merge D2 pull #1229

src/link.c

@@ -79,10 +79,6 @@ void writeFilename(OutBuffer *buf, const char *filename)
     writeFilename(buf, filename, strlen(filename));
 }
 
-/*****************************
- * Check to see if the linker error is the lack of _dmain, which means the
- * user failed to specify a main function. Print that error if so.
- */
 #if linux || __APPLE__ || __FreeBSD__ || __OpenBSD__ || __sun
 #define NME_MAX_OFFSET 100
 
@@ -92,32 +88,37 @@ void writeFilename(OutBuffer *buf, const char *filename)
 #define NME_ERROR_MSG "undefined reference to `_Dmain'"
 #endif
 
+/*****************************
+ * As it forwards the linker error message to stderr, checks for the presence
+ * of an error indicating lack of a main function (NME_ERR_MSG).
+ *
+ * Returns:
+ *      1 if there is a no main error
+ *     -1 if there is an IO error
+ *      0 otherwise
+ */
 int findNoMainError(int fd) {
-    FILE *stream;
-    int nmeFound;
-    int ch;
+    FILE *stream = fdopen(fd, "rb");
 
-    stream = fdopen(fd, "rb");
-    nmeFound = 0;
+    if (stream == NULL) return -1;
 
-    if (stream == NULL)
+    int nmeFound = 0;
+    while (true)
     {
-        perror("failed to open pipe");
-        return -1;
-    }
-
-    while (1)
-    {
-        char buffer[NME_MAX_OFFSET+1];
-        size_t buffer_i;
 
         // read into buffer while forwarding
-        buffer_i = 0;
+        char buffer[NME_MAX_OFFSET+1];
+        size_t buffer_i = 0;
+        int ch;
         while (buffer_i < NME_MAX_OFFSET)
         {
             ch = fgetc(stream);
+            if (ferror(stream)) return -1;
             if (ch == EOF) break;
+
             fputc(ch, stderr);
+            if (ferror(stream)) return -1;
+
             if (ch == '\n') break;
             buffer[buffer_i] = ch;
             buffer_i++;
@@ -137,16 +138,22 @@ int findNoMainError(int fd) {
         while (ch != '\n')
         {
             ch = fgetc(stream);
+            if (ferror(stream)) return -1;
             if (ch == EOF) goto Lend;
+
             fputc(ch, stderr);
+            if (ferror(stream)) return -1;
         }
     }
 
     // output the rest
-    while (1) {
-        ch = fgetc(stream);
+    while (true) {
+        int ch = fgetc(stream);
+        if (ferror(stream)) return -1;
         if (ch == EOF) break;
+
         fputc(ch, stderr);
+        if (ferror(stream)) return -1;
     }
 
   Lend:
@@ -671,10 +678,16 @@ int runLINK()
         if (status)
         {
             int nme = findNoMainError(fds[0]);
-            printf("--- errorlevel %d\n", status);
-
-            if (nme)
-                error(0, "no main function specified");
+            if (nme == -1)
+            {
+                perror("Error with the linker pipe");
+                return -1;
+            }
+            else
+            {
+                printf("--- errorlevel %d\n", status);
+                if (nme == 1) error(0, "no main function specified");
+            }
         }
     }
     else if (WIFSIGNALED(status))