commit 3ab2d595610b8c4d6a43423fb2566e272ae534ec
parent ff7b6c1a8eee0760b4dbbe94b5d04ca85d49f943
Author: Ember Sawady <ecs@d2evs.net>
Date: Wed, 7 Jun 2023 05:54:39 +0000
Improve +libc argv/argc/envp initialization
Previously, we had libc run @init, which meant that we couldn't make use
of the argc and argv it passed into rt::start_ha and we needed to do
terrible hacks in rt::start_linux. While we're here, delete the
now-unnecessary os/+linux/environ+libc.ha, which was out of sync with
os/+linux/environ.ha anyways
Signed-off-by: Ember Sawady <ecs@d2evs.net>
Diffstat:
9 files changed, 47 insertions(+), 163 deletions(-)
diff --git a/linux/start+libc.ha b/linux/start+libc.ha
@@ -4,8 +4,6 @@ use rt;
use format::elf;
@init fn init_linux() void = {
- rt::start_linux();
-
let i = 0;
for (rt::envp[i] != null) {
i += 1;
diff --git a/os/+linux/environ+libc.ha b/os/+linux/environ+libc.ha
@@ -1,126 +0,0 @@
-// License: MPL-2.0
-// (c) 2022 Alexey Yerin <yyp@disroot.org>
-use bytes;
-use rt;
-use strings;
-use types::c;
-
-// The command line arguments provided to the program. By convention, the first
-// member is usually the name of the program.
-export let args: []str = [];
-
-// Statically allocate arg strings if there are few enough arguments, saves a
-// syscall if we don't need it.
-let args_static: [32]str = [""...];
-
-@init fn init_environ() void = {
- rt::start_linux();
- if (rt::argc < len(args_static)) {
- args = args_static[..rt::argc];
- for (let i = 0z; i < rt::argc; i += 1) {
- args[i] = c::tostr(rt::argv[i]: *const c::char)!;
- };
- } else {
- args = alloc([], rt::argc);
- for (let i = 0z; i < rt::argc; i += 1) {
- append(args, c::tostr(rt::argv[i]: *const c::char)!);
- };
- };
-
-};
-
-@fini fn fini_environ() void = {
- if (rt::argc >= len(args_static)) {
- free(args);
- };
- free(envp);
-};
-
-// Looks up an environment variable and returns its value, or void if unset.
-export fn getenv(name: const str) (str | void) = {
- const name_b = strings::toutf8(name);
- for (let i = 0z; rt::envp[i] != null; i += 1) {
- const item = rt::envp[i]: *[*]u8;
- const ln = c::strlen(item: *c::char);
- const eq: size = match (bytes::index(item[..ln], '=')) {
- case void =>
- abort("Environment violates System-V invariants");
- case let i: size =>
- yield i;
- };
- if (bytes::equal(name_b, item[..eq])) {
- const ln = c::strlen(item: *const c::char);
- return strings::fromutf8(item[eq+1..ln])!;
- };
- };
-};
-
-// Looks up an environment variable and returns its value, or a default value if
-// unset.
-export fn tryenv(name: const str, default: str) str = match (getenv(name)) {
-case let s: str =>
- yield s;
-case void =>
- yield default;
-};
-
-let envp: []str = [];
-
-// Returns a slice of the environment strings in the form KEY=VALUE.
-export fn getenvs() []str = {
- if (len(envp) != 0) {
- return envp;
- };
- for (let i = 0z; rt::envp[i] != null; i += 1) {
- append(envp, c::tostr(rt::envp[i]: *const c::char)!);
- };
- return envp;
-};
-
-let uts: rt::utsname = rt::utsname { ... };
-let uts_valid: bool = false;
-
-// Returns the host kernel name
-export fn sysname() const str = {
- if (!uts_valid) {
- rt::uname(&uts) as void;
- uts_valid = true;
- };
- return c::tostr(&uts.sysname: *const c::char)!;
-};
-
-// Returns the host system hostname
-export fn hostname() const str = {
- if (!uts_valid) {
- rt::uname(&uts) as void;
- uts_valid = true;
- };
- return c::tostr(&uts.nodename: *const c::char)!;
-};
-
-// Returns the host kernel version
-export fn release() const str = {
- if (!uts_valid) {
- rt::uname(&uts) as void;
- uts_valid = true;
- };
- return c::tostr(&uts.release: *const c::char)!;
-};
-
-// Returns the host operating system version
-export fn version() const str = {
- if (!uts_valid) {
- rt::uname(&uts) as void;
- uts_valid = true;
- };
- return c::tostr(&uts.version: *const c::char)!;
-};
-
-// Returns the host CPU architecture
-export fn machine() const str = {
- if (!uts_valid) {
- rt::uname(&uts) as void;
- uts_valid = true;
- };
- return c::tostr(&uts.machine: *const c::char)!;
-};
diff --git a/rt/+linux/platformstart+libc.ha b/rt/+linux/platformstart+libc.ha
@@ -1,23 +0,0 @@
-// License: MPL-2.0
-// (c) 2021-2022 Alexey Yerin <yyp@disroot.org>
-
-export fn start_linux() void = {
- // Here we use a cool strategy of re-constructing argv and argc without
- // knowing their original values. Since environ is placed just after
- // them, it's possible to traverse backwards calculating how many
- // entries were processed and comparing that value to the one at
- // current position.
