C compiler bug when running this code #23312

RpxdYTX · 2024-12-30T04:45:41Z

Describe the bug

I'm a total V beginner, but bear with me, i was trying to make a language analysis tool for a simple project, but it just spits a C error

Reproduction Steps

Here's the (simplified) code:

// main.v
module main

import os

fn main() {
    file := os.read_file(...) or { panic("Couldn't open") }
    
    for node in Parser.new(file) { dump(node) }
}

pub fn todo() { panic("todo") }

pub fn first[T, U](iter T, f fn(usize, U) bool) ?U {
    mut ret := ?U(none)
    for i, e in iter { if f(usize(i), e) {
        ret = e
        break
    } }
    return ret
}

pub fn take_while(s string, f fn(usize, rune) bool) string {
    mut runes := [] rune {}
    for i, r in s.runes() {
        if !f(usize(i), r) { break }
        runes << r
    }
    
    return runes.string()
}

// lexer.v
module main

import encoding.utf8

pub type Token = TokenType1 | TokenType2...

pub struct Lexer {
    str    string
    mut: i usize
}

pub fn Lexer.new(str string) Lexer { return Lexer { str, 0 } }

pub fn (self Lexer) peek() ?Token {
    tkn, _ := self.lex()?
    return tkn
}

pub fn (mut self Lexer) next() ?Token {
    tkn, i := self.lex()?
    self.i += i
    return tkn
}

fn (self Lexer) lex() ?(Token, usize) { ... }

// parser.v
module main

pub type Node = NodeTypes...

pub fn (self Node) is_expr() bool { ... }

pub struct Parser { mut: lexer Lexer }

pub fn Parser.new(str string) Parser { return Parser { Lexer.new(str) } }

pub fn (mut self Parser) next() ?Node { ... }

Expected Behavior

It should just work or at least not cause c errors

Current Behavior

================== C compilation error (from cc): ==============
cc: /data/data/com.termux/files/usr/tmp/v_10246/hex.01JGAX0GMQ7AY9BBNGWHZ5Y2EK.tmp.c:8745:29: error: call to undeclared function 'main__Lexer_next'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
cc:  8745 |                 _option_main__Token _t2 = main__Lexer_next(&_t1);
cc:       |                                           ^
cc: /data/data/com.termux/files/usr/tmp/v_10246/hex.01JGAX0GMQ7AY9BBNGWHZ5Y2EK.tmp.c:8745:29: note: did you mean 'main__Lexer_lex'?
cc: /data/data/com.termux/files/usr/tmp/v_10246/hex.01JGAX0GMQ7AY9BBNGWHZ5Y2EK.tmp.c:8658:56: note: 'main__Lexer_lex' declared here
cc:  8658 | VV_LOCAL_SYMBOL _option_multi_return_main__Token_usize main__Lexer_lex(main__Lexer self) {
cc:       |                                                        ^
cc: /data/data/com.termux/files/usr/tmp/v_10246/hex.01JGAX0GMQ7AY9BBNGWHZ5Y2EK.tmp.c:8745:23: error: initializing '_option_main__Token' (aka 'struct _option_main__Token') with an expression of incompatible type 'int'
cc:  8745 |                 _option_main__Token _t2 = main__Lexer_next(&_t1);
cc:       |                                     ^     ~~~~~~~~~~~~~~~~~~~~~~
cc: 2 errors generated.
================================================================
(You can pass `-cg`, or `-show-c-output` as well, to print all the C error messages).
builder error:
==================
C error found. It should never happen, when compiling pure V code.

Possible Solution

No response

Additional Information/Context

In the function first, the original code just returned e if f(...) were true, but that was yielding a V error and i did this instead. This is a helper function that gets the first element matching some criteria, if any. I use it on the Parser.next function to ignore skippable tokens

V version

V 0.4.9 4225a34

Environment details (OS name and version, etc.)

