Use crates.io posix-regex and support extended regex

.gitmodules

@@ -2,10 +2,6 @@
 	path = openlibm
 	url = https://github.com/JuliaMath/openlibm.git
 	branch = master
-[submodule "posix-regex"]
-	path = posix-regex
-	url = https://gitlab.redox-os.org/redox-os/posix-regex.git
-	branch = master
 [submodule "compiler-builtins"]
 	path = compiler-builtins
 	url = https://gitlab.redox-os.org/redox-os/compiler-builtins.git

Cargo.lock

@@ -373,7 +373,9 @@ checksum = "b4596b6d070b27117e987119b4dac604f3c58cfb0b191112e24771b2faeac1a6"
 
 [[package]]
 name = "posix-regex"
-version = "0.1.2"
+version = "0.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "66df580334caab2f744839ab1be85493d7ec731a92d6cf928008ab0b212bf3bc"
 
 [[package]]
 name = "proc-macro2"

Cargo.toml

@@ -25,7 +25,7 @@ cc = "1"
 [dependencies]
 bitflags = "2"
 cbitset = "0.2"
-posix-regex = { path = "posix-regex", features = ["no_std"] }
+posix-regex = { version = "0.1.4", features = ["no_std"] }
 
 # TODO: For some reason, rand_jitter hasn't been updated to use the latest rand_core
 rand = { version = "0.8", default-features = false, features = ["small_rng"] }

src/header/regex/mod.rs

@@ -46,13 +46,10 @@ pub const REG_BADRPT: c_int = 14;
 #[no_mangle]
 #[linkage = "weak"] // redefined in GIT
 pub unsafe extern "C" fn regcomp(out: *mut regex_t, pat: *const c_char, cflags: c_int) -> c_int {
-    if cflags & REG_EXTENDED == REG_EXTENDED {
-        return REG_ENOSYS;
-    }
-
     let pat = slice::from_raw_parts(pat as *const u8, strlen(pat));
     let res = PosixRegexBuilder::new(pat)
         .with_default_classes()
+        .extended(cflags & REG_EXTENDED == REG_EXTENDED)
         .compile_tokens();
 
     match res {
@@ -92,10 +89,6 @@ pub unsafe extern "C" fn regexec(
     pmatch: *mut regmatch_t,
     eflags: c_int,
 ) -> c_int {
-    if eflags & REG_EXTENDED == REG_EXTENDED {
-        return REG_ENOSYS;
-    }
-
     let regex = &*regex;
 
     // Allow specifying a compiler argument to the executor and viceversa