Merge pull request #5987 from jasonKercher/os2-libc-env-linux

os2: Use libc for linux environment if not no-crt.
This commit is contained in:
Jeroen van Rijn
2025-12-03 10:30:48 +00:00
committed by GitHub
2 changed files with 349 additions and 220 deletions

View File

@@ -7,242 +7,371 @@ import "base:intrinsics"
import "core:sync"
import "core:slice"
import "core:strings"
import "core:sys/linux"
// TODO: IF NO_CRT:
// Override the libc environment functions' weak linkage to
// allow us to interact with 3rd party code that DOES link
// to libc. Otherwise, our environment can be out of sync.
// ELSE:
// Just use the libc.
_ :: sync
_ :: slice
_ :: linux
NOT_FOUND :: -1
when ODIN_NO_CRT {
// TODO: Override the libc environment functions' weak linkage to
// allow us to interact with 3rd party code that DOES link
// to libc. Otherwise, our environment can be out of sync.
// the environment is a 0 delimited list of <key>=<value> strings
_env: [dynamic]string
NOT_FOUND :: -1
_env_mutex: sync.Recursive_Mutex
// the environment is a 0 delimited list of <key>=<value> strings
_env: [dynamic]string
// We need to be able to figure out if the environment variable
// is contained in the original environment or not. This also
// serves as a flag to determine if we have built _env.
_org_env_begin: uintptr // atomic
_org_env_end: uintptr // guarded by _env_mutex
_env_mutex: sync.Recursive_Mutex
// Returns value + index location into _env
// or -1 if not found
_lookup :: proc(key: string) -> (value: string, idx: int) {
sync.guard(&_env_mutex)
// We need to be able to figure out if the environment variable
// is contained in the original environment or not. This also
// serves as a flag to determine if we have built _env.
_org_env_begin: uintptr // atomic
_org_env_end: uintptr // guarded by _env_mutex
for entry, i in _env {
if k, v := _kv_from_entry(entry); k == key {
return v, i
}
}
return "", -1
}
// Returns value + index location into _env
// or -1 if not found
_lookup :: proc(key: string) -> (value: string, idx: int) {
sync.guard(&_env_mutex)
_lookup_env_alloc :: proc(key: string, allocator: runtime.Allocator) -> (value: string, found: bool) {
if intrinsics.atomic_load_explicit(&_org_env_begin, .Acquire) == 0 {
_build_env()
}
if v, idx := _lookup(key); idx != -1 {
found = true
value, _ = clone_string(v, allocator)
}
return
}
_lookup_env_buf :: proc(buf: []u8, key: string) -> (value: string, err: Error) {
if intrinsics.atomic_load_explicit(&_org_env_begin, .Acquire) == 0 {
_build_env()
}
if v, idx := _lookup(key); idx != -1 {
if len(buf) >= len(v) {
copy(buf, v)
return string(buf[:len(v)]), nil
}
return "", .Buffer_Full
}
return "", .Env_Var_Not_Found
}
_lookup_env :: proc{_lookup_env_alloc, _lookup_env_buf}
_set_env :: proc(key, v_new: string) -> Error {
if intrinsics.atomic_load_explicit(&_org_env_begin, .Acquire) == 0 {
_build_env()
}
sync.guard(&_env_mutex)
// all key values are stored as "key=value\x00"
kv_size := len(key) + len(v_new) + 2
if v_curr, idx := _lookup(key); idx != NOT_FOUND {
if v_curr == v_new {
return nil
}
unordered_remove(&_env, idx)
if !_is_in_org_env(v_curr) {
// We allocated this key-value. Possibly resize and
// overwrite the value only. Otherwise, treat as if it
// wasn't in the environment in the first place.
k_addr, v_addr := _kv_addr_from_val(v_curr, key)
if len(v_new) > len(v_curr) {
k_addr = ([^]u8)(runtime.heap_resize(k_addr, kv_size))
if k_addr == nil {
return .Out_Of_Memory
}
v_addr = &k_addr[len(key) + 1]
for entry, i in _env {
if k, v := _kv_from_entry(entry); k == key {
return v, i
}
intrinsics.mem_copy_non_overlapping(v_addr, raw_data(v_new), len(v_new))
v_addr[len(v_new)] = 0
append(&_env, string(k_addr[:kv_size]))
return nil
}
return "", -1
}
k_addr := ([^]u8)(runtime.heap_alloc(kv_size))
if k_addr == nil {
return .Out_Of_Memory
}
intrinsics.mem_copy_non_overlapping(k_addr, raw_data(key), len(key))
k_addr[len(key)] = '='
val_slice := k_addr[len(key) + 1:]
intrinsics.mem_copy_non_overlapping(&val_slice[0], raw_data(v_new), len(v_new))
val_slice[len(v_new)] = 0
append(&_env, string(k_addr[:kv_size - 1]))
return nil
}
_unset_env :: proc(key: string) -> bool {
if intrinsics.atomic_load_explicit(&_org_env_begin, .Acquire) == 0 {
_build_env()
}
sync.guard(&_env_mutex)
v: string
i: int
if v, i = _lookup(key); i == -1 {
return false
}
unordered_remove(&_env, i)
if _is_in_org_env(v) {
return true
}
// if we got this far, the environment variable
// existed AND was allocated by us.
