Add some basic args parsing so we can test stuff from the CLI

1 files changed, 66 insertions, 23 deletions

diff --git a/cup/main.c b/cup/main.c
index a5bce4b..15460ff 100644
--- a/cup/main.c
+++ b/cup/main.c
@@ -6,34 +6,77 @@
 #include "generator.h"
 #include "unistd.h"
 
+char *filename = NULL;
+char *source = NULL;
+i64 source_len = 0;
+bool dump_ast = false;
+
+#define MAX_STDIN_SOURCE_LEN 2048
+
+void usage(int exit_status)
+{
+    printf("Usage: cup [options] <file>\n");
+    printf("Options:\n");
+    printf("  -c <code>  Code to compile\n");
+    printf("  -h         Show this help\n");
+    printf("  -d         Dump AST to stdout\n");
+    printf("Output file will be named `output.nasm`\n");
+    exit(exit_status);
+}
+
+void parse_args(int argc, char **argv)
+{
+    for (int i = 1; i < argc; i++) {
+        if (strcmp(argv[i], "-c") == 0) {
+            source_len = strlen(argv[i+1]);
+            source = calloc(source_len + 1, 1);
+            strcpy(source, argv[i+1]);
+            i++;
+            filename = "CLI";
+        } else if (strcmp(argv[i], "-h") == 0) {
+            usage(0);
+        } else if (strcmp(argv[i], "-d") == 0) {
+            dump_ast = true;
+        } else if (filename == NULL) {
+            if (strcmp(argv[i], "-") == 0) {
+                filename = "stdin";
+                source = calloc(MAX_STDIN_SOURCE_LEN, 1);
+                source_len = fread(source, 1, MAX_STDIN_SOURCE_LEN, stdin);
+                if (source_len == MAX_STDIN_SOURCE_LEN) {
+                    fprintf(stderr, "Source too long to use through stdin\n");
+                    exit(1);
+                }
+            } else {
+                filename = argv[i];
+                // Read entire file into memory
+                FILE *fp = fopen(filename, "r");
+                fseek(fp, 0, SEEK_END);
+                source_len = ftell(fp);
+                fseek(fp, 0, SEEK_SET);
+                source = malloc(source_len + 1);
+                fread(source, source_len, 1, fp);
+                source[source_len] = 0;
+                fclose(fp);
+            }
+        } else {
+            usage(1);
+        }
+    }
+}
+
 int main(int argc, char**argv) {
-    char *filename = argc > 1 ? argv[1] : "./examples/return-0.cup";
-
-    // Read entoire file into memory
-    FILE *fp = fopen(filename, "r");
-    fseek(fp, 0, SEEK_END);
-    long fsize = ftell(fp);
-    fseek(fp, 0, SEEK_SET);
-    char *source = malloc(fsize + 1);
-    fread(source, fsize, 1, fp);
-    source[fsize] = 0;
-    fclose(fp);
-
-    // Lexer
-    Lexer lexer = Lexer_new(filename, source, fsize);
+    parse_args(argc, argv);
+
+    Lexer lexer = Lexer_new(filename, source, source_len);
     Node *ast = parse_program(&lexer);
-    
-     print_ast(ast);
+
+    if (dump_ast)
+        print_ast(ast);
 
     FILE *f = fopen("output.nasm", "w");
     generate_asm(ast, f);
 
-    // Token token;
-    // while ( (token = Lexer_next(&lexer)).type != TOKEN_EOF) {
-    //     Token_print(stdout, &token);
-    //     printf("\n");
-    // }
-    
+
     free(source);
     return 0;
-}
\ No newline at end of file
+}