New versions straight from Jeffrey Ollie's web site
diff --git a/Modules/regexpr.c b/Modules/regexpr.c
index 87f747f..0b6ec8b 100644
--- a/Modules/regexpr.c
+++ b/Modules/regexpr.c
@@ -1,3 +1,7 @@
+/*
+ * -*- mode: c-mode; c-file-style: python -*-
+ */
+
/* regexpr.c
*
* Author: Tatu Ylonen <ylo@ngs.fi>
@@ -57,6 +61,12 @@
#endif /* __STDC__ */
#endif /* THINK_C */
+/* The original code blithely assumed that sizeof(short) == 2. Not
+ * always true. Original instances of "(short)x" were replaced by
+ * SHORT(x), where SHORT is #defined below. */
+
+#define SHORT(x) ((x) & 0x8000 ? (x) - 0x10000 : (x))
+
/* The stack implementation is taken from an idea by Andrew Kuchling.
* It's a doubly linked list of arrays. The advantages of this over a
* simple linked list are that the number of mallocs required are
@@ -75,27 +85,27 @@
typedef union item_t
{
- struct
- {
- int num;
- int level;
- char *start;
- char *end;
- } reg;
- struct
- {
- int count;
- int level;
- int phantom;
- char *code;
- char *text;
- } fail;
- struct
- {
- int num;
- int level;
- int count;
- } cntr;
+ struct
+ {
+ int num;
+ int level;
+ char *start;
+ char *end;
+ } reg;
+ struct
+ {
+ int count;
+ int level;
+ int phantom;
+ char *code;
+ char *text;
+ } fail;
+ struct
+ {
+ int num;
+ int level;
+ int count;
+ } cntr;
} item_t;
#define STACK_PAGE_SIZE 256
@@ -105,43 +115,98 @@
typedef struct item_page_t
{
- item_t items[STACK_PAGE_SIZE];
- struct item_page_t *prev;
- struct item_page_t *next;
+ item_t items[STACK_PAGE_SIZE];
+ struct item_page_t *prev;
+ struct item_page_t *next;
} item_page_t;
typedef struct match_state
{
- /* Structure to encapsulate the stack. */
- struct
- {
- /* index into the curent page. If index == 0 and you need
- * to pop and item, move to the previous page and set
- * index = STACK_PAGE_SIZE - 1. Otherwise decrement index
- * to push a page. If index == STACK_PAGE_SIZE and you
- * need to push a page move to the next page and set index
- * = 0. If there is no new next page, allocate a new page
- * and link it in. Otherwise, increment index to push a
- * page. */
- int index;
- item_page_t *current; /* Pointer to the current page. */
- item_page_t first; /* First page is statically allocated. */
- } stack;
- char *start[NUM_REGISTERS];
- char *end[NUM_REGISTERS];
+ /* The number of registers that have been pushed onto the stack
+ * since the last failure point. */
- int changed[NUM_REGISTERS];
- /* The number of registers that have been pushed onto the stack
- * since the last failure point. */
- int count;
- /* Used to control when registers need to be pushed onto the
- * stack. */
- int level;
- /* The number of failure points on the stack. */
- int point;
+ int count;
+
+ /* Used to control when registers need to be pushed onto the
+ * stack. */
+
+ int level;
+
+ /* The number of failure points on the stack. */
+
+ int point;
+
+ /* Storage for the registers. Each register consists of two
+ * pointers to characters. So register N is represented as
+ * start[N] and end[N]. The pointers must be converted to
+ * offsets from the beginning of the string before returning the
+ * registers to the calling program. */
+
+ char *start[NUM_REGISTERS];
+ char *end[NUM_REGISTERS];
+
