C error when assigning variable to const int_type ptr

Describe the bug

Builder error:

const x = 3

fn main() {
	_ := &x
}

Works:

const x = int(3)

fn main() {
	_ := &x
}

Expected Behavior

Both versions work.

Current Behavior

/tmp/v_1000/const_ptr.13403185457188648864.tmp.c:12442: error: lvalue expected
builder error: 
==================
C error. This should never happen.

This is a compiler bug, please report it using `v bug file.v`.

https://github.com/vlang/v/issues/new/choose

You can also use #help on Discord: https://discord.gg/vlang

Reproduction Steps

above

Possible Solution

v/vlib/v/gen/c/cgen.v

Lines 5311 to 5319 in 815439a

    
           if typ == ast.int_type { 
        
           	// TODO: use g.const_decl_write_precomputed here too. 
        
           	// For now, use #define macros, so existing code compiles 
        
           	// with -cstrict. Add checker errors for overflows instead, 
        
           	// so V can catch them earlier, instead of relying on the 
        
           	// C compiler for that. 
        
           	g.const_decl_simple_define(mod, name, ct_value.str()) 
        
           	return true 
        
           }

Additional Information/Context

No response

V version

0.4.0 815439a

Environment details (OS name and version, etc.)

OS: linux, Pop!_OS 22.04 LTS
Processor: 16 cpus, 64bit, little endian, 11th Gen Intel(R) Core(TM) i7-11800H @ 2.30GHz

getwd: /home/turiiya/Dev/vlang/v
vexe: /home/turiiya/Dev/vlang/v/v
vexe mtime: 2023-08-16 05:27:47

vroot: OK, value: /home/turiiya/Dev/vlang/v
VMODULES: OK, value: /home/turiiya/.vmodules
VTMP: OK, value: /tmp/v_1000

Git version: git version 2.34.1
Git vroot status: weekly.2023.33
.git/config present: true

CC version: cc (Ubuntu 12.3.0-1ubuntu1~22.04) 12.3.0
thirdparty/tcc status: thirdparty-linux-amd64 12f392c3

imho the first case should be a checker error instead.

const x = 3 is treated as a literal, and implemented as a C macro.

It is substituted everywhere it is used at compile time, and thus does not have a specific address.

const x = int(3) is implemented as a constant global in C, i.e. it has a single location, and thus an address as well.

For me a proper error would be satisfying enough.
I think this will also be the solution that will be the simplest to implement while covering the most cases at the same time.

Navigation Menu

Repository navigation

C error when assigning variable to const int_type ptr #19146

Describe the bug

Expected Behavior

Current Behavior

Reproduction Steps

Possible Solution

Additional Information/Context

V version

Environment details (OS name and version, etc.)

Metadata

Assignees

Labels

Type

Projects

Milestone

Relationships

Development

	if typ == ast.int_type {
	// TODO: use g.const_decl_write_precomputed here too.
	// For now, use #define macros, so existing code compiles
	// with -cstrict. Add checker errors for overflows instead,
	// so V can catch them earlier, instead of relying on the
	// C compiler for that.
	g.const_decl_simple_define(mod, name, ct_value.str())
	return true
	}

C error when assigning variable to const int_type ptr #19146

Description

Describe the bug

Expected Behavior

Current Behavior

Reproduction Steps

Possible Solution

Additional Information/Context

V version

Environment details (OS name and version, etc.)

Activity

spytheman commented on Aug 16, 2023

ttytm commented on Aug 16, 2023

Metadata

Metadata

Assignees

Labels

Type

Projects

Milestone

Relationships

Development

Issue actions