1 files changed, 119 insertions, 0 deletions
diff --git a/src/args.c b/src/args.c
new file mode 100644
index 0000000..b31def5
--- /dev/null
+++ b/src/args.c
@@ -0,0 +1,119 @@
+#include <stdio.h>
+#include <string.h>
+#include <stdbool.h>
+
+#include "args.h"
+
+#define HDASS_VERSION "0.1.0"
+
+static bool match_assembler(const char* name, enum Assembler* out)
+{
+	if (strcmp(name, "nasm") == 0)
+	{
+		*out = ASSEMBLER_NASM;
+		return true;
+	}
+	if (strcmp(name, "fasm") == 0)
+	{
+		*out = ASSEMBLER_FASM;
+		return true;
+	}
+	if (strcmp(name, "masm") == 0)
+	{
+		*out = ASSEMBLER_MASM;
+		return true;
+	}
+	return false;
+}
+
+void print_version(void)
+{
+	printf("hdass %s\n", HDASS_VERSION);
+}
+
+void print_usage(const char* program)
+{
+	printf("hachem's dumb assembly super set\n\n");
+	printf("usage: %s <input.hdass> [options]\n\n", program);
+	printf("options:\n");
+	printf("  -o, --output <file>   write output to <file> (default: stdout)\n");
+	printf("  -t, --target <name>   target assembler: nasm, fasm, masm (default: nasm)\n");
+	printf("  -h, --help            print this help and exit\n");
+	printf("  -v, --version         print version and exit\n");
+}
+
+enum ParseResult parse_args(int argc, char** argv, struct Args* args)
+{
+	const char* program = argv[0];
+
+	args->input_path = NULL;
+	args->output_path = NULL;
+	args->target = ASSEMBLER_NASM;
+
+	for (int i = 1; i < argc; i += 1)
+	{
+		const char* arg = argv[i];
+
+		if (strcmp(arg, "-h") == 0 || strcmp(arg, "--help") == 0)
+		{
+			print_usage(program);
+			return PARSE_EXIT;
+		}
+
+		if (strcmp(arg, "-v") == 0 || strcmp(arg, "--version") == 0)
+		{
+			print_version();
+			return PARSE_EXIT;
+		}
+
+		if (strcmp(arg, "-o") == 0 || strcmp(arg, "--output") == 0)
+		{
+			i += 1;
+			if (i >= argc)
+			{
+				fprintf(stderr, "error: '%s' requires an argument\n", arg);
+				return PARSE_ERROR;
+			}
+			args->output_path = argv[i];
+			continue;
+		}
+
+		if (strcmp(arg, "-t") == 0 || strcmp(arg, "--target") == 0)
+		{
+			i += 1;
+			if (i >= argc)
+			{
+				fprintf(stderr, "error: '%s' requires an argument\n", arg);
+				return PARSE_ERROR;
+			}
+			if (!match_assembler(argv[i], &args->target))
+			{
+				fprintf(stderr, "error: unknown target '%s'\n", argv[i]);
+				return PARSE_ERROR;
+			}
+			continue;
+		}
+
+		if (arg[0] == '-')
+		{
+			fprintf(stderr, "error: unknown option '%s'\n", arg);
+			return PARSE_ERROR;
+		}
+
+		if (args->input_path != NULL)
+		{
+			fprintf(stderr, "error: multiple input files given ('%s' and '%s')\n", args->input_path, arg);
+			return PARSE_ERROR;
+		}
+
+		args->input_path = arg;
+	}
+
+	if (args->input_path == NULL)
+	{
+		fprintf(stderr, "error: no input file given\n");
+		return PARSE_ERROR;
+	}
+
+	return PARSE_OK;
+}