https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89227
Bug ID: 89227
Summary: gotools test cmd/go fails with link error "call lacks
nop, can't restore toc; recompile with -fPIC"
Product: gcc
Version: 9.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: go
Assignee: ian at airs dot com
Reporter: boger at gcc dot gnu.org
CC: cmang at google dot com, wschmidt at gcc dot gnu.org
Target Milestone: ---
Target: ppc64le
I'm not sure when this testcase started failing. I can get it to fail
consistently if I configure my gccgo build with lto
(--enable-languages=c,c++,go,lto). However after searching the gcc-testresults
output, it only fails intermittently on those runs, and they don't configure
with lto.
gotools.log shows this:
Running cmd/go
cd check-go-dir/src/cmd/go &&
PATH=/home/boger/gccgo.work/trunk/bld/gotools:/home/boger/golang/base/go/bin:/home/boger/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin
GCCGO='/home/boger/gccgo.work/trunk/bld/gotools/check-gccgo'
CC='/home/boger/gccgo.work/trunk/bld/gotools/check-gcc'
GCCGOTOOLDIR='/home/boger/gccgo.work/trunk/bld/gotools' GO_TESTING_GOTOOLS=yes
LD_LIBRARY_PATH=/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/.libs
GOROOT=/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo
GOCACHE=/home/boger/gccgo.work/trunk/bld/gotools/gocache-test
GOPATH=/home/boger/gccgo.work/trunk/bld/gotools/check-go-dir
/home/boger/gccgo.work/trunk/bld/gotools/go test -test.short -test.timeout=600s
-test.v
# cmd/go.test
/home/boger/gccgo.work/trunk/bld/gotools/check-go-dir/src/cmd/go/script_test.go:283:
error: call lacks nop, can't restore toc; recompile with -fPIC
collect2: error: ld returned 1 exit status
FAIL cmd/go [build failed]
Here are the steps I use to get down to a compile command to test with:
>cd bld/gotools
>make check-go-tool
This will generate the directories needed for the above command. In order to
see everything, you might need to remove directory gocache_test.
Submit the above command, adding -x -work before -test.short and direct that
into a file like this:
cd check-go-dir/src/cmd/go &&
PATH=/home/boger/gccgo.work/trunk/bld/gotools:/home/boger/golang/base/go/bin:/home/boger/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin
GCCGO='/home/boger/gccgo.work/trunk/bld/gotools/check-gccgo'
CC='/home/boger/gccgo.work/trunk/bld/gotools/check-gcc'
GCCGOTOOLDIR='/home/boger/gccgo.work/trunk/bld/gotools' GO_TESTING_GOTOOLS=yes
LD_LIBRARY_PATH=/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/.libs
GOROOT=/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo
GOCACHE=/home/boger/gccgo.work/trunk/bld/gotools/gocache-test
GOPATH=/home/boger/gccgo.work/trunk/bld/gotools/check-go-dir
/home/boger/gccgo.work/trunk/bld/gotools/go test -x -work -test.short
-test.timeout=600s -test.v 2> link.out
The error message happens because the call to testenv.HasLink does not have a
nop following its 'bl' instruction. This call occurs in script_test.go. In the
link.out find the value for $WORK and then the compile command that includes
script_test.go.
I was able to minimize the go files to these, and put the output file into the
current directory instead of under $WORK.
../../../../check-gccgo -c -g -fdebug-prefix-map=$WORK=/tmp/go-build
-gno-record-gcc-switches -fgo-pkgpath=cmd/go_test -O0 -o _go_.o -I
$WORK/b104/_importcfgroot_ ./go_test.go ./proxy_test.go ./script_test.go -v
Using the -v output I use this command:
/home/boger/gccgo.work/trunk/bld/./gcc/go1 ./go_test.go ./proxy_test.go
./script_test.go -quiet -dumpbase go_test.go -auxbase-strip _go_.o -g
-gno-record-gcc-switches -O0 -version
-fdebug-prefix-map=/tmp/go-build260802146=/tmp/go-build
-fgo-pkgpath=cmd/go_test -I /tmp/go-build260802146/b104/_importcfgroot_ -I
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo
-L/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo
-L/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/.libs
-L/home/boger/gccgo.work/trunk/bld/./gcc
-L/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/../libstdc++-v3/src/.libs
-L/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/../libstdc++-v3/libsupc++/.libs
-L/lib/powerpc64le-linux-gnu -L/lib/../lib64 -L/usr/lib/powerpc64le-linux-gnu
-fdump-rtl-expand -o /tmp/ccqwFgbq.s
I can see in the asm output file, that there is no nop following the call to
HasLink:
.LBB2080:
.loc 5 283 18
bl internal..z2ftestenv.HasLink
.LEHE4985:
mr 9,3
But there is one after all other calls in the file including others from
testenv.
I did an rtl dump too although not sure what this is telling me. The call to
HasLink looks like this:
(call_insn 1086 1085 1973 191 (parallel [
(set (reg:DI 3 3)
(call (mem:SI (symbol_ref:DI ("internal..z2ftestenv.HasLink")
[flags 0x3] <function_decl 0x73998cf76d00 testenv.HasLink>) [0 testenv.HasLink
S4 A8])
(const_int 0 [0])))
(clobber (reg:DI 65 lr))
]) "./script_test.go":283:18 -1
(expr_list:REG_EH_REGION (const_int 1 [0x1])
(nil))
(expr_list (use (reg:DI 2 2))
(nil)))
(note 1973 1086 1087 192 [bb 192] NOTE_INSN_BASIC_BLOCK)
The interesting information here is that the flags on this call are 0x3 but all
other calls in the file have flags 0x41. I have not found what the flags mean
yet but that looks like it could be the problem.
