Compiling a simple hello world program

[VarLad]

❯ arocc test.c -o test
thread 12150 panic: integer cast truncated bits
/home/varlad/arocc/src/Parser.zig:226:19: 0x2b86bc in Parser.addList (arocc)
    const start = @intCast(u32, p.data.items.len);
                  ^
/home/varlad/arocc/src/Parser.zig:3275:71: 0x2a317c in Parser.condExpr (arocc)
        .data = .{ .if3 = .{ .cond = cond.node, .body = (try p.addList(&.{ then_expr.node, else_expr.node })).start } },
                                                                      ^
/home/varlad/arocc/src/Parser.zig:2491:27: 0x28a5c0 in Parser.macroExpr (arocc)
    const res = p.condExpr() catch |e| switch (e) {
                          ^
/home/varlad/arocc/src/Preprocessor.zig:415:28: 0x26ef1f in Preprocessor.expr (arocc)
    return parser.macroExpr();
                           ^
/home/varlad/arocc/src/Preprocessor.zig:121:40: 0x267f80 in Preprocessor.preprocess (arocc)
                        if (try pp.expr(&tokenizer)) {
                                       ^
/home/varlad/arocc/src/Preprocessor.zig:1098:22: 0x26fecb in Preprocessor.include (arocc)
    try pp.preprocess(new_source);
                     ^
/home/varlad/arocc/src/Preprocessor.zig:205:55: 0x268a8a in Preprocessor.preprocess (arocc)
                    .keyword_include => try pp.include(&tokenizer),
                                                      ^
/home/varlad/arocc/src/Preprocessor.zig:1098:22: 0x26fecb in Preprocessor.include (arocc)
    try pp.preprocess(new_source);
                     ^
/home/varlad/arocc/src/Preprocessor.zig:205:55: 0x268a8a in Preprocessor.preprocess (arocc)
                    .keyword_include => try pp.include(&tokenizer),
                                                      ^
/home/varlad/arocc/src/Preprocessor.zig:1098:22: 0x26fecb in Preprocessor.include (arocc)
    try pp.preprocess(new_source);
                     ^
/home/varlad/arocc/src/Preprocessor.zig:205:55: 0x268a8a in Preprocessor.preprocess (arocc)
                    .keyword_include => try pp.include(&tokenizer),
                                                      ^
/home/varlad/arocc/src/main.zig:209:22: 0x25f5ac in processSource (arocc)
    try pp.preprocess(source);
                     ^
/home/varlad/arocc/src/main.zig:196:22: 0x25884e in handleArgs (arocc)
        processSource(comp, source, builtin, user_macros) catch |e| switch (e) {
                     ^
/home/varlad/arocc/src/main.zig:33:15: 0x24f8c2 in main (arocc)
    handleArgs(&comp, args) catch |err| switch (err) {
              ^
/home/varlad/zig-master/lib/std/start.zig:507:29: 0x2481cc in std.start.callMain (arocc)
            return root.main();
                            ^
/home/varlad/zig-master/lib/std/start.zig:452:12: 0x22c1ce in std.start.callMainWithArgs (arocc)
    return @call(.{ .modifier = .always_inline }, callMain, .{});
           ^
/home/varlad/zig-master/lib/std/start.zig:366:17: 0x22b1f6 in std.start.posixCallMainAndExit (arocc)
    std.os.exit(@call(.{ .modifier = .always_inline }, callMainWithArgs, .{ argc, argv, envp }));
                ^
/home/varlad/zig-master/lib/std/start.zig:279:5: 0x22b002 in std.start._start (arocc)
    @call(.{ .modifier = .never_inline }, posixCallMainAndExit, .{});
    ^
fish: Job 1, 'arocc test.c -o test' terminated by signal SIGABRT (Abort)

where test.c reads

#include "stdio.h"

int main()
{
	printf("Well, heck");
	return 0;
}

Built with Zig v0.9.0-dev.861+311797f68 via zig build

[Vexu]

With 7222741 the compiler no longer crashes but you need to add your own minimal stddef.h and stdarg.h (at least with glibc).

