cosmopolitan/libc/runtime/cosmo.S
Justine Tunney 14e192e5ba Introduce --strace flag for system call tracing
This is similar to the --ftrace (c function call trace) flag, except
it's less noisy since it only logs system calls to stderr. Having this
flag is valuable because (1) system call tracing tells us a lot about
the behavior of complex programs and (2) it's usually very hard to get
system call tracing on various operating systems, e.g. strace, ktrace,
dtruss, truss, nttrace, etc. Especially on Apple platforms where even
with the special boot trick, debuggers still aren't guaranteed to work.

    make -j8 o//examples
    o//examples/hello.com --strace

This is enabled by default in MODE=, MODE=opt, and MODE=dbg. In MODE=dbg
extra information will be printed.

    make -j8 MODE=dbg o/dbg/examples
    o/dbg/examples/hello.com --strace |& less

This change also changes:

- Rename IsText() → _istext()
- Rename IsUtf8() → _isutf8()
- Fix madvise() on Windows NT
- Fix empty string case of inet_ntop()
- vfork() wrapper now saves and restores errno
- Update xsigaction() to yoink syscall support
2022-03-18 18:07:28 -07:00

111 lines
3.4 KiB
ArmAsm

/*-*- mode:unix-assembly; indent-tabs-mode:t; tab-width:8; coding:utf-8 -*-│
vi: set et ft=asm ts=8 tw=8 fenc=utf-8 :vi
Copyright 2020 Justine Alexandra Roberts Tunney
Permission to use, copy, modify, and/or distribute this software for
any purpose with or without fee is hereby granted, provided that the
above copyright notice and this permission notice appear in all copies.
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
PERFORMANCE OF THIS SOFTWARE.
*/
#include "libc/dce.h"
#include "libc/macros.internal.h"
#include "libc/notice.inc"
#include "libc/sysv/consts/prot.h"
#include "libc/sysv/consts/map.h"
#include "libc/calls/strace.internal.h"
#include "libc/dce.h"
.text.startup
// Cosmopolitan runtime.
//
// @param edi is argc
// @param rsi is argv
// @param rdx is environ
// @param rcx is auxv
// @noreturn
cosmo: push %rbp
mov %rsp,%rbp
mov %edi,%r12d
mov %rsi,%r13
mov %rdx,%r14
mov %rcx,%r15
#ifdef SYSDEBUG
call __strace_init
mov %eax,%r12d
#endif /* SYSDEBUG */
#ifdef __FAST_MATH__
push %rax
stmxcsr (%rsp)
orl $0x8040,(%rsp)
ldmxcsr (%rsp)
pop %rax
#endif
call _init
ezlea __init_array_start,ax # static ctors in forward order
.weak __init_array_start # could be called multiple times
ezlea __init_array_end,cx # idempotency recommended
.weak __init_array_end # @see ape/ape.lds
1: cmp %rax,%rcx
je 2f
push %rax
push %rcx
call .Largs
call *(%rax)
pop %rcx
pop %rax
add $8,%rax
jmp 1b
2: call .Largs
.weak main
call main
xchg %eax,%edi
call exit
.Largs: mov %r12d,%edi
mov %r13,%rsi
mov %r14,%rdx
mov %r15,%rcx
ret
.endfn cosmo,weak
#ifdef __PG__
.init.start 306,_init_ftrace
push %rdi
push %rsi
mov %r12d,%edi
mov %r13,%rsi
mov %r14,%rdx
mov %r15,%rcx
call program_executable_name_init
mov %r12d,%edi
mov %r13,%rsi
call ftrace_init
mov %eax,%r12d
pop %rsi
pop %rdi
.init.end 306,_init_ftrace
#endif
#if IsModeDbg()
#ifdef SYSDEBUG
.init.start 307,_init_printargs
push %rdi
push %rsi
mov %r12d,%edi
mov %r13,%rsi
mov %r14,%rdx
mov %r15,%rcx
call __printargs
pop %rsi
pop %rdi
.init.end 307,_init_printargs
#endif
#endif