make-dissectors: Use g_file_set_contents()

Also add some more errors checks, we only pass valid files to make-dissectors.

Change-Id: I9c068e47f35ee6c3da0112ee9ce905af35030475
Reviewed-on: https://code.wireshark.org/review/24625
Reviewed-by: João Valverde <j@v6e.pt>
Petri-Dish: João Valverde <j@v6e.pt>
Tested-by: Petri Dish Buildbot
Reviewed-by: Anders Broman <a.broman58@gmail.com>

1 files changed, 39 insertions, 25 deletions

diff --git a/epan/dissectors/make-dissectors.c b/epan/dissectors/make-dissectors.c
index ffc35a4366..bca8ce1e38 100644
--- a/epan/dissectors/make-dissectors.c
+++ b/epan/dissectors/make-dissectors.c
@@ -16,6 +16,7 @@
 #include <wsutil/glib-compat.h>
 
 #define ARRAY_RESERVED_SIZE     2048
+#define STRING_RESERVED_SIZE    (300 * 1024)
 
 #ifdef _WIN32
   #define SEP   "\r\n"
@@ -50,21 +51,27 @@ static void
 scan_file(const char *file, GPtrArray *protos, GPtrArray *handoffs)
 {
     char *contents;
+    GError *err = NULL;
 
-    if (!g_file_get_contents(file, &contents, NULL, NULL))
-        return;
+    if (!g_file_get_contents(file, &contents, NULL, &err)) {
+        fprintf(stderr, "%s: %s\n", file, err->message);
+        exit(1);
+    }
     scan_matches(protos_regex, contents, protos);
     scan_matches(handoffs_regex, contents, handoffs);
     g_free(contents);
 }
 
 static void
-scan_list(const char *list, GPtrArray *protos, GPtrArray *handoffs)
+scan_list(const char *file, GPtrArray *protos, GPtrArray *handoffs)
 {
     char *contents, *arg;
+    GError *err = NULL;
 
-    if (!g_file_get_contents(list, &contents, NULL, NULL))
-        return;
+    if (!g_file_get_contents(file, &contents, NULL, NULL)) {
+        fprintf(stderr, "%s: %s\n", file, err->message);
+        exit(1);
+    }
     for (arg = strtok(contents, SEP); arg != NULL; arg = strtok(NULL, SEP)) {
         scan_file(arg, protos, handoffs);
     }
@@ -76,7 +83,9 @@ int main(int argc, char **argv)
     GPtrArray *protos = NULL, *handoffs = NULL;
     GError *err = NULL;
     guint i;
-    FILE *out;
+    GString *s;
+    const char *outfile;
+    guint count_protos, count_handoffs;
 
     if (argc < 3) {
         fprintf(stderr, "Usage: %s <outfile> <infiles...>\n", argv[0]);
@@ -99,6 +108,7 @@ int main(int argc, char **argv)
         exit(1);
     }
 
+    outfile = argv[1];
     for (int arg = 2; arg < argc; arg++) {
         if (argv[arg][0] == '@') {
             scan_list(&argv[arg][1], protos, handoffs);
@@ -113,16 +123,12 @@ int main(int argc, char **argv)
         exit(1);
     }
 
-    out = fopen(argv[1], "w");
-    if (out == NULL) {
-        fprintf(stderr, "Error opening file: %s: %s\n", argv[1], strerror(errno));
-        exit(1);
-    }
-
     g_ptr_array_sort(protos, compare_symbols);
     g_ptr_array_sort(handoffs, compare_symbols);
 
-    fprintf(out,
+    s = g_string_sized_new(STRING_RESERVED_SIZE);
+
+    g_string_append(s,
            "/*\n"
            " * Do not modify this file. Changes will be overwritten.\n"
            " *\n"
@@ -130,52 +136,60 @@ int main(int argc, char **argv)
            " * \"make-dissectors\".\n"
            " */\n"
            "\n"
-           "#include <ws_symbol_export.h>\n"
            "#include <dissectors.h>\n"
            "\n");
 
-    fprintf(out,
+    g_string_append_printf(s,
            "const gulong dissector_reg_proto_count = %d;\n"
            "const gulong dissector_reg_handoff_count = %d;\n"
            "\n",
             protos->len, handoffs->len);
 
     for (i = 0; i < protos->len; i++) {
-        fprintf(out, "void %s(void);\n", (char *)protos->pdata[i]);
+        g_string_append_printf(s, "void %s(void);\n", (char *)protos->pdata[i]);
     }
-    fprintf(out,
+    g_string_append(s,
            "\n"
            "dissector_reg_t dissector_reg_proto[] = {\n");
     for (i = 0; i < protos->len; i++) {
-        fprintf(out, "    { \"%s\", %s },\n", (char *)protos->pdata[i], (char *)protos->pdata[i]);
+        g_string_append_printf(s, "    { \"%s\", %s },\n", (char *)protos->pdata[i], (char *)protos->pdata[i]);
     }
-    fprintf(out,
+    g_string_append(s,
            "    { NULL, NULL }\n"
            "};\n"
            "\n");
 
     for (i = 0; i < handoffs->len; i++) {
-        fprintf(out, "void %s(void);\n", (char *)handoffs->pdata[i]);
+        g_string_append_printf(s, "void %s(void);\n", (char *)handoffs->pdata[i]);
     }
-    fprintf(out,
+    g_string_append(s,
            "\n"
            "dissector_reg_t dissector_reg_handoff[] = {\n");
     for (i = 0; i < handoffs->len; i++) {
-        fprintf(out, "    { \"%s\", %s },\n", (char *)handoffs->pdata[i], (char *)handoffs->pdata[i]);
+        g_string_append_printf(s, "    { \"%s\", %s },\n", (char *)handoffs->pdata[i], (char *)handoffs->pdata[i]);
     }
-    fprintf(out,
+    g_string_append(s,
            "    { NULL, NULL }\n"
            "};\n");
 
-    fclose(out);
+    if (!g_file_set_contents(outfile, s->str, s->len, &err)) {
+        fprintf(stderr, "%s: %s\n", outfile, err->message);
+        exit(1);
+    }
+
+    count_protos = protos->len;
+    count_handoffs = handoffs->len;
 
-    printf("Found %u registrations and %u handoffs.\n", protos->len, handoffs->len);
+    g_string_free(s, TRUE);
 
     g_regex_unref(protos_regex);
     g_regex_unref(handoffs_regex);
 
     g_ptr_array_free(protos, TRUE);
     g_ptr_array_free(handoffs, TRUE);
+
+    printf("Found %u registrations and %u handoffs.\n",
+                count_protos, count_handoffs);
 }
 
 /*