zig/lib/c/string.zig
GasInfinity f0649dd978
feat(libzigc): use common implementations for strings.h and string.h
* forwards all functions to their equivalent `std`
* removes their musl, wasi-libc and mingw implementations
2026-01-17 22:37:29 +01:00

299 lines
14 KiB
Zig

const builtin = @import("builtin");
const std = @import("std");
const common = @import("common.zig");
comptime {
if (builtin.target.isMuslLibC() or builtin.target.isWasiLibC()) {
// memcpy implemented in compiler_rt
// memmove implemented in compiler_rt
// memset implemented in compiler_rt
// memcmp implemented in compiler_rt
@export(&memchr, .{ .name = "memchr", .linkage = common.linkage, .visibility = common.visibility });
@export(&strcpy, .{ .name = "strcpy", .linkage = common.linkage, .visibility = common.visibility });
@export(&strncpy, .{ .name = "strncpy", .linkage = common.linkage, .visibility = common.visibility });
@export(&strcat, .{ .name = "strcat", .linkage = common.linkage, .visibility = common.visibility });
@export(&strncat, .{ .name = "strncat", .linkage = common.linkage, .visibility = common.visibility });
@export(&strcmp, .{ .name = "strcmp", .linkage = common.linkage, .visibility = common.visibility });
@export(&strncmp, .{ .name = "strncmp", .linkage = common.linkage, .visibility = common.visibility });
@export(&strcoll, .{ .name = "strcoll", .linkage = common.linkage, .visibility = common.visibility });
@export(&strxfrm, .{ .name = "strxfrm", .linkage = common.linkage, .visibility = common.visibility });
@export(&strchr, .{ .name = "strchr", .linkage = common.linkage, .visibility = common.visibility });
@export(&strrchr, .{ .name = "strrchr", .linkage = common.linkage, .visibility = common.visibility });
@export(&strcspn, .{ .name = "strcspn", .linkage = common.linkage, .visibility = common.visibility });
@export(&strspn, .{ .name = "strspn", .linkage = common.linkage, .visibility = common.visibility });
@export(&strpbrk, .{ .name = "strpbrk", .linkage = common.linkage, .visibility = common.visibility });
@export(&strstr, .{ .name = "strstr", .linkage = common.linkage, .visibility = common.visibility });
@export(&strtok, .{ .name = "strtok", .linkage = common.linkage, .visibility = common.visibility });
// strlen is in compiler_rt
@export(&strtok_r, .{ .name = "strtok_r", .linkage = common.linkage, .visibility = common.visibility });
@export(&stpcpy, .{ .name = "stpcpy", .linkage = common.linkage, .visibility = common.visibility });
@export(&stpncpy, .{ .name = "stpncpy", .linkage = common.linkage, .visibility = common.visibility });
@export(&strnlen, .{ .name = "strnlen", .linkage = common.linkage, .visibility = common.visibility });
@export(&memmem, .{ .name = "memmem", .linkage = common.linkage, .visibility = common.visibility });
@export(&memccpy, .{ .name = "memccpy", .linkage = common.linkage, .visibility = common.visibility });
@export(&strsep, .{ .name = "strsep", .linkage = common.linkage, .visibility = common.visibility });
@export(&strlcat, .{ .name = "strlcat", .linkage = common.linkage, .visibility = common.visibility });
@export(&strlcpy, .{ .name = "strlcpy", .linkage = common.linkage, .visibility = common.visibility });
@export(&explicit_bzero, .{ .name = "explicit_bzero", .linkage = common.linkage, .visibility = common.visibility });
@export(&strchrnul, .{ .name = "strchrnul", .linkage = common.linkage, .visibility = common.visibility });
@export(&strcasestr, .{ .name = "strcasestr", .linkage = common.linkage, .visibility = common.visibility });
@export(&memrchr, .{ .name = "memrchr", .linkage = common.linkage, .visibility = common.visibility });
@export(&mempcpy, .{ .name = "mempcpy", .linkage = common.linkage, .visibility = common.visibility });
@export(&__strcoll_l, .{ .name = "__strcoll_l", .linkage = common.linkage, .visibility = common.visibility });
@export(&__strxfrm_l, .{ .name = "__strxfrm_l", .linkage = common.linkage, .visibility = common.visibility });
@export(&__strcoll_l, .{ .name = "strcoll_l", .linkage = common.linkage, .visibility = common.visibility });
@export(&__strxfrm_l, .{ .name = "strxfrm_l", .linkage = common.linkage, .visibility = common.visibility });
// These symbols are not in the public ABI of musl/wasi. However they depend on these exports internally.
