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/*
* upb - a minimalist implementation of protocol buffers.
*
* Copyright (c) 2012 Google Inc. See LICENSE for details.
* Author: Josh Haberman <jhaberman@gmail.com>
*/
// Linux doesn't provide setjmp/longjmp, boo.
typedef void *jmp_buf[3]; // rsp, rbp, rip
static inline int _setjmp(jmp_buf env) {
register int ret asm ("%eax");
__asm__ __volatile__ goto (
" movq %%rsp, 0(%0)\n" // Save rsp
" movq %%rbp, 8(%0)\n" // Save rbp
" movq $1f, 16(%0)\n" // Save rip
" jmp %l[setup]\n"
"1:"
: // No outputs allowed (GCC limitation).
: "b" (env) // Input
: // All registers clobbered except rsp, which save in env.
"%rcx", "%rdx", "%rdi", "%rsi", "memory", "cc",
"%r8" , "%r9" , "%r10", "%r11", "%r12", "%r13", "%r14", "%r15"
: setup // Target labels.
);
return ret;
setup:
return 0;
}
__attribute__((__noreturn__))
static inline void _longjmp(jmp_buf env, int val) {
__asm__ __volatile__ (
" movq 0(%0), %%rsp\n" // Restore rsp
" movq 8(%0), %%rbp\n" // Restore rbp
" movq %0, %%rbx\n" // Restore rbx
" jmpq *16(%0)\n" // Jump to saved rip
: // No output.
: "r" (env), "a" (val) // Move val to %eax
);
__builtin_unreachable();
}
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