V full version: V 0.4.9 b487986.4225a34
OS: termux, 3.18.140-SIMPLE-KERNEL_V1.1, #1 SMP PREEMPT Sun Apr 18 03:22:59 -03 2021
Processor: 4 cpus, 64bit, little endian

getwd: /storage/emulated/0/Documents/hex
vexe: /data/data/com.termux/files/home/.v/v
vexe mtime: 2024-12-30 04:25:37

vroot: OK, value: /data/data/com.termux/files/home/.v
VMODULES: OK, value: /data/data/com.termux/files/home/.vmodules
VTMP: OK, value: /data/data/com.termux/files/usr/tmp/v_10246

Git version: git version 2.47.1
Git vroot status: 4225a34
.git/config present: true

CC version: clang version 19.1.6
emcc version: N/A
thirdparty/tcc status: thirdparty-unknown-unknown de82a13

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_{Huly®: V_0.6-21744}

The text was updated successfully, but these errors were encountered:

RpxdYTX · 2024-12-30T05:33:05Z

Making first a function to work solely on Lexer made it work, though it's still weird that this bug happened.
Should i close the issue?

RpxdYTX · 2024-12-30T05:40:40Z

Used -d callstack with the v.debug module in the todo function and another c error popped up

spytheman · 2024-12-30T15:24:21Z

Try compiling with -no-skip-unused or provide complete source code, not just snippets, so that we can reproduce the problem locally 1:1.

RpxdYTX · 2024-12-30T16:24:44Z

-no-skip-unsed didn't solve the todo issue, but it did solve the old error
This is the old source code, the one that yielded the error:

// main.v
module main

import os
import v.debug

fn main() {
    file := os.read_file('main.hex') or { panic("Couldn't open main.hex") }
    
    for node in Parser.new(file) { dump(node) }
}

pub fn todo() {
    debug.dump_callstack()
    panic("TODO")
}

pub fn first[T, U](mut iter T, f fn(usize, U) bool) ?U {
    mut ret := ?U(none)
    for i, e in iter { if f(usize(i), e) {
        ret = ?U(e)
        break
    } }
    return ret
}

pub fn take_while(s string, f fn(usize, rune) bool) string {
    mut runes := [] rune {}
    for i, r in s.runes() {
        if !f(usize(i), r) { break }
        runes << r
    }
    
    return runes.string()
}

// lexer.v
module main

import encoding.utf8

pub type Token = WsTkn      |

    StrTkn     | IdentTkn   |
    
    FnTkn                   |
    
    ColonTkn                |
    LParenTkn  | RParenTkn  |
    LCBraceTkn | RCBraceTkn |
    
    UnknownTkn

pub fn (self Token) skip() bool { return self is WsTkn }
//pub fn (self Token) sym()  bool { return self is  }
//pub fn (self Token) kw()   bool { return self is FnTkn }

pub struct Lexer {
    str    string
    mut: i usize
}

pub fn Lexer.new(str string) Lexer { return Lexer { str, 0 } }

pub fn (self Lexer) peek() ?Token {
    tkn, _ := self.lex()?
    return tkn
}

pub fn (mut self Lexer) next() ?Token {
    tkn, i := self.lex()?
    self.i += i
    return tkn
}

pub fn (mut self Lexer) rwnd() { self.i = 0 }

pub struct WsTkn {}

pub struct StrTkn { pub: str string }
pub struct IdentTkn { pub: ident string }

pub struct FnTkn {}

pub struct ColonTkn {}
pub struct LParenTkn {}
pub struct RParenTkn {}
pub struct LCBraceTkn {}
pub struct RCBraceTkn {}

pub struct UnknownTkn { token string }

fn (self Lexer) lex() ?(Token, usize) {
    str := self.str[self.i..]
    if str.len == 0 { return none }
    
    ws := take_while(str, |_, c| utf8.is_space(c))
    if ws.len > 0 { return Token(WsTkn {}), usize(ws.len) }
    
    mut str_lit := take_while(str, |i, c|
        (i == 0 && c.bytes()[0] == `"`)
        || (i != 0 && c.bytes()[0] != `"`)
    )
    if str_lit.len > 0 {
        if str[str_lit.len] != `"` { todo() }
        
        str_lit = str_lit[1..]
        return Token(StrTkn { str_lit }), usize(str_lit.len + 2)
    }
    
