[zig cc] failure to compile php-opcache with jit enabled

[henderkes]

Zig Version

0.15-dev

Steps to Reproduce and Observed Behavior

git clone https://github.com/crazywhalecc/static-php-cli
cd static-php-cli
composer install
export CC="zig cc -target x86_64-linux-gnu.2.17"
bin/spc download -e opcache
bin/spc build "opcache" --enable-zts --build-cli --debug

Expected Behavior

Compiles correctly.

Actual behaviour:

ext/opcache/jit/ir/minilua /home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/dynasm.lua  -D X64=1 -o ext/opcache/jit/ir/ir_emit_x86.h /home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/ir_x86.dasc
thread 14509 panic: 4.294967296e9 is outside the range of representable values of type 'int'
ext/opcache/jit/ir/dynasm/minilua.c:1638:1: 0x1052ce2 in luaH_get (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
lua_number2int(k,n);
^
ext/opcache/jit/ir/dynasm/minilua.c:1655:16: 0x1054e60 in luaH_set (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
const TValue*p=luaH_get(t,key);
               ^
ext/opcache/jit/ir/dynasm/minilua.c:3145:12: 0x1096435 in addk (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
TValue*idx=luaH_set(L,fs->h,k);
           ^
ext/opcache/jit/ir/dynasm/minilua.c:3169:8: 0x1096302 in luaK_numberK (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
return addk(fs,&o,&o);
       ^
ext/opcache/jit/ir/dynasm/minilua.c:3334:15: 0x10980ee in luaK_exp2RK (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
(e->k==VKNUM)?luaK_numberK(fs,e->u.nval):
              ^
ext/opcache/jit/ir/dynasm/minilua.c:3528:8: 0x10a40e6 in codecomp (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
int o2=luaK_exp2RK(fs,e2);
       ^
ext/opcache/jit/ir/dynasm/minilua.c:3621:13: 0x108f5bb in luaK_posfix (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
case OPR_GE:codecomp(fs,OP_LE,0,e1,e2);break;
            ^
ext/opcache/jit/ir/dynasm/minilua.c:4293:1: 0x108d91b in subexpr (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
luaK_posfix(ls->fs,op,v,&v2);
^
ext/opcache/jit/ir/dynasm/minilua.c:4300:1: 0x108d0be in expr (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
subexpr(ls,v,0);
^
ext/opcache/jit/ir/dynasm/minilua.c:4376:1: 0x108cf95 in cond (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
expr(ls,&v);
^
ext/opcache/jit/ir/dynasm/minilua.c:4515:10: 0x108cc1d in test_then_block (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
condexit=cond(ls);
         ^
ext/opcache/jit/ir/dynasm/minilua.c:4524:7: 0x108a65a in ifstat (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
flist=test_then_block(ls);
      ^
ext/opcache/jit/ir/dynasm/minilua.c:4631:1: 0x108a3d2 in statement (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
ifstat(ls,line);
^
ext/opcache/jit/ir/dynasm/minilua.c:4683:8: 0x107b588 in chunk (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
islast=statement(ls);
       ^
ext/opcache/jit/ir/dynasm/minilua.c:4076:1: 0x109a240 in body (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
chunk(ls);
^
ext/opcache/jit/ir/dynasm/minilua.c:4548:1: 0x108b3b7 in localfunc (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
body(ls,&b,0,ls->linenumber);
^
ext/opcache/jit/ir/dynasm/minilua.c:4659:1: 0x108a494 in statement (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
localfunc(ls);
^
ext/opcache/jit/ir/dynasm/minilua.c:4683:8: 0x107b588 in chunk (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
islast=statement(ls);
       ^
ext/opcache/jit/ir/dynasm/minilua.c:3930:1: 0x10790ca in luaY_parser (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
chunk(&lexstate);
^
ext/opcache/jit/ir/dynasm/minilua.c:1241:4: 0x10786c4 in f_parser (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
tf=luaY_parser(L,p->z,
   ^
ext/opcache/jit/ir/dynasm/minilua.c:1044:1: 0x1021823 in luaD_rawrunprotected (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
LUAI_TRY(L,&lj,
^
ext/opcache/jit/ir/dynasm/minilua.c:1215:8: 0x1077c5f in luaD_pcall (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
status=luaD_rawrunprotected(L,func,u);
       ^
ext/opcache/jit/ir/dynasm/minilua.c:1255:8: 0x10776e4 in luaD_protectedparser (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
status=luaD_pcall(L,f_parser,&p,savestack(L,L->top),L->errfunc);
       ^
ext/opcache/jit/ir/dynasm/minilua.c:5795:8: 0x1076f30 in lua_load (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
status=luaD_protectedparser(L,&z,chunkname);
       ^
ext/opcache/jit/ir/dynasm/minilua.c:6198:8: 0x1076e9d in luaL_loadbuffer (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
return lua_load(L,getS,&ls,name);
       ^