@export(&stpcpy, .{ .name = "__stpcpy", .linkage = common.linkage, .visibility = common.visibility });
@export(&stpncpy, .{ .name = "__stpncpy", .linkage = common.linkage, .visibility = common.visibility });
@export(&strchrnul, .{ .name = "__strchrnul", .linkage = common.linkage, .visibility = common.visibility });
@export(&memrchr, .{ .name = "__memrchr", .linkage = common.linkage, .visibility = common.visibility });
}
if (builtin.target.isMinGW()) {
@export(&strnlen, .{ .name = "strnlen", .linkage = common.linkage, .visibility = common.visibility });
@export(&mempcpy, .{ .name = "mempcpy", .linkage = common.linkage, .visibility = common.visibility });
@export(&strtok_r, .{ .name = "strtok_r", .linkage = common.linkage, .visibility = common.visibility });
}
}
fn memchr(ptr: *const anyopaque, value: c_int, len: usize) callconv(.c) ?*anyopaque {
const bytes: [*]const u8 = @ptrCast(ptr);
return @constCast(bytes[std.mem.findScalar(u8, bytes[0..len], @truncate(@as(c_uint, @bitCast(value)))) orelse return null ..]);
}
fn strcpy(noalias dst: [*]c_char, noalias src: [*:0]const c_char) callconv(.c) [*]c_char {
_ = stpcpy(dst, src);
return dst;
}
fn strncpy(noalias dst: [*]c_char, noalias src: [*:0]const c_char, max: usize) callconv(.c) [*]c_char {
_ = stpncpy(dst, src, max);
return dst;
}
fn strcat(noalias dst: [*:0]c_char, noalias src: [*:0]const c_char) callconv(.c) [*:0]c_char {
return strncat(dst, src, std.math.maxInt(usize));
}
fn strncat(noalias dst: [*:0]c_char, noalias src: [*:0]const c_char, max: usize) callconv(.c) [*:0]c_char {
const dst_len = std.mem.len(@as([*:0]u8, @ptrCast(dst)));
const src_len = strnlen(src, max);
@memcpy(dst[dst_len..][0..src_len], src[0..src_len]);
dst[dst_len + src_len] = 0;
return dst[0..(dst_len + src_len) :0].ptr;
}
fn strcmp(a: [*:0]const c_char, b: [*:0]const c_char) callconv(.c) c_int {
return strncmp(a, b, std.math.maxInt(usize));
}
fn strncmp(a: [*:0]const c_char, b: [*:0]const c_char, max: usize) callconv(.c) c_int {
return switch (std.mem.boundedOrderZ(u8, @ptrCast(a), @ptrCast(b), max)) {
.eq => 0,
.gt => 1,
.lt => -1,
};
}
fn strcoll(a: [*:0]const c_char, b: [*:0]const c_char) callconv(.c) c_int {
return strcmp(a, b);
}
fn __strcoll_l(a: [*:0]const c_char, b: [*:0]const c_char, locale: *anyopaque) callconv(.c) c_int {
_ = locale;
return strcoll(a, b);
}
// NOTE: If 'max' is 0, 'dst' is allowed to be a null pointer
fn strxfrm(noalias dst: ?[*]c_char, noalias src: [*:0]const c_char, max: usize) callconv(.c) usize {
const src_len = std.mem.len(@as([*:0]const u8, @ptrCast(src)));
if (src_len < max) @memcpy(dst.?[0 .. src_len + 1], src[0 .. src_len + 1]);
return src_len;
}
fn __strxfrm_l(noalias dst: ?[*]c_char, noalias src: [*:0]const c_char, max: usize, locale: *anyopaque) callconv(.c) usize {
_ = locale;
return strxfrm(dst, src, max);
}
fn strchr(str: [*:0]const c_char, value: c_int) callconv(.c) ?[*:0]c_char {
const str_u8: [*:0]const u8 = @ptrCast(str);
const len = std.mem.len(str_u8);
if (value == 0) return @constCast(str + len);
return @constCast(str[std.mem.findScalar(u8, str_u8[0..len], @truncate(@as(c_uint, @bitCast(value)))) orelse return null ..]);
}
fn strrchr(str: [*:0]const c_char, value: c_int) callconv(.c) ?[*:0]c_char {
const str_u8: [*:0]const u8 = @ptrCast(str);
