lib: Add mlibc

Signed-off-by: Ian Moffett <ian@osmora.org>

1 files changed, 253 insertions, 0 deletions

diff --git a/lib/mlibc/options/glibc/generic/getopt-stubs.cpp b/lib/mlibc/options/glibc/generic/getopt-stubs.cpp
new file mode 100644
index 0000000..d13d4eb
--- /dev/null
+++ b/lib/mlibc/options/glibc/generic/getopt-stubs.cpp
@@ -0,0 +1,253 @@
+#include <assert.h>
+#include <bits/ensure.h>
+#include <getopt.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <frg/optional.hpp>
+#include <mlibc/debug.hpp>
+
+char *optarg;
+int optind = 1;
+int opterr = 1;
+int optopt;
+
+namespace {
+
+int __optpos = 1;
+
+enum GetoptMode {
+	Short,
+	Long,
+	LongOnly,
+};
+
+int getopt_common(int argc, char * const argv[], const char *optstring, const struct option *longopts, int *longindex, enum GetoptMode mode) {
+	auto longopt_consume = [&](const char *arg, char *s, int k, bool colon) -> frg::optional<int> {
+		// Consume the option and its argument.
+		if(longopts[k].has_arg == required_argument) {
+			if(s) {
+				// Consume the long option and its argument.
+				optarg = s + 1;
+				optind++;
+			}else if(argv[optind + 1]) {
+				// Consume the long option.
+				optind++;
+
+				// Consume the option's argument.
+				optarg = argv[optind];
+				optind++;
+			}else{
+				/*	If an error was detected, and the first character of optstring is not a colon,
+					and the external variable opterr is nonzero (which is the default),
+					getopt() prints an error message. */
+				if(!colon && opterr)
+					fprintf(stderr, "--%s requires an argument.\n", arg);
+				/*	If the first character of optstring is a colon (':'), then getopt()
+					returns ':' instead of '?' to indicate a missing option argument. */
+				return colon ? ':' : '?';
+			}
+		}else if(longopts[k].has_arg == optional_argument) {
+			if(s) {
+				// Consume the long option and its argument.
+				optarg = s + 1;
+				optind++;
+			}else{
+				// Consume the long option.
+				optarg = nullptr;
+				optind++;
+			}
+		}else{
+			__ensure(longopts[k].has_arg == no_argument);
+
+			// Consume the long option.
+			optind++;
+		}
+
+		return frg::null_opt;
+	};
+
+	bool colon = optstring[0] == ':';
+	bool stop_at_first_nonarg = (optstring[0] == '+' || getenv("POSIXLY_CORRECT"));
+
+	// glibc extension: Setting optind to zero causes a full reset.
+	// TODO: Should we really reset opterr and the other flags?
+	if(!optind
+#if __MLIBC_BSD_OPTION
+		|| optreset
+#endif //__MLIBC_BSD_OPTION
+		) {
+		optarg = nullptr;
+		optind = 1;
+		opterr = 1;
+		optopt = 0;
+		__optpos = 1;
+#if __MLIBC_BSD_OPTION
+		optreset = 0;
+#endif //__MLIBC_BSD_OPTION
+	}
+
+	auto isOptionArg = [](char *arg){
+		// If the first character of arg '-', and the arg is not exactly
+		// equal to "-" or "--", then the arg is an option argument.
+		return arg[0] == '-' && strcmp(arg, "-") && strcmp(arg, "--");
+	};
+
+	while(optind < argc) {
+		char *arg = argv[optind];
+		if(!isOptionArg(arg)) {
+			if(stop_at_first_nonarg) {
+				return -1;
+			}
+
+			bool further_options = false;
+			int skip = optind;
+
+			for(; skip < argc; ++skip) {
+				if(isOptionArg(argv[skip])) {
+					further_options = true;
+					break;
+				}
+			}
+
+			if(further_options) {
+				optind += skip - optind;
+				continue;
+			} else {
+				optarg = nullptr;
+				return -1;
+			}
+		}
+
+		if(arg[1] == '-') {
+			arg += 2;
+