    ident := take_while(str, |i, c|
        (i == 0 && (c.bytes()[0] == `_` || c.bytes()[0].is_letter()))
        || (i != 0 && (c.bytes()[0] == `_` || c.bytes()[0].is_alnum()))
    )
    if ident.len > 0 {
        tkn := match ident {
            "fn" { Token(FnTkn {}) }
            else { Token(IdentTkn { ident }) }
        }
        
        return tkn, usize(ident.len)
    }
    
    sym := str.runes()[0]
    tkn := match sym {
        `:` { Token(ColonTkn {}) }
        `(` { Token(LParenTkn {}) }
        `)` { Token(RParenTkn {}) }
        `{` { Token(LCBraceTkn {}) }
        `}` { Token(RCBraceTkn {}) }
        
        else { Token(UnknownTkn { sym.str() }) }
    }
    
    return tkn, usize(sym.length_in_bytes())
}

// parser.v
module main

pub type Node =
    StrNode    |
    BlockNode  |
    FnCallNode |
    
    FnDeclNode |
    
    UnknownNode

pub fn (self Node) is_expr() bool { return match self
    StrNode, BlockNode, FnCallNode { true }
    else { false }
} }

pub struct Parser { mut: lexer Lexer }

pub fn Parser.new(str string) Parser { return Parser { Lexer.new(str) } }

pub fn (mut self Parser) rwnd() { self.lexer.rwnd() }

pub struct StrNode { pub: str string }
pub struct BlockNode { pub: exprs [] Node }
pub struct FnCallNode {
    pub:
    name string
    args [] Node
}

pub struct FnDeclNode {
    pub:
    name   string
    params [] string
    expr   Node
}

pub struct UnknownNode { pub: tkn Token }

fn non_skip_tkn(_ usize, tkn Token) bool { return !tkn.skip() }
pub fn (mut self Parser) next() ?Node {
    tkn := first(mut self.lexer, non_skip_tkn)?
    
    return match tkn {
        StrTkn { Node(StrNode { tkn.str }) }
        LCBraceTkn {
            mut exprs := [] Node {}
            mut token := self.lexer.peek()?
            for token !is RCBraceTkn {
                exprs << self.next()?
                token = self.lexer.peek()?
            }
            
            Node(BlockNode { exprs })
        }
        IdentTkn {
            name := tkn.ident
            mut token := first(mut self.lexer, non_skip_tkn)?
            
            if token !is LParenTkn { todo() }
            mut args := [] Node {} // todo
            
            token = first(mut self.lexer, non_skip_tkn)?
            if token !is RParenTkn { todo() }
            
            Node(FnCallNode { name, args })
        }
        
        FnTkn {
            ident := first(mut self.lexer, non_skip_tkn)?
            if ident !is IdentTkn { todo() }
            
            name := (ident as IdentTkn).ident
            mut token := first(mut self.lexer, non_skip_tkn)?
            if token !is LParenTkn { todo() }
            
            params := [] string {} // todo
            token = first(mut self.lexer, non_skip_tkn)?
            if token !is RParenTkn { todo() }
            
            token = first(mut self.lexer, non_skip_tkn)?
            if token !is ColonTkn { todo() }
            
