commit 243e2da69a3139591441c3495637875794bb4d55
parent cf4664d5e2f2c2e3d14e018c247754fd894c08e9
Author: William Casarin <jb55@jb55.com>
Date: Sun, 18 Jul 2021 15:36:34 -0700
loops, fix br_if
Diffstat:
3 files changed, 155 insertions(+), 52 deletions(-)
diff --git a/src/cursor.h b/src/cursor.h
@@ -49,7 +49,7 @@ static inline void make_array(struct array *a, u8* start, u8 *end, unsigned int
static inline unsigned char *array_index(struct array *a, int ind)
{
- u8 *p = a->cur.start + a->elem_size * ind;
+ u8 *p = a->cur.start + a->elem_size * ind;
if (unlikely(p >= a->cur.end)) {
return NULL;
}
@@ -176,6 +176,17 @@ static inline int pull_data_into_cursor(struct cursor *cursor,
}
+static inline int cursor_drop(struct cursor *cur, int len)
+{
+ if (unlikely(cur->p - len < cur->start)) {
+ printf("cursor drop oob\n");
+ return 0;
+ }
+
+ cur->p -= len;
+ return 1;
+}
+
static inline unsigned char *cursor_top(struct cursor *cur, int len)
{
if (unlikely(cur->p - len < cur->start)) {
@@ -200,7 +211,7 @@ static inline int cursor_pop(struct cursor *cur, u8 *data, int len)
printf("cursor_pop oob\n");
return 0;
}
-
+
cur->p -= len;
memcpy(data, cur->p, len);
diff --git a/src/wasm.c b/src/wasm.c
@@ -2711,7 +2711,7 @@ static int prepare_call(struct wasm_interp *interp, int func_index)
return 1;
}
-int interp_code(struct wasm_interp *interp);
+static int interp_code(struct wasm_interp *interp);
static int interp_call(struct wasm_interp *interp, int func_index)
{
@@ -2789,7 +2789,7 @@ static struct label *index_frame_label(struct wasm_interp *interp, int ind)
return index_label(&interp->labels, frame->fn, ind);
}
-static int resolve_label(struct label *label, struct cursor *code)
+static INLINE int resolve_label(struct label *label, struct cursor *code)
{
if (is_label_resolved(label)) {
return 1;
@@ -2907,15 +2907,22 @@ static INLINE int cursor_push_resolver(struct cursor *stack, struct resolver *re
return cursor_push(stack, (u8*)resolver, sizeof(*resolver));
}
+struct tag_info {
+ u8 flags;
+ u8 end_tag;
+};
+
// when we encounter a control instruction, try to resolve the label, otherwise
// push the label index to the resolver stack for resolution later
-static int push_label_checkpoint(struct wasm_interp *interp, struct label **label, u8 end_tag)
+static int push_label_checkpoint(struct wasm_interp *interp, struct label **label,
+ u8 start_tag, u8 end_tag)
{
u32 instr_pos;
int ind, fns;
struct resolver resolver;
struct callframe *frame;
+ resolver.start_tag = start_tag;
resolver.end_tag = end_tag;
resolver.label = 0;
@@ -2972,6 +2979,11 @@ static int interp_jump(struct wasm_interp *interp, int jmp)
return 1;
}
+static INLINE int jump_to_label(struct wasm_interp *interp, struct label *label)
+{
+ return interp_jump(interp, label->jump);
+}
+
static int pop_label_and_jump(struct wasm_interp *interp, int jump)
{
if (!pop_label_checkpoint(interp))
@@ -2980,7 +2992,7 @@ static int pop_label_and_jump(struct wasm_interp *interp, int jump)
return interp_jump(interp, jump);
}
-static int parse_block(struct expr_parser *p, struct block *block, u8 end_tag)
+static int parse_block(struct expr_parser *p, struct block *block, u8 start_tag, u8 end_tag)
{
struct label *label = NULL;
@@ -2989,7 +3001,7 @@ static int parse_block(struct expr_parser *p, struct block *block, u8 end_tag)
// if we don't have an interpreter instance, we don't care about
// label resolution (NOT TRUE ANYMORE!)
