disable recursion checks in interpreter when fuzzing

Author: addisoncrump

configure.ac

@@ -530,9 +530,14 @@ AM_CONDITIONAL(WITH_UNICODE, test "x$enable_unicode" = "xyes")
 AM_CONDITIONAL(WITH_VALGRIND, test "x$enable_valgrind" = "xyes")
 AM_CONDITIONAL(WITH_FUZZ_SUPPORT, test "x$enable_fuzz_support" = "xyes")
 
-if test "$enable_fuzz_support" = "yes" -a "$enable_pcre2_8" = "no"; then
-  echo "** ERROR: Fuzzer support requires the 8-bit library"
-  exit 1
+if test "$enable_fuzz_support" = "yes"; then
+  if test "$enable_pcre2_8" = "no"; then
+    echo "** ERROR: Fuzzer support requires the 8-bit library"
+    exit 1
+  fi
+  AC_DEFINE([SUPPORT_FUZZ], [], [
+    Define to any value to enable support for fuzzing, which adjusts some
+    behaviours for consistency between JIT and interpreter.])
 fi
 
 # Checks for typedefs, structures, and compiler characteristics.

src/config.h.in

@@ -292,6 +292,10 @@ sure both macros are undefined; an emulation function will then be used. */
    backward compatibility; new code need not use it. */
 #undef STDC_HEADERS
 
+/* Define to any value to enable support for fuzzing, which adjusts some
+   behaviours for consistency between JIT and interpreter. */
+#undef SUPPORT_FUZZ
+
 /* Define to any value to enable support for Just-In-Time compiling. */
 #undef SUPPORT_JIT
 

src/pcre2_match.c

@@ -5441,8 +5441,10 @@ fprintf(stderr, "++ %2ld op=%3d %s\n", Fecode - mb->start_code, *Fecode,
         P = (heapframe *)((char *)N - frame_size);
         if (N->group_frame_type == (GF_RECURSE | number))
           {
+#ifndef SUPPORT_FUZZ
           if (Feptr == P->eptr && mb->last_used_ptr == P->recurse_last_used)
             return PCRE2_ERROR_RECURSELOOP;
+#endif // SUPPORT_FUZZ
           break;
           }
         offset = P->last_group_offset;