// minimal stddef.h
typedef long ptrdiff_t;
typedef unsigned long size_t;
typedef int wchar_t;
#define NULL ((void*)0)

With all that there are still a bunch of compiler errors due to bugs and unimplemented features.

[Vexu]

With 8af9873 and 634c286 I'm now able to successfully parse that simple hello world on my machine using arocc test.c -Wno-macro-redefined. Note that since there is no backend yet the command will just dump the resulting AST.

[VarLad]

Now I get

fatal error: could not find Aro builtin headers

I guess I'll have to define stddef.h and stdargs.h

Any help with that?

[Vexu]

You don't need to but it isn't able to find the correct headers. Can you give which arocc? Using zig-out/bin/arocc works for me.

[VarLad]

Okay, I cut pasted it from zig-out/bin/arocc to .local/bin/arocc

I pasted it back and made a symlink in .local/bin
Now it works but now I get this

via ↯ v0.9.0-dev.861+311797f68 
❯ arocc test.c -o test
/usr/include/bits/wordsize.h:4:10: warning: '__WORDSIZE' macro redefined
# define __WORDSIZE	64
         ^
/usr/include/bits/wordsize.h:12:10: warning: '__WORDSIZE_TIME64_COMPAT32' macro redefined
# define __WORDSIZE_TIME64_COMPAT32	1
         ^
/usr/include/bits/wordsize.h:14:10: warning: '__SYSCALL_WORDSIZE' macro redefined
# define __SYSCALL_WORDSIZE		64
         ^
/usr/include/bits/long-double.h:21:9: warning: '__LDOUBLE_REDIRECTS_TO_FLOAT128_ABI' macro redefined
#define __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI 0
        ^
4 warnings generated.
typedef: 'long'
 name: ptrdiff_t

typedef: 'unsigned long'
 name: size_t

typedef: 'int'
 name: wchar_t

struct_decl_two: 'struct (anonymous struct at /home/varlad/arocc/include/stddef.h:10:9)'
  record_field_decl: 'long long'
   name: __aro_max_align_ll
  record_field_decl: 'long double'
   name: __aro_max_align_ld

typedef: 'struct (anonymous struct at /home/varlad/arocc/include/stddef.h:10:9)'
 name: max_align_t

typedef: 'int'
 name: va_list

typedef: 'int'
 name: __gnuc_va_list

typedef: 'unsigned char'
 name: __u_char

typedef: 'unsigned short'
 name: __u_short

typedef: 'unsigned int'
 name: __u_int

typedef: 'unsigned long'
 name: __u_long

typedef: 'signed char'
 name: __int8_t

typedef: 'unsigned char'
 name: __uint8_t

typedef: 'short'
 name: __int16_t

typedef: 'unsigned short'
 name: __uint16_t

typedef: 'int'
 name: __int32_t

typedef: 'unsigned int'
 name: __uint32_t

typedef: 'long'
 name: __int64_t

typedef: 'unsigned long'
 name: __uint64_t

typedef: 'signed char'
 name: __int_least8_t

typedef: 'unsigned char'
 name: __uint_least8_t

typedef: 'short'
 name: __int_least16_t

typedef: 'unsigned short'
 name: __uint_least16_t

typedef: 'int'
 name: __int_least32_t

typedef: 'unsigned int'
 name: __uint_least32_t

typedef: 'long'
 name: __int_least64_t

typedef: 'unsigned long'
 name: __uint_least64_t

typedef: 'long'
 name: __quad_t

typedef: 'unsigned long'
 name: __u_quad_t

typedef: 'long'
 name: __intmax_t

typedef: 'unsigned long'
 name: __uintmax_t

typedef: 'unsigned long'
 name: __dev_t

typedef: 'unsigned int'
 name: __uid_t

typedef: 'unsigned int'
 name: __gid_t

typedef: 'unsigned long'
 name: __ino_t

typedef: 'unsigned long'
 name: __ino64_t

typedef: 'unsigned int'
 name: __mode_t

typedef: 'unsigned long'
 name: __nlink_t

typedef: 'long'
 name: __off_t

typedef: 'long'
 name: __off64_t

typedef: 'int'
 name: __pid_t

struct_decl_two: 'struct (anonymous struct at /usr/include/bits/typesizes.h:73:24)'
  record_field_decl: '[2]int'
   name: __val

