Merge branch 'endian' into 'master'

Add `endian.h`

See merge request !497

src/header/endian/cbindgen.toml

+sys_includes = ["stdint.h"]
+include_guard = "_RELIBC_ENDIAN_H"
+trailer = "#include <machine/endian.h>"
+language = "C"
+style = "Tag"
+no_includes = true
+cpp_compat = true

src/header/endian/mod.rs

+//! endian.h implementation for Redox, following
+//! https://pubs.opengroup.org/onlinepubs/9799919799/basedefs/endian.h.html
+
+use crate::platform::types::*;
+
+#[no_mangle]
+extern "C" fn be16toh(x: uint16_t) -> uint16_t {
+    uint16_t::from_be(x)
+}
+
+#[no_mangle]
+extern "C" fn be32toh(x: uint32_t) -> uint32_t {
+    uint32_t::from_be(x)
+}
+
+#[no_mangle]
+extern "C" fn be64toh(x: uint64_t) -> uint64_t {
+    uint64_t::from_be(x)
+}
+
+#[no_mangle]
+extern "C" fn htobe16(x: uint16_t) -> uint16_t {
+    x.to_be()
+}
+
+#[no_mangle]
+extern "C" fn htobe32(x: uint32_t) -> uint32_t {
+    x.to_be()
+}
+
+#[no_mangle]
+extern "C" fn htobe64(x: uint64_t) -> uint64_t {
+    x.to_be()
+}
+
+#[no_mangle]
+extern "C" fn htole16(x: uint16_t) -> uint16_t {
+    x.to_le()
+}
+
+#[no_mangle]
+extern "C" fn htole32(x: uint32_t) -> uint32_t {
+    x.to_le()
+}
+
+#[no_mangle]
+extern "C" fn htole64(x: uint64_t) -> uint64_t {
+    x.to_le()
+}
+
+#[no_mangle]
+extern "C" fn le16toh(x: uint16_t) -> uint16_t {
+    uint16_t::from_le(x)
+}
+
+#[no_mangle]
+extern "C" fn le32toh(x: uint32_t) -> uint32_t {
+    uint32_t::from_le(x)
+}
+
+#[no_mangle]
+extern "C" fn le64toh(x: uint64_t) -> uint64_t {
+    uint64_t::from_le(x)
+}

src/header/mod.rs

@@ -11,6 +11,7 @@ pub mod dirent;
 pub mod dl_tls;
 pub mod dlfcn;
 pub mod elf;
+pub mod endian;
 pub mod errno;
 pub mod fcntl;
 pub mod float;

tests/Makefile

@@ -14,6 +14,7 @@ EXPECT_NAMES=\
 	crypt/sha512 \
 	destructor \
 	dirent/scandir \
+	endian \
 	errno \
 	error \
 	fcntl/create \

tests/endian.c

+#include <assert.h>
+#include <endian.h>
+#include <stdint.h>
+
+#include "test_helpers.h"
+
+int main() {
+    uint16_t zero_u16 = 0;
+    assert(be16toh(zero_u16) == zero_u16);
+    assert(htobe16(zero_u16) == zero_u16);
+    assert(htole16(zero_u16) == zero_u16);
+    assert(le16toh(zero_u16) == zero_u16);
+
+    uint16_t value_be_u16 = 0x0123;
+    uint16_t value_le_u16 = 0x2301;
+    assert(be16toh(value_be_u16) == value_le_u16);
+    assert(htobe16(value_le_u16) == value_be_u16);
+    assert(htole16(value_le_u16) == value_le_u16);
+    assert(le16toh(value_le_u16) == value_le_u16);
+
+    uint32_t zero_u32 = 0;
+    assert(be32toh(zero_u32) == zero_u32);
+    assert(htobe32(zero_u32) == zero_u32);
+    assert(htole32(zero_u32) == zero_u32);
+    assert(le32toh(zero_u32) == zero_u32);
+
+    uint32_t value_be_u32 = 0x01234567;
+    uint32_t value_le_u32 = 0x67452301;
+    assert(be32toh(value_be_u32) == value_le_u32);
+    assert(htobe32(value_le_u32) == value_be_u32);
+    assert(htole32(value_le_u32) == value_le_u32);
+    assert(le32toh(value_le_u32) == value_le_u32);
+
+    uint64_t zero_u64 = 0;
+    assert(be64toh(zero_u64) == zero_u64);
+    assert(htobe64(zero_u64) == zero_u64);
+    assert(htole64(zero_u64) == zero_u64);
+    assert(le64toh(zero_u64) == zero_u64);
+
+    uint64_t value_be_u64 = 0x0123456789ABCDEF;
+    uint64_t value_le_u64 = 0xEFCDAB8967452301;
+    assert(be64toh(value_be_u64) == value_le_u64);
+    assert(htobe64(value_le_u64) == value_be_u64);
+    assert(htole64(value_le_u64) == value_le_u64);
+    assert(le64toh(value_le_u64) == value_le_u64);
+}