feat: cleaned up character lexing

1 files changed, 86 insertions, 47 deletions

diff --git a/sys/cmd/cc/lex.c b/sys/cmd/cc/lex.c
index 20c6f9c..03aba4b 100644
--- a/sys/cmd/cc/lex.c
+++ b/sys/cmd/cc/lex.c
@@ -82,7 +82,7 @@ static uint8 Atoi[256] =
 
 static
 error
-escape(Lexer *lx, int x, int *flag, vlong *val)
+escapechar(Lexer *lx, int x, int islong, int esc, vlong *val)
 {
     int i, u, c;
     vlong l;
@@ -90,14 +90,14 @@ escape(Lexer *lx, int x, int *flag, vlong *val)
     c = getrune(lx);
 
     switch (c) {
+    case '\\':
+        break;
     case EOF: 
         errorat(lx->pos, "EOF in string");
         return 1;
     case '\n':
         errorat(lx->pos, "newline in string");
         return 1;
-    case '\\':
-        break;
     default:
         if (c == x) 
             return 1;
@@ -110,12 +110,11 @@ escape(Lexer *lx, int x, int *flag, vlong *val)
 
 	switch(c) {
 	case 'x':
-		i = 2;
-		*flag = 1;	
+		i = islong ? 4 : 2;
 		goto hex;
 
 	case 'u':
-		i = 4;
+		i = islong ? 8 : 4;
 		u = 1;
 		goto hex;
 
@@ -126,17 +125,17 @@ escape(Lexer *lx, int x, int *flag, vlong *val)
 
 	case '0': case '1': case '2': case '3':
 	case '4': case '5': case '6': case '7':
-		*flag = 1;
+        i = islong ? 4 : 2;
 		goto oct;
 
-	case 'a':  c = '\a'; break;
-	case 'b':  c = '\b'; break;
-	case 'f':  c = '\f'; break;
-	case 'n':  c = '\n'; break;
-	case 'r':  c = '\r'; break;
-	case 't':  c = '\t'; break;
-	case 'v':  c = '\v'; break;
-	case '\\': c = '\\'; break;
+	case 'a': c = '\a'; break;
+	case 'b': c = '\b'; break;
+	case 'f': c = '\f'; break;
+	case 'n': c = '\n'; break;
+	case 'r': c = '\r'; break;
+	case 't': c = '\t'; break;
+	case 'v': c = '\v'; break;
+	case '\\':c = '\\'; break;
 
 	default:
 		if(c != x) errorat(lx->pos, "unknown escape sequence: %c", c);
@@ -160,7 +159,6 @@ hex:
 			l = l*16 + c-'A' + 10;
 			continue;
 		}
-		errorat(lx->pos, "non-hex character in escape sequence: %c", c);
 		ungetbyte(lx);
 		break;
 	}
@@ -169,22 +167,25 @@ hex:
 		l = RuneErr;
 	}
 	*val = l;
+    if (esc) 
+        *val |= RuneMask + 1;
 	return 0;
 
 oct:
 	l = c - '0';
-	for (i = 2; i > 0; i--) {
+	for (; i > 0; i--) {
 		c = getbyte(lx);
 		if (c >= '0' && c <= '7') {
 			l = l*8 + c-'0';
 			continue;
 		}
-		errorat(lx->pos, "non-octal character in escape sequence: %c", c);
 		ungetbyte(lx);
 	}
 	if (l > 255) errorat(lx->pos, "octal escape value > 255: %d", l);
 
 	*val = l;
+    if (esc) 
+        *val |= RuneMask + 1;
 	return 0;
 }
 
@@ -234,7 +235,7 @@ Token
 lex(Lexer *lx)
 {
     int    b, n, f;
-    vlong  v;
+    vlong  v, _;
     uint   u;
     rune   r;
     string s;
@@ -249,10 +250,28 @@ GetByte:
 Dispatch:
     tok.pos.beg = lx->pos;
 
-    if (b >= RuneSelf || isalpha(b) || b == '_')
-        goto TAlpha;
+    if (b >= RuneSelf || b == '_')
+        goto Talpha;
+    if (isalpha(b)) {
+        goto Talpha;
+
+        n = b;
+        b = getbyte(lx);
+        if (b == '\'') {
+            if (escapechar(lx, '\'', 1, 0, &v)) 
+                b = '\'';
+            if (!escapechar(lx, '\'', 1, 0, &_)) {
+                errorat(lx->pos, "missing ' at end of character constant");
+            }
+            tok.kind  = Alit | Vrune;
+            tok.val.r = v;
+            goto Return;
+        }
+        ungetbyte(lx);
+        b = n;
+    }
     if (isdigit(b))
-        goto TNum;
+        goto Tnum;
 
     switch (b) {
     case '\n': 
@@ -263,12 +282,13 @@ Dispatch:
                 lx->pos.line++;
         goto Dispatch;
 