typedef: 'struct (anonymous struct at /usr/include/bits/typesizes.h:73:24)'
 name: __fsid_t

typedef: 'long'
 name: __clock_t

typedef: 'unsigned long'
 name: __rlim_t

typedef: 'unsigned long'
 name: __rlim64_t

typedef: 'unsigned int'
 name: __id_t

typedef: 'long'
 name: __time_t

typedef: 'unsigned int'
 name: __useconds_t

typedef: 'long'
 name: __suseconds_t

typedef: 'long'
 name: __suseconds64_t

typedef: 'int'
 name: __daddr_t

typedef: 'int'
 name: __key_t

typedef: 'int'
 name: __clockid_t

typedef: '*void'
 name: __timer_t

typedef: 'long'
 name: __blksize_t

typedef: 'long'
 name: __blkcnt_t

typedef: 'long'
 name: __blkcnt64_t

typedef: 'unsigned long'
 name: __fsblkcnt_t

typedef: 'unsigned long'
 name: __fsblkcnt64_t

typedef: 'unsigned long'
 name: __fsfilcnt_t

typedef: 'unsigned long'
 name: __fsfilcnt64_t

typedef: 'long'
 name: __fsword_t

typedef: 'long'
 name: __ssize_t

typedef: 'long'
 name: __syscall_slong_t

typedef: 'unsigned long'
 name: __syscall_ulong_t

typedef: 'long'
 name: __loff_t

typedef: '*char'
 name: __caddr_t

typedef: 'long'
 name: __intptr_t

typedef: 'unsigned int'
 name: __socklen_t

typedef: 'int'
 name: __sig_atomic_t

struct_decl: 'struct (anonymous struct at /usr/include/bits/types/__mbstate_t.h:13:9)'
  record_field_decl: 'int'
   name: __count

  union_decl_two: 'union (anonymous union at /usr/include/bits/types/__mbstate_t.h:16:3)'
    record_field_decl: 'unsigned int'
     name: __wch
    record_field_decl: '[4]char'
     name: __wchb

  record_field_decl: 'union (anonymous union at /usr/include/bits/types/__mbstate_t.h:16:3)'
   name: __value

typedef: 'struct (anonymous struct at /usr/include/bits/types/__mbstate_t.h:13:9)'
 name: __mbstate_t

struct_decl_two: 'struct _G_fpos_t'
  record_field_decl: 'long'
   name: __pos
  record_field_decl: 'struct (anonymous struct at /usr/include/bits/types/__mbstate_t.h:13:9)'
   name: __state

typedef: 'struct _G_fpos_t'
 name: __fpos_t

struct_decl_two: 'struct _G_fpos64_t'
  record_field_decl: 'long'
   name: __pos
  record_field_decl: 'struct (anonymous struct at /usr/include/bits/types/__mbstate_t.h:13:9)'
   name: __state

