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refactor std.zig.system.NativeTargetInfo functions

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to make them a bit easier to test.
This commit is contained in:
Andrew Kelley 2020-02-29 21:31:03 -05:00
parent c903b76010
commit 48cef8d5be
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GPG Key ID: 7C5F548F728501A9
1 changed files with 34 additions and 31 deletions
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65
lib/std/zig/system.zig
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@ -399,17 +399,38 @@ pub const NativeTargetInfo = struct {
return result;
}
const env_file = std.fs.openFileAbsoluteC("/usr/bin/env", .{}) catch |err| switch (err) {
error.NoSpaceLeft => unreachable,
error.NameTooLong => unreachable,
error.PathAlreadyExists => unreachable,
error.SharingViolation => unreachable,
error.InvalidUtf8 => unreachable,
error.BadPathName => unreachable,
error.PipeBusy => unreachable,
error.IsDir,
error.NotDir,
error.AccessDenied,
error.NoDevice,
error.FileNotFound,
error.FileTooBig,
error.Unexpected,
=> return defaultAbiAndDynamicLinker(cpu, os, cross_target),
else => |e| return e,
};
defer env_file.close();
// If Zig is statically linked, such as via distributed binary static builds, the above
// trick won't work. The next thing we fall back to is the same thing, but for /usr/bin/env.
// Since that path is hard-coded into the shebang line of many portable scripts, it's a
// reasonably reliable path to check for.
return abiAndDynamicLinkerFromUsrBinEnv(cpu, os, ld_info_list, cross_target) catch |err| switch (err) {
return abiAndDynamicLinkerFromFile(env_file, cpu, os, ld_info_list, cross_target) catch |err| switch (err) {
error.FileSystem,
error.SystemResources,
error.SymLinkLoop,
error.ProcessFdQuotaExceeded,
error.SystemFdQuotaExceeded,
error.DeviceBusy,
=> |e| return e,
error.UnableToReadElfFile,
@ -418,7 +439,6 @@ pub const NativeTargetInfo = struct {
error.InvalidElfEndian,
error.InvalidElfFile,
error.InvalidElfMagic,
error.UsrBinEnvNotAvailable,
error.Unexpected,
error.UnexpectedEndOfFile,
error.NameTooLong,
@ -461,32 +481,15 @@ pub const NativeTargetInfo = struct {
};
}
fn abiAndDynamicLinkerFromUsrBinEnv(
pub fn abiAndDynamicLinkerFromFile(
file: fs.File,
cpu: Target.Cpu,
os: Target.Os,
ld_info_list: []const LdInfo,
cross_target: CrossTarget,
) !NativeTargetInfo {
const env_file = std.fs.openFileAbsoluteC("/usr/bin/env", .{}) catch |err| switch (err) {
error.NoSpaceLeft => unreachable,
error.NameTooLong => unreachable,
error.PathAlreadyExists => unreachable,
error.SharingViolation => unreachable,
error.InvalidUtf8 => unreachable,
error.BadPathName => unreachable,
error.PipeBusy => unreachable,
error.IsDir => return error.UsrBinEnvNotAvailable,
error.NotDir => return error.UsrBinEnvNotAvailable,
error.AccessDenied => return error.UsrBinEnvNotAvailable,
error.NoDevice => return error.UsrBinEnvNotAvailable,
error.FileNotFound => return error.UsrBinEnvNotAvailable,
error.FileTooBig => return error.UsrBinEnvNotAvailable,
else => |e| return e,
};
var hdr_buf: [@sizeOf(elf.Elf64_Ehdr)]u8 align(@alignOf(elf.Elf64_Ehdr)) = undefined;
_ = try preadFull(env_file, &hdr_buf, 0, hdr_buf.len);
_ = try preadFull(file, &hdr_buf, 0, hdr_buf.len);
const hdr32 = @ptrCast(*elf.Elf32_Ehdr, &hdr_buf);
const hdr64 = @ptrCast(*elf.Elf64_Ehdr, &hdr_buf);
if (!mem.eql(u8, hdr32.e_ident[0..4], "\x7fELF")) return error.InvalidElfMagic;
@ -526,7 +529,7 @@ pub const NativeTargetInfo = struct {
// Reserve some bytes so that we can deref the 64-bit struct fields
// even when the ELF file is 32-bits.
