Add error code for unsupported jit features (#441)

Co-authored-by: Zoltan Herczeg <hzmester@freemail.hu>

ChangeLog

@@ -72,6 +72,9 @@ The condition could erroneously be treated as true if a branch matched but
 overran the current position. This bug was in the interpreter only; matching 
 with JIT was correct.
 
+12. Add a new error code (PCRE2_ERROR_JIT_UNSUPPORTED) which is yielded
+for unsupported jit features.
+
 
 Version 10.44 07-June-2024
 --------------------------

doc/pcre2_jit_compile.3

@@ -23,11 +23,12 @@ details are given in the
 documentation.
 .P
 The availability of JIT support can be tested by calling
-\fBpcre2_compile_jit()\fP with a NULL first argument and the single option
-PCRE2_JIT_TEST_ALLOC. Such a call returns zero if JIT is available and has a
-working allocator. Otherwise it returns PCRE2_ERROR_NOMEMORY if JIT is
-available but cannot allocate executable memory, or PCRE2_ERROR_NULL if JIT
-support is not compiled.
+\fBpcre2_compile_jit()\fP with a single option PCRE2_JIT_TEST_ALLOC (the
+code argument is ignored, so a NULL value is accepted). Such a call
+returns zero if JIT is available and has a working allocator. Otherwise
+it returns PCRE2_ERROR_NOMEMORY if JIT is available but cannot allocate
+executable memory, or PCRE2_ERROR_JIT_UNSUPPORTED if JIT support is not
+compiled.
 .P
 Otherwise, the first argument must be a pointer that was returned by a
 successful call to \fBpcre2_compile()\fP, and the second must contain one or
@@ -46,7 +47,8 @@ for success, or a negative error code otherwise. In particular,
 PCRE2_ERROR_JIT_BADOPTION is returned if JIT is not supported or if an unknown
 bit is set in \fIoptions\fP. The function can also return PCRE2_ERROR_NOMEMORY
 if JIT is unable to allocate executable memory for the compiler, even if it was
-because of a system security restriction.
+because of a system security restriction. In a few cases, the function may
+return with PCRE2_ERROR_JIT_UNSUPPORTED for unsupported features.
 .P
 There is a complete description of the PCRE2 native API in the
 .\" HREF

doc/pcre2jit.3

@@ -54,11 +54,11 @@ executable memory in which to build its compiled code. The only guarantee from
 be used.
 .P
 As of release 10.45 there is a more informative way to test for JIT support. If
-\fBpcre2_compile_jit()\fP is called with a NULL first argument and the single
-option PCRE2_JIT_TEST_ALLOC, it returns zero if JIT is available and has a
-working allocator. Otherwise it returns PCRE2_ERROR_NOMEMORY if JIT is
-available but cannot allocate executable memory, or PCRE2_ERROR_NULL if JIT
-support is not compiled.
+\fBpcre2_compile_jit()\fP is called with the single option PCRE2_JIT_TEST_ALLOC
+it returns zero if JIT is available and has a working allocator. Otherwise it
+returns PCRE2_ERROR_NOMEMORY if JIT is available but cannot allocate executable
+memory, or PCRE2_ERROR_JIT_UNSUPPORTED if JIT support is not compiled. The
+code argument is ignored, so it can be a NULL value.
 .P
 A simple program does not need to check availability in order to use JIT when
 possible. The API is implemented in a way that falls back to the interpretive

src/pcre2.h.in

@@ -408,6 +408,7 @@ released, the numbers must not be changed. */
 #define PCRE2_ERROR_INTERNAL_DUPMATCH (-65)
 #define PCRE2_ERROR_DFA_UINVALID_UTF  (-66)
 #define PCRE2_ERROR_INVALIDOFFSET     (-67)
+#define PCRE2_ERROR_JIT_UNSUPPORTED   (-68)
 
 
 /* Request types for pcre2_pattern_info() */

src/pcre2_error.c

@@ -276,6 +276,7 @@ static const unsigned char match_error_texts[] =
   "internal error - duplicate substitution match\0"
   "PCRE2_MATCH_INVALID_UTF is not supported for DFA matching\0"
   "INTERNAL ERROR: invalid substring offset\0"
+  "feature is not supported by the JIT compiler\0"
   ;
 
 

src/pcre2_jit_compile.c

@@ -14280,7 +14280,7 @@ common->ovector_start += sizeof(sljit_sw);
 if (!check_opcode_types(common, common->start, ccend))
   {
   SLJIT_FREE(common->optimized_cbracket, allocator_data);
-  return PCRE2_ERROR_NOMEMORY;
+  return PCRE2_ERROR_JIT_UNSUPPORTED;
   }
 
 /* Checking flags and updating ovector_start. */
@@ -14865,15 +14865,19 @@ if (executable_allocator_is_working == -1)
     }
   else executable_allocator_is_working = 0;
   }
+#endif
 
 if (options & PCRE2_JIT_TEST_ALLOC)
   {
   if (options != PCRE2_JIT_TEST_ALLOC)
     return PCRE2_ERROR_JIT_BADOPTION;
 
+#ifdef SUPPORT_JIT
   return executable_allocator_is_working ? 0 : PCRE2_ERROR_NOMEMORY;
-  }
+#else
+  return PCRE2_ERROR_JIT_UNSUPPORTED;
 #endif
+  }
 
 if (code == NULL)
   return PCRE2_ERROR_NULL;

src/pcre2test.c

@@ -8616,7 +8616,7 @@ if (arg != NULL && arg[0] != CHAR_MINUS)
       {
       case 0: break;
       case PCRE2_ERROR_NOMEMORY: yield = 1; break;
-      case PCRE2_ERROR_NULL: yield = 2; break;
+      case PCRE2_ERROR_JIT_UNSUPPORTED: yield = 2; break;
       default: yield = 3; break;
       }
     printf("%d\n", yield);

testdata/testoutput17

@@ -6,11 +6,11 @@
 # JIT does not support this pattern (callout at start of condition).
 
 /(?(?C1)(?=a)a)/I
-JIT compilation was not successful (no more memory)
+JIT compilation was not successful (feature is not supported by the JIT compiler)
 Capture group count = 0
 May match empty string
 Subject length lower bound = 0
-JIT compilation was not successful (no more memory)
+JIT compilation was not successful (feature is not supported by the JIT compiler)
 
 # The following pattern cannot be compiled by JIT.