// std.mem.len(str) + 1 to not special case '\0'
return @constCast(str[std.mem.findScalarLast(u8, str_u8[0 .. std.mem.len(str_u8) + 1], @truncate(@as(c_uint, @bitCast(value)))) orelse return null ..]);
}
fn strcspn(dst: [*:0]const c_char, values: [*:0]const c_char) callconv(.c) usize {
const dst_slice = std.mem.span(@as([*:0]const u8, @ptrCast(dst)));
return std.mem.findAny(u8, dst_slice, std.mem.span(@as([*:0]const u8, @ptrCast(values)))) orelse dst_slice.len;
}
fn strspn(dst: [*:0]const c_char, values: [*:0]const c_char) callconv(.c) usize {
const dst_slice = std.mem.span(@as([*:0]const u8, @ptrCast(dst)));
return std.mem.findNone(u8, dst_slice, std.mem.span(@as([*:0]const u8, @ptrCast(values)))) orelse dst_slice.len;
}
fn strpbrk(haystack: [*:0]const c_char, needle: [*:0]const c_char) callconv(.c) ?[*:0]c_char {
return @constCast(haystack[std.mem.findAny(u8, std.mem.span(@as([*:0]const u8, @ptrCast(haystack))), std.mem.span(@as([*:0]const u8, @ptrCast(needle)))) orelse return null ..]);
}
fn strstr(haystack: [*:0]const c_char, needle: [*:0]const c_char) callconv(.c) ?[*:0]c_char {
return @constCast(haystack[std.mem.find(u8, std.mem.span(@as([*:0]const u8, @ptrCast(haystack))), std.mem.span(@as([*:0]const u8, @ptrCast(needle)))) orelse return null ..]);
}
fn strtok(noalias maybe_str: ?[*:0]c_char, noalias values: [*:0]const c_char) callconv(.c) ?[*:0]c_char {
const state = struct {
var str: ?[*:0]c_char = null;
};
return strtok_r(maybe_str, values, &state.str);
}
// strlen is in compiler_rt
fn strtok_r(noalias maybe_str: ?[*:0]c_char, noalias values: [*:0]const c_char, noalias state: *?[*:0]c_char) callconv(.c) ?[*:0]c_char {
const str = if (maybe_str) |str|
str
else if (state.*) |state_str|
state_str
else
return null;
const str_bytes = std.mem.span(@as([*:0]u8, @ptrCast(str)));
const values_bytes = std.mem.span(@as([*:0]const u8, @ptrCast(values)));
const tok_start = std.mem.findNone(u8, str_bytes, values_bytes) orelse return null;
if (std.mem.findAnyPos(u8, str_bytes, tok_start, values_bytes)) |tok_end| {
str[tok_end] = 0;
state.* = str[tok_end + 1 ..];
} else {
state.* = str[str_bytes.len..];
}
return str[tok_start..];
}
fn stpcpy(noalias dst: [*]c_char, noalias src: [*:0]const c_char) callconv(.c) [*]c_char {
const src_len = std.mem.len(@as([*:0]const u8, @ptrCast(src)));
@memcpy(dst[0 .. src_len + 1], src[0 .. src_len + 1]);
return dst + src_len;
}
fn stpncpy(noalias dst: [*]c_char, noalias src: [*:0]const c_char, max: usize) callconv(.c) [*]c_char {
const src_len = strnlen(src, max);
const copying_len = @min(max, src_len);
@memcpy(dst[0..copying_len], src[0..copying_len]);
@memset(dst[copying_len..][0 .. max - copying_len], 0x00);
return dst + copying_len;
}
fn strnlen(str: [*:0]const c_char, max: usize) callconv(.c) usize {
return std.mem.findScalar(u8, @ptrCast(str[0..max]), 0) orelse max;
}
fn memmem(haystack: *const anyopaque, haystack_len: usize, needle: *const anyopaque, needle_len: usize) callconv(.c) ?*anyopaque {
const haystack_bytes: [*:0]const u8 = @ptrCast(haystack);
const needle_bytes: [*:0]const u8 = @ptrCast(needle);
return @constCast(haystack_bytes[std.mem.find(u8, haystack_bytes[0..haystack_len], needle_bytes[0..needle_len]) orelse return null ..]);
}
