Add callout_error to pcre2test and stop the fuzzer after 100 callouts.

ChangeLog

@@ -266,6 +266,9 @@ auto_callout".
 pattern with PCRE2_UCP set without PCRE2_UTF if a class required all wide
 characters to match (for example, /[\s[:^ascii:]]/).
 
+40. The callout_error modifier has been added to pcre2test to make it possible 
+to return PCRE2_ERROR_CALLOUT from a callout.
+
 
 Version 10.22 29-July-2016
 --------------------------

doc/pcre2test.1

@@ -1,4 +1,4 @@
-.TH PCRE2TEST 1 "23 December 2016" "PCRE 10.23"
+.TH PCRE2TEST 1 "28 December 2016" "PCRE 10.23"
 .SH NAME
 pcre2test - a program for testing Perl-compatible regular expressions.
 .SH SYNOPSIS
@@ -1040,6 +1040,7 @@ pattern.
       altglobal                  alternative global matching
       callout_capture            show captures at callout time
       callout_data=<n>           set a value to pass via callouts
+      callout_error=<n>[:<m>]    control callout error
       callout_fail=<n>[:<m>]     control callout failure
       callout_none               do not supply a callout function
       copy=<number or name>      copy captured substring
@@ -1133,14 +1134,20 @@ does no capturing); it is ignored, with a warning message, if present.
 .sp
 A callout function is supplied when \fBpcre2test\fP calls the library matching
 functions, unless \fBcallout_none\fP is specified. If \fBcallout_capture\fP is
-set, the current captured groups are output when a callout occurs.
+set, the current captured groups are output when a callout occurs. The default 
+return from the callout function is zero, which allows matching to continue.
 .P
 The \fBcallout_fail\fP modifier can be given one or two numbers. If there is
-only one number, 1 is returned instead of 0 when a callout of that number is
+only one number, 1 is returned instead of 0 (causing matching to backtrack)
-reached. If two numbers are given, 1 is returned when callout <n> is reached
+when a callout of that number is reached. If two numbers (<n>:<m>) are given, 1
-for the <m>th time. Note that callouts with string arguments are always given
+is returned when callout <n> is reached and there have been at least <m>
-the number zero. See "Callouts" below for a description of the output when a
+callouts. The \fBcallout_error\fP modifier is similar, except that 
-callout it taken.
+PCRE2_ERROR_CALLOUT is returned, causing the entire matching process to be 
+aborted. If both these modifiers are set for the same callout number,
+\fBcallout_error\fP takes precedence.
+.P
+Note that callouts with string arguments are always given the number zero. See
+"Callouts" below for a description of the output when a callout it taken.
 .P
 The \fBcallout_data\fP modifier can be given an unsigned or a negative number.
 This is set as the "user data" that is passed to the matching function, and
@@ -1751,6 +1758,6 @@ Cambridge, England.
 .rs
 .sp
 .nf
-Last updated: 23 December 2016
+Last updated: 28 December 2016
 Copyright (c) 1997-2016 University of Cambridge.
 .fi

src/pcre2_fuzzsupport.c

@@ -32,6 +32,17 @@ Written by Philip Hazel, October 2016
    PCRE2_NOTEMPTY_ATSTART|PCRE2_PARTIAL_HARD| \
    PCRE2_PARTIAL_SOFT|PCRE2_NO_JIT)
    
+/* This is the callout function. Its only purpose is to halt matching if there 
+are more than 100 callouts, as one way of stopping too much time being spent on 
+fruitless matches. The callout data is a pointer to the counter. */
+
+static int callout_function(pcre2_callout_block *cb, void *callout_data)
+{
+(void)cb;  /* Avoid unused parameter warning */
+*((uint32_t *)callout_data) += 1;
+return (*((uint32_t *)callout_data) > 100)? PCRE2_ERROR_CALLOUT : 0;
+}
+   
 /* Putting in this apparently unnecessary prototype prevents gcc from giving a 
 "no previous prototype" warning when compiling at high warning level. */ 
 
@@ -77,6 +88,7 @@ likewise do the match with and without the options. */
 
 for (i = 0; i < 2; i++)
   {
+  uint32_t callout_count;
   int errorcode;
   PCRE2_SIZE erroroffset;
   pcre2_code *code;
@@ -147,8 +159,9 @@ for (i = 0; i < 2; i++)
 #endif
         return 0;
         }
-      pcre2_set_match_limit(match_context, 100);
+      (void)pcre2_set_match_limit(match_context, 100);
-      pcre2_set_recursion_limit(match_context, 100); 
+      (void)pcre2_set_recursion_limit(match_context, 100); 
+      (void)pcre2_set_callout(match_context, callout_function, &callout_count); 
       }
 
     /* Match twice, with and without options */
@@ -168,6 +181,7 @@ for (i = 0; i < 2; i++)
         ((match_options & PCRE2_PARTIAL_SOFT) != 0)? ",partial_soft" : "");
 #endif
 