+ /* Keeps track of whether a register has changed recently. */
+
+ int changed[NUM_REGISTERS];
+
+ /* Structure to encapsulate the stack. */
+ struct
+ {
+ /* index into the curent page. If index == 0 and you need
+ * to pop an item, move to the previous page and set index
+ * = STACK_PAGE_SIZE - 1. Otherwise decrement index to
+ * push a page. If index == STACK_PAGE_SIZE and you need
+ * to push a page move to the next page and set index =
+ * 0. If there is no new next page, allocate a new page
+ * and link it in. Otherwise, increment index to push a
+ * page. */
+
+ int index;
+ item_page_t *current; /* Pointer to the current page. */
+ item_page_t first; /* First page is statically allocated. */
+ } stack;
} match_state;
+/* Initialize a state object */
+
+/* #define NEW_STATE(state) \ */
+/* memset(&state, 0, (void *)(&state.stack) - (void *)(&state)); \ */
+/* state.stack.current = &state.stack.first; \ */
+/* state.stack.first.prev = NULL; \ */
+/* state.stack.first.next = NULL; \ */
+/* state.stack.index = 0; \ */
+/* state.level = 1 */
+
+#define NEW_STATE(state, nregs) \
+{ \
+ int i; \
+ for (i = 0; i < nregs; i++) \
+ { \
+ state.start[i] = NULL; \
+ state.end[i] = NULL; \
+ state.changed[i] = 0; \
+ } \
+ state.stack.current = &state.stack.first; \
+ state.stack.first.prev = NULL; \
+ state.stack.first.next = NULL; \
+ state.stack.index = 0; \
+ state.level = 1; \
+ state.count = 0; \
+ state.level = 0; \
+ state.point = 0; \
+}
+
+/* Free any memory that might have been malloc'd */
+
+#define FREE_STATE(state) \
+while(state.stack.first.next != NULL) \
+{ \
+ state.stack.current = state.stack.first.next; \
+ state.stack.first.next = state.stack.current->next; \
+ free(state.stack.current); \
+}
+
/* Discard the top 'count' stack items. */
#define STACK_DISCARD(stack, count, on_error) \
@@ -226,24 +291,6 @@
#define STACK_EMPTY(stack) ((stack.index == 0) && \
(stack.current->prev == NULL))
-
-/* Initialize a state object */
-
-#define NEW_STATE(state) \
-memset(&state, 0, sizeof(match_state)); \
-state.stack.current = &state.stack.first; \
-state.level = 1
-
-/* Free any memory that might have been malloc'd */
-
-#define FREE_STATE(state) \
-while(state.stack.first.next != NULL) \
-{ \
- state.stack.current = state.stack.first.next; \
- state.stack.first.next = state.stack.current->next; \
- free(state.stack.current); \
-}
-
/* Return the start of register 'reg' */
#define GET_REG_START(state, reg) (state.start[reg])
@@ -302,22 +349,6 @@
/* Update the last failure point with a new position in the text. */
-/* #define UPDATE_FAILURE(state, xtext, on_error) \ */
-/* { \ */
-/* item_t *item; \ */
-/* STACK_DISCARD(state.stack, state.count, on_error); \ */
-/* STACK_TOP(state.stack, item, on_error); \ */
-/* item->fail.text = xtext; \ */
-/* state.count = 0; \ */
-/* } */
-
-/* #define UPDATE_FAILURE(state, xtext, on_error) \ */
-/* { \ */
-/* item_t *item; \ */
-/* STACK_BACK(state.stack, item, state.count + 1, on_error); \ */
-/* item->fail.text = xtext; \ */
-/* } */
-
#define UPDATE_FAILURE(state, xtext, on_error) \
{ \
item_t *item; \
@@ -391,7 +422,8 @@
Cwordbound, /* match if at word boundary */
Cnotwordbound, /* match if not at word boundary */
