C codegen for struct with function member has gcc generating warnings

[thomas-mangin]

Describe the bug

V can generate working C code (as the compiler can handle the miss-generated C), which is normally not visible when compiling.

Reproduction Steps

with the following 'test.v' file:

module main

type Function = fn (int)

struct MyStruct {
        func Function @[required]
}

fn implementation(size int) {
        println('size is ${size}')
}

fn main() {
        m := MyStruct{
                func: implementation
        }
        println('${m}')
}

v -cc gcc -dump-c-flags compilation_flags.rsp -keepc test.v
gcc @compilation_flags.rsp

/private/tmp/v_501/test.tmp.c:2174:41: warning: too many arguments in call to 'main__Function_str'
        string _t1 = main__Function_str(it.func);
                     ~~~~~~~~~~~~~~~~~~        ^
/private/tmp/v_501/test.tmp.c:2174:33: warning: passing arguments to 'main__Function_str' without a prototype is deprecated in all versions of C and is not supported in C2x [-Wdeprecated-non-prototype]
        string _t1 = main__Function_str(it.func);
                                       ^
2 warnings generated.
ld: warning: REFERENCED_DYNAMICALLY flag on symbol '_catch_exception_raise' is deprecated
ld: warning: REFERENCED_DYNAMICALLY flag on symbol '_catch_exception_raise_state' is deprecated
ld: warning: REFERENCED_DYNAMICALLY flag on symbol '_catch_exception_raise_state_identity' is deprecated

grep main__Function_str /private/tmp/v_501/test.tmp.c

static string main__Function_str(); // auto
static string main__Function_str() { return _SLIT("fn (int)");}
        string _t1 = main__Function_str(it.func);

// V auto functions:
static string indent_main__MyStruct_str(main__MyStruct it, int indent_count) {
	string indents = string_repeat(_SLIT("    "), indent_count);
	string _t1 = main__Function_str(it.func);
	string res = str_intp( 7, _MOV((StrIntpData[]){
		{_SLIT("MyStruct{\n"), 0, {.d_c=0}},
		{_SLIT0, 0xfe10, {.d_s=indents}}, {_SLIT("    func: "), 0, {.d_c=0}}, {_SLIT(""), 16, {.d_s=_t1}}, {_SLIT(""), 0, {.d_c=0}},
		{_SLIT("\n"), 0xfe10, {.d_s=indents}}, {_SLIT("}"), 0, {.d_c=0}},
	}));
	string_free(&_t1);
	string_free(&indents);
	return res;
}

Expected Behavior

the definition has the parameter or the call does not.

Current Behavior

nothing wrong as far as users a concerned

Possible Solution

No response

Additional Information/Context

No response

V version

V 0.4.6 4475759

Environment details (OS name and version, etc.)

V full version: V 0.4.6 cc14272.4475759
OS: macos, macOS, 14.5, 23F79
Processor: 10 cpus, 64bit, little endian, Apple M1 Max

getwd: /Users/thomas/Code/github.com/ze-community/ze/main
vexe: /Users/thomas/Unix/local/v/master/v
vexe mtime: 2024-07-06 14:05:43

vroot: OK, value: /Users/thomas/Unix/local/v/master
VMODULES: OK, value: /Users/thomas/Unix/data/v/modules
VTMP: OK, value: /tmp/v_501

Git version: git version 2.45.2
Git vroot status: weekly.2024.27-25-g4475759c (5 commit(s) behind V master)
.git/config present: true

CC version: Apple clang version 15.0.0 (clang-1500.3.9.4)
thirdparty/tcc status: thirdparty-macos-arm64 5c1d002f

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[spytheman]

The warnings depend on the used C compiler.
For me, gcc-11 does not produce any for the code in the example, while clang-18 does.

[spytheman]

As a temporary workaround, until we fix the codegen so that the generated code can be more strict, you can pass -w to the C compiler, to suppress the warnings, i.e. use:
gcc @compilation_flags.rsp -w

[thomas-mangin]

Thank you @spytheman - The code is compiling. This is more for information and to tidy things than report a blocker.

[spytheman]

It is a problem, and it should be fixed. C compilers tend to get stricter and stricter, and in time, it can become an error too (gcc-14 made some of its warnings errors by default).