typedef: 'struct _G_fpos64_t'
 name: __fpos64_t

typedef: 'struct _IO_FILE'
 name: __FILE

typedef: 'struct _IO_FILE'
 name: FILE

typedef: 'void'
 name: _IO_lock_t

struct_decl: 'struct _IO_FILE'
  record_field_decl: 'int'
   name: _flags

  record_field_decl: '*char'
   name: _IO_read_ptr

  record_field_decl: '*char'
   name: _IO_read_end

  record_field_decl: '*char'
   name: _IO_read_base

  record_field_decl: '*char'
   name: _IO_write_base

  record_field_decl: '*char'
   name: _IO_write_ptr

  record_field_decl: '*char'
   name: _IO_write_end

  record_field_decl: '*char'
   name: _IO_buf_base

  record_field_decl: '*char'
   name: _IO_buf_end

  record_field_decl: '*char'
   name: _IO_save_base

  record_field_decl: '*char'
   name: _IO_backup_base

  record_field_decl: '*char'
   name: _IO_save_end

  record_field_decl: '*struct _IO_marker'
   name: _markers

  record_field_decl: '*struct _IO_FILE'
   name: _chain

  record_field_decl: 'int'
   name: _fileno

  record_field_decl: 'int'
   name: _flags2

  record_field_decl: 'long'
   name: _old_offset

  record_field_decl: 'unsigned short'
   name: _cur_column

  record_field_decl: 'signed char'
   name: _vtable_offset

  record_field_decl: '[1]char'
   name: _shortbuf

  record_field_decl: '*void'
   name: _lock

  record_field_decl: 'long'
   name: _offset

  record_field_decl: '*struct _IO_codecvt'
   name: _codecvt

  record_field_decl: '*struct _IO_wide_data'
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  record_field_decl: '*struct _IO_FILE'
   name: _freeres_list

  record_field_decl: '*void'
   name: _freeres_buf

  record_field_decl: 'unsigned long'
   name: __pad5

  record_field_decl: 'int'
   name: _mode

  record_field_decl: '[20]char'
   name: _unused2

typedef: 'long'
 name: off_t

typedef: 'long'
 name: ssize_t

typedef: 'struct _G_fpos_t'
 name: fpos_t

extern_var: '*struct _IO_FILE'
 name: stdin

extern_var: '*struct _IO_FILE'
 name: stdout

extern_var: '*struct _IO_FILE'
 name: stderr

fn_proto: 'fn (__filename: *const char) int'
 name: remove

fn_proto: 'fn (__old: *const char, __new: *const char) int'
 name: rename

fn_proto: 'fn (__oldfd: int, __old: *const char, __newfd: int, __new: *const char) int'
 name: renameat

fn_proto: 'fn () *struct _IO_FILE'
 name: tmpfile

fn_proto: 'fn (__s: *char) *char'
 name: tmpnam

fn_proto: 'fn (__s: *char) *char'
 name: tmpnam_r

fn_proto: 'fn (__dir: *const char, __pfx: *const char) *char'
 name: tempnam

fn_proto: 'fn (__stream: *struct _IO_FILE) int'
 name: fclose

fn_proto: 'fn (__stream: *struct _IO_FILE) int'
 name: fflush

fn_proto: 'fn (__stream: *struct _IO_FILE) int'
 name: fflush_unlocked

fn_proto: 'fn (__filename: restrict *const char, __modes: restrict *const char) *struct _IO_FILE'
 name: fopen

fn_proto: 'fn (__filename: restrict *const char, __modes: restrict *const char, __stream: restrict *struct _IO_FILE) *struct _IO_FILE'
 name: freopen

fn_proto: 'fn (__fd: int, __modes: *const char) *struct _IO_FILE'
 name: fdopen

fn_proto: 'fn (__s: *void, __len: unsigned long, __modes: *const char) *struct _IO_FILE'
 name: fmemopen

fn_proto: 'fn (__bufloc: **char, __sizeloc: *unsigned long) *struct _IO_FILE'
 name: open_memstream

fn_proto: 'fn (__stream: restrict *struct _IO_FILE, __buf: restrict *char) void'
 name: setbuf

fn_proto: 'fn (__stream: restrict *struct _IO_FILE, __buf: restrict *char, __modes: int, __n: unsigned long) int'
 name: setvbuf

fn_proto: 'fn (__stream: restrict *struct _IO_FILE, __buf: restrict *char, __size: unsigned long) void'
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fn_proto: 'fn (__stream: *struct _IO_FILE) void'
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fn_proto: 'fn (__stream: restrict *struct _IO_FILE, __format: restrict *const char, ...) int'
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fn_proto: 'fn (__format: restrict *const char, ...) int'
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fn_proto: 'fn (__s: restrict *char, __format: restrict *const char, ...) int'
 name: sprintf

fn_proto: 'fn (__s: restrict *struct _IO_FILE, __format: restrict *const char, __arg: int) int'
 name: vfprintf

fn_proto: 'fn (__format: restrict *const char, __arg: int) int'
 name: vprintf

fn_proto: 'fn (__s: restrict *char, __format: restrict *const char, __arg: int) int'
 name: vsprintf

