readtags,refactor: take an action after parsing command line

The original code called findTag or listTags directly in the process
of command line parsing. This change introduces new data structure
named actionSpec. During parsing command line, readtags builds an
actionSpec. After parsing readtags takes an action based on the
actionSpec.

Signed-off-by: Masatake YAMATO <[email protected]>

Author: masatake

extra-cmds/readtags-cmd.c

@@ -46,6 +46,16 @@ struct inputSpec {
 	char *tempFileName;
 };
 
+struct actionSpec {
+	enum {
+		ACTION_NONE,
+		ACTION_FIND = 1 << 0,
+		ACTION_LIST = 1 << 1,
+		ACTION_LIST_PTAGS = 1 << 2,
+	} action;
+	const char *name;			/* for ACTION_FIND */
+};
+
 static const char *ProgramName;
 static int debugMode;
 #ifdef READTAGS_DSL
@@ -696,7 +706,6 @@ static void printVersion(void)
 
 extern int main (int argc, char **argv)
 {
-	int actionSupplied = 0;
 	int i;
 	int ignore_prefix = 0;
 
@@ -706,6 +715,10 @@ extern int main (int argc, char **argv)
 		.tagFileName = "tags",
 		.tempFileName = NULL,
 	};
+	struct actionSpec actionSpec = {
+		.action  = ACTION_NONE,
+		.name = NULL,
+	};
 
 	memset (&printOpts, 0, sizeof (printOpts));
 	memset (&readOpts, 0, sizeof (readOpts));
@@ -732,10 +745,8 @@ extern int main (int argc, char **argv)
 		const char *const arg = argv [i];
 		if (ignore_prefix || arg [0] != '-')
 		{
-			if (canon)
-				canon->ptags = 0;
-			findTag (&inputSpec, arg, &readOpts, &printOpts, canon);
-			actionSupplied = 1;
+			actionSpec.action |= ACTION_FIND;
+			actionSpec.name = arg;
 		}
 		else if (arg [0] == '-' && arg [1] == '\0')
 			ignore_prefix = 1;
@@ -746,13 +757,7 @@ extern int main (int argc, char **argv)
 				debugMode++;
 			else if (strcmp (optname, "list-pseudo-tags") == 0
 					 || strcmp (optname, "with-pseudo-tags") == 0)
-			{
-				if (canon)
-					canon->ptags = 1;
-				listTags (&inputSpec, 1, &printOpts, canon);
-				if (optname[0] == 'l')
-					actionSupplied = 1;
-			}
+				actionSpec.action |= ACTION_LIST_PTAGS;
 			else if (strcmp (optname, "help") == 0)
 				printUsage (stdout, 0);
 #ifdef READTAGS_DSL
@@ -794,12 +799,7 @@ extern int main (int argc, char **argv)
 			else if (strcmp (optname, "prefix-match") == 0)
 				readOpts.matchOpts |= TAG_PARTIALMATCH;
 			else if (strcmp (optname, "list") == 0)
-			{
-				if (canon)
-					canon->ptags = 0;
-				listTags (&inputSpec, 0, &printOpts, canon);
-				actionSupplied = 1;
-			}
+				actionSpec.action |= ACTION_LIST;
 			else if (strcmp (optname, "line-number") == 0)
 				printOpts.lineNumber = 1;
 			else if (strcmp (optname, "tag-file") == 0)
@@ -900,11 +900,7 @@ extern int main (int argc, char **argv)
 					case 'd': debugMode++; break;
 					case 'D':
 					case 'P':
-						if (canon)
-							canon->ptags = 1;
-						listTags (&inputSpec, 1, &printOpts, canon);
-						if (arg  [j] == 'D')
-							actionSupplied = 1;
+						actionSpec.action |= ACTION_LIST_PTAGS;
 						break;
 					case 'h': printUsage (stdout, 0); break;
 #ifdef READTAGS_DSL
@@ -930,10 +926,7 @@ extern int main (int argc, char **argv)
 					case 'i': readOpts.matchOpts |= TAG_IGNORECASE;   break;
 					case 'p': readOpts.matchOpts |= TAG_PARTIALMATCH; break;
 					case 'l':
-						if (canon)
-							canon->ptags = 0;
-						listTags (&inputSpec, 0, &printOpts, canon);
-						actionSupplied = 1;
+						actionSpec.action |= ACTION_LIST;
 						break;
 					case 'n': printOpts.lineNumber = 1; break;
 					case 't':
@@ -995,13 +988,39 @@ extern int main (int argc, char **argv)
 			}
 		}
 	}
-	if (! actionSupplied)
+
+
+	if (actionSpec.action == ACTION_NONE)
 	{
 		fprintf (stderr,
 			"%s: no action specified: specify one of NAME, -l or -D\n",
 			ProgramName);
 		exit (1);
 	}
+
+	if ((actionSpec.action & ACTION_FIND) && (actionSpec.action & ACTION_LIST))
+	{
+		fprintf (stderr,
+				 "%s: choose either an action: finding a tag or listing all\n",
+				 ProgramName);
+		exit (1);
+	}
+
+	if (actionSpec.action & ACTION_LIST_PTAGS)
+	{
+		if (canon)
+			canon->ptags = 1;
+		listTags (&inputSpec, 1, &printOpts, canon);
+		if (canon)
+			canon->ptags = 0;
+	}
+
+	if (actionSpec.action & ACTION_FIND)
+		findTag (&inputSpec, actionSpec.name, &readOpts, &printOpts, canon);
+	else if (actionSpec.action & ACTION_LIST)
+		listTags (&inputSpec, 0, &printOpts, canon);
+
+
 #ifdef READTAGS_DSL
 	if (Qualifier)
 		q_destroy (Qualifier);