65 lines
1.9 KiB
Zig
65 lines
1.9 KiB
Zig
// This file is in a package which has the root source file exposed as "@root".
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// It is included in the compilation unit when exporting an executable.
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const root = @import("@root");
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const std = @import("std");
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const want_main_symbol = std.target.linking_libc;
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const want_start_symbol = !want_main_symbol;
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const exit = std.os.posix.exit;
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var argc_ptr: &usize = undefined;
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export nakedcc fn _start() -> noreturn {
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@setGlobalLinkage(_start, if (want_start_symbol) GlobalLinkage.Strong else GlobalLinkage.Internal);
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if (!want_start_symbol) {
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unreachable;
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}
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switch (@compileVar("arch")) {
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Arch.x86_64 => {
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argc_ptr = asm("lea %[argc], [rsp]": [argc] "=r" (-> &usize));
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},
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Arch.i386 => {
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argc_ptr = asm("lea %[argc], [esp]": [argc] "=r" (-> &usize));
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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 callMainAndExit() -> noreturn {
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const argc = *argc_ptr;
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const argv = @ptrcast(&&u8, &argc_ptr[1]);
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const envp = @ptrcast(&?&u8, &argv[argc + 1]);
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callMain(argc, argv, envp) %% exit(1);
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exit(0);
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}
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var args_data: [32][]u8 = undefined;
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fn callMain(argc: usize, argv: &&u8, envp: &?&u8) -> %void {
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// TODO create args API to make it work with > 32 args
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const args = args_data[0...argc];
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for (args) |_, i| {
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const ptr = argv[i];
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args[i] = ptr[0...std.cstr.len(ptr)];
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}
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var env_count: usize = 0;
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while (envp[env_count] != null; env_count += 1) {}
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std.os.environ_raw = @ptrcast(&&u8, envp)[0...env_count];
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return root.main(args);
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}
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export fn main(c_argc: i32, c_argv: &&u8, c_envp: &?&u8) -> i32 {
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@setGlobalLinkage(main, if (want_main_symbol) GlobalLinkage.Strong else GlobalLinkage.Internal);
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if (!want_main_symbol) {
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unreachable;
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}
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callMain(usize(c_argc), c_argv, c_envp) %% return 1;
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return 0;
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}
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