            node := self.next()?
            if !node.is_expr() { todo() }
            
            Node(FnDeclNode { name, params, node })
        }
        
        else { Node(UnknownNode { tkn }) }
    }
}

RpxdYTX · 2024-12-30T16:28:13Z

Using debug.dump_callstack() with -d callstack errors with

================== C compilation error (from cc): ==============
cc:        |                                       ~~                                                                            ^~~~~~~~~
cc: /data/data/com.termux/files/usr/tmp/v_10246/hex.01JGC68SV7BHYMXC3HWJVJ2FB0.tmp.c:26377:15: error: expected expression
cc:  26377 |         bool ret = f(, );
cc:        |                      ^
cc: /data/data/com.termux/files/usr/tmp/v_10246/hex.01JGC68SV7BHYMXC3HWJVJ2FB0.tmp.c:26377:17: error: expected expression
cc:  26377 |         bool ret = f(, );
cc:        |                        ^
cc: /data/data/com.termux/files/usr/tmp/v_10246/hex.01JGC68SV7BHYMXC3HWJVJ2FB0.tmp.c:26408:15: error: expected expression
cc:  26408 |         bool ret = f(, );
cc:        |                      ^
cc: /data/data/com.termux/files/usr/tmp/v_10246/hex.01JGC68SV7BHYMXC3HWJVJ2FB0.tmp.c:26408:17: error: expected expression
cc:  26408 |         bool ret = f(, );
... (the original output was 26 lines long, and was truncated to 12 lines)
================================================================
(You can pass `-cg`, or `-show-c-output` as well, to print all the C error messages).

On both the old and the new source code. Runinng without -d callstack makes the code run, but then todo is useless

JalonSolov · 2024-12-30T16:36:27Z

Can you supply a main.hex file to use with this code? A random file may/may not show the same problems.

RpxdYTX · 2024-12-30T16:45:00Z

The code never ran, so i thought it was irrelevant, anyways: ``` fn main(): { println("Hello, World!") } ``` The code currently doesn't parse correctly, but since `todo` yields an error when callstack is enabled, I can't pinpoint what is wrong in the logic rn Em seg, 30 de dez de 2024 13:36, JalonSolov ***@***.***> escreveu:

…

Can you supply a main.hex file to use with this code? A random file may/may not show the same problems. — Reply to this email directly, view it on GitHub <#23312 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ARV73ERG2K5HSROZNRA2JJT2IFZCDAVCNFSM6AAAAABULPNIUWVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDKNRVGY4TKMRUGU> . You are receiving this because you authored the thread.Message ID: ***@***.***>

spytheman · 2024-12-30T18:01:50Z

It is better to open another issue for the second problem, than to discuss several issues in the same thread.

The first issue is going to get solved in #23321 .

RpxdYTX · 2024-12-30T18:22:23Z

Should i open another issue then?

felipensp · 2024-12-30T18:51:03Z

Should i open another issue then?

Sure, for callstack issue. Please.

RpxdYTX added the Bug This tag is applied to issues which reports bugs. label Dec 30, 2024

felipensp self-assigned this Dec 30, 2024

felipensp added the Unit: markused Bugs/feature requests, that are related to the -skip-unused. label Dec 30, 2024

felipensp mentioned this issue Dec 30, 2024

markused: fix for iterator method not marked as used #23321

Merged

felipensp added the Status: Confirmed This bug has been confirmed to be valid by a contributor. label Dec 30, 2024

RpxdYTX mentioned this issue Dec 30, 2024

Using debug.dump_callstack() with -d callstack causes a C error #23323

Open

spytheman closed this as completed in #23321 Dec 30, 2024

spytheman closed this as completed in ab707dc Dec 30, 2024

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C compiler bug when running this code #23312

C compiler bug when running this code #23312

RpxdYTX commented Dec 30, 2024 •

edited by huly-for-github bot

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RpxdYTX commented Dec 30, 2024

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spytheman commented Dec 30, 2024

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RpxdYTX commented Dec 30, 2024

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RpxdYTX commented Dec 30, 2024 via email

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RpxdYTX commented Dec 30, 2024

felipensp commented Dec 30, 2024

C compiler bug when running this code #23312

C compiler bug when running this code #23312

Comments

RpxdYTX commented Dec 30, 2024 • edited by huly-for-github bot Loading

Describe the bug

Reproduction Steps

Expected Behavior

Current Behavior

Possible Solution

Additional Information/Context

V version

Environment details (OS name and version, etc.)

RpxdYTX commented Dec 30, 2024

RpxdYTX commented Dec 30, 2024 • edited Loading

spytheman commented Dec 30, 2024

RpxdYTX commented Dec 30, 2024 • edited Loading

RpxdYTX commented Dec 30, 2024

JalonSolov commented Dec 30, 2024

RpxdYTX commented Dec 30, 2024 via email

spytheman commented Dec 30, 2024

RpxdYTX commented Dec 30, 2024

felipensp commented Dec 30, 2024

RpxdYTX commented Dec 30, 2024 •

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