commit cc85b900aa6e0317b4332bccf945761e19955bc9
parent aae7d899797b594d46110bf644c40c98824295ac
Author: William Casarin <jb55@jb55.com>
Date: Fri, 16 Jul 2021 15:36:55 -0700
resolver offsets
This allows us to keep track of resolver stacks for each callframe
Signed-off-by: William Casarin <jb55@jb55.com>
Diffstat:
3 files changed, 84 insertions(+), 35 deletions(-)
diff --git a/src/cursor.h b/src/cursor.h
@@ -159,6 +159,26 @@ static inline int pull_data_into_cursor(struct cursor *cursor,
return 1;
}
+
+static inline unsigned char *cursor_top(struct cursor *cur, int len)
+{
+ if (unlikely(cur->p - len < cur->start)) {
+ printf("cursor_top oob\n");
+ return NULL;
+ }
+ return cur->p - len;
+}
+
+static inline int cursor_top_int(struct cursor *cur, int *i)
+{
+ u8 *p;
+ if (unlikely(!(p = cursor_top(cur, sizeof(*i))))) {
+ return 0;
+ }
+ *i = *((int*)p);
+ return 1;
+}
+
static inline int cursor_pop(struct cursor *cur, u8 *data, int len)
{
if (unlikely(cur->p - len < cur->start)) {
diff --git a/src/wasm.c b/src/wasm.c
@@ -43,37 +43,20 @@ struct expr_parser {
static INLINE struct callframe *top_callframe(struct cursor *cur)
{
- if (unlikely(cur->p <= cur->start)) {
- return NULL;
- }
- return ((struct callframe*)cur->p) - 1;
+ return (struct callframe*)cursor_top(cur, sizeof(struct callframe));
}
static INLINE struct cursor *interp_codeptr(struct wasm_interp *interp)
{
struct callframe *frame;
- frame = top_callframe(&interp->callframes);
- if (unlikely(!frame))
+ if (unlikely(!(frame = top_callframe(&interp->callframes))))
return 0;
return &frame->code;
}
-static INLINE int cursor_popdata(struct cursor *cur, unsigned char *dest, int len)
-{
- if (unlikely(cur->p - len < cur->start))
- return 0;
-
- cur->p -= len;
-
- if (dest)
- memcpy(dest, cur->p, len);
-
- return 1;
-}
-
static INLINE int cursor_popval(struct cursor *cur, struct val *val)
{
- return cursor_popdata(cur, (unsigned char*)val, sizeof(*val));
+ return cursor_pop(cur, (unsigned char*)val, sizeof(*val));
}
static const char *valtype_name(enum valtype valtype)
@@ -364,12 +347,12 @@ static INLINE int cursor_push_callframe(struct cursor *cur, struct callframe *fr
static INLINE int cursor_pop_callframe(struct cursor *cur, struct callframe *frame)
{
- return cursor_popdata(cur, (unsigned char*)frame, sizeof(*frame));
+ return cursor_pop(cur, (u8*)frame, sizeof(*frame));
}
static INLINE int cursor_popint(struct cursor *cur, int *i)
{
- return cursor_popdata(cur, (unsigned char *)i, sizeof(int));
+ return cursor_pop(cur, (u8 *)i, sizeof(int));
}
@@ -2239,6 +2222,27 @@ static INLINE int call_func(struct wasm_interp *interp, struct func *func, int f
return interp_error(interp, "corrupt func type: %02x", func->type);
}
+static inline int count_resolvers(struct wasm_interp *interp)
+{
+ return cursor_count(&interp->resolver_stack, sizeof(struct resolver));
+}
+
+static inline int count_local_resolvers(struct wasm_interp *interp, int *count)
+{
+ int offset;
+ u8 *p;
+ if (unlikely(!cursor_top_int(&interp->resolver_offsets, &offset))) {
+ return interp_error(interp, "no top resolver offset?");
+ }
+ p = interp->resolver_stack.start + offset * sizeof(struct resolver);
+ if (unlikely(p < interp->resolver_stack.start ||
+ p >= interp->resolver_stack.end)) {
+ return interp_error(interp, "resolver offset oob?");
+ }
+ *count = (interp->resolver_stack.p - p) / sizeof(struct resolver);
+ return 1;
+}
+
static int prepare_call(struct wasm_interp *interp, int func_index)
{
static u8 tmp[0xFF];
@@ -2265,6 +2269,11 @@ static int prepare_call(struct wasm_interp *interp, int func_index)
if (unlikely(!cursor_push_int(&interp->locals_offsets, offset)))
return interp_error(interp, "push locals offset");
+ offset = count_resolvers(interp);
+ /* this is like locals offsets but for label resolvers */
+ if (unlikely(!cursor_push_int(&interp->resolver_offsets, offset)))
+ return interp_error(interp, "push resolver offset");
+
/* get type signature to know how many locals to push as params */
if (unlikely(!(functype = get_function_type(interp, func_index)))) {
return interp_error(interp,
@@ -2338,7 +2347,6 @@ static int interp_call(struct wasm_interp *interp)
return 0;
}
