x86_64-windows-gnu broken, CMakeFiles/zig2.dir/zig2.c.obj Errors out #261

Beneppe commented 2026年05月16日 17:07:30 +02:00

When producing zig2.c.obj on

** Visual Studio 2026 Developer Command Prompt v18.5.2
[vcvarsall.bat] Environment initialized for: 'x64'

error C2466: cannot allocate an array of constant size 0
on multiple occasions.

FAILED: [code=2] CMakeFiles/zig2.dir/zig2.c.obj
C:\PROGRA~1\MIB055~118円\COMMUN~1\VC\Tools\MSVC1450円~1.357\bin\Hostx64\x64\cl.exe /nologo -IC:\Users7743円l\Desktop\Giit\SRC\zig\stage1 -IC:\Users7743円l\Desktop\Giit\SRC\out-win\host\include /DWIN32 /D_WINDOWS /O2 /Ob2 /DNDEBUG -MD /Od /showIncludes /FoCMakeFiles\zig2.dir\zig2.c.obj /FdCMakeFiles\zig2.dir\ /FS -c C:\Users7743円l\Desktop\Giit\SRC\out-win\build-zig-host\zig2.c
cl : Command line warning D9025 : overriding '/O2' with '/Od'
C:\Users7743円l\Desktop\Giit\SRC\out-win\build-zig-host\zig2.c(12953): error C2466: cannot allocate an array of constant size 0
...
C:\Users7743円l\Desktop\Giit\SRC\out-win\build-zig-host\zig2.c(72213): error C2466: cannot allocate an array of constant size 0
C:\Users7743円l\Desktop\Giit\SRC\out-win\build-zig-host\zig2.c(135660): warning C4273: 'free': inconsistent dll linkage
C:\Program Files (x86)\Windows Kits10円\include10円.0.26100.0\ucrt\corecrt_malloc.h(89): note: see previous definition of 'free'
C:\Users7743円l\Desktop\Giit\SRC\out-win\build-zig-host\zig2.c(168891): warning C4273: 'malloc': inconsistent dll linkage
C:\Program Files (x86)\Windows Kits10円\include10円.0.26100.0\ucrt\corecrt_malloc.h(101): note: see previous definition of 'malloc'
C:\Users7743円l\Desktop\Giit\SRC\out-win\build-zig-host\zig2.c(168897): warning C4273: 'realloc': inconsistent dll linkage
C:\Program Files (x86)\Windows Kits10円\include10円.0.26100.0\ucrt\corecrt_malloc.h(126): note: see previous definition of 'realloc'
C:\Users7743円l\Desktop\Giit\SRC\out-win\build-zig-host\zig2.c(168900): warning C4028: formal parameter 1 different from declaration
C:\Users7743円l\Desktop\Giit\SRC\out-win\build-zig-host\zig2.c(168900): warning C4273: '_msize': inconsistent dll linkage
C:\Program Files (x86)\Windows Kits10円\include10円.0.26100.0\ucrt\corecrt_malloc.h(113): note: see previous definition of '_msize'
ninja: build stopped: subcommand failed.

When producing zig2.c.obj on ``` ** Visual Studio 2026 Developer Command Prompt v18.5.2 [vcvarsall.bat] Environment initialized for: 'x64' ``` error C2466: cannot allocate an array of constant size 0 on multiple occasions. ``` FAILED: [code=2] CMakeFiles/zig2.dir/zig2.c.obj C:\PROGRA~1\MIB055~118円\COMMUN~1\VC\Tools\MSVC1450円~1.357\bin\Hostx64\x64\cl.exe /nologo -IC:\Users7743円l\Desktop\Giit\SRC\zig\stage1 -IC:\Users7743円l\Desktop\Giit\SRC\out-win\host\include /DWIN32 /D_WINDOWS /O2 /Ob2 /DNDEBUG -MD /Od /showIncludes /FoCMakeFiles\zig2.dir\zig2.c.obj /FdCMakeFiles\zig2.dir\ /FS -c C:\Users7743円l\Desktop\Giit\SRC\out-win\build-zig-host\zig2.c cl : Command line warning D9025 : overriding '/O2' with '/Od' C:\Users7743円l\Desktop\Giit\SRC\out-win\build-zig-host\zig2.c(12953): error C2466: cannot allocate an array of constant size 0 ... C:\Users7743円l\Desktop\Giit\SRC\out-win\build-zig-host\zig2.c(72213): error C2466: cannot allocate an array of constant size 0 C:\Users7743円l\Desktop\Giit\SRC\out-win\build-zig-host\zig2.c(135660): warning C4273: 'free': inconsistent dll linkage C:\Program Files (x86)\Windows Kits10円\include10円.0.26100.0\ucrt\corecrt_malloc.h(89): note: see previous definition of 'free' C:\Users7743円l\Desktop\Giit\SRC\out-win\build-zig-host\zig2.c(168891): warning C4273: 'malloc': inconsistent dll linkage C:\Program Files (x86)\Windows Kits10円\include10円.0.26100.0\ucrt\corecrt_malloc.h(101): note: see previous definition of 'malloc' C:\Users7743円l\Desktop\Giit\SRC\out-win\build-zig-host\zig2.c(168897): warning C4273: 'realloc': inconsistent dll linkage C:\Program Files (x86)\Windows Kits10円\include10円.0.26100.0\ucrt\corecrt_malloc.h(126): note: see previous definition of 'realloc' C:\Users7743円l\Desktop\Giit\SRC\out-win\build-zig-host\zig2.c(168900): warning C4028: formal parameter 1 different from declaration C:\Users7743円l\Desktop\Giit\SRC\out-win\build-zig-host\zig2.c(168900): warning C4273: '_msize': inconsistent dll linkage C:\Program Files (x86)\Windows Kits10円\include10円.0.26100.0\ucrt\corecrt_malloc.h(113): note: see previous definition of '_msize' ninja: build stopped: subcommand failed. ```

