From: Wolfgang (Blub) Bumiller <blub@speed.at>
Date: Tue, 2 Oct 2012 15:51:03 +0000 (+0200)
Subject: Cleaner crc implementation
X-Git-Tag: 0.1-rc1~27
X-Git-Url: https://git.xonotic.org/?a=commitdiff_plain;h=5dd8e23dfdcb7056c34f016a4774773405dc9001;p=xonotic%2Fgmqcc.git

Cleaner crc implementation
---

diff --git a/gmqcc.h b/gmqcc.h
index 40f8de0..5e34c94 100644
--- a/gmqcc.h
+++ b/gmqcc.h
@@ -210,8 +210,8 @@ void  util_endianswap    (void *,  int, int);
 size_t util_strtocmd    (const char *, char *, size_t);
 size_t util_strtononcmd (const char *, char *, size_t);
 
-uint16_t util_crc16(const char *, int, const short);
-uint32_t util_crc32(const char *, int, const short);
+uint16_t util_crc16(uint16_t crc, const char *data, size_t len);
+uint32_t util_crc32(uint32_t crc, const char *data, size_t len);
 
 #ifdef NOTRACK
 #    define mem_a(x) malloc(x)
diff --git a/parser.c b/parser.c
index 9740932..d865212 100644
--- a/parser.c
+++ b/parser.c
@@ -2899,14 +2899,20 @@ void parser_cleanup()
     mem_d(parser);
 }
 
-extern const uint16_t util_crc16_table[];
-static uint16_t stream_crc16(uint16_t old, const char *str)
+static uint16_t progdefs_crc_sum(uint16_t old, const char *str)
 {
-    printf("%s", str);
-    while (*str) {
-        old = (old<<8) ^ util_crc16_table[(old >> 8) ^ ((unsigned char)*str)];
-        ++str;
-    }
+    return util_crc16(old, str, strlen(str));
+}
+
+static void progdefs_crc_file(const char *str)
+{
+    /* write to progdefs.h here */
+}
+
+static uint16_t progdefs_crc_both(uint16_t old, const char *str)
+{
+    old = progdefs_crc_sum(old, str);
+    progdefs_crc_file(str);
     return old;
 }
 
@@ -2915,54 +2921,53 @@ static void generate_checksum(parser_t *parser)
     uint16_t crc = 0xFFFF;
     size_t i;
 