ext/opcache/jit/ir/dynasm/minilua.c:6354:19: 0x1070ef1 in luaB_loadstring (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
return load_aux(L,luaL_loadbuffer(L,s,l,chunkname));
                  ^
ext/opcache/jit/ir/dynasm/minilua.c:1170:3: 0x103696c in luaD_precall (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
n=(*curr_func(L)->c.f)(L);
  ^
ext/opcache/jit/ir/dynasm/minilua.c:5142:8: 0x10437b0 in luaV_execute (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
switch(luaD_precall(L,ra,nresults)){
       ^
ext/opcache/jit/ir/dynasm/minilua.c:1203:1: 0x1034395 in luaD_call (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
luaV_execute(L,1);
^
ext/opcache/jit/ir/dynasm/minilua.c:5768:1: 0x10c2a3d in f_call (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
luaD_call(L,c->func,c->nresults);
^
ext/opcache/jit/ir/dynasm/minilua.c:1044:1: 0x1021823 in luaD_rawrunprotected (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
LUAI_TRY(L,&lj,
^
ext/opcache/jit/ir/dynasm/minilua.c:1215:8: 0x1077c5f in luaD_pcall (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
status=luaD_rawrunprotected(L,func,u);
       ^
ext/opcache/jit/ir/dynasm/minilua.c:5785:8: 0x101e3d2 in lua_pcall (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
status=luaD_pcall(L,f_call,&c,savestack(L,c.func),func);
       ^
ext/opcache/jit/ir/dynasm/minilua.c:6383:8: 0x1070f86 in luaB_pcall (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
status=lua_pcall(L,lua_gettop(L)-1,(-1),0);
       ^
ext/opcache/jit/ir/dynasm/minilua.c:1170:3: 0x103696c in luaD_precall (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
n=(*curr_func(L)->c.f)(L);
  ^
ext/opcache/jit/ir/dynasm/minilua.c:5142:8: 0x10437b0 in luaV_execute (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
switch(luaD_precall(L,ra,nresults)){
       ^
ext/opcache/jit/ir/dynasm/minilua.c:1203:1: 0x1034395 in luaD_call (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
luaV_execute(L,1);
^
ext/opcache/jit/ir/dynasm/minilua.c:5768:1: 0x10c2a3d in f_call (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
luaD_call(L,c->func,c->nresults);
^
ext/opcache/jit/ir/dynasm/minilua.c:1044:1: 0x1021823 in luaD_rawrunprotected (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
LUAI_TRY(L,&lj,
^
ext/opcache/jit/ir/dynasm/minilua.c:1215:8: 0x1077c5f in luaD_pcall (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
status=luaD_rawrunprotected(L,func,u);
       ^
ext/opcache/jit/ir/dynasm/minilua.c:5785:8: 0x101e3d2 in lua_pcall (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
status=luaD_pcall(L,f_call,&c,savestack(L,c.func),func);
       ^
ext/opcache/jit/ir/dynasm/minilua.c:6383:8: 0x1070f86 in luaB_pcall (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
status=lua_pcall(L,lua_gettop(L)-1,(-1),0);
       ^
ext/opcache/jit/ir/dynasm/minilua.c:1170:3: 0x103696c in luaD_precall (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
n=(*curr_func(L)->c.f)(L);
  ^
ext/opcache/jit/ir/dynasm/minilua.c:5142:8: 0x10437b0 in luaV_execute (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
switch(luaD_precall(L,ra,nresults)){
       ^
ext/opcache/jit/ir/dynasm/minilua.c:1203:1: 0x1034395 in luaD_call (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
luaV_execute(L,1);
^
ext/opcache/jit/ir/dynasm/minilua.c:5768:1: 0x10c2a3d in f_call (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
luaD_call(L,c->func,c->nresults);
^
ext/opcache/jit/ir/dynasm/minilua.c:1044:1: 0x1021823 in luaD_rawrunprotected (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
LUAI_TRY(L,&lj,
^
ext/opcache/jit/ir/dynasm/minilua.c:1215:8: 0x1077c5f in luaD_pcall (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
status=luaD_rawrunprotected(L,func,u);
       ^
ext/opcache/jit/ir/dynasm/minilua.c:5785:8: 0x101e3d2 in lua_pcall (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
status=luaD_pcall(L,f_call,&c,savestack(L,c.func),func);
       ^
ext/opcache/jit/ir/dynasm/minilua.c:7769:4: 0x101c380 in main (/home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/dynasm/minilua.c)
if(lua_pcall(L,argc-2,0,0)){
   ^
???:?:?: 0x7faaa8703347 in ??? (libc.so.6)
Unwind information for `libc.so.6:0x7faaa8703347` was not available, trace may be incomplete

???:?:?: 0x7faaa870340a in ??? (libc.so.6)
/usr/lib/zig/libc/glibc/sysdeps/x86_64/start-2.33.S:120:0: 0x101c079 in ??? (/usr/lib/zig/libc/glibc/sysdeps/x86_64/start-2.33.S)
 call *__libc_start_main@GOTPCREL(%rip)

ext/opcache/jit/ir/gen_ir_fold_hash < /home/m/static-php-cli/source/php-src/ext/opcache/jit/ir/ir_fold.h > ext/opcache/jit/ir/ir_fold_hash.h
make: *** [Makefile:327: ext/opcache/jit/ir/ir_emit_x86.h] Aborted (core dumped)
make: *** Waiting for unfinished jobs....