Beneppe commented 2026年05月17日 01:43:06 +02:00

Err for both x86_64-windows-gnu and x86_64-windows-msvc

Err for both x86_64-windows-gnu and x86_64-windows-msvc

squeek502 commented 2026年05月17日 01:44:15 +02:00

Relevant issue is ziglang/zig#31576

Relevant issue is https://codeberg.org/ziglang/zig/issues/31576

Beneppe commented 2026年05月17日 13:25:08 +02:00

Building with clang-cl.exe instead, also errors, but this time is does not seem like ziglang/zig#31576 is the culprit:

[16/19] Building C object CMakeFiles\zig2.dir\zig2.c.obj
FAILED: [code=1] CMakeFiles/zig2.dir/zig2.c.obj
C:\clang+llvm-22.1.2-x86_64-pc-windows-msvc\bin\clang-cl.exe /nologo -IC:\Users7円743l\Desktop\Giit\SRC\zig\stage1 -IC:\Users7円743l\Desktop\Giit\SRC\out-win\host\include /DWIN32 /D_WINDOWS /O2 /Ob2 /DNDEBUG -MD /Od -clang:-MD -clang:-MTCMakeFiles\zig2.dir\zig2.c.obj -clang:-MFCMakeFiles\zig2.dir\zig2.c.obj.d /FoCMakeFiles\zig2.dir\zig2.c.obj /FdCMakeFiles\zig2.dir\ -c -- C:\Users7円743l\Desktop\Giit\SRC\out-win\build-zig-host\zig2.c
C:\Users7円743l\Desktop\Giit\SRC\out-win\build-zig-host\zig2.c(289,29): error: field '__p__environ' declared as a function
 289 | struct process_Environ_743 environ;
 | ^
C:\Program Files (x86)\Windows Kits1円0\include1円0.0.26100.0\ucrt\stdlib.h(1344,21): note: expanded from macro 'environ'
 1344 | #define environ _environ
 | ^
C:\Program Files (x86)\Windows Kits1円0\include1円0.0.26100.0\ucrt\stdlib.h(1171,25): note: expanded from macro '_environ'
 1171 | #define _environ (*__p__environ()) // Pointer to narrow environment table
 | ^
C:\Users7円743l\Desktop\Giit\SRC\out-win\build-zig-host\zig2.c(291,19): error: static assertion failed due to requirement 'sizeof(struct process_Init_Minimal_741) == 24': incorrect size
 291 | zig_static_assert(sizeof (struct process_Init_Minimal_741) == 24, "incorrect size");
 | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
C:\Users7円743l\Desktop\Giit\SRC\zig\stage1\zig.h(158,53): note: expanded from macro 'zig_static_assert'
 158 | #define zig_static_assert(cond, msg) _Static_assert(cond, msg)
 | ^~~~
C:\Users7円743l\Desktop\Giit\SRC\out-win\build-zig-host\zig2.c(291,60): note: expression evaluates to '1 == 24'
 291 | zig_static_assert(sizeof (struct process_Init_Minimal_741) == 24, "incorrect size");
 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~
C:\Users7円743l\Desktop\Giit\SRC\zig\stage1\zig.h(158,53): note: expanded from macro 'zig_static_assert'
 158 | #define zig_static_assert(cond, msg) _Static_assert(cond, msg)
 | ^~~~

But the problem is not neccessarily that the "C backend emits incorrect type layouts for MSVC", but rather that the variable name environ is already a defined macro in

C:\Program Files (x86)\Windows Kits1円0\include1円0.0.26100.0\ucrt\stdlib.h(1344,21): note: expanded from macro 'environ'
 1344 | #define environ _environ
 | ^