fn_proto: 'fn (__s: restrict *char, __maxlen: unsigned long, __format: restrict *const char, ...) int'
 name: snprintf

fn_proto: 'fn (__s: restrict *char, __maxlen: unsigned long, __format: restrict *const char, __arg: int) int'
 name: vsnprintf

fn_proto: 'fn (__fd: int, __fmt: restrict *const char, __arg: int) int'
 name: vdprintf

fn_proto: 'fn (__fd: int, __fmt: restrict *const char, ...) int'
 name: dprintf

fn_proto: 'fn (__stream: restrict *struct _IO_FILE, __format: restrict *const char, ...) int'
 name: fscanf

fn_proto: 'fn (__format: restrict *const char, ...) int'
 name: scanf

fn_proto: 'fn (__s: restrict *const char, __format: restrict *const char, ...) int'
 name: sscanf

typedef: 'float'
 name: _Float32

typedef: 'double'
 name: _Float64

typedef: 'double'
 name: _Float32x

typedef: 'long double'
 name: _Float64x

fn_proto: 'fn (__stream: restrict *struct _IO_FILE, __format: restrict *const char, ...) int'
 name: __isoc99_fscanf

fn_proto: 'fn (__format: restrict *const char, ...) int'
 name: __isoc99_scanf

fn_proto: 'fn (__s: restrict *const char, __format: restrict *const char, ...) int'
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fn_proto: 'fn (__s: restrict *struct _IO_FILE, __format: restrict *const char, __arg: int) int'
 name: vfscanf

fn_proto: 'fn (__format: restrict *const char, __arg: int) int'
 name: vscanf

fn_proto: 'fn (__s: restrict *const char, __format: restrict *const char, __arg: int) int'
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fn_proto: 'fn (__s: restrict *struct _IO_FILE, __format: restrict *const char, __arg: int) int'
 name: __isoc99_vfscanf

fn_proto: 'fn (__format: restrict *const char, __arg: int) int'
 name: __isoc99_vscanf

fn_proto: 'fn (__s: restrict *const char, __format: restrict *const char, __arg: int) int'
 name: __isoc99_vsscanf

fn_proto: 'fn (__stream: *struct _IO_FILE) int'
 name: fgetc

fn_proto: 'fn (__stream: *struct _IO_FILE) int'
 name: getc

fn_proto: 'fn () int'
 name: getchar

fn_proto: 'fn (__stream: *struct _IO_FILE) int'
 name: getc_unlocked

fn_proto: 'fn () int'
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fn_proto: 'fn (__stream: *struct _IO_FILE) int'
 name: fgetc_unlocked

fn_proto: 'fn (__c: int, __stream: *struct _IO_FILE) int'
 name: fputc

fn_proto: 'fn (__c: int, __stream: *struct _IO_FILE) int'
 name: putc

fn_proto: 'fn (__c: int) int'
 name: putchar

fn_proto: 'fn (__c: int, __stream: *struct _IO_FILE) int'
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fn_proto: 'fn (__c: int, __stream: *struct _IO_FILE) int'
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fn_proto: 'fn (__c: int) int'
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fn_proto: 'fn (__stream: *struct _IO_FILE) int'
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fn_proto: 'fn (__w: int, __stream: *struct _IO_FILE) int'
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fn_proto: 'fn (__s: restrict *char, __n: int, __stream: restrict *struct _IO_FILE) *char'
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fn_proto: 'fn (__lineptr: restrict **char, __n: restrict *unsigned long, __delimiter: int, __stream: restrict *struct _IO_FILE) long'
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fn_proto: 'fn (__lineptr: restrict **char, __n: restrict *unsigned long, __delimiter: int, __stream: restrict *struct _IO_FILE) long'
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fn_proto: 'fn (__lineptr: restrict **char, __n: restrict *unsigned long, __stream: restrict *struct _IO_FILE) long'
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fn_proto: 'fn (__s: restrict *const char, __stream: restrict *struct _IO_FILE) int'
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fn_proto: 'fn (__s: *const char) int'
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fn_proto: 'fn (__c: int, __stream: *struct _IO_FILE) int'
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fn_proto: 'fn (__ptr: restrict *void, __size: unsigned long, __n: unsigned long, __stream: restrict *struct _IO_FILE) unsigned long'
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fn_proto: 'fn (__ptr: restrict *const void, __size: unsigned long, __n: unsigned long, __s: restrict *struct _IO_FILE) unsigned long'
 name: fwrite