- if (p->interp != NULL && !push_label_checkpoint(p->interp, &label, i_end))
+ if (p->interp != NULL && !push_label_checkpoint(p->interp, &label, start_tag, i_end))
return note_error(p->errs, p->code, "push checkpoint");
if (label && is_label_resolved(label)) {
@@ -3023,11 +3035,10 @@ static INLINE int parse_memarg(struct cursor *code, struct memarg *memarg)
static int parse_instr(struct expr_parser *p, u8 tag, struct instr *op)
{
- /*
- debug("%04lX parsing instr %s (0x%02x)\n",
- p->code->p - 1 - p->code->start, instr_name(tag), tag);
- */
+ /*debug("%04lX parsing instr %s (0x%02x)\n",
+ p->code->p - 1 - p->code->start, instr_name(tag), tag);*/
+ op->pos = p->code->p - 1 - p->code->start;
op->tag = tag;
switch (tag) {
@@ -3037,9 +3048,11 @@ static int parse_instr(struct expr_parser *p, u8 tag, struct instr *op)
return pull_byte(p->code, &op->memidx);
case i_block:
+ return parse_block(p, &op->block, i_block, i_end);
case i_loop:
+ return parse_block(p, &op->block, i_loop, i_end);
case i_if:
- return parse_block(p, &op->block, i_end);
+ return parse_block(p, &op->block, i_if, i_end);
case i_else:
case i_end:
@@ -3228,14 +3241,14 @@ static int parse_instr(struct expr_parser *p, u8 tag, struct instr *op)
return note_error(p->errs, p->code, "unhandled tag: 0x%x", tag);
}
-static int branch_jump(struct wasm_interp *interp, u8 end_tag)
+static int branch_jump(struct wasm_interp *interp, u8 start_tag, u8 end_tag)
{
u8 *instrs;
int instrs_len;
struct expr_parser parser;
struct label *label;
- if (!push_label_checkpoint(interp, &label, end_tag)) {
+ if (!push_label_checkpoint(interp, &label, start_tag, end_tag)) {
return interp_error(interp, "label checkpoint");
}
@@ -3273,7 +3286,7 @@ static int interp_block(struct wasm_interp *interp)
return interp_error(interp, "couldn't parse blocktype");
}
- if (unlikely(!push_label_checkpoint(interp, &label, i_end))) {
+ if (unlikely(!push_label_checkpoint(interp, &label, i_block, i_end))) {
return interp_error(interp, "block label checkpoint");
}
@@ -3302,7 +3315,7 @@ static int interp_if(struct wasm_interp *interp)
return 1;
}
- if (unlikely(!branch_jump(interp, i_if))) {
+ if (unlikely(!branch_jump(interp, i_if, i_if))) {
return interp_error(interp, "jump");
}
@@ -3322,25 +3335,42 @@ static int interp_i32_eqz(struct wasm_interp *interp)
return cursor_pushval(&interp->stack, &res);
}
-static INLINE int top_resolver_stack(struct cursor *stack, int index, struct resolver **resolver)
+static INLINE struct resolver *top_resolver_stack(struct cursor *stack, int index)
{
struct resolver *p = (struct resolver*)stack->p;
p = &p[-(index+1)];
if (p < (struct resolver*)stack->start)
- return 0;
- *resolver = p;
- return 1;
+ return NULL;
+ return p;
+}
+
+static INLINE struct resolver *top_resolver(struct wasm_interp *interp, int index)
+{
+ return top_resolver_stack(&interp->resolver_stack, index);
+}
+
+static INLINE struct label *top_label(struct wasm_interp *interp, int index)
+{
+ struct resolver *resolver;
+
+ if (unlikely(!(resolver = top_resolver(interp, index)))) {
+ interp_error(interp, "invalid resolver index %d", index);
+ return NULL;
+ }
+
+ return index_frame_label(interp, resolver->label);
}
static int unresolved_break(struct wasm_interp *interp, int index)
{
struct expr_parser parser;
- struct resolver *resolver;
struct callframe *frame;
struct label *label;
u8 *instrs;
int instrs_len;
+ struct resolver *resolver;
+ debug("breaking %d times from unresolved label\n", index+1);
make_interp_expr_parser(interp, &parser);
if (unlikely(!(frame = top_callframe(&interp->callframes)))) {
@@ -3348,21 +3378,16 @@ static int unresolved_break(struct wasm_interp *interp, int index)
}
while (index-- >= 0) {
- if (unlikely(!top_resolver_stack(&interp->resolver_stack, 0,
- &resolver))) {
+ if (unlikely(!(resolver = top_resolver(interp, 0)))) {
return interp_error(interp, "invalid resolver index %d",
- index);
+ index);
}
- debug("unresolved break index %d, ends at i_%s\n", index,
- instr_name(resolver->end_tag));
-
- // TODO: breaking from functions (return)
- if (unlikely(!(label = index_label(&interp->labels, frame->fn,
- resolver->label)))) {
+ if (unlikely(!(label = index_frame_label(interp, resolver->label)))) {
return interp_error(interp, "no label");
}
+ // TODO: breaking from functions (return)
if (is_label_resolved(label)) {
return pop_label_and_jump(interp, label->jump);
}
@@ -3383,18 +3408,13 @@ static int unresolved_break(struct wasm_interp *interp, int index)
static int interp_br_jump(struct wasm_interp *interp, int index)
{
struct label *label;
- struct resolver *resolver = NULL;
-
