Use freestanding mode, but encounter incompatible size_t redefinition error by C

[PegasusPlusUS]

V doctor:

V full version: V 0.4.8 2ab1523
OS: windows, Microsoft Windows Server 2022 Standard v20348 64-bit
Processor: 8 cpus, 64bit, little endian, 

getwd: E:\Export\tinyos\ch01_bootsector\v
vexe: C:\Users\ping\scoop\apps\v\0.4.8\v.exe
vexe mtime: 2024-09-28 16:45:40

vroot: OK, value: C:\Users\ping\scoop\apps\v\0.4.8
VMODULES: OK, value: C:\Users\ping\.vmodules
VTMP: OK, value: C:\Users\ping\AppData\Local\Temp\2\v_0

Git version: git version 2.45.1.windows.1
Git vroot status: Error: fatal: not a git repository (or any of the parent directories): .git
.git/config present: false

CC version: Error: 'cc' is not recognized as an internal or external command,

operable program or batch file.


thirdparty/tcc: N/A

What did you do?
./v -g -o vdbg cmd/v && ./vdbg bootsector.v

fn main() {
    message := "Hello, World!"

    for ch in message {
        asm x86 {
            mov ah, 0x0e
            mov al, ch
            int 0x10
        }
    }

    // Infinite loop to keep the program running
    for {}
}

What did you expect to see?

Compile OK

What did you see instead?

bootsector.v:4:9: warning: unused variable: `ch`
    2 |     message := "Hello, World!"
    3 | 
    4 |     for ch in message {
      |         ~~
    5 |         asm x86 {
    6 |             mov ah, 0x0e
C:/Users/ping/AppData/Local/Temp/2/v_0/bootsector.01JFM5TKDDTX2P0VENQFFRDHXB.tmp.c:7059: at print_backtrace_skipping_top_frames_tcc: Backtrace
C:/Users/ping/AppData/Local/Temp/2/v_0/bootsector.01JFM5TKDDTX2P0VENQFFRDHXB.tmp.c:7026: by print_backtrace_skipping_top_frames
C:/Users/ping/AppData/Local/Temp/2/v_0/bootsector.01JFM5TKDDTX2P0VENQFFRDHXB.tmp.c:7927: by unhandled_exception_handler
7ffe189fbfc2 : by ???
C:/Users/ping/AppData/Local/Temp/2/v_0/bootsector.01JFM5TKDDTX2P0VENQFFRDHXB.tmp.c:13479: at main__main: RUNTIME ERROR: invalid memory access
C:/Users/ping/AppData/Local/Temp/2/v_0/bootsector.01JFM5TKDDTX2P0VENQFFRDHXB.tmp.c:13523: by wmain
00467040 : by ???
004671a3 : by ???
7ffe18304cb0 : by ???

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_{Huly®: V_0.6-21662}

[kbkpbot]

fn main() {
    message := "Hello, World!"

    for ch in message {
        asm x86 {
            mov ah, 0x0e
            mov al, ch                     // ch is a x86 register, cx high part. not the var ch
            int 0x10
        }
    }

    // Infinite loop to keep the program running
    for {}
}

maybe fix to :

fn main() {
    message := "Hello, World!"

    for c in message {
        asm x86 {
            mov ah, 0x0e
            mov al, c
            int 0x10
           ; r (c) as c
        }
    }

    // Infinite loop to keep the program running
    for {}
}

BTW:

.text:0000000000417AEF                 int     10h             ; - VIDEO - WRITE CHARACTER AND ADVANCE CURSOR (TTY WRITE)
.text:0000000000417AEF                                         ; AL = character, BH = display page (alpha modes)
.text:0000000000417AEF                                         ; BL = foreground color (graphics modes)

[PegasusPlusUS]

Now first warning is eliminated, the bug reported still occurs, I check the generated C, it seems if compile as -freestanding will cause incompatible size_t error.

[PegasusPlusUS]

v -gc none -freestanding -cg -o bootsector.asm bootsector.v
C:/Users/ping/AppData/Local/Temp/2/v_0/bootsector.asm.01JFNH47KAPKZYSHXHPWBW80GK.tmp.c:468: error: incompatible redefinition of 'size_t'
builder error:
==================
C error found. It should never happen, when compiling pure V code.
This is a V compiler bug, please report it using `v bug file.v`,
or goto https://github.com/vlang/v/issues/new/choose .
You can also use #help on Discord: https://discord.gg/vlang .
make: *** [Makefile:4: bootsector.asm] Error 1

[felipensp]

I see no redifinition error.

[kbkpbot]

   -freestanding
      Build the executable without dependency on libc.
      Supported only on `linux` targets currently.

V does not support -freestanding mode under windows yet.
Even remove the size_t definition from the cgen, it will cause other errors, because it try to use builtin/linux_bare, maybe someone can provide builtin/windows_bare ....

For test:
fix vlib/v/gen/c/cheaders.v,
comment out the line typedef long unsigned int size_t;

v self

then you can compile.

[PegasusPlusUS]

I see, thanks! I'll try to test on Linux to generate bare-metal code (As I already installed tinyc, i686-elf-gcc, I guess they can help cross-compile to bare-metal code on Windows also).

BTW, though -freestanding is not supported on Windows, I finally got my bootsector running on logic implemented in V at Windows, with the help of generating C code from V compiler, :).