Csyntaxspec, /* matches syntax code (1 byte follows) */
- Cnotsyntaxspec /* matches if syntax code does not match (1 byte foll)*/
+ Cnotsyntaxspec, /* matches if syntax code does not match (1 byte foll)*/
+ Crepeat1
};
enum regexp_syntax_op /* syntax codes for plain and quoted characters */
@@ -581,6 +613,8 @@
case Cwordbound:
case Cnotwordbound:
{
+ for (a = 0; a < 256; a++)
+ fastmap[a] = 1;
break;
}
case Csyntaxspec:
@@ -648,7 +682,7 @@
{
a = (unsigned char)code[pos++];
a |= (unsigned char)code[pos++] << 8;
- pos += (int)(short)a;
+ pos += (int)SHORT(a);
if (visited[pos])
{
/* argh... the regexp contains empty loops. This is not
@@ -664,10 +698,15 @@
{
a = (unsigned char)code[pos++];
a |= (unsigned char)code[pos++] << 8;
- a = pos + (int)(short)a;
+ a = pos + (int)SHORT(a);
re_compile_fastmap_aux(code, a, visited, can_be_null, fastmap);
break;
}
+ case Crepeat1:
+ {
+ pos += 2;
+ break;
+ }
default:
{
abort(); /* probably some opcode is missing from this switch */
@@ -754,10 +793,11 @@
char ch;
int a;
int b;
+ int num_instructions = 0;
a = (unsigned char)*code++;
a |= (unsigned char)*code++ << 8;
- a = (int)(short)a;
+ a = (int)SHORT(a);
p1 = code + a + 3; /* skip the failure_jump */
assert(p1[-3] == Cfailure_jump);
@@ -775,6 +815,7 @@
/* loop until we find something that consumes a character */
loop_p1:
+ num_instructions++;
switch (*p1++)
{
case Cbol:
@@ -824,6 +865,7 @@
/* now we know that we can't backtrack. */
while (p1 != p2 - 3)
{
+ num_instructions++;
switch (*p1++)
{
case Cend:
@@ -873,11 +915,22 @@
}
}
+ make_update_jump:
code -= 3;
a += 3; /* jump to after the Cfailure_jump */
code[0] = Cupdate_failure_jump;
code[1] = a & 0xff;
code[2] = a >> 8;
+ if (num_instructions > 1)
+ return 1;
+ assert(num_instructions == 1);
+ /* if the only instruction matches a single character, we can do
+ * better
+ */
+ p1 = code + 3 + a; /* start of sole instruction */
+ if (*p1 == Cset || *p1 == Cexact || *p1 == Canychar ||
+ *p1 == Csyntaxspec || *p1 == Cnotsyntaxspec)
+ code[0] = Crepeat1;
return 1;
make_normal_jump:
@@ -939,6 +992,7 @@
case Cjump:
case Cdummy_failure_jump:
case Cfailure_jump:
+ case Crepeat1:
{
code += 2;
break;
@@ -1111,7 +1165,8 @@
re_compile_initialize();
bufp->used = 0;
bufp->fastmap_accurate = 0;
- bufp->uses_registers = 0;
+ bufp->uses_registers = 1;
+ bufp->num_registers = 1;
translate = bufp->translate;
pattern = bufp->buffer;
alloc = bufp->allocated;
@@ -1289,6 +1344,7 @@
STORE(Cstart_memory);
STORE(next_register);
open_registers[num_open_registers++] = next_register;
+ bufp->num_registers++;
next_register++;
}
paren_depth++;
@@ -1545,27 +1601,8 @@
code = bufp->buffer;
translate = bufp->translate;
-/* translated = NULL; */
-/* if (bufp->translate) */
-/* { */
-/* char *t1; */
-/* char *t2; */
-
-/* translated = malloc(size); */
-/* if (translated == NULL) */
-/* goto error; */
-
-/* t1 = string; */
-/* t2 = translated; */
-/* while(t1 < textend) */
-/* *t2++ = bufp->translate[*t1++]; */
-
-/* text = translated + pos; */
-/* textstart = translated; */
-/* textend = translated + size; */
-/* } */
- NEW_STATE(state);
+ NEW_STATE(state, bufp->num_registers);
continue_matching:
switch (*code++)
@@ -1587,7 +1624,7 @@
}
else
{
- for (a = 1; a < RE_NREGS; a++)
