Re-factor pcre2_dfa_match() to use the heap instead of the stack for workspace

vectors when doing recursive function calls.


git-svn-id: svn://vcs.exim.org/pcre2/code/trunk@932 6239d852-aaf2-0410-a92c-79f79f948069

1 files changed, 8 insertions, 4 deletions

diff --git a/src/config.h.in b/src/config.h.in
index 7a3a861..14b48e9 100644
--- a/src/config.h.in
+++ b/src/config.h.in
@@ -132,8 +132,9 @@ sure both macros are undefined; an emulation function will then be used. */
 /* Define to 1 if you have the <zlib.h> header file. */
 #undef HAVE_ZLIB_H
 
-/* This limits the amount of memory that pcre2_match() may use while matching
-   a pattern. The value is in kilobytes. */
+/* This limits the amount of memory that may be used while matching a pattern.
+   It applies to both pcre2_match() and pcre2_dfa_match(). It does not apply
+   to JIT matching. The value is in kilobytes. */
 #undef HEAP_LIMIT
 
 /* The value of LINK_SIZE determines the number of bytes used to store links
@@ -148,7 +149,8 @@ sure both macros are undefined; an emulation function will then be used. */
 
 /* The value of MATCH_LIMIT determines the default number of times the
    pcre2_match() function can record a backtrack position during a single
-   matching attempt. There is a runtime interface for setting a different
+   matching attempt. The value is also used to limit a loop counter in
+   pcre2_dfa_match(). There is a runtime interface for setting a different
    limit. The limit exists in order to catch runaway regular expressions that
    take for ever to determine that they do not match. The default is set very
    large so that it does not accidentally catch legitimate cases. */
@@ -161,7 +163,9 @@ sure both macros are undefined; an emulation function will then be used. */
    MATCH_LIMIT_DEPTH provides this facility. To have any useful effect, it
    must be less than the value of MATCH_LIMIT. The default is to use the same
    value as MATCH_LIMIT. There is a runtime method for setting a different
-   limit. */
+   limit. In the case of pcre2_dfa_match(), this limit controls the depth of
+   the internal nested function calls that are used for pattern recursions,
+   lookarounds, and atomic groups. */
 #undef MATCH_LIMIT_DEPTH
 
 /* This limit is parameterized just in case anybody ever wants to change it.