+			// Determine the end of the option name (vs. the start of the argument).
+			auto s = strchr(arg, '=');
+			size_t n = s ? (s - arg) : strlen(arg);
+
+			int k = -1;
+			for(int i = 0; longopts[i].name; i++) {
+				if(strncmp(arg, longopts[i].name, n) || longopts[i].name[n])
+					continue;
+
+				if(k >= 0) {
+					if(opterr)
+						fprintf(stderr, "Multiple option declaration detected: %s\n", arg);
+					return '?';
+				}
+				k = i;
+			}
+
+			if(k == -1) {
+				if(opterr)
+					fprintf(stderr, "--%s is not a valid option.\n", arg);
+				return '?';
+			}
+
+			if(longindex)
+				*longindex = k;
+
+			if(auto r = longopt_consume(arg, s, k, colon); r)
+				return r.value();
+
+			if(!longopts[k].flag) {
+				return longopts[k].val;
+			}else{
+				*longopts[k].flag = longopts[k].val;
+				return 0;
+			}
+		}else{
+			/* handle short options, i.e. options with only one dash prefixed; e.g. `program -s` */
+			unsigned int i = __optpos;
+			while(true) {
+				if(mode == GetoptMode::LongOnly) {
+					const char *lo_arg = &arg[1];
+					auto s = strchr(lo_arg, '=');
+					size_t n = s ? (s - lo_arg) : strlen(lo_arg);
+					int k = -1;
+
+					for(int longopt = 0; longopts[longopt].name; longopt++) {
+						if(strncmp(lo_arg, longopts[longopt].name, n) || longopts[longopt].name[n])
+							continue;
+
+						if(k >= 0) {
+							if(opterr)
+								fprintf(stderr, "Multiple option declaration detected: %s\n", arg);
+							return '?';
+						}
+
+						k = longopt;
+					}
+
+					if(k != -1) {
+						if(auto r = longopt_consume(lo_arg, s, k, colon); r)
+							return r.value();
+
+						if(!longopts[k].flag) {
+							return longopts[k].val;
+						}else{
+							*longopts[k].flag = longopts[k].val;
+							return 0;
+						}
+					}
+				}
+
+				auto opt = strchr(optstring, arg[i]);
+				if(opt) {
+					if(opt[1] == ':') {
+						bool required = (opt[2] != ':');
+
+						if(arg[i+1]) {
+							optarg = arg + i + 1;
+						} else if(optind + 1 < argc && argv[optind + 1] && (required || argv[optind + 1][0] != '-')) {
+							/* there is an argument to this short option, separated by a space */
+							optarg = argv[optind + 1];
+							optind++;
+							__optpos = 1;
+						} else if(!required) {
+							optarg = nullptr;
+						} else {
+							__optpos = 1;
+							optopt = arg[i];
+							return colon ? ':' : '?';
+						}
+						optind++;
+					} else {
+						if(arg[i+1]) {
+							__optpos++;
+						} else if(arg[i]) {
+							optind++;
+						} else {
+							return -1;
+						}
+					}
+
+					return arg[i];
+				} else {
+					/*	If getopt() does not recognize an option character, it prints an error message to stderr,
+						stores the character in optopt, and returns '?'. The calling program may prevent
+						the error message by setting opterr to 0. */
+					optopt = arg[1];
+					if(opterr)
+						fprintf(stderr, "%s is not a valid option.\n", arg);
+					return '?';
+				}
+			}
+		}
+	}
+	return -1;
+}
+
+}
+
+int getopt_long(int argc, char * const argv[], const char *optstring,
+		const struct option *longopts, int *longindex) {
+	return getopt_common(argc, argv, optstring, longopts, longindex, GetoptMode::Long);
+}
+
+int getopt_long_only(int argc, char * const argv[], const char *optstring,
+		const struct option *longopts, int *longindex) {
+	return getopt_common(argc, argv, optstring, longopts, longindex, GetoptMode::LongOnly);
+}