- if (unlikely(!top_resolver_stack(&interp->resolver_stack, index, &resolver))) {
- return interp_error(interp, "invalid resolver index %d", index);
- }
- if (unlikely(!(label = index_frame_label(interp, resolver->label)))) {
- return interp_error(interp, "index label");
+ if (unlikely(!(label = top_label(interp, index)))) {
+ return interp_error(interp, "no label?");
}
if (is_label_resolved(label)) {
- return interp_jump(interp, label->jump);
+ return pop_label_and_jump(interp, label->jump);
}
return unresolved_break(interp, index);
@@ -4052,13 +4072,38 @@ static int interp_extend(struct wasm_interp *interp, enum valtype to,
return 1;
}
+static INLINE int interp_drop(struct wasm_interp *interp)
+{
+ return cursor_drop(&interp->stack, sizeof(struct val));
+}
+
+static int interp_loop(struct wasm_interp *interp)
+{
+ struct blocktype blocktype;
+ struct cursor *code;
+ struct label *label;
+
+ if (unlikely(!(code = interp_codeptr(interp)))) {
+ return interp_error(interp, "empty callstack?");
+ }
+
+ if (unlikely(!parse_blocktype(code, &interp->errors, &blocktype))) {
+ return interp_error(interp, "couldn't parse blocktype");
+ }
+
+ if (unlikely(!push_label_checkpoint(interp, &label, i_loop, i_end))) {
+ return interp_error(interp, "block label checkpoint");
+ }
+
+ return 1;
+}
+
+
static int interp_instr(struct wasm_interp *interp, struct instr *instr)
{
interp->ops++;
- debug("%04lX %-30s | ",
- interp_codeptr(interp)->p - 1 - interp_codeptr(interp)->start,
- show_instr(instr));
+ debug("%04X %-30s | ", instr->pos, show_instr(instr));
#if DEBUG
print_linestack(&interp->stack);
@@ -4118,6 +4163,8 @@ static int interp_instr(struct wasm_interp *interp, struct instr *instr)
case i_i64_load32_s: return interp_load(interp, &instr->memarg, val_i64, 32, 1);
case i_i64_load32_u: return interp_load(interp, &instr->memarg, val_i64, 32, 0);
+ case i_drop: return interp_drop(interp);
+ case i_loop: return interp_loop(interp);
case i_if: return interp_if(interp);
case i_end: return pop_label_checkpoint(interp);
case i_call: return interp_call(interp, instr->integer);
@@ -4148,33 +4195,59 @@ static int is_control_instr(u8 tag)
return 0;
}
-int interp_code(struct wasm_interp *interp)
+
+static INLINE int interp_parse_instr(struct wasm_interp *interp,
+ struct cursor *code, struct expr_parser *parser,
+ struct instr *instr)
+{
+ u8 tag;
+
+ if (unlikely(!pull_byte(code, &tag))) {
+ return interp_error(interp, "no more instrs to pull");
+ }
+
+ instr->tag = tag;
+
+ if (is_control_instr(tag)) {
+ debug("control instr %s\n", instr_name(tag));
+ } else if (!parse_instr(parser, instr->tag, instr)) {
+ return interp_error(interp, "parse instr");
+ }
+
+ return 1;
+}
+
+static int interp_code(struct wasm_interp *interp)
{
int offset, num_resolvers = 0;
- struct cursor *code;
struct instr instr;
struct expr_parser parser;
- u8 tag;
+ struct resolver *resolver;
+ struct label *label;
+ struct cursor *code;
+ struct callframe *frame;
make_interp_expr_parser(interp, &parser);
+ if (unlikely(!(frame = top_callframe(&interp->callframes)))) {
+ return interp_error(interp, "no callframe");
+ }
+
for (;;) {
if (unlikely(!(code = interp_codeptr(interp)))) {
return interp_error(interp, "codeptr");
}
- if (unlikely(!pull_byte(code, &tag))) {
- return interp_error(interp, "no more instrs to pull");
- }
-
- instr.tag = tag;
-
- if (!is_control_instr(instr.tag) &&
- !parse_instr(&parser, instr.tag, &instr)) {
+ if (unlikely(!interp_parse_instr(interp, code, &parser, &instr))) {
return interp_error(interp, "parse instr");
}
if (instr.tag == i_end) {
+ if (unlikely(!(resolver = top_resolver(interp, 0)))) {
+ // no more resolvers, we done.
+ return 1;
+ }
+
if (unlikely(!count_local_resolvers(interp,
&num_resolvers))) {
return interp_error(interp,
@@ -4189,6 +4262,23 @@ int interp_code(struct wasm_interp *interp)
}
break;
}
+
+ // if we hit the end of a loop, continue at the start
+ if (resolver && resolver->start_tag == i_loop) {
+ if (unlikely(!(label =
+ index_label(&interp->labels, frame->fn,
+ resolver->label)))) {
+ return interp_error(interp, "no loop label?");
+ }
+
+ resolve_label(label, code);
+
+ if (!interp_jump(interp, label_instr_pos(label))) {
+ return interp_error(interp, "jump to loop label");
+ }
+
+ continue;
+ }
}
if (unlikely(!interp_instr(interp, &instr))) {
diff --git a/src/wasm.h b/src/wasm.h
@@ -476,6 +476,7 @@ struct memarg {
struct instr {
enum instr_tag tag;
+ int pos;
union {
struct memarg memarg;
struct block block;
@@ -551,6 +552,7 @@ struct callframe {
struct resolver {
u16 label;
u8 end_tag;
+ u8 start_tag;
unsigned char unused;
};