[alexrp]

This means there's undefined behavior in that code. Ideally that needs to be fixed, but you can try compiling with -fno-sanitize=undefined.

[henderkes]

I'm not sure about the undefined behaviour, that's up to the php team. With -fno-sanitize=undefined:

[henderkes]

Clang (and obviously gcc) both succeed, zig cc fails no matter the target.

Edit: Oh, when passing -fno-sanitize=undefined right after zig cc, I get a different error:

warning: ignoring deprecated linker optimization setting '1'
ld.lld: error: undefined symbol: _Unwind_Backtrace
>>> referenced by zend_jit_ir.c:3228 (ext/opcache/jit/zend_jit_ir.c:3228)
>>>               ext/opcache/jit/zend_jit.o:(zend_jit_touch_vm_stack_data)

ld.lld: error: undefined symbol: _Unwind_GetCFA
>>> referenced by zend_jit_ir.c:3215 (ext/opcache/jit/zend_jit_ir.c:3215)
>>>               ext/opcache/jit/zend_jit.o:(zend_jit_unwind_cb)
make: *** [Makefile:250: sapi/cli/php] Error 1

[alexrp]

Edit: Oh, when passing -fno-sanitize=undefined right after zig cc, I get a different error:

Those symbols are provided by libunwind, i.e. -lunwind.

[henderkes]

I've tried that, to no avail. -lunwind isn't found and when I install libunwind(-devel) and link against libunwind.so.8 it still throws the same error. I cannot find a libunwind.a at all.

Not to mention that I wouldn't want a dependency on a libunwind package that isn't preinstalled. Gcc (gcc_s) and clang (libunwind?) manage to link it statically without any delendencies other than the C runtime ones.

[andrewrk]

Can you clarify what you mean when you say "-lunwind isn't found"? This library is provided by Zig so there is no search and therefore no possible failure to be found.

[henderkes]

I've added -lunwind to EXTRA_LIBS, LIBS and LDFLAGS to try and with the latter, the ./configure step fails by saying -lunwind is not found, C compiler cannot create programs.With the former the error message doesn't change, Unwind... unresolved symbols.

[andrewrk]

the ./configure step fails by saying -lunwind is not found, C compiler cannot create programs

This suggests that ./configure is configuring with a compiler other than zig cc / zig c++.

[henderkes]

It's configuring with zig-cc, which is a bash script I've created because many libraries fail when the CC script has a space.

Contents can be found here:
crazywhalecc/static-php-cli#806 (comment)

The check against --version is necessary, because zig cc -target native-native-gnu.2.17 --version returns with exit code 1, leading more libraries to fail.

[andrewrk]

Maybe try putting into that script -lunwind, rather than those environment variables. Perhaps autotools is doing its own searching for libunwind and reporting failure without actually running the compiler. Zig never says "libunwind not found"; it simply compiles it from source if requested.

[henderkes]

Hmm good idea, although I believe it being set via conventional LDFLAGS/LIBS should also work. Or implicitly linked as (I assume?) Clang does it.

[andrewrk]

Well, zig can't do anything if autotools is complaining before zig even gets run.

If zig cc feels like putting a square peg into a round hole, you could try making a build.zig script instead. It's a bit more involved but more powerful and you can bypass autotools completely, making this also work on a Windows host, for example.

[henderkes]

Well, zig can't do anything if autotools is complaining before zig even gets run.

Zig was run and failed on the failing autoconfigure. ./configure checks run $CC ... confest.c with the -llibs specified in LIBS (and in php's case EXTRA_LIBS).

If zig cc feels like putting a square peg into a round hole, you could try making a build.zig script instead. It's a bit more involved but more powerful and you can bypass autotools completely, making this also work on a Windows host, for example.

I'm maintaining a project to (dynamically and especially statically) compile php with all common extensions. For that, I'm relying on the source code and autotool scripts of php and its extensions, with a few patches here and there. Replacing all of those with zig specific logic, nevermind getting it upstreamed, is a bit outside the realm of a hobby project 😅

I'm confident we can utilise zig in the future to simplify our builds for old platforms and other architectures, that's why I'm raising all the issues here where zig cc fails, but gcc and clang succeed.

It's mighty impressive to me that with just a few patches to our code (and zigs headers) I was able to build a list of >100 c and c++ libraries targeting glibc 2.17.