fn_proto: 'fn (__ptr: restrict *void, __size: unsigned long, __n: unsigned long, __stream: restrict *struct _IO_FILE) unsigned long'
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fn_proto: 'fn (__ptr: restrict *const void, __size: unsigned long, __n: unsigned long, __stream: restrict *struct _IO_FILE) unsigned long'
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fn_proto: 'fn (__stream: *struct _IO_FILE, __off: long, __whence: int) int'
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fn_proto: 'fn (__stream: *struct _IO_FILE) long'
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fn_proto: 'fn (__stream: *struct _IO_FILE) void'
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fn_proto: 'fn (__stream: *struct _IO_FILE, __off: long, __whence: int) int'
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fn_proto: 'fn (__stream: *struct _IO_FILE) long'
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fn_proto: 'fn (__stream: restrict *struct _IO_FILE, __pos: restrict *struct _G_fpos_t) int'
 name: fgetpos

fn_proto: 'fn (__stream: *struct _IO_FILE, __pos: *const struct _G_fpos_t) int'
 name: fsetpos

fn_proto: 'fn (__stream: *struct _IO_FILE) void'
 name: clearerr

fn_proto: 'fn (__stream: *struct _IO_FILE) int'
 name: feof

fn_proto: 'fn (__stream: *struct _IO_FILE) int'
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fn_proto: 'fn (__stream: *struct _IO_FILE) void'
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fn_proto: 'fn (__stream: *struct _IO_FILE) int'
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fn_proto: 'fn (__stream: *struct _IO_FILE) int'
 name: ferror_unlocked

fn_proto: 'fn (__s: *const char) void'
 name: perror

fn_proto: 'fn (__stream: *struct _IO_FILE) int'
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fn_proto: 'fn (__stream: *struct _IO_FILE) int'
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fn_proto: 'fn (__command: *const char, __modes: *const char) *struct _IO_FILE'
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fn_proto: 'fn (__stream: *struct _IO_FILE) int'
 name: pclose

fn_proto: 'fn (__s: *char) *char'
 name: ctermid

fn_proto: 'fn (__stream: *struct _IO_FILE) void'
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fn_proto: 'fn (__stream: *struct _IO_FILE) int'
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fn_proto: 'fn (__stream: *struct _IO_FILE) void'
 name: funlockfile

fn_proto: 'fn (*struct _IO_FILE) int'
 name: __uflow

fn_proto: 'fn (*struct _IO_FILE, int) int'
 name: __overflow

fn_def: 'fn (...) int'
 name: main
 body:
  compound_stmt_two: 'void'
    call_expr_one: 'int'
     lhs:
      function_to_pointer: '*fn (__format: restrict *const char, ...) int'
        decl_ref_expr: 'fn (__format: restrict *const char, ...) int' lvalue
         name: printf
     arg:
      array_to_pointer: 'd[11]char'
        string_literal_expr: '[11]char' lvalue
         data: "Well, heck"
    return_stmt: 'void'
     expr:
      int_literal: 'int' (value: 0)
       value: 0

I guess you're right, it just throws the AST at me

Any way to get the output binary though?

[ehaas]

Any way to get the output binary though?

This is just a frontend - no code generation currently. I can't speak for Vexu but the stated goal from the README is that it becomes good enough that Zig's translate-c can use it and thus be entirely self-hosted instead of relying on clang for parsing the C. The Zig compiler could also use the AST from this project for the stage2 C codegen, instead of emitting strings.

[VarLad]

Thanks! Hope its usable enough to replace the use of clang in Zig soon enough 🙂

[VarLad]

@Vexu This looks interesting!
Is it something I can try?

If so, any instructions?

[VarLad]

Ahh, right, in the README.md!
Sorry to ping! Thanks again!

This was pretty fast!