$compile_error should locate the actual location of the error

[kbkpbot]

Describe the bug

Currently , $compile_error() will point to where it is called, not the real location of error.

Reproduction Steps

compile_error.v

module main

fn son[T](val T) {
        $if T !is int {
                $compile_error('son only taken int as input')
        }
}

fn main() {
        son(false)
}

v compile_error.v

Expected Behavior

something like this:

$ v compile_error.v
compile_error.v:5:3: error: son only taken int as input
    9 | fn main() {
   10 |        son(false)
        |~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   11 |}

Current Behavior

$ v compile_error.v
compile_error.v:5:3: error: son only taken int as input
    3 | fn son[T](val T) {
    4 |     $if T !is int {
    5 |         $compile_error('son only taken int as input')
      |         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    6 |     }
    7 | }

Possible Solution

No response

Additional Information/Context

Found be PR #24573

V version

V 0.4.10 ed7a8a3.52c7130

Environment details (OS name and version, etc.)

V full version	V 0.4.10 ed7a8a3.52c7130
OS	linux, Ubuntu 24.04.2 LTS
Processor	8 cpus, 64bit, little endian, Intel(R) Core(TM) i7-9700 CPU @ 3.00GHz
Memory	6.98GB/15.51GB
V executable	/media/HD/github/kbkpbot/v/v
V last modified time	2025-05-25 10:51:48
V home dir	OK, value: /media/HD/github/kbkpbot/v
VMODULES	OK, value: /home/mars/.vmodules
VTMP	OK, value: /tmp/v_1000
Current working dir	OK, value: /home/mars/v/bug
Git version	git version 2.43.0
V git status	weekly.2025.17-162-g0f4e12e7
.git/config present	true
cc version	cc (Ubuntu 13.3.0-6ubuntu2~24.04) 13.3.0
gcc version	gcc (Ubuntu 13.3.0-6ubuntu2~24.04) 13.3.0
clang version	Ubuntu clang version 18.1.3 (1ubuntu1)
tcc version	tcc version 0.9.28rc 2025-02-13 HEAD@f8bd136d (x86_64 Linux)
tcc git status	thirdparty-linux-amd64 696c1d84
emcc version	N/A
glibc version	ldd (Ubuntu GLIBC 2.39-0ubuntu8.4) 2.39

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[huly-for-github]

Connected to Huly®: V_0.6-22940

[kbkpbot]

1. Introduce something like @FN, such as @CALLER to make $compile_error(@CALLER,msg) can access caller's location;
2. Introduce something like attribute, such as $compile_error() @[caller] to access caller's location;
3. Or modify $compile_error() to let it has a hidden param for calller's location.

[tankf33der]

@kbkpbot

Now better error message:

24575.v:5:17: error: son only taken int as input
    3 | fn son[T](val T) {
    4 |         $if T !is int {
    5 |                 $compile_error('son only taken int as input')
      |                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    6 |         }
    7 | }
called from 24575.v:10:9
    8 | 
    9 | fn main() {
   10 |         son(false)
      |         ~~~~~~~~~~
   11 | }