fn strsep(maybe_str: *?[*:0]c_char, values: [*:0]const c_char) callconv(.c) ?[*]c_char {
if (maybe_str.*) |str| {
const values_bytes = std.mem.span(@as([*:0]const u8, @ptrCast(values)));
const str_bytes = std.mem.span(@as([*:0]u8, @ptrCast(str)));
const found = std.mem.findAny(u8, str_bytes, values_bytes) orelse {
maybe_str.* = null;
return str;
};
str[found] = 0;
maybe_str.* = str[found + 1 ..];
return str;
}
return null;
}
fn strlcat(dst: [*:0]c_char, src: [*:0]const c_char, dst_total_len: usize) callconv(.c) usize {
const dst_len = strnlen(dst, dst_total_len);
const src_bytes = std.mem.span(@as([*:0]const u8, @ptrCast(src)));
if (dst_total_len == dst_len) return dst_len + src_bytes.len;
const copying_len = @min(dst_total_len - (dst_len + 1), src_bytes.len);
@memcpy(dst[dst_len..][0..copying_len], src[0..copying_len]);
dst[dst_len + copying_len] = 0;
return dst_len + src_bytes.len;
}
fn strlcpy(dst: [*]c_char, src: [*:0]const c_char, dst_total_len: usize) callconv(.c) usize {
const src_bytes = std.mem.span(@as([*:0]const u8, @ptrCast(src)));
if (dst_total_len != 0) {
const copying_len = @min(src_bytes.len, dst_total_len - 1);
@memcpy(dst[0..copying_len], src[0..copying_len]);
dst[copying_len] = 0;
}
return src_bytes.len;
}
fn memccpy(noalias dst: *anyopaque, noalias src: *const anyopaque, value: c_int, len: usize) callconv(.c) *anyopaque {
const dst_bytes: [*]u8 = @ptrCast(dst);
const src_bytes: [*]const u8 = @ptrCast(src);
const value_u8: u8 = @truncate(@as(c_uint, @bitCast(value)));
const copying_len = std.mem.findScalar(u8, src_bytes[0..len], value_u8) orelse len;
@memcpy(dst_bytes[0..copying_len], src_bytes[0..copying_len]);
return dst_bytes + copying_len;
}
fn explicit_bzero(ptr: *anyopaque, len: usize) callconv(.c) void {
const bytes: [*]u8 = @ptrCast(ptr);
std.crypto.secureZero(u8, bytes[0..len]);
}
fn strchrnul(str: [*:0]const c_char, value: c_int) callconv(.c) [*:0]c_char {
const str_u8: [*:0]const u8 = @ptrCast(str);
const len = std.mem.len(str_u8);
if (value == 0) return @constCast(str + len);
return @constCast(str[std.mem.findScalar(u8, str_u8[0..len], @truncate(@as(c_uint, @bitCast(value)))) orelse len ..]);
}
fn strcasestr(haystack: [*:0]const c_char, needle: [*:0]const c_char) callconv(.c) ?[*:0]c_char {
return @constCast(haystack[std.ascii.findIgnoreCase(std.mem.span(@as([*:0]const u8, @ptrCast(haystack))), std.mem.span(@as([*:0]const u8, @ptrCast(needle)))) orelse return null ..]);
}
fn memrchr(ptr: *const anyopaque, value: c_int, len: usize) callconv(.c) ?*anyopaque {
const bytes: [*]const u8 = @ptrCast(ptr);
return @constCast(bytes[std.mem.findScalarLast(u8, bytes[0..len], @truncate(@as(c_uint, @bitCast(value)))) orelse return null ..]);
}
fn mempcpy(noalias dst: *anyopaque, noalias src: *const anyopaque, len: usize) callconv(.c) *anyopaque {
const dst_bytes: [*]u8 = @ptrCast(dst);
const src_bytes: [*]const u8 = @ptrCast(src);
@memcpy(dst_bytes[0..len], src_bytes[0..len]);
return dst_bytes + len;
}
test strncmp {
try std.testing.expect(strncmp(@ptrCast("a"), @ptrCast("b"), 1) < 0);
try std.testing.expect(strncmp(@ptrCast("a"), @ptrCast("c"), 1) < 0);
try std.testing.expect(strncmp(@ptrCast("b"), @ptrCast("a"), 1) > 0);
try std.testing.expect(strncmp(@ptrCast("\xff"), @ptrCast("\x02"), 1) > 0);
}