This gets used in

struct process_Init_Minimal_741 { /* process.Init.Minimal */
 struct process_Args_745 args;
 struct process_Environ_743 environ;
};

And causes all my errors downstream

**Building with clang-cl.exe** instead, also errors, but this time is does not seem like [ziglang/zig#31576](https://codeberg.org/ziglang/zig/issues/31576) is the culprit: ``` bash [16/19] Building C object CMakeFiles\zig2.dir\zig2.c.obj FAILED: [code=1] CMakeFiles/zig2.dir/zig2.c.obj C:\clang+llvm-22.1.2-x86_64-pc-windows-msvc\bin\clang-cl.exe /nologo -IC:\Users7743円l\Desktop\Giit\SRC\zig\stage1 -IC:\Users7743円l\Desktop\Giit\SRC\out-win\host\include /DWIN32 /D_WINDOWS /O2 /Ob2 /DNDEBUG -MD /Od -clang:-MD -clang:-MTCMakeFiles\zig2.dir\zig2.c.obj -clang:-MFCMakeFiles\zig2.dir\zig2.c.obj.d /FoCMakeFiles\zig2.dir\zig2.c.obj /FdCMakeFiles\zig2.dir\ -c -- C:\Users7743円l\Desktop\Giit\SRC\out-win\build-zig-host\zig2.c C:\Users7743円l\Desktop\Giit\SRC\out-win\build-zig-host\zig2.c(289,29): error: field '__p__environ' declared as a function 289 | struct process_Environ_743 environ; | ^ C:\Program Files (x86)\Windows Kits10円\include10円.0.26100.0\ucrt\stdlib.h(1344,21): note: expanded from macro 'environ' 1344 | #define environ _environ | ^ C:\Program Files (x86)\Windows Kits10円\include10円.0.26100.0\ucrt\stdlib.h(1171,25): note: expanded from macro '_environ' 1171 | #define _environ (*__p__environ()) // Pointer to narrow environment table | ^ C:\Users7743円l\Desktop\Giit\SRC\out-win\build-zig-host\zig2.c(291,19): error: static assertion failed due to requirement 'sizeof(struct process_Init_Minimal_741) == 24': incorrect size 291 | zig_static_assert(sizeof (struct process_Init_Minimal_741) == 24, "incorrect size"); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ C:\Users7743円l\Desktop\Giit\SRC\zig\stage1\zig.h(158,53): note: expanded from macro 'zig_static_assert' 158 | #define zig_static_assert(cond, msg) _Static_assert(cond, msg) | ^~~~ C:\Users7743円l\Desktop\Giit\SRC\out-win\build-zig-host\zig2.c(291,60): note: expression evaluates to '1 == 24' 291 | zig_static_assert(sizeof (struct process_Init_Minimal_741) == 24, "incorrect size"); | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~ C:\Users7743円l\Desktop\Giit\SRC\zig\stage1\zig.h(158,53): note: expanded from macro 'zig_static_assert' 158 | #define zig_static_assert(cond, msg) _Static_assert(cond, msg) | ^~~~ ``` But the problem is not neccessarily that the "C backend emits incorrect type layouts for MSVC", but rather that the variable name environ is already a defined macro in ``` bash C:\Program Files (x86)\Windows Kits10円\include10円.0.26100.0\ucrt\stdlib.h(1344,21): note: expanded from macro 'environ' 1344 | #define environ _environ | ^ ``` This gets used in ``` c struct process_Init_Minimal_741 { /* process.Init.Minimal */ struct process_Args_745 args; struct process_Environ_743 environ; }; ``` And causes all my errors downstream

Beneppe commented 2026年05月17日 14:33:57 +02:00

I believe we need to add "environ" to
https://codeberg.org/ziglang/zig/blame/branch/master/src/codegen/c.zig const reserved_idents = std.StaticStringMap(void)
and update zig1.wasm.

Skipping this for now by simply adding:

#undef environ

allows to pass my previous environ related errors, but now i hit this again

@squeek502 wrote in #261 (comment):

Relevant issue is ziglang/zig#31576

So yeah, this is a twofold issue:

1. The reserved var name "environ"
2. The "C backend emits incorrect type layouts for MSVC #31576"

I believe we need to add "environ" to https://codeberg.org/ziglang/zig/blame/branch/master/src/codegen/c.zig const reserved_idents = std.StaticStringMap(void) and update zig1.wasm. Skipping this for now by simply adding: ``` c #undef environ ``` allows to pass my previous environ related errors, but now i hit this again @squeek502 wrote in https://codeberg.org/ziglang/zig-bootstrap/issues/261#issuecomment-15088395: > Relevant issue is ziglang/zig#31576 So yeah, this is a twofold issue: 1. The reserved var name "environ" 2. The "C backend emits incorrect type layouts for MSVC #31576"