Standardize error message logging; updates.

crater.c

@@ -48,8 +48,7 @@ static void parse_args(int argc, char *argv[])
             print_version();
             exit(0);
         } else {
-            printf("Error: unknown argument: %s\n", argv[i]);
-            exit(1);
+            FATAL("unknown argument: %s", argv[i])
         }
     }
 }
@@ -65,7 +64,7 @@ static bool ends_with(char *input, char *suffix)
 }
 
 /* Load all potential ROM files in roms/ into a data structure. */
-static int load_rom_paths(char ***path_ptr)
+static int get_rom_paths(char ***path_ptr)
 {
     DIR *dirp;
     struct dirent *entry;
@@ -76,19 +75,19 @@ static int load_rom_paths(char ***path_ptr)
     if (dirp) {
         paths = malloc(sizeof(char*) * psize);
         if (!paths)
-            out_of_memory();
+            OUT_OF_MEMORY()
         while ((entry = readdir(dirp))) {
             path = entry->d_name;
             if (ends_with(path, ".gg") || ends_with(path, ".bin")) {
                 if (npaths >= psize) {
                     paths = realloc(paths, sizeof(char*) * (psize *= 2));
                     if (!paths)
-                        out_of_memory();
+                        OUT_OF_MEMORY()
                 }
                 paths[npaths] = malloc(sizeof(char*) *
                         (strlen(path) + strlen(ROMS_DIR) + 1));
                 if (!paths[npaths])
-                    out_of_memory();
+                    OUT_OF_MEMORY()
                 strcpy(paths[npaths], ROMS_DIR "/");
                 strcat(paths[npaths], path);
                 npaths++;
@@ -96,18 +95,14 @@ static int load_rom_paths(char ***path_ptr)
         }
         closedir(dirp);
     } else {
-        if (errno == ENOENT)
-            printf("Warning: couldn't find roms/ directory.\n");
-        else
-            perror("Warning: couldn't open roms/ directory");
+        WARN_ERRNO("couldn't open 'roms/'")
     }
     *path_ptr = paths;
     return npaths;
 }
 
 /* Find all potential ROM files in the roms/ directory, then ask the user which
- * one they want to run.
- */
+   one they want to run. */
 static char* get_rom_path_from_user()
 {
     char **paths, *path, *input = NULL;
@@ -116,7 +111,7 @@ static char* get_rom_path_from_user()
     size_t size = 0;
     ssize_t len;
 
-    npaths = load_rom_paths(&paths);
+    npaths = get_rom_paths(&paths);
     for (i = 0; i < npaths; i++)
         printf("[%2d] %s\n", i + 1, paths[i]);
     if (npaths)
@@ -126,7 +121,7 @@ static char* get_rom_path_from_user()
 
     len = getline(&input, &size, stdin);
     if (!input)
-        out_of_memory();
+        OUT_OF_MEMORY()
     if (len > 0 && input[len - 1] == '\n')
         input[len - 1] = '\0';
     index = strtol(input, NULL, 10);
@@ -147,14 +142,24 @@ static char* get_rom_path_from_user()
 int main(int argc, char *argv[])
 {
     char *rom_path;
+    rom_type *rom;
 
     parse_args(argc, argv);
+    printf("crater: a Sega Game Gear emulator\n\n");
     rom_path = argc > 1 ? argv[1] : get_rom_path_from_user();
+    if (rom_path[0] == '\0')
+        FATAL("no image given")
 
-    // TODO: main logic hook here
-    printf("Loading ROM: %s\n", rom_path);
-
+    if (!(rom = open_rom(rom_path))) {
+        if (errno == ENOMEM)
+            OUT_OF_MEMORY()
+        else
+            FATAL_ERRNO("couldn't load ROM image '%s'", rom_path)
+    }
+    printf("Loaded ROM image: %s.\n", rom_path);
     if (argc <= 1)
         free(rom_path);
+
+    close_rom(rom);
     return 0;
 }

src/errors.c

@@ -1,13 +0,0 @@
-/* Copyright (C) 2014 Ben Kurtovic <ben.kurtovic@gmail.com>
-   Released under the terms of the MIT License. See LICENSE for details. */
-
-#include <stdio.h>
-#include <stdlib.h>
-
-#include "errors.h"
-
-/* Called after an out-of-memory error. Prints a message and dies. */
-void out_of_memory() {
-    printf("Error: couldn't allocate memory.\n");
-    exit(1);
-}

src/errors.h

@@ -3,4 +3,25 @@
 
 #pragma once
 
-void out_of_memory();
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+/* Internal usage only */
+
+#define LOG_MSG(level, extra, after, ...) {      \
+        fprintf(stderr, level ": " __VA_ARGS__); \
+        extra;                                   \
+        fprintf(stderr, ".\n");                  \
+        after;                                   \
+    }
+#define PRINT_ERRNO() fprintf(stderr, ": %s", strerror(errno))
+
+/* Public error logging macros */
+
+#define FATAL(...)       LOG_MSG("Error",   {},            exit(EXIT_FAILURE), __VA_ARGS__)
+#define FATAL_ERRNO(...) LOG_MSG("Error",   PRINT_ERRNO(), exit(EXIT_FAILURE), __VA_ARGS__)
+#define WARN(...)        LOG_MSG("Warning", {},            {},                 __VA_ARGS__)
+#define WARN_ERRNO(...)  LOG_MSG("Warning", PRINT_ERRNO(), {},                 __VA_ARGS__)
+
+#define OUT_OF_MEMORY() FATAL("couldn't allocate enough memory")

src/rom.c

@@ -1,22 +1,30 @@
 /* Copyright (C) 2014 Ben Kurtovic <ben.kurtovic@gmail.com>
    Released under the terms of the MIT License. See LICENSE for details. */
 
+#include <stdio.h>
 #include <stdlib.h>
 
 #include "rom.h"
-#include "errors.h"
 
-rom_type* load_rom(char *path)
+/* Create and return a ROM object located at the given path. Return NULL if
+   there was an error; errno will be set appropriately. */
+rom_type* open_rom(char *path)
 {
     rom_type *rom;
+    FILE* fp;
+
+    if (!(fp = fopen(path, "r")))
+        return NULL;
+    if (!(rom = malloc(sizeof(rom_type))))
+        return NULL;
+
+    // load data from file into a buffer
 
-    rom = malloc(sizeof(rom_type));
-    if (!rom)
-        out_of_memory();
     return rom;
 }
 
-void unload_rom(rom_type *rom)
+/* Free a ROM object previously created with open_rom(). */
+void close_rom(rom_type *rom)
 {
     free(rom);
 }

src/rom.h

@@ -3,7 +3,14 @@
 
 #pragma once
 
+/* Structs */
+
 typedef struct {
     char* name;
     char* data;
 } rom_type;
+
+/* Functions */
+
+rom_type* open_rom(char*);
+void close_rom(rom_type*);