const ph_reserve: usize = @sizeOf(elf.Elf64_Phdr) - @sizeOf(elf.Elf32_Phdr);
const ph_read_byte_len = try preadFull(env_file, ph_buf[0 .. ph_buf.len - ph_reserve], phoff, phentsize);
const ph_read_byte_len = try preadFull(file, ph_buf[0 .. ph_buf.len - ph_reserve], phoff, phentsize);
var ph_buf_i: usize = 0;
while (ph_buf_i < ph_read_byte_len and ph_i < phnum) : ({
ph_i += 1;
@ -541,7 +544,7 @@ pub const NativeTargetInfo = struct {
const p_offset = elfInt(is_64, need_bswap, ph32.p_offset, ph64.p_offset);
const p_filesz = elfInt(is_64, need_bswap, ph32.p_filesz, ph64.p_filesz);
if (p_filesz > result.dynamic_linker.buffer.len) return error.NameTooLong;
_ = try preadFull(env_file, result.dynamic_linker.buffer[0..p_filesz], p_offset, p_filesz);
_ = try preadFull(file, result.dynamic_linker.buffer[0..p_filesz], p_offset, p_filesz);
// PT_INTERP includes a null byte in p_filesz.
const len = p_filesz - 1;
// dynamic_linker.max_byte is "max", not "len".
@ -573,7 +576,7 @@ pub const NativeTargetInfo = struct {
// even when the ELF file is 32-bits.
const dyn_reserve: usize = @sizeOf(elf.Elf64_Dyn) - @sizeOf(elf.Elf32_Dyn);
const dyn_read_byte_len = try preadFull(
env_file,
file,
dyn_buf[0 .. dyn_buf.len - dyn_reserve],
dyn_off,
dyn_size,
@ -617,14 +620,14 @@ pub const NativeTargetInfo = struct {
var sh_buf: [16 * @sizeOf(elf.Elf64_Shdr)]u8 align(@alignOf(elf.Elf64_Shdr)) = undefined;
if (sh_buf.len < shentsize) return error.InvalidElfFile;
_ = try preadFull(env_file, &sh_buf, str_section_off, shentsize);
_ = try preadFull(file, &sh_buf, str_section_off, shentsize);
const shstr32 = @ptrCast(*elf.Elf32_Shdr, @alignCast(@alignOf(elf.Elf32_Shdr), &sh_buf));
const shstr64 = @ptrCast(*elf.Elf64_Shdr, @alignCast(@alignOf(elf.Elf64_Shdr), &sh_buf));
const shstrtab_off = elfInt(is_64, need_bswap, shstr32.sh_offset, shstr64.sh_offset);
const shstrtab_size = elfInt(is_64, need_bswap, shstr32.sh_size, shstr64.sh_size);
var strtab_buf: [4096:0]u8 = undefined;
const shstrtab_len = std.math.min(shstrtab_size, strtab_buf.len);
const shstrtab_read_len = try preadFull(env_file, &strtab_buf, shstrtab_off, shstrtab_len);
const shstrtab_read_len = try preadFull(file, &strtab_buf, shstrtab_off, shstrtab_len);
const shstrtab = strtab_buf[0..shstrtab_read_len];
const shnum = elfInt(is_64, need_bswap, hdr32.e_shnum, hdr64.e_shnum);
@ -634,7 +637,7 @@ pub const NativeTargetInfo = struct {
// even when the ELF file is 32-bits.
const sh_reserve: usize = @sizeOf(elf.Elf64_Shdr) - @sizeOf(elf.Elf32_Shdr);
const sh_read_byte_len = try preadFull(
env_file,
file,
sh_buf[0 .. sh_buf.len - sh_reserve],
shoff,
shentsize,
@ -667,7 +670,7 @@ pub const NativeTargetInfo = struct {
if (dynstr) |ds| {
const strtab_len = std.math.min(ds.size, strtab_buf.len);
const strtab_read_len = try preadFull(env_file, &strtab_buf, ds.offset, shstrtab_len);
const strtab_read_len = try preadFull(file, &strtab_buf, ds.offset, shstrtab_len);
const strtab = strtab_buf[0..strtab_read_len];
// TODO this pointer cast should not be necessary
const rpath_list = mem.toSliceConst(u8, @ptrCast([*:0]u8, strtab[rpoff..].ptr));
@ -763,7 +766,7 @@ pub const NativeTargetInfo = struct {
};
}
const LdInfo = struct {
pub const LdInfo = struct {
ld: DynamicLinker,
abi: Target.Abi,
};