Fixed an issue in the backtracking optimization of character repeats …

…in JIT (PCRE2Project#135)
minipli-oss · Jul 14, 2022 · 4851890 · 4851890
1 parent 3e52db5
commit 4851890
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Showing 3 changed files with 14 additions and 10 deletions.
diff --git a/ChangeLog b/ChangeLog
@@ -29,6 +29,9 @@ supported (even though that function would do nothing in that case) at the
 request of a user who doesn't even want to link with pcre_jit_compile.o. Also
 tidied up an untidy #ifdef arrangement in pcre2test.
 
+8. Fixed an issue in the backtracking optimization of character repeats in
+JIT. Furthermore optimize star repetitions, not just plus repetitions.
+
 
 Version 10.40 15-April-2022
 ---------------------------

diff --git a/src/pcre2_jit_compile.c b/src/pcre2_jit_compile.c
@@ -11517,19 +11517,19 @@ if (exact > 1)
     }
   }
 else if (exact == 1)
-  {
   compile_char1_matchingpath(common, type, cc, &backtrack->topbacktracks, TRUE);
 
-  if (early_fail_type == type_fail_range)
-    {
-    OP1(SLJIT_MOV, TMP1, 0, SLJIT_MEM1(SLJIT_SP), early_fail_ptr);
-    OP1(SLJIT_MOV, TMP2, 0, SLJIT_MEM1(SLJIT_SP), early_fail_ptr + (int)sizeof(sljit_sw));
-    OP2(SLJIT_SUB, TMP1, 0, TMP1, 0, TMP2, 0);
-    OP2(SLJIT_SUB, TMP2, 0, STR_PTR, 0, TMP2, 0);
-    add_jump(compiler, &backtrack->topbacktracks, CMP(SLJIT_LESS_EQUAL, TMP2, 0, TMP1, 0));
+if (early_fail_type == type_fail_range)
+  {
+  /* Range end first, followed by range start. */
+  OP1(SLJIT_MOV, TMP1, 0, SLJIT_MEM1(SLJIT_SP), early_fail_ptr);
+  OP1(SLJIT_MOV, TMP2, 0, SLJIT_MEM1(SLJIT_SP), early_fail_ptr + (int)sizeof(sljit_sw));
+  OP2(SLJIT_SUB, TMP1, 0, TMP1, 0, TMP2, 0);
+  OP2(SLJIT_SUB, TMP2, 0, STR_PTR, 0, TMP2, 0);
+  add_jump(compiler, &backtrack->topbacktracks, CMP(SLJIT_LESS_EQUAL, TMP2, 0, TMP1, 0));
 
-    OP1(SLJIT_MOV, SLJIT_MEM1(SLJIT_SP), early_fail_ptr + (int)sizeof(sljit_sw), STR_PTR, 0);
-    }
+  OP1(SLJIT_MOV, SLJIT_MEM1(SLJIT_SP), early_fail_ptr, STR_PTR, 0);
+  OP1(SLJIT_MOV, SLJIT_MEM1(SLJIT_SP), early_fail_ptr + (int)sizeof(sljit_sw), STR_PTR, 0);
   }
 
 switch(opcode)

diff --git a/src/pcre2_jit_test.c b/src/pcre2_jit_test.c
@@ -354,6 +354,7 @@ static struct regression_test_case regression_test_cases[] = {
 	{ MU, A, 0, 0, "_[ab]+_*a", "_aa" },
 	{ MU, A, 0, 0, "#(A+)#\\d+", "#A#A#0" },
 	{ MU, A, 0, 0, "(?P<size>\\d+)m|M", "4M" },
+	{ M, PCRE2_NEWLINE_CRLF, 0, 0, "\\n?.+#", "\n,\n,#" },
 
 	/* Bracket repeats with limit. */
 	{ MU, A, 0, 0, "(?:(ab){2}){5}M", "abababababababababababM" },