System: Linux
AC_CHECK_FUNC, configure, nixos |
Architecture: x86_64 | Type of failure: None/Unknown
(amd64) |
Test Case: | Blocked By:
Blocking: | Related Tickets:
Differential Rev(s): | Wiki Page:
-------------------------------------+-------------------------------------
Code in [[GhcFile(configure.ac)]] incorrectly assesses that pthread
functions will be available without explicitly providing `-lpthread` to
gcc. This causes the build to fail.
Forcing `need_lpthread=1` in [[GhcFile(configure.ac)]] causes the build to
succeed and produce a perfectly functional GHC.
From conversation on #GHC:
"It looks like the combination of the following two commits has caused the
breakage: e94bfb677298de3c4b4e0d1223fbc589849b79be,
c0872bf99ff891e440f118bf9eea20b980c2cfca.[[br]]
The first makes the configure script check if the `-lpthread` argument is
required when building GHC, and the second uses that knowledge at runtime
to decide whether to pass `-lpthread` when linking programs. [[br]]
Stage 0 builds stage 1 just fine, since it doesn't have these commits and
decides whether to pass `-lpthread` based purely on the platform. But the
code from the first commit is yielding a false result (I don't know why),
so stage 1 fails to build stage 2, since the second commit makes it use
the false result to choose not to pass `-lpthread`."
Also, doesn't determining the need for `-lpthread` like this have
problematic implications for cross compilation? Whether `-lpthread` is
required could be different between linking GHC and GHC doing linking
(e.g. a cross compiler built on a system that does need the flag targeting
a system that doesn't.)
Ignoring that, using AX_PTHREAD or ACX_PTHREAD could potentially help
resolve the issue.
Relevant code from [[GhcFile(configure.ac)]]:
{{{#!bash
dnl Some platforms (e.g. Android's Bionic) have pthreads support available
dnl without linking against libpthread. Check whether -lpthread is
necessary
dnl to use pthreads.
dnl
dnl Note that it is important that this happens before we
AC_CHECK_LIB(thread)
AC_MSG_CHECKING(whether -lpthread is needed for pthreads)
AC_CHECK_FUNC(pthread_create,
[
AC_MSG_RESULT(no)
need_lpthread=0
],
[
AC_CHECK_LIB(pthread, pthread_create,
[
AC_MSG_RESULT(yes)
need_lpthread=1
],
[
AC_MSG_RESULT([no pthreads support found.])
need_lpthread=0
])
])
AC_DEFINE_UNQUOTED([NEED_PTHREAD_LIB], [$need_lpthread],
[Define 1 if we need to link code using pthreads with -lpthread])
}}}
System information:
Linux nixos 4.9.30 x86_64 GNU/Linux
gcc 5.4.0
ghc 7.10.3
Attempting to build GHC HEAD fails with
{{{#!bash
...
"inplace/bin/ghc-stage1" -hisuf hi -osuf o -hcsuf hc -static -O0 -H64m
-Wall -Iincludes -Iincludes/dist -Iincludes/dist-
derivedconstants/header -Iincludes/dist-ghcconstants/header -this-unit-
id ghc-8.3 -hide-all-packages -i -icompiler/backpack -icompiler/basicTypes
-icompiler/cmm -icompiler/codeGen -icompiler/coreSyn -icompiler/deSugar
-icompiler/ghci -icompiler/hsSyn -icompiler/iface -icompiler/llvmGen
-icompiler/main -icompiler/nativeGen -icompiler/parser -icompiler/prelude
-icompiler/profiling -icompiler/rename -icompiler/simplCore
-icompiler/simplStg -icompiler/specialise -icompiler/stgSyn
-icompiler/stranal -icompiler/typecheck -icompiler/types -icompiler/utils
-icompiler/vectorise -icompiler/stage2/build -Icompiler/stage2/build
-icompiler/stage2/build/./autogen -Icompiler/stage2/build/./autogen
-Icompiler/. -Icompiler/parser -Icompiler/utils
-Icompiler/../rts/dist/build -Icompiler/stage2 -optP-DGHCI -optP-include
-optPcompiler/stage2/build/./autogen/cabal_macros.h -package-id