k_addr, _ := _kv_addr_from_val(v, key)
runtime.heap_free(k_addr)
return true
}
_clear_env :: proc() {
sync.guard(&_env_mutex)
for kv in _env {
if !_is_in_org_env(kv) {
runtime.heap_free(raw_data(kv))
_lookup_env_alloc :: proc(key: string, allocator: runtime.Allocator) -> (value: string, found: bool) {
if intrinsics.atomic_load_explicit(&_org_env_begin, .Acquire) == 0 {
_build_env()
}
}
clear(&_env)
// nothing resides in the original environment either
intrinsics.atomic_store_explicit(&_org_env_begin, ~uintptr(0), .Release)
_org_env_end = ~uintptr(0)
}
_environ :: proc(allocator: runtime.Allocator) -> (environ: []string, err: Error) {
if intrinsics.atomic_load_explicit(&_org_env_begin, .Acquire) == 0 {
_build_env()
}
sync.guard(&_env_mutex)
env := make([dynamic]string, 0, len(_env), allocator) or_return
defer if err != nil {
for e in env {
delete(e, allocator)
if v, idx := _lookup(key); idx != -1 {
found = true
value, _ = clone_string(v, allocator)
}
delete(env)
}
for entry in _env {
s := clone_string(entry, allocator) or_return
append(&env, s)
}
environ = env[:]
return
}
// The entire environment is stored as 0 terminated strings,
// so there is no need to clone/free individual variables
export_cstring_environment :: proc(allocator: runtime.Allocator) -> []cstring {
if intrinsics.atomic_load_explicit(&_org_env_begin, .Acquire) == 0 {
// The environment has not been modified, so we can just
// send the original environment
org_env := _get_original_env()
n: int
for ; org_env[n] != nil; n += 1 {}
return slice.clone(org_env[:n + 1], allocator)
}
sync.guard(&_env_mutex)
// NOTE: already terminated by nil pointer via + 1
env := make([]cstring, len(_env) + 1, allocator)
for entry, i in _env {
env[i] = cstring(raw_data(entry))
}
return env
}
_build_env :: proc() {
sync.guard(&_env_mutex)
if intrinsics.atomic_load_explicit(&_org_env_begin, .Acquire) != 0 {
return
}
_env = make(type_of(_env), runtime.heap_allocator())
cstring_env := _get_original_env()
intrinsics.atomic_store_explicit(&_org_env_begin, uintptr(rawptr(cstring_env[0])), .Release)
for i := 0; cstring_env[i] != nil; i += 1 {
bytes := ([^]u8)(cstring_env[i])
n := len(cstring_env[i])
_org_env_end = uintptr(&bytes[n])
append(&_env, string(bytes[:n]))
_lookup_env_buf :: proc(buf: []u8, key: string) -> (value: string, err: Error) {
if intrinsics.atomic_load_explicit(&_org_env_begin, .Acquire) == 0 {
_build_env()
}
if v, idx := _lookup(key); idx != -1 {
if len(buf) >= len(v) {
copy(buf, v)
return string(buf[:len(v)]), nil
}
return "", .Buffer_Full
}
return "", .Env_Var_Not_Found
}
_lookup_env :: proc{_lookup_env_alloc, _lookup_env_buf}
_set_env :: proc(key, v_new: string) -> Error {
if intrinsics.atomic_load_explicit(&_org_env_begin, .Acquire) == 0 {
_build_env()
}
sync.guard(&_env_mutex)
// all key values are stored as "key=value\x00"
kv_size := len(key) + len(v_new) + 2
if v_curr, idx := _lookup(key); idx != NOT_FOUND {
if v_curr == v_new {
return nil
}
unordered_remove(&_env, idx)
if !_is_in_org_env(v_curr) {
// We allocated this key-value. Possibly resize and
// overwrite the value only. Otherwise, treat as if it
// wasn't in the environment in the first place.