-	crc = stream_crc16(crc, "\n/* file generated by qcc, do not modify */\n\ntypedef struct\n{");
-	crc = stream_crc16(crc, "\tint\tpad[28];\n");
+	crc = progdefs_crc_both(crc, "\n/* file generated by qcc, do not modify */\n\ntypedef struct\n{");
+	crc = progdefs_crc_sum(crc, "\tint\tpad[28];\n");
 	/*
-	crc = stream_crc16(crc, "\tint\tpad;\n");
-	crc = stream_crc16(crc, "\tint\tofs_return[3];\n");
-	crc = stream_crc16(crc, "\tint\tofs_parm0[3];\n");
-	crc = stream_crc16(crc, "\tint\tofs_parm1[3];\n");
-	crc = stream_crc16(crc, "\tint\tofs_parm2[3];\n");
-	crc = stream_crc16(crc, "\tint\tofs_parm3[3];\n");
-	crc = stream_crc16(crc, "\tint\tofs_parm4[3];\n");
-	crc = stream_crc16(crc, "\tint\tofs_parm5[3];\n");
-	crc = stream_crc16(crc, "\tint\tofs_parm6[3];\n");
-	crc = stream_crc16(crc, "\tint\tofs_parm7[3];\n");
+	progdefs_crc_file("\tint\tpad;\n");
+	progdefs_crc_file("\tint\tofs_return[3];\n");
+	progdefs_crc_file("\tint\tofs_parm0[3];\n");
+	progdefs_crc_file("\tint\tofs_parm1[3];\n");
+	progdefs_crc_file("\tint\tofs_parm2[3];\n");
+	progdefs_crc_file("\tint\tofs_parm3[3];\n");
+	progdefs_crc_file("\tint\tofs_parm4[3];\n");
+	progdefs_crc_file("\tint\tofs_parm5[3];\n");
+	progdefs_crc_file("\tint\tofs_parm6[3];\n");
+	progdefs_crc_file("\tint\tofs_parm7[3];\n");
 	*/
 	for (i = 0; i < parser->crc_globals; ++i) {
 	    if (!ast_istype(parser->globals[i].var, ast_value))
 	        continue;
 	    switch (parser->globals[i].var->expression.vtype) {
-	        case TYPE_FLOAT:    crc = stream_crc16(crc, "\tfloat\t"); break;
-	        case TYPE_VECTOR:   crc = stream_crc16(crc, "\tvec3_t\t"); break;
-	        case TYPE_STRING:   crc = stream_crc16(crc, "\tstring_t\t"); break;
-	        case TYPE_FUNCTION: crc = stream_crc16(crc, "\tfunc_t\t"); break;
+	        case TYPE_FLOAT:    crc = progdefs_crc_both(crc, "\tfloat\t"); break;
+	        case TYPE_VECTOR:   crc = progdefs_crc_both(crc, "\tvec3_t\t"); break;
+	        case TYPE_STRING:   crc = progdefs_crc_both(crc, "\tstring_t\t"); break;
+	        case TYPE_FUNCTION: crc = progdefs_crc_both(crc, "\tfunc_t\t"); break;
 	        default:
-	            crc = stream_crc16(crc, "\tint\t");
+	            crc = progdefs_crc_both(crc, "\tint\t");
 	            break;
 	    }
-	    crc = stream_crc16(crc, parser->globals[i].name);
-	    crc = stream_crc16(crc, ";\n");
+	    crc = progdefs_crc_both(crc, parser->globals[i].name);
+	    crc = progdefs_crc_both(crc, ";\n");
 	}
-	crc = stream_crc16(crc, "} globalvars_t;\n\ntypedef struct\n{\n");
+	crc = progdefs_crc_both(crc, "} globalvars_t;\n\ntypedef struct\n{\n");
 	for (i = 0; i < parser->crc_fields; ++i) {
 	    if (!ast_istype(parser->fields[i].var, ast_value))
 	        continue;
 	    switch (parser->fields[i].var->expression.next->expression.vtype) {
-	        case TYPE_FLOAT:    crc = stream_crc16(crc, "\tfloat\t"); break;
-	        case TYPE_VECTOR:   crc = stream_crc16(crc, "\tvec3_t\t"); break;
-	        case TYPE_STRING:   crc = stream_crc16(crc, "\tstring_t\t"); break;
-	        case TYPE_FUNCTION: crc = stream_crc16(crc, "\tfunc_t\t"); break;
+	        case TYPE_FLOAT:    crc = progdefs_crc_both(crc, "\tfloat\t"); break;
+	        case TYPE_VECTOR:   crc = progdefs_crc_both(crc, "\tvec3_t\t"); break;
+	        case TYPE_STRING:   crc = progdefs_crc_both(crc, "\tstring_t\t"); break;
+	        case TYPE_FUNCTION: crc = progdefs_crc_both(crc, "\tfunc_t\t"); break;
 	        default:
-	            crc = stream_crc16(crc, "\tint\t");
+	            crc = progdefs_crc_both(crc, "\tint\t");
 	            break;
 	    }
-	    crc = stream_crc16(crc, parser->fields[i].name);
-	    crc = stream_crc16(crc, ";\n");
+	    crc = progdefs_crc_both(crc, parser->fields[i].name);
+	    crc = progdefs_crc_both(crc, ";\n");
 	}
-	crc = stream_crc16(crc, "} entvars_t;\n\n");
+	crc = progdefs_crc_both(crc, "} entvars_t;\n\n");
 
-printf("GOT CRC %u\n", crc);
 	code_crc = crc;
 }
 
diff --git a/util.c b/util.c
index 3186595..e1db03f 100644
--- a/util.c
+++ b/util.c
@@ -285,7 +285,7 @@ static const uint32_t util_crc32_table[] = {
     0x54DE5729, 0x23D967BF, 0xB3667A2E, 0xC4614AB8, 0x5D681B02, 0x2A6F2B94,
     0xB40BBE37, 0xC30C8EA1, 0x5A05DF1B, 0x2D02EF8D
 };
-const uint16_t util_crc16_table[] = {
+static const uint16_t util_crc16_table[] = {
     0x0000,     0x1021,     0x2042,     0x3063,     0x4084,     0x50A5,
     0x60C6,     0x70E7,     0x8108,     0x9129,     0xA14A,     0xB16B,
     0xC18C,     0xD1AD,     0xE1CE,     0xF1EF,     0x1231,     0x0210,
@@ -334,13 +334,14 @@ const uint16_t util_crc16_table[] = {
 /*
  * Implements a CRC function for X worth bits using (uint[X]_t)
  * as type. and util_crc[X]_table.
+ * Streamable QCC compatible CRC functions.
  */
 #define CRC(X) \
-uint##X##_t util_crc##X(const char *k, int len, const short clamp) {  \
-    register uint##X##_t h= (uint##X##_t)0xFFFFFFFF;                  \
+uint##X##_t util_crc##X(uint##X##_t current, const char *k, size_t len) {  \
+    register uint##X##_t h= current;                                  \
     for (; len; --len, ++k)                                           \
-        h = util_crc##X##_table[(h^((unsigned char)*k))&0xFF]^(h>>8); \
-    return (~h)%clamp;                                                \
+        h = util_crc##X##_table[(h>>8)^((unsigned char)*k)]^(h<<8);   \
+    return h;                                                         \
 }
 CRC(32)
 CRC(16)