base-4.10.0.0 -package-id deepseq-1.4.3.0 -package-id directory-1.3.0.2
-package-id process-1.6.0.0 -package-id bytestring-0.10.8.2 -package-id
binary-0.8.4.1 -package-id time-1.8.0.1 -package-id containers-0.5.10.2
-package-id array-0.5.1.2 -package-id filepath-1.4.1.2 -package-id
template-haskell-2.12.0.0 -package-id hpc-0.6.0.3 -package-id
transformers-0.5.2.0 -package-id ghc-boot-8.3 -package-id ghc-boot-th-8.3
-package-id ghci-8.3 -package-id unix-2.7.2.2 -package-id terminfo-0.4.1.0
-Wall -fno-warn-name-shadowing -this-unit-id ghc -XHaskell2010 -optc-
DTHREADED_RTS -DGHCI_TABLES_NEXT_TO_CODE -DSTAGE=2 -Rghc-timing -O0 -no-
user-package-db -rtsopts -Wnoncanonical-monad-instances -odir
compiler/stage2/build -hidir compiler/stage2/build -stubdir
compiler/stage2/build -dynamic-too -c compiler/hsSyn/HsTypes.hs -o
compiler/stage2/build/HsTypes.o -dyno compiler/stage2/build/HsTypes.dyn_o
includes/rts/OSThreads.h:58:0: error:
error: undefined reference to 'pthread_mutex_trylock'
|
58 | return pthread_mutex_trylock(mutex);
| ^
includes/rts/OSThreads.h:58:0: error:
error: undefined reference to 'pthread_mutex_trylock'
|
58 | return pthread_mutex_trylock(mutex);
| ^
rts/posix/OSThreads.c:137:0: error:
error: undefined reference to 'pthread_create'
|
137 | int result = pthread_create(pId, NULL, (void *(*)(void
*))startProc, param);
| ^
rts/posix/OSThreads.c:139:0: error:
error: undefined reference to 'pthread_detach'
|
139 | pthread_detach(*pId);
| ^
rts/posix/OSThreads.c:141:0: error:
error: undefined reference to 'pthread_setname_np'
|
141 | pthread_setname_np(*pId, name);
| ^
rts/posix/OSThreads.c:184:0: error:
error: undefined reference to 'pthread_key_create'
|
184 | if ((r = pthread_key_create(key, NULL)) != 0) {
| ^
rts/posix/OSThreads.c:203:0: error:
error: undefined reference to 'pthread_setspecific'
|
203 | if ((r = pthread_setspecific(*key,value)) != 0) {
| ^
rts/posix/OSThreads.c:212:0: error:
error: undefined reference to 'pthread_key_delete'
|
212 | if ((r = pthread_key_delete(*key)) != 0) {
| ^
rts/posix/OSThreads.c:233:0: error:
error: undefined reference to 'pthread_create'
|
233 | int result = pthread_create(&tid, NULL,
| ^
rts/posix/OSThreads.c:236:0: error:
error: undefined reference to 'pthread_detach'
|
236 | pthread_detach(tid);
| ^
rts/posix/OSThreads.c:192:0: error:
error: undefined reference to 'pthread_getspecific'
|
192 | return pthread_getspecific(*key);
| ^
rts/posix/OSThreads.c:371:0: error:
error: undefined reference to 'pthread_kill'
|
371 | pthread_kill(id, SIGPIPE);
| ^
rts/posix/itimer/Pthread.c:171:0: error:
error: undefined reference to 'pthread_create'
|
171 | if (! pthread_create(&thread, NULL, itimer_thread_func,
(void*)handle_tick)) {
| ^
rts/posix/itimer/Pthread.c:210:0: error:
error: undefined reference to 'pthread_join'
|
210 | if (pthread_join(thread, NULL)) {
| ^
rts/posix/itimer/Pthread.c:173:0: error:
error: undefined reference to 'pthread_setname_np'
|
173 | pthread_setname_np(thread, "ghc_ticker");
| ^
rts/posix/itimer/Pthread.c:214:0: error:
error: undefined reference to 'pthread_detach'
|
214 | pthread_detach(thread);
| ^
includes/rts/OSThreads.h:58:0: error:
error: undefined reference to 'pthread_mutex_trylock'
|
58 | return pthread_mutex_trylock(mutex);
| ^
collect2: error: ld returned 1 exit status
`gcc' failed in phase `Linker'. (Exit code: 1)
make[1]: *** [iserv/ghc.mk:72: iserv/stage2/build/tmp/ghc-iserv] Error 1
make[1]: *** Waiting for unfinished jobs....
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