k_addr, v_addr := _kv_addr_from_val(v_curr, key)
if len(v_new) > len(v_curr) {
k_addr = ([^]u8)(runtime.heap_resize(k_addr, kv_size))
if k_addr == nil {
return .Out_Of_Memory
}
v_addr = &k_addr[len(key) + 1]
}
intrinsics.mem_copy_non_overlapping(v_addr, raw_data(v_new), len(v_new))
v_addr[len(v_new)] = 0
append(&_env, string(k_addr[:kv_size]))
return nil
}
}
k_addr := ([^]u8)(runtime.heap_alloc(kv_size))
if k_addr == nil {
return .Out_Of_Memory
}
intrinsics.mem_copy_non_overlapping(k_addr, raw_data(key), len(key))
k_addr[len(key)] = '='
val_slice := k_addr[len(key) + 1:]
intrinsics.mem_copy_non_overlapping(&val_slice[0], raw_data(v_new), len(v_new))
val_slice[len(v_new)] = 0
append(&_env, string(k_addr[:kv_size - 1]))
return nil
}
_unset_env :: proc(key: string) -> bool {
if intrinsics.atomic_load_explicit(&_org_env_begin, .Acquire) == 0 {
_build_env()
}
sync.guard(&_env_mutex)
v: string
i: int
if v, i = _lookup(key); i == -1 {
return true
}
unordered_remove(&_env, i)
if _is_in_org_env(v) {
return true
}
// if we got this far, the environment variable
// existed AND was allocated by us.
k_addr, _ := _kv_addr_from_val(v, key)
runtime.heap_free(k_addr)
return true
}
_clear_env :: proc() {
sync.guard(&_env_mutex)
for kv in _env {
if !_is_in_org_env(kv) {
runtime.heap_free(raw_data(kv))
}
}
clear(&_env)
// nothing resides in the original environment either
intrinsics.atomic_store_explicit(&_org_env_begin, ~uintptr(0), .Release)
_org_env_end = ~uintptr(0)
}
_environ :: proc(allocator: runtime.Allocator) -> (environ: []string, err: Error) {
if intrinsics.atomic_load_explicit(&_org_env_begin, .Acquire) == 0 {
_build_env()
}
sync.guard(&_env_mutex)
env := make([dynamic]string, 0, len(_env), allocator) or_return
defer if err != nil {
for e in env {
delete(e, allocator)
}
delete(env)
}
for entry in _env {
s := clone_string(entry, allocator) or_return
append(&env, s)
}
environ = env[:]
return
}
// The entire environment is stored as 0 terminated strings,
// so there is no need to clone/free individual variables
export_cstring_environment :: proc(allocator: runtime.Allocator) -> []cstring {
if intrinsics.atomic_load_explicit(&_org_env_begin, .Acquire) == 0 {
// The environment has not been modified, so we can just
// send the original environment
org_env := _get_original_env()
n: int
for ; org_env[n] != nil; n += 1 {}
return slice.clone(org_env[:n + 1], allocator)
}
sync.guard(&_env_mutex)
// NOTE: already terminated by nil pointer via + 1
env := make([]cstring, len(_env) + 1, allocator)
for entry, i in _env {
env[i] = cstring(raw_data(entry))
}
return env
}
_build_env :: proc() {
sync.guard(&_env_mutex)
if intrinsics.atomic_load_explicit(&_org_env_begin, .Acquire) != 0 {
return
}
_env = make(type_of(_env), runtime.heap_allocator())
cstring_env := _get_original_env()
intrinsics.atomic_store_explicit(&_org_env_begin, uintptr(rawptr(cstring_env[0])), .Release)
for i := 0; cstring_env[i] != nil; i += 1 {
bytes := ([^]u8)(cstring_env[i])
n := len(cstring_env[i])
_org_env_end = uintptr(&bytes[n])
append(&_env, string(bytes[:n]))
}
}
_get_original_env :: #force_inline proc() -> [^]cstring {
// essentially &argv[argc] which should be a nil pointer!
#no_bounds_check env: [^]cstring = &runtime.args__[len(runtime.args__)]
assert(env[0] == nil)
return &env[1]
}
_kv_from_entry :: #force_inline proc(entry: string) -> (k, v: string) {
eq_idx := strings.index_byte(entry, '=')
if eq_idx == -1 {
return entry, ""
}
return entry[:eq_idx], entry[eq_idx + 1:]
}
_kv_addr_from_val :: #force_inline proc(val: string, key: string) -> ([^]u8, [^]u8) {
v_addr := raw_data(val)
k_addr := ([^]u8)(&v_addr[-(len(key) + 1)])
return k_addr, v_addr
}
_is_in_org_env :: #force_inline proc(env_data: string) -> bool {
addr := uintptr(raw_data(env_data))
return addr >= intrinsics.atomic_load_explicit(&_org_env_begin, .Acquire) && addr < _org_env_end
}
} else {
// We are linking with libc, so use libc env functions
foreign import libc "system:c"
@(default_calling_convention="c")
foreign libc {
@(link_name="environ")
libc_environ: [^]cstring
@(link_name="__errno_location")
libc_errno_location :: proc() -> ^int ---
getenv :: proc(name: cstring) -> cstring ---
setenv :: proc(name: cstring, val: cstring, overwrite: b32) -> i32 ---
unsetenv :: proc(name: cstring) -> i32 ---
}
_lookup_env_alloc :: proc(key: string, allocator: runtime.Allocator) -> (value: string, found: bool) {
if key == "" {
return
}
temp_allocator := TEMP_ALLOCATOR_GUARD({ allocator })
ckey := strings.clone_to_cstring(key, temp_allocator)
cval := getenv(ckey)
if cval == nil {
return
}
found = true
value = strings.clone(string(cval), allocator) // NOTE(laytan): what if allocation fails?