+ for (a = 1; a < bufp->num_registers; a++)
{
if ((GET_REG_START(state, a) == NULL) ||
(GET_REG_END(state, a) == NULL))
@@ -1599,10 +1636,13 @@
old_regs->start[a] = GET_REG_START(state, a) - textstart;
old_regs->end[a] = GET_REG_END(state, a) - textstart;
}
+ for (; a < RE_NREGS; a++)
+ {
+ old_regs->start[a] = -1;
+ old_regs->end[a] = -1;
+ }
}
}
-/* if(translated) */
-/* free(translated); */
FREE_STATE(state);
return match_end - pos;
}
@@ -1703,18 +1743,18 @@
{
a = (unsigned char)*code++;
a |= (unsigned char)*code++ << 8;
- code += (int)(short)a;
+ code += (int)SHORT(a);
goto continue_matching;
}
case Cdummy_failure_jump:
{
a = (unsigned char)*code++;
a |= (unsigned char)*code++ << 8;
- a = (int)(short)a;
+ a = (int)SHORT(a);
assert(*code == Cfailure_jump);
b = (unsigned char)code[1];
b |= (unsigned char)code[2] << 8;
- PUSH_FAILURE(state, code + (int)(short)b + 3, NULL, goto error);
+ PUSH_FAILURE(state, code + (int)SHORT(b) + 3, NULL, goto error);
code += a;
goto continue_matching;
}
@@ -1722,10 +1762,120 @@
{
a = (unsigned char)*code++;
a |= (unsigned char)*code++ << 8;
- a = (int)(short)a;
+ a = (int)SHORT(a);
PUSH_FAILURE(state, code + a, text, goto error);
goto continue_matching;
}
+ case Crepeat1:
+ {
+ char *pinst;
+ a = (unsigned char)*code++;
+ a |= (unsigned char)*code++ << 8;
+ a = (int)SHORT(a);
+ pinst = code + a;
+ /* pinst is sole instruction in loop, and it matches a
+ * single character. Since Crepeat1 was originally a
+ * Cupdate_failure_jump, we also know that backtracking is
+ * useless: so long as the single-character expression matches,
+ * it must be used. Also, in the case of +, we've already
+ * matched one character, so + can't fail: nothing here can
+ * cause a failure.
+ */
+ switch (*pinst++)
+ {
+ case Cset:
+ {
+ if (translate)
+ {
+ while (text < textend)
+ {
+ ch = translate[(unsigned char)*text];
+ if (pinst[ch/8] & (1<<(ch & 7)))
+ text++;
+ else
+ break;
+ }
+ }
+ else
+ {
+ while (text < textend)
+ {
+ ch = (unsigned char)*text;
+ if (pinst[ch/8] & (1<<(ch & 7)))
+ text++;
+ else
+ break;
+ }
+ }
+ break;
+ }
+ case Cexact:
+ {
+ ch = (unsigned char)*pinst;
+ if (translate)
+ {
+ while (text < textend &&
+ translate[(unsigned char)*text] == ch)
+ text++;
+ }
+ else
+ {
+ while (text < textend && (unsigned char)*text == ch)
+ text++;
+ }
+ break;
+ }
+ case Canychar:
+ {
+ while (text < textend && (unsigned char)*text != '\n')
+ text++;
+ break;
+ }
+ case Csyntaxspec:
+ {
+ a = (unsigned char)*pinst;
+ if (translate)
+ {
+ while (text < textend &&
+ translate[SYNTAX(*text)] == a)
+ text++;
+ }
+ else
+ {
+ while (text < textend && SYNTAX(*text) == a)
+ text++;
+ }
+ break;
+ }
+ case Cnotsyntaxspec:
+ {
+ a = (unsigned char)*pinst;
+ if (translate)
+ {
+ while (text < textend &&
+ translate[SYNTAX(*text)] != a)
+ text++;
+ }
+ else
+ {
+ while (text < textend && SYNTAX(*text) != a)
+ text++;
+ }
+ break;
+ }
+ default:
+ {
+ abort();
+ /*NOTREACHED*/
+ }
+ }
+ /* due to the funky way + and * are compiled, the top failure-
+ * stack entry at this point is actually a success entry --
+ * update it & pop it
+ */
+ UPDATE_FAILURE(state, text, goto error);
+ goto fail; /* i.e., succeed <wink/sigh> */
+ }
case Cbegbuf:
{
if (text == textstart)