scc

commit b79a63cfb2cd56d47c30f9e8f219eb5a11350aa8
parent 5bc9511fcaa1b5906607d25c747ab28c1b25b4eb
Author: FRIGN <dev@frign.de>
Date:   Wed, 25 May 2016 10:55:33 +0200

[cc1] Add arg.h and refactor main.c

There are three reasons for this:

1) It greatly simplifies the main() code and makes it more
   maintainable
2) arg.h is awesome. Thanks Christoph!
3) the -I and -D flags only supported one way, the argument
   directly following the flag, e.g.
      -DBEANER
   However, gcc also supports the syntax
      -D BEANER
   Now, one might argue which one is better, but we must face
   the reality that scripts can break if used in the former
   case (and honestly, I see no reason to omit the space).

While at it, I refactored the whole main() function to make it
simpler and more readable.

Diffstat:
A
cc1/arg.h
 | 
65
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
M
cc1/main.c
 | 
85
+++++++++++++++++++++++++++++++++++++------------------------------------------

2 files changed, 105 insertions(+), 45 deletions(-)
diff --git a/cc1/arg.h b/cc1/arg.h
@@ -0,0 +1,65 @@
+/*
+ * Copy me if you can.
+ * by 20h
+ */
+
+#ifndef ARG_H__
+#define ARG_H__
+
+extern char *argv0;
+
+/* use main(int argc, char *argv[]) */
+#define ARGBEGIN	for (argv0 = *argv, argv++, argc--;\
+					argv[0] && argv[0][0] == '-'\
+					&& argv[0][1];\
+					argc--, argv++) {\
+				char argc_;\
+				char **argv_;\
+				int brk_;\
+				if (argv[0][1] == '-' && argv[0][2] == '\0') {\
+					argv++;\
+					argc--;\
+					break;\
+				}\
+				for (brk_ = 0, argv[0]++, argv_ = argv;\
+						argv[0][0] && !brk_;\
+						argv[0]++) {\
+					if (argv_ != argv)\
+						break;\
+					argc_ = argv[0][0];\
+					switch (argc_)
+
+/* Handles obsolete -NUM syntax */
+#define ARGNUM				case '0':\
+					case '1':\
+					case '2':\
+					case '3':\
+					case '4':\
+					case '5':\
+					case '6':\
+					case '7':\
+					case '8':\
+					case '9'
+
+#define ARGEND			}\
+			}
+
+#define ARGC()		argc_
+
+#define ARGNUMF()	(brk_ = 1, estrtonum(argv[0], 0, INT_MAX))
+
+#define EARGF(x)	((argv[0][1] == '\0' && argv[1] == NULL)?\
+				((x), abort(), (char *)0) :\
+				(brk_ = 1, (argv[0][1] != '\0')?\
+					(&argv[0][1]) :\
+					(argc--, argv++, argv[0])))
+
+#define ARGF()		((argv[0][1] == '\0' && argv[1] == NULL)?\
+				(char *)0 :\
+				(brk_ = 1, (argv[0][1] != '\0')?\
+					(&argv[0][1]) :\
+					(argc--, argv++, argv[0])))
+
+#define LNGARG()	&argv[0][0]
+
+#endif
diff --git a/cc1/main.c b/cc1/main.c
@@ -7,12 +7,15 @@
 
 #include "../inc/cc.h"
 #include "arch.h"
+#include "arg.h"
 #include "cc1.h"
 
+char *argv0;
+
 int warnings;
 jmp_buf recover;
 
-static char *output, *arg0;
+static char *output;
 int onlycpp;
 
 static void
@@ -27,61 +30,51 @@ clean(void)
 static void
 usage(void)
 {
-	fprintf(stderr,
-	        "usage: %s [-E] [-Dmacro[=value]] [-Idir] [-w] [-d] [-o output] [input]\n",
-	        arg0);
-	exit(1);
+	die("usage: %s [-E] [-Dmacro[=value]] [-Idir] [-w] [-d] [-o output]"
+	    "          [input]\n", argv0);
 }
 
 int
 main(int argc, char *argv[])
 {
-	char c, *cp;
+	char *base;
 
 	atexit(clean);
 
-	arg0 = (cp = strrchr(*argv, '/')) ? cp+1 : *argv;
-	if (!strcmp(arg0, "cpp"))
+	ARGBEGIN {
+	case 'w':
+		warnings = 1;
+		break;
+	case 'E':
 		onlycpp = 1;
+		break;
+	case 'D':
+		defmacro(EARGF(usage()));
+		break;
+	case 'd':
+		DBGON();
+		break;
+	case 'I':
+		incdir(EARGF(usage()));
+		break;
+	case 'o':
+		output = EARGF(usage());
+		break;
+	default:
+		usage();
+	} ARGEND
 
-	for (;;) {
-	nextiter:
-		--argc, ++argv;
-		if (!*argv || argv[0][0] != '-' || argv[0][1] == '-')
-			break;
-		for (cp = &argv[0][1]; (c = *cp); cp++) {
-			switch (c) {
-			case 'w':
-				warnings = 1;
-				break;
-			case 'E':
-				onlycpp = 1;
-				break;
-			case 'D':
-				defmacro(cp+1);
-				goto nextiter;
-			case 'd':
-				DBGON();
-				break;
-			case 'I':
-				incdir(cp+1);
-				goto nextiter;
-			case 'o':
-				if (!*++argv || argv[0][0] == '-')
-					usage();
-				--argc;
-				output = *argv;
-				break;
-			default:
-				usage();
-			}
-		}
-	}
+	if (argc > 1)
+		usage();
+
+	/* if run as cpp, only run the preprocessor */
+	if (!(base = strrchr(argv0, '/')))
+		base = argv0;
+	if (!strcmp(base, "cpp"))
+		onlycpp = 1;
 
 	if (output && !freopen(output, "w", stdout))
 		die("error opening output: %s", strerror(errno));
-	if (argc > 1)
-		usage();
 
 	icpp();
 	ilex(*argv);
@@ -89,8 +82,10 @@ main(int argc, char *argv[])
 	if (onlycpp) {
 		outcpp();
 	} else {
-		for (next(); yytoken != EOFTOK; decl())
-			/* nothing */;
+		next();
+
+		while (yytoken != EOFTOK)
+			decl();
 	}
 
 	return 0;