nqasm: add command line processing

3 files changed, 82 insertions, 18 deletions

diff --git a/common.h b/common.h
new file mode 100644
index 0000000..82a6328
--- /dev/null
+++ b/common.h
@@ -0,0 +1,24 @@
+#ifndef NQ_COMMON_H
+#define NQ_COMMON_H
+
+#include <errno.h>
+#include <stdio.h>
+
+extern const char *progname;
+
+#define ERROR(...) \
+	do { \
+		fprintf(stderr, "%s: ", progname); \
+		fprintf(stderr, __VA_ARGS__); \
+		fprintf(stderr, "\n"); \
+	} while (0)
+
+#define PERROR(str) \
+	do { \
+		int err = errno; \
+		fprintf(stderr, "%s: ", progname); \
+		errno = err; \
+		perror(str); \
+	} while (0)
+
+#endif
diff --git a/nqasm.c b/nqasm.c
index e915bd7..15b3238 100644
--- a/nqasm.c
+++ b/nqasm.c
@@ -1,7 +1,9 @@
 #include <assert.h>
 #include <stdint.h>
 #include <stdio.h>
+#include <unistd.h>
 
+#include "common.h"
 #include "mnemonics.h"
 #include "nqasm.h"
 
@@ -9,6 +11,8 @@
 #include "parser.h"
 #include "vector.h"
 
+const char *progname;
+
 struct label {
 	const char *name;
 	uint16_t addr;
@@ -94,7 +98,7 @@ static long eval_argument(const struct argument *arg, uint16_t pc)
 	}
 }
 
-static void assemble_instruction(const struct instruction *inst, uint16_t pc)
+static void assemble_instruction(FILE *out, const struct instruction *inst, uint16_t pc)
 {
 	const struct mnemonic *mnem = &mnemonics[inst->mnem];
 	uint16_t bits = mnem->bits;
@@ -132,7 +136,7 @@ static void assemble_instruction(const struct instruction *inst, uint16_t pc)
 		bits |= (value & 255) << ops[i].shift;
 	}
 
-	printf("%04x\n", bits);
+	fprintf(out, "%04x\n", bits);
 }
 
 void add_label(const char *name)
@@ -149,8 +153,56 @@ void add_label(const char *name)
 	};
 }
 
+static void usage(void)
+{
+	printf("usage: %s [-o output] [input]\n", progname);
+	printf("       %s -h\n", progname);
+	printf("\n");
+	printf("\t%-16s %s\n", "-h",        "display this help text and exit");
+	printf("\t%-16s %s\n", "-o output", "write output to 'output' (default=stdout)");
+	printf("\t%-16s %s\n", "input",     "read input from 'input' (default=stdin)");
+}
+
 int main(int argc, char **argv)
 {
+	const char *outname = NULL;
+	int error = 0;
+
+	extern int   optind;
+	extern char *optarg;
+
+	progname = argv[0];
+	for (int opt; (opt = getopt(argc, argv, "+ho:")) != -1;) {
+		switch (opt) {
+		case 'h':
+			usage();
+			return 0;
+		case 'o':
+			outname = optarg;
+			break;
+		default:
+			error = 1;
+		}
+	}
+
+	if (optind < argc - 1) {
+		ERROR("Too many input files");
+		return 1;
+	}
+	if (error) return 1;
+
+	FILE *out = stdout;
+
+	if (optind < argc && !(yyin = fopen(argv[optind], "r"))) {
+		PERROR("Error opening input file");
+		return 1;
+	}
+	if (outname && !(out = fopen(outname, "w"))) {
+		PERROR("Error opening output file");
+		fclose(yyin);
+		return 1;
+	}
+
 	labels_init();
 	instrs_init();
 
@@ -159,9 +211,11 @@ int main(int argc, char **argv)
 	vector_sort(&labels->v, cmp_label);
 
 	for (size_t i = 0; i < instrs->v.count; i++) {
-		assemble_instruction(instrs->i + i, 2 * i);
+		assemble_instruction(out, instrs->i + i, 2 * i);
 	}
 
+	fclose(yyin);
+	fclose(out);
 	return 0;
 }
 
diff --git a/nqdasm.c b/nqdasm.c
index f918136..bb26d81 100644
--- a/nqdasm.c
+++ b/nqdasm.c
@@ -5,25 +5,11 @@
 #include <string.h>
 #include <unistd.h>
 
+#include "common.h"
 #include "mnemonics.h"
 
 const char *progname;
 
-#define ERROR(...) \
-	do { \
-		fprintf(stderr, "%s: ", progname); \
-		fprintf(stderr, __VA_ARGS__); \
-		fprintf(stderr, "\n"); \
-	} while (0)
-
-#define PERROR(str) \
-	do { \
-		int err = errno; \
-		fprintf(stderr, "%s: ", progname); \
-		errno = err; \
-		perror(str); \
-	} while (0)
-
 static struct line {
 	int      label;
 	uint16_t value;