From: H. Peter Anvin <hpa@zytor.com>
Date: Sat, 27 Oct 2007 04:38:02 +0000 (-0700)
Subject: readnum(): handle prefix-suffix collision like "0h"
X-Git-Tag: nasm-2.11.05~1820
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=083f0c32e7528e09c92e793f235d40919ca193c1;p=platform%2Fupstream%2Fnasm.git

readnum(): handle prefix-suffix collision like "0h"

Suffixed versions of zero will look like both a prefix and a suffix.
Reject the prefixed version as being too short to decode.
---

diff --git a/nasmlib.c b/nasmlib.c
index ee947c2..a1a1af0 100644
--- a/nasmlib.c
+++ b/nasmlib.c
@@ -220,7 +220,7 @@ int64_t readnum(char *str, bool *error)
 {
     char *r = str, *q;
     int32_t pradix, sradix, radix;
-    int plen, slen;
+    int plen, slen, len;
     uint64_t result, checklimit;
     int digit, last;
     bool warn = false;
@@ -245,6 +245,13 @@ int64_t readnum(char *str, bool *error)
     while (lib_isnumchar(*q))
         q++;                    /* find end of number */
 
+    len = q-r;
+    if (!len) {
+	/* Not numeric */
+	*error = true;
+	return 0;
+    }
+
     /*
      * Handle radix formats:
      *
@@ -255,12 +262,12 @@ int64_t readnum(char *str, bool *error)
     pradix = sradix = 0;
     plen = slen = 0;
 
-    if (*r == '0' && (pradix = radix_letter(r[1])) != 0)
+    if (len > 2 && *r == '0' && (pradix = radix_letter(r[1])) != 0)
 	plen = 2;
-    else if (*r == '$')
+    else if (len > 1 && *r == '$')
 	pradix = 16, plen = 1;
 
-    if ((sradix = radix_letter(q[-1])) != 0)
+    if (len > 1 && (sradix = radix_letter(q[-1])) != 0)
 	slen = 1;
 
     if (pradix > sradix) {
@@ -276,17 +283,6 @@ int64_t readnum(char *str, bool *error)
     }
 
     /*
-     * If this number has been found for us by something other than
-     * the ordinary scanners, then it might be malformed by having
-     * nothing between the prefix and the suffix. Check this case
-     * now.
-     */
-    if (r >= q) {
-        *error = true;
-        return 0;
-    }
-
-    /*
      * `checklimit' must be 2**(32|64) / radix. We can't do that in
      * 32/64-bit arithmetic, which we're (probably) using, so we
      * cheat: since we know that all radices we use are even, we
diff --git a/test/radix.asm b/test/radix.asm
index 2c0afab..d5b6e0e 100644
--- a/test/radix.asm
+++ b/test/radix.asm
@@ -23,6 +23,9 @@
 	dd 1010_0101x		; Hex
 	dd $1010_0101		; Hex
 
+	db 0h			; Zero!
+	db 0x			; Zero!
+	db 0b			; Zero!
 	db 0dh			; Hex
 	db 0bh			; Hex
 	db 0dx			; Hex
@@ -35,7 +38,7 @@
 	;; Floating-point constants
 	;; All of these should output B4A21147
 	dd 3.7282705e+4		; Decimal
-	dd 00003.7282705e+4 	; Decimal
+	dd 00003.7282705e+4	; Decimal
 	dd 0d3.7282705e+4	; Decimal
 	dd 0t3.7282705e+4	; Decimal