mirror of
https://github.com/ziglang/zig.git
synced 2025-12-11 16:53:06 +00:00
07a71fc322
* instead of emitting a breakpoint for a debug safety crash,
zig calls a panic function which prints an error message
and a stack trace and then calls abort.
* on freestanding OS, this panic function has a default
implementation of a simple infinite loop.
* users can override the panic implementation by providing
`pub fn panic(message: []const u8) -> unreachable { }`
* workaround for LLVM segfaulting when you try to use cold
calling convention on ARM.
closes #245
56 lines
1.4 KiB
Zig
56 lines
1.4 KiB
Zig
// This file is in a package which has the root source file exposed as "@root".
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const root = @import("@root");
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const std = @import("std");
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const linux = std.linux;
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const cstr = std.cstr;
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const want_start_symbol = switch(@compileVar("os")) {
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Os.linux => true,
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else => false,
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};
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const want_main_symbol = !want_start_symbol;
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var argc: usize = undefined;
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var argv: &&u8 = undefined;
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export nakedcc fn _start() -> unreachable {
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@setFnVisible(this, want_start_symbol);
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switch (@compileVar("arch")) {
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Arch.x86_64 => {
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argc = asm("mov (%%rsp), %[argc]": [argc] "=r" (-> usize));
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argv = asm("lea 0x8(%%rsp), %[argv]": [argv] "=r" (-> &&u8));
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},
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Arch.i386 => {
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argc = asm("mov (%%esp), %[argc]": [argc] "=r" (-> usize));
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argv = asm("lea 0x4(%%esp), %[argv]": [argv] "=r" (-> &&u8));
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},
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else => @compileError("unsupported arch"),
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}
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callMainAndExit()
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}
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fn callMain() -> %void {
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const args = @alloca([]u8, argc);
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for (args) |_, i| {
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const ptr = argv[i];
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args[i] = ptr[0...cstr.len(ptr)];
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}
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return root.main(args);
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}
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fn callMainAndExit() -> unreachable {
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callMain() %% linux.exit(1);
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linux.exit(0);
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}
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export fn main(c_argc: i32, c_argv: &&u8) -> i32 {
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@setFnVisible(this, want_main_symbol);
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argc = usize(c_argc);
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argv = c_argv;
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callMain() %% return 1;
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return 0;
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}
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