AMK's revised version of the previous patch.

gvanrossum · gvanrossum · commit dda6696be67b · 1998-05-07T15:32:44.000Z
diff --git a/Modules/pcre-int.h b/Modules/pcre-int.h
@@ -3,7 +3,7 @@
 *************************************************/
 
 
-#define PCRE_VERSION       "1.07 16-Feb-1998"
+#define PCRE_VERSION       "1.09 28-Apr-1998"
 
 
 /* This is a library of functions to support regular expressions whose syntax
@@ -80,11 +80,12 @@ only some permitted at run or study time. */
 #ifdef FOR_PYTHON
 #define PUBLIC_OPTIONS \
   (PCRE_CASELESS|PCRE_EXTENDED|PCRE_ANCHORED|PCRE_MULTILINE| \
-   PCRE_DOTALL|PCRE_DOLLAR_ENDONLY|PCRE_EXTRA|PCRE_LOCALE)
+   PCRE_DOTALL|PCRE_DOLLAR_ENDONLY|PCRE_EXTRA|PCRE_UNGREEDY| \
+   PCRE_LOCALE)
 #else
 #define PUBLIC_OPTIONS \
   (PCRE_CASELESS|PCRE_EXTENDED|PCRE_ANCHORED|PCRE_MULTILINE| \
-   PCRE_DOTALL|PCRE_DOLLAR_ENDONLY|PCRE_EXTRA)
+   PCRE_DOTALL|PCRE_DOLLAR_ENDONLY|PCRE_EXTRA|PCRE_UNGREEDY)
 #endif
 #define PUBLIC_EXEC_OPTIONS \
   (PCRE_CASELESS|PCRE_ANCHORED|PCRE_MULTILINE|PCRE_NOTBOL|PCRE_NOTEOL| \
diff --git a/Modules/pcre.h b/Modules/pcre.h
@@ -34,6 +34,7 @@ extern "C" {
 #define PCRE_EXTRA           0x0040
 #define PCRE_NOTBOL          0x0080
 #define PCRE_NOTEOL          0x0100
+#define PCRE_UNGREEDY        0x0400
 #ifdef FOR_PYTHON
 #define PCRE_LOCALE          0x0200
 #endif
diff --git a/Modules/pypcre.c b/Modules/pypcre.c
@@ -1216,6 +1216,7 @@ compile_branch(int options, int *brackets, uschar **codeptr,
 int repeat_type, op_type;
 int repeat_min, repeat_max;
 int bravalue, length;
+int greedy_default, greedy_non_default;
 register int c;
 register uschar *code = *codeptr;
 const uschar *ptr = *ptrptr;
@@ -1224,6 +1225,11 @@ uschar *previous = NULL;
 uschar class[32];
 uschar *class_flag;  /* Pointer to the single-byte flag for OP_CLASS_L */
 
+/* Set up the default and non-default settings for greediness */
+ 
+greedy_default = ((options & PCRE_UNGREEDY) != 0);
+greedy_non_default = greedy_default ^ 1;
+ 
 /* Switch on next character until the end of the branch */
 
 for (;; ptr++)
@@ -1536,10 +1542,13 @@ for (;; ptr++)
       goto FAILED;
       }
 
-    /* If the next character is '?' this is a minimizing repeat. Advance to the
+    /* If the next character is '?' this is a minimizing repeat, by default,
+    but if PCRE_UNGREEDY is set, it works the other way round. Advance to the
     next character. */
 
-    if (ptr[1] == '?') { repeat_type = 1; ptr++; } else repeat_type = 0;
+    if (ptr[1] == '?')
+      { repeat_type = greedy_non_default; ptr++; }
+    else repeat_type = greedy_default;
 
     /* If the maximum is zero then the minimum must also be zero; Perl allows
     this case, so we do too - by simply omitting the item altogether. */
@@ -1628,14 +1637,20 @@ for (;; ptr++)
         /* If the mininum is 1 and the previous item was a character string,
         we either have to put back the item that got cancelled if the string
         length was 1, or add the character back onto the end of a longer
-        string. For a character type nothing need be done; it will just get put
-        back naturally. */
+        string. For a character type nothing need be done; it will just get
+        put back naturally. Note that the final character is always going to
+        get added below. */
 
         else if (*previous == OP_CHARS)
           {
           if (code == previous) code += 2; else previous[1]++;
           }
 
+        /*  For a single negated character we also have to put back the
+        item that got cancelled. */
+
+        else if (*previous == OP_NOT) code++;
+
         /* If the maximum is unlimited, insert an OP_STAR. */
 
         if (repeat_max < 0)
@@ -2484,7 +2499,7 @@ while ((c = *(++ptr)) != 0)
         ptr += 2;
         break;
         }
-      /* Else fall thourh */
+      /* Else fall through */
 
       /* Else loop setting valid options until ) is met. Anything else is an
       error. */
@@ -2725,14 +2740,15 @@ printf("Length = %d top_bracket = %d top_backref=%d\n",
 
 if (re->options != 0)
   {
-  printf("%s%s%s%s%s%s%s\n",
+  printf("%s%s%s%s%s%s%s%s\n",
     ((re->options & PCRE_ANCHORED) != 0)? "anchored " : "",
     ((re->options & PCRE_CASELESS) != 0)? "caseless " : "",
     ((re->options & PCRE_EXTENDED) != 0)? "extended " : "",
     ((re->options & PCRE_MULTILINE) != 0)? "multiline " : "",
     ((re->options & PCRE_DOTALL) != 0)? "dotall " : "",
     ((re->options & PCRE_DOLLAR_ENDONLY) != 0)? "endonly " : "",
-    ((re->options & PCRE_EXTRA) != 0)? "extra " : "");
+    ((re->options & PCRE_EXTRA) != 0)? "extra " : "",
+    ((re->options & PCRE_UNGREEDY) != 0)? "ungreedy " : "");  
   }
 
 if ((re->options & PCRE_FIRSTSET) != 0)
@@ -3070,7 +3086,7 @@ static int grow_stack(match_data *md)
   if (md->offset_top == NULL || md->eptr == NULL || md->ecode == NULL ||
       md->off_num == NULL || md->r1 == NULL || md->r2 == NULL) 
     {
-      PyErr_SetString(PyExc_MemoryError, "Can't increase failure stack for re operation");
+      PyErr_NoMemory();
       longjmp(md->error_env, 1);
     }
   return 0;