+      callout_count = 0;
       errorcode = pcre2_match(code, (PCRE2_SPTR)data, (PCRE2_SIZE)size, 0,
         match_options, match_data, match_context);
 

src/pcre2test.c

@@ -175,7 +175,7 @@ void vms_setsymbol( char *, char *, int );
 #endif
 #endif
 
-#define CFAIL_UNSET UINT32_MAX  /* Unset value for cfail fields */
+#define CFORE_UNSET UINT32_MAX  /* Unset value for cfail/cerror fields */
 #define DFA_WS_DIMENSION 1000   /* Size of DFA workspace */
 #define DEFAULT_OVECCOUNT 15    /* Default ovector count */
 #define JUNK_OFFSET 0xdeadbeef  /* For initializing ovector */
@@ -495,6 +495,7 @@ typedef struct datctl {    /* Structure for data line modifiers. */
   uint32_t  control;       /* Must be in same position as patctl */
   uint32_t  control2;      /* Must be in same position as patctl */
    uint8_t  replacement[REPLACE_MODSIZE];  /* So must this */
+  uint32_t  cerror[2];
   uint32_t  cfail[2];
    int32_t  callout_data;
    int32_t  copy_numbers[MAXCPYGET];
@@ -549,6 +550,7 @@ static modstruct modlist[] = {
   { "bsr",                        MOD_CTC,  MOD_BSR, 0,                          CO(bsr_convention) },
   { "callout_capture",            MOD_DAT,  MOD_CTL, CTL_CALLOUT_CAPTURE,        DO(control) },
   { "callout_data",               MOD_DAT,  MOD_INS, 0,                          DO(callout_data) },
+  { "callout_error",              MOD_DAT,  MOD_IN2, 0,                          DO(cerror) },
   { "callout_fail",               MOD_DAT,  MOD_IN2, 0,                          DO(cfail) },
   { "callout_info",               MOD_PAT,  MOD_CTL, CTL_CALLOUT_INFO,           PO(control) },
   { "callout_none",               MOD_DAT,  MOD_CTL, CTL_CALLOUT_NONE,           DO(control) },
@@ -5459,8 +5461,17 @@ if (callout_data_ptr != NULL)
     }
   }
 
-return (cb->callout_number != dat_datctl.cfail[0])? 0 :
+callout_count++;
-       (++callout_count >= dat_datctl.cfail[1])? 1 : 0;
+
+if (cb->callout_number == dat_datctl.cerror[0] &&
+    callout_count >= dat_datctl.cerror[1])
+  return PCRE2_ERROR_CALLOUT;
+
+if (cb->callout_number == dat_datctl.cfail[0] &&
+    callout_count >= dat_datctl.cfail[1])
+  return 1;
+
+return 0;
 }
 
 
@@ -6123,7 +6134,9 @@ if ((pat_patctl.control & CTL_POSIX) != 0)
   regmatch_t *pmatch = NULL;
   const char *msg = "** Ignored with POSIX interface:";
 
-  if (dat_datctl.cfail[0] != CFAIL_UNSET || dat_datctl.cfail[1] != CFAIL_UNSET)
+  if (dat_datctl.cerror[0] != CFORE_UNSET || dat_datctl.cerror[1] != CFORE_UNSET)
+    prmsg(&msg, "callout_error");
+  if (dat_datctl.cfail[0] != CFORE_UNSET || dat_datctl.cfail[1] != CFORE_UNSET)
     prmsg(&msg, "callout_fail");
   if (dat_datctl.copy_numbers[0] >= 0 || dat_datctl.copy_names[0] != 0)
     prmsg(&msg, "copy");
@@ -7347,7 +7360,8 @@ memset(&def_datctl, 0, sizeof(datctl));
 def_datctl.oveccount = DEFAULT_OVECCOUNT;
 def_datctl.copy_numbers[0] = -1;
 def_datctl.get_numbers[0] = -1;
-def_datctl.cfail[0] = def_datctl.cfail[1] = CFAIL_UNSET;
+def_datctl.cerror[0] = def_datctl.cerror[1] = CFORE_UNSET;
+def_datctl.cfail[0] = def_datctl.cfail[1] = CFORE_UNSET;
 
 /* Scan command line options. */
 

testdata/testinput2

@@ -1062,8 +1062,8 @@
 
 /(?C0)(abc(?C1))*/I
     abcabcabc
-    abcabc\=callout_fail=1:3
+    abcabc\=callout_fail=1:4
-    abcabcabc\=callout_fail=1:3
+    abcabcabc\=callout_fail=1:4
 
 /(\d{3}(?C))*/I
     123\=callout_capture
@@ -4956,4 +4956,7 @@ a)"xI
 
 /((?(?C'')\Q\E(?!((?(?C'')(?!X=X));=)r*X=X));=)/
 
+/abcd/auto_callout
+    abcd\=callout_error=255:2
+
 # End of testinput2 

testdata/testoutput2

@@ -3550,14 +3550,14 @@ Subject length lower bound = 0
   1 ^        ^    )*
  0: abcabcabc
  1: abc
-    abcabc\=callout_fail=1:3
+    abcabc\=callout_fail=1:4
 --->abcabc
   0 ^          (
   1 ^  ^       )*
   1 ^     ^    )*
  0: abcabc
  1: abc
-    abcabcabc\=callout_fail=1:3
+    abcabcabc\=callout_fail=1:4
 --->abcabcabc
   0 ^             (
   1 ^  ^          )*
@@ -15439,6 +15439,13 @@ Failed: error 128 at offset 11: assertion expected after (?( or (?(?C)
 
 /((?(?C'')\Q\E(?!((?(?C'')(?!X=X));=)r*X=X));=)/
 
+/abcd/auto_callout
+    abcd\=callout_error=255:2
+--->abcd
+ +0 ^        a
+ +1 ^^       b
+Failed: error -37: callout error code
+
 # End of testinput2 
 Error -63: PCRE2_ERROR_BADDATA (unknown error number)
 Error -62: bad serialized data