commit 7b339344a860bcb148b919539d6f249f63e81293
parent e9cc6cbd1bf133f792687ed14137b6bdfca95af2
Author: William Casarin <jb55@jb55.com>
Date: Tue, 13 Jul 2021 17:37:19 -0700
checkpoints wip
Signed-off-by: William Casarin <jb55@jb55.com>
Diffstat:
| M | src/wasm.c | | | 245 | ++++++++++++++++++++++++++++++++++++++++++++++--------------------------------- |
| M | src/wasm.h | | | 6 | ++++++ |
2 files changed, 149 insertions(+), 102 deletions(-)
diff --git a/src/wasm.c b/src/wasm.c
@@ -2149,7 +2149,6 @@ static int parse_instrs_until(struct wasm_interp *interp, u8 stop_instr,
for (;;) {
if (!pull_byte(code, &tag) && tag == stop_instr) {
parsed_instrs->end = code->p;
- resolve_label(interp);
return 1;
}
@@ -2175,9 +2174,140 @@ static int parse_block(struct wasm_interp *interp, struct block *block, u8 end_t
return 0;
}
- return parse_instrs_until(interp, end_tag, &block->instrs);
+ if (!label_checkpoint(interp)) {
+ interp_error(interp, "checkpoint");
+ return 0;
+ }
+
+ if (!parse_instrs_until(interp, end_tag, &block->instrs)) {
+ interp_error(interp, "checkpoint");
+ return 0;
+ }
+
+ return resolve_label(interp);
+}
+
+static inline int parse_memarg(struct cursor *code, struct memarg *memarg)
+{
+ return leb128_read(code, &memarg->offset) &&
+ leb128_read(code, &memarg->align);
+}
+
+static inline u16 *func_num_labels(struct wasm_interp *interp, int fn)
+{
+ u16 *num = (u16*)array_index(&interp->num_labels, fn);
+ assert(num);
+ assert(*num <= MAX_LABELS);
+ return num;
+}
+
+static inline void set_label_pos(struct label *label, u32 pos)
+{
+ assert(!(pos & 0x80000000));
+ label->instr_pos = pos;
+}
+
+static int find_label(struct wasm_interp *interp, int fn, u32 instr_pos)
+{
+ u16 *num_labels, i;
+ struct label *label;
+
+ num_labels = func_num_labels(interp, fn);
+ label = index_label(&interp->labels, fn, 0);
+ assert(label);
+
+ for (i = 0; i < *num_labels; label++) {
+ assert((u8*)label < interp->labels.cur.end);
+ if (label_instr_pos(label) == instr_pos)
+ return i;
+ i++;
+ }
+
+ return -1;
+}
+
+// upsert an unresolved label
+static int upsert_label(struct wasm_interp *interp, int fn,
+ u32 instr_pos, int *ind)
+{
+ struct label *label;
+ u16 *num_labels;
+
+ num_labels = func_num_labels(interp, fn);
+
+ debug("upsert_label: %d labels for %s\n",
+ *num_labels, get_function_name(interp->module, fn));
+
+ if (*num_labels > 0 && ((*ind = find_label(interp, fn, instr_pos)) == 0)) {
+ // we already have the label
+ return 1;
+ }
+
+ if (*num_labels + 1 > MAX_LABELS) {
+ interp_error(interp, "too many labels in %s (> %d)",
+ get_function_name(interp->module, fn), MAX_LABELS);
+ return 0;
+ }
+
+ *ind = *num_labels;
+ label = index_label(&interp->labels, fn, *ind);
+ assert(label);
+
+ set_label_pos(label, instr_pos);
+ *num_labels = *num_labels + 1;
+
+ return 2;
+}
+
+static int label_checkpoint(struct wasm_interp *interp)
+{
+ u32 instr_pos;
+ int ind;
+
+ int fns;
+ struct label *label;
+ struct callframe *frame;
+
+ fns = functions_count(interp->module);
+ frame = top_callframe(&interp->callframes);
+
+ if (!frame) {
+ interp_error(interp, "no callframes available?");
+ return 0;
+ } else if (frame->fn >= fns) {
+ interp_error(interp, "invalid fn index?");
+ return 0;
+ }
+
+ instr_pos = frame->code.p - frame->code.start;
+ if (!upsert_label(interp, frame->fn, instr_pos, &ind)) {
+ interp_error(interp, "upsert label");
+ return 0;
+ }
+