- /* call the function! */
if (unlikely(!interp_code(interp))) {
return interp_error(interp, "call %s",
get_function_name_for_error(interp, func_index));
@@ -2422,9 +2430,9 @@ static INLINE int pop_resolver(struct wasm_interp *interp, struct resolver *reso
if (!cursor_pop(&interp->resolver_stack, (u8*)resolver, sizeof(*resolver))) {
return interp_error(interp, "pop resolver");
}
- debug("popped resolver stack %d i_%s %ld\n",
+ debug("popped resolver stack %d i_%s %d\n",
resolver->label, instr_name(resolver->end_tag),
- cursor_count(&interp->resolver_stack, sizeof(*resolver)));
+ count_resolvers(interp));
return 1;
}
@@ -3018,7 +3026,7 @@ static int interp_instr(struct wasm_interp *interp, u8 tag)
int interp_code(struct wasm_interp *interp)
{
unsigned char tag;
- int offset;
+ int offset, num_resolvers = 0;
struct cursor *code;
for (;;) {
@@ -3027,14 +3035,28 @@ int interp_code(struct wasm_interp *interp)
}
if (unlikely(!pull_byte(code, &tag))) {
- //cursor_print_around(code, 10);
- return interp_error(interp, "instr tag");
- }
-
- if (unlikely(tag == i_end)) {
- if (!cursor_popint(&interp->locals_offsets, &offset))
- return interp_error(interp, "pop locals_offset");
- break;
+ return interp_error(interp, "no more instrs to pull");
+ }
+
+ if (tag == i_end) {
+ if (unlikely(!count_local_resolvers(interp,
+ &num_resolvers))) {
+ return interp_error(interp,
+ "count local resolvers");
+ }
+
+ if (num_resolvers == 0) {
+ if (!cursor_popint(&interp->resolver_offsets,
+ &offset)) {
+ return interp_error(interp,
+ "pop resolver_offsets");
+ }
+ if (!cursor_popint(&interp->locals_offsets,
+ &offset))
+ return interp_error(interp,
+ "pop locals_offset");
+ break;
+ }
}
if (unlikely(!interp_instr(interp, tag))) {
@@ -3100,11 +3122,12 @@ void wasm_interp_init(struct wasm_interp *interp, struct module *module)
unsigned char *mem;
int ok, fns, errors_size, stack_size, locals_size, offsets_size,
callframes_size, resolver_size, labels_size, num_labels_size,
- labels_capacity, num_labels_elemsize, memsize;
+ labels_capacity, num_labels_elemsize, memsize, resolver_offsets_size;
memset(interp, 0, sizeof(*interp));
interp->module = module;
interp->module->start_fn = -1;
+ interp->prev_resolvers = 0;
//stack = calloc(1, STACK_SPACE);
fns = functions_count(module);
@@ -3118,6 +3141,7 @@ void wasm_interp_init(struct wasm_interp *interp, struct module *module)
num_labels_size = fns * num_labels_elemsize;
locals_size = sizeof(struct val) * 0xFF;
offsets_size = sizeof(int) * 0xFF;
+ resolver_offsets_size = offsets_size;
callframes_size = sizeof(struct callframe) * 0xFF;
resolver_size = sizeof(struct resolver) * MAX_LABELS;
@@ -3131,6 +3155,7 @@ void wasm_interp_init(struct wasm_interp *interp, struct module *module)
num_labels_size +
locals_size +
offsets_size +
+ resolver_offsets_size +
callframes_size +
resolver_size;
@@ -3145,6 +3170,7 @@ void wasm_interp_init(struct wasm_interp *interp, struct module *module)
cursor_slice(&interp->mem, &interp->errors.cur, errors_size) &&
cursor_slice(&interp->mem, &interp->locals, locals_size) &&
cursor_slice(&interp->mem, &interp->locals_offsets, offsets_size) &&
+ cursor_slice(&interp->mem, &interp->resolver_offsets, resolver_offsets_size) &&
cursor_slice(&interp->mem, &interp->callframes, callframes_size) &&
cursor_slice(&interp->mem, &interp->resolver_stack, resolver_size) &&
array_alloc(&interp->mem, &interp->labels, labels_capacity) &&
@@ -3177,6 +3203,7 @@ int interp_wasm_module(struct wasm_interp *interp)
// reset cursors
reset_cursor(&interp->stack);
reset_cursor(&interp->resolver_stack);
+ reset_cursor(&interp->resolver_offsets);
reset_cursor(&interp->errors.cur);
reset_cursor(&interp->locals);
reset_cursor(&interp->locals_offsets);
diff --git a/src/wasm.h b/src/wasm.h
@@ -472,6 +472,7 @@ struct resolver {
struct wasm_interp {
struct module *module;
+ int prev_resolvers;
struct errors errors; /* struct error */
size_t ops;
@@ -481,6 +482,7 @@ struct wasm_interp {
struct cursor mem; /* u8/mixed */
struct cursor locals; /* struct val */
struct cursor locals_offsets; /* int */
+ struct cursor resolver_offsets; /* int */
struct array labels; /* struct labels */
struct array num_labels;