+    Tchar:
     case '\'':
-        if (escape(lx, '\'', &f, &v)) {
+        if (escapechar(lx, '\'', 0, 0, &v)) {
             errorat(lx->pos, "empty literal or escaped ' in char literal");
             v = '\'';
         }
-        if (!escape(lx, '\'', &f, &v)) {
+        if (!escapechar(lx, '\'', 0, 0, &_)) {
             errorat(lx->pos, "missing '");
             ungetbyte(lx);
         }
@@ -279,15 +299,15 @@ Dispatch:
         }
         tok.kind  = Alit | Vchar;
         tok.val.c = v;
-    break;
+        break;
 
     case '"':
         s = str·makecap("", 0, 8);
         for (;;) {
-            if (escape(lx, '"', &f, &v))
+            if (escapechar(lx, '"', 0, 1, &v))
                 break;
 
-            if (v < RuneSelf || f)
+            if (v & (RuneMask + 1))
                 str·appendbyte(&s, v);
             else {
                 r = v;
@@ -301,7 +321,7 @@ Dispatch:
         intern(&tok.val.s);
 
         str·free(s);
-    break;
+        break;
 
     case '.':
         tok.kind = Adot;
@@ -309,7 +329,7 @@ Dispatch:
 
         if (isdigit(b)) {
             // *lx->b++ = b;
-            goto TFlt;
+            goto Tflt;
         } else if (b == '.') {
             b = getbyte(lx);
             if (b != '.') {
@@ -319,7 +339,7 @@ Dispatch:
             }
         }
         ungetbyte(lx);
-    break;
+        break;
 
     case '<':
         tok.kind = Alt;
@@ -336,7 +356,7 @@ Dispatch:
             tok.kind = Alteq;
         else 
             ungetbyte(lx);
-    break;
+        break;
 
     case '>':
         tok.kind = Agt;
@@ -353,7 +373,7 @@ Dispatch:
             tok.kind = Agteq;
         else 
             ungetbyte(lx);
-    break;
+        break;
 
     case '/': 
         tok.kind = Adiv;
@@ -385,7 +405,7 @@ Dispatch:
             goto Dispatch;
         } else 
             ungetbyte(lx);
-    break;
+        break;
 
     case '#':
         if (domacro(lx)) {
@@ -394,7 +414,6 @@ Dispatch:
             return tok;
         }
         goto GetByte;
-    break;
 
     case EOF:
         popio(lx);
@@ -432,7 +451,7 @@ Dispatch:
 
     goto Return;
 
-    TNum:
+    Tnum:
         e = lx->buf + arrlen(lx->buf);
         do {
             if (lx->b >= e) {
@@ -443,12 +462,11 @@ Dispatch:
         } while (b = getbyte(lx), isdigit(b) || b == '_');
         
         if (b == '.' || tolower(b) == 'e')
-            goto TFlt;
-    TInt:
+            goto Tflt;
+    Tint:
         r = b;
         n = 10;
         s = lx->buf;
-        ungetbyte(lx);
         if (*s == '0') {
             b = *++s;
             switch (b) {
@@ -485,18 +503,39 @@ Dispatch:
 
             v = v * n + f;
         }
+
         b = r;
-        tok.kind  = Alit | Vint;
+        tok.kind  = Alit;
         tok.val.i = v;
-        /* TODO: Suffixes!
-        if (tolower(b) == 'u') {
-            tok.kind |= Vusgn;
+
+        if (b == 'u' || b == 'U') {
+            tok.kind |= Vun;
             b = getbyte(lx);
         }
-        */
-    goto Return;
+        if (b == 'l' || b == 'L') {
+            r = getbyte(lx);
+            if (r == 'l' || r == 'L') {
+                if (r != b)
+                    errorat(lx->pos, "mismatched case on long long integer suffix");
+                tok.kind |= Vvlong;
+                r = getbyte(lx);
+            } else 
+                tok.kind |= Vlong;
+
+            if (r == 'u' || r == 'U') {
+                if (tok.kind & Vun)
+                    errorat(lx->pos, "multiple unsigned designators on integer suffix");
+                tok.kind |= Vun;
+                goto Return;
+            }
+            ungetbyte(lx);
+        } else
+            tok.kind |= Vint;
+
+        ungetbyte(lx);
+        goto Return;
 
-    TFlt:
+    Tflt:
         if (b == '.') {
             *lx->b++ = b;
             b = getbyte(lx);
@@ -530,9 +569,9 @@ Dispatch:
         tok.kind  = Alit | Vfloat;
         tok.val.f = d;
 
-    goto Return;
+        goto Return;
 
-    TAlpha:
+    Talpha:
         u = b; 
         s = lx->buf;
         e = lx->buf + arrlen(lx->buf);