return
}
_lookup_env_buf :: proc(buf: []u8, key: string) -> (value: string, error: Error) {
if key == "" {
return
}
if len(key) + 1 > len(buf) {
return "", .Buffer_Full
} else {
copy(buf, key)
}
cval := getenv(cstring(raw_data(buf)))
if cval == nil {
return
}
if value = string(cval); value == "" {
return "", .Env_Var_Not_Found
} else {
if len(value) > len(buf) {
return "", .Buffer_Full
} else {
copy(buf, value)
return string(buf[:len(value)]), nil
}
}
}
_lookup_env :: proc{_lookup_env_alloc, _lookup_env_buf}
_set_env :: proc(key, value: string) -> (err: Error) {
temp_allocator := TEMP_ALLOCATOR_GUARD({})
ckey := strings.clone_to_cstring(key, temp_allocator) or_return
cval := strings.clone_to_cstring(value, temp_allocator) or_return
if setenv(ckey, cval, true) != 0 {
errno := libc_errno_location()^
err = _get_platform_error(cast(linux.Errno)errno)
//err = _get_platform_error_from_errno()
}
return
}
_unset_env :: proc(key: string) -> (ok: bool) {
temp_allocator := TEMP_ALLOCATOR_GUARD({})
ckey := strings.clone_to_cstring(key, temp_allocator)
ok = unsetenv(ckey) == 0
return
}
_clear_env :: proc() {
for entry := libc_environ[0]; entry != nil; entry = libc_environ[0] {
key := strings.truncate_to_byte(string(entry), '=')
_unset_env(key)
}
}
_environ :: proc(allocator: runtime.Allocator) -> (environ: []string, err: Error) {
n := 0
for entry := libc_environ[0]; entry != nil; n, entry = n+1, libc_environ[n] {}
r := make([dynamic]string, 0, n, allocator) or_return
defer if err != nil {
for e in r {
delete(e, allocator)
}
delete(r)
}
for i, entry := 0, libc_environ[0]; entry != nil; i, entry = i+1, libc_environ[i] {
append(&r, strings.clone(string(entry), allocator) or_return)
}
environ = r[:]
return
}
export_cstring_environment :: proc(allocator: runtime.Allocator) -> []cstring {
env := make([dynamic]cstring, allocator)
for i, entry := 0, libc_environ[0]; entry != nil; i, entry = i+1, libc_environ[i] {
append(&env, entry)
}
append(&env, nil)
return env[:]
}
}
_get_original_env :: #force_inline proc() -> [^]cstring {
// essentially &argv[argc] which should be a nil pointer!
#no_bounds_check env: [^]cstring = &runtime.args__[len(runtime.args__)]
assert(env[0] == nil)
return &env[1]
}
_kv_from_entry :: #force_inline proc(entry: string) -> (k, v: string) {
eq_idx := strings.index_byte(entry, '=')
if eq_idx == -1 {
return entry, ""
}
return entry[:eq_idx], entry[eq_idx + 1:]
}
_kv_addr_from_val :: #force_inline proc(val: string, key: string) -> ([^]u8, [^]u8) {
v_addr := raw_data(val)
k_addr := ([^]u8)(&v_addr[-(len(key) + 1)])
return k_addr, v_addr
}
_is_in_org_env :: #force_inline proc(env_data: string) -> bool {
addr := uintptr(raw_data(env_data))
return addr >= intrinsics.atomic_load_explicit(&_org_env_begin, .Acquire) && addr < _org_env_end
}

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@@ -80,7 +80,7 @@ _unset_env :: proc(key: string) -> (ok: bool) {
// NOTE(laytan): clearing the env is weird, why would you ever do that?
_clear_env :: proc() {
for i, entry := 0, posix.environ[0]; entry != nil; i, entry = i+1, posix.environ[i] {
for entry := libc_environ[0]; entry != nil; entry = libc_environ[0] {
key := strings.truncate_to_byte(string(entry), '=')
_unset_env(key)
}