- let argv_ptr = c_environ: uintptr - size(*u8): uintptr * 2;
- let i = 0z;
- for (*(argv_ptr: **u8): uintptr: size != i; i += 1) {
- argv_ptr -= size(*u8): uintptr;
- };
-
- argc = i;
- argv = (argv_ptr + size(*u8): uintptr): *[*]*u8;
- envp = c_environ;
-};
-
-@init fn start_linux() void = start_linux();
-
-let @symbol("environ") c_environ: *[*]nullable *u8;
diff --git a/rt/+linux/platformstart.ha b/rt/+linux/platformstart-libc.ha
diff --git a/rt/hare+libc.sc b/rt/hare+libc.sc
@@ -14,10 +14,10 @@ SECTIONS {
*(.rela.plt)
}
- .init_array : {
- PROVIDE_HIDDEN (__init_array_start = .);
+ .libc_init_array : {
+ PROVIDE_HIDDEN (__libc_init_array_start = .);
KEEP (*(.init_array))
- PROVIDE_HIDDEN (__init_array_end = .);
+ PROVIDE_HIDDEN (__libc_init_array_end = .);
}
.fini_array : {
diff --git a/rt/start+libc.ha b/rt/start+libc.ha
@@ -4,10 +4,19 @@
@symbol(".main") fn main() void;
@symbol("exit") fn c_exit(status: int) void;
+const @symbol("__libc_init_array_start") init_start: [*]*fn() void;
+const @symbol("__libc_init_array_end") init_end: [*]*fn() void;
const @symbol("__fini_array_start") fini_start: [*]*fn() void;
const @symbol("__fini_array_end") fini_end: [*]*fn() void;
-export fn init() void = void;
+// Run all global initialization functions.
+export fn init() void = {
+ const ninit = (&init_end: uintptr - &init_start: uintptr): size
+ / size(*fn() void);
+ for (let i = 0z; i < ninit; i += 1) {
+ init_start[i]();
+ };
+};
// Run all global finalization functions.
export fn fini() void = {
@@ -18,8 +27,16 @@ export fn fini() void = {
};
};
-export @symbol("main") @noreturn fn start_ha() void = {
- // libc runs @init and @fini for us (unless rt::exit() is called)
+export @symbol("main") @noreturn fn start_ha(c_argc: int, c_argv: *[*]*u8) void = {
+ argc = c_argc: size;
+ argv = c_argv;
+ envp = c_envp;
+ // we deliberately prevent libc from running @init for us, in order to
+ // be able to initialize argc/argv/envp beforehand. we can still get
+ // away with just using libc for @fini though
+ init();
main();
c_exit(0);
};
+
+let @symbol("environ") c_envp: *[*]nullable *u8;
diff --git a/rt/start+test+libc.ha b/rt/start+test+libc.ha
@@ -3,11 +3,20 @@
@symbol("__test_main") fn test_main() size;
-export fn init() void = void;
-
+const @symbol("__libc_init_array_start") init_start: [*]*fn() void;
+const @symbol("__libc_init_array_end") init_end: [*]*fn() void;
const @symbol("__fini_array_start") fini_start: [*]*fn() void;
const @symbol("__fini_array_end") fini_end: [*]*fn() void;
+// Run all global initialization functions.
+export fn init() void = {
+ const ninit = (&init_end: uintptr - &init_start: uintptr): size
+ / size(*fn() void);
+ for (let i = 0z; i < ninit; i += 1) {
+ init_start[i]();
+ };
+};
+
// Run all global finalization functions.
export fn fini() void = {
const nfini = (&fini_end: uintptr - &fini_start: uintptr): size
@@ -17,7 +26,16 @@ export fn fini() void = {
};
};
-export @symbol("main") fn main() int = {
+export @symbol("main") fn start_ha(c_argc: int, c_argv: *[*]*u8) int = {
+ argc = c_argc: size;
+ argv = c_argv;
+ envp = c_envp;
+ // we deliberately prevent libc from running @init for us, in order to
+ // be able to initialize argc/argv/envp beforehand. we can still get
+ // away with just using libc for @fini though
+ init();
const nfail = test_main();
return if (nfail > 0) 1 else 0;
};
+
+let @symbol("environ") c_envp: *[*]nullable *u8;
diff --git a/scripts/gen-stdlib b/scripts/gen-stdlib
@@ -24,7 +24,7 @@ gensrcs_rt() {
+linux/errno.ha \
+linux/types.ha \
+linux/segmalloc.ha \
- +linux/platformstart.ha \
+ +linux/platformstart-libc.ha \
+linux/prctl.ha \
+linux/'+$(ARCH)'.ha \
+linux/syscallno+'$(ARCH)'.ha \
diff --git a/stdlib.mk b/stdlib.mk
@@ -8,7 +8,7 @@ stdlib_rt_linux_srcs = \
$(STDLIB)/rt/+linux/errno.ha \
$(STDLIB)/rt/+linux/types.ha \
$(STDLIB)/rt/+linux/segmalloc.ha \
- $(STDLIB)/rt/+linux/platformstart.ha \
+ $(STDLIB)/rt/+linux/platformstart-libc.ha \
$(STDLIB)/rt/+linux/prctl.ha \
$(STDLIB)/rt/+linux/+$(ARCH).ha \
$(STDLIB)/rt/+linux/syscallno+$(ARCH).ha \
@@ -2401,7 +2401,7 @@ testlib_rt_linux_srcs = \
$(STDLIB)/rt/+linux/errno.ha \
$(STDLIB)/rt/+linux/types.ha \
$(STDLIB)/rt/+linux/segmalloc.ha \
- $(STDLIB)/rt/+linux/platformstart.ha \
+ $(STDLIB)/rt/+linux/platformstart-libc.ha \
$(STDLIB)/rt/+linux/prctl.ha \
$(STDLIB)/rt/+linux/+$(ARCH).ha \
$(STDLIB)/rt/+linux/syscallno+$(ARCH).ha \