+ if (!(label = index_label(&interp->labels, frame->fn, ind))) {
+ interp_error(interp, "couldn't index label");
+ return 0;
+ }
+
+ if (label_is_resolved(label)) {
+ frame->code.p = frame->code.start + label->jump;
+ if (frame->code.p >= frame->code.end) {
+ interp_error(interp, "code pointer at or past end, evil jump?");
+ return 0;
+ }
+ return 1;
+ }
+
+ if (!cursor_push_u16(&interp->resolver_stack, ind)) {
+ interp_error(interp, "push label index to resolver stack oob");
+ return 0;
+ }
+
+ return 1;
}
+
static int parse_instr(struct wasm_interp *interp, u8 tag, struct instr *op)
{
struct cursor *code;
@@ -2196,7 +2326,7 @@ static int parse_instr(struct wasm_interp *interp, u8 tag, struct instr *op)
case i_block:
case i_loop:
case i_if:
- return parse_block(interp, &op->block, i_end);
+ return parse_block(interp, &op->blocks[0], i_end);
case i_else:
return parse_block(interp, &op->blocks[0], i_else) &&
@@ -2205,16 +2335,14 @@ static int parse_instr(struct wasm_interp *interp, u8 tag, struct instr *op)
case i_end:
return 1;
- case i_br:
- case i_br_if:
- case i_br_table:
case i_call:
- case i_call_indirect:
case i_local_get:
case i_local_set:
case i_local_tee:
case i_global_get:
case i_global_set:
+ return leb128_read(code, &op->integer);
+
case i_i32_load:
case i_i64_load:
case i_f32_load:
@@ -2238,6 +2366,12 @@ static int parse_instr(struct wasm_interp *interp, u8 tag, struct instr *op)
case i_i64_store8:
case i_i64_store16:
case i_i64_store32:
+ return parse_memarg(code, &op->memarg);
+
+ case i_br:
+ case i_br_if:
+ case i_br_table:
+ case i_call_indirect:
interp_error(interp, "consume dynamic-size op");
return 0;
@@ -2331,105 +2465,12 @@ static int parse_instr(struct wasm_interp *interp, u8 tag, struct instr *op)
return 0;
}
-static inline void set_label_pos(struct label *label, u32 pos)
-{
- assert(!(pos & 0x80000000));
- label->instr_pos = pos;
-}
-
-static inline u16 *func_num_labels(struct wasm_interp *interp, int fn)
-{
- u16 *num = (u16*)array_index(&interp->num_labels, fn);
- assert(num);
- assert(*num <= MAX_LABELS);
- return num;
-}
-
-static int find_label(struct wasm_interp *interp, int fn, u32 instr_pos)
-{
- u16 *num_labels, i;
- struct label *label;
-
- num_labels = func_num_labels(interp, fn);
- label = index_label(&interp->labels, fn, 0);
- assert(label);
-
- for (i = 0; i < *num_labels; label++) {
- assert((u8*)label < interp->labels.cur.end);
- if (label_instr_pos(label) == instr_pos)
- return i;
- i++;
- }
-
- return -1;
-}
-
-// upsert an unresolved label
-static int upsert_label(struct wasm_interp *interp, int fn,
- u32 instr_pos, int *ind)
-{
- struct label *label;
- u16 *num_labels;
-
- num_labels = func_num_labels(interp, fn);
-
- debug("upsert_label: %d labels for %s\n",
- *num_labels, get_function_name(interp->module, fn));
-
- if (*num_labels > 0 && ((*ind = find_label(interp, fn, instr_pos)) == 0)) {
- // we already have the label
- return 1;
- }
-
- if (*num_labels + 1 > MAX_LABELS) {
- interp_error(interp, "too many labels in %s (> %d)",
- get_function_name(interp->module, fn), MAX_LABELS);
- return 0;
- }
-
- *ind = *num_labels;
- label = index_label(&interp->labels, fn, *ind);
- assert(label);
-
- set_label_pos(label, instr_pos);
- *num_labels = *num_labels + 1;
-
- return 2;
-}
-
static int branch_jump(struct wasm_interp *interp, u8 end_tag)
{
- u32 instr_pos;
- int ind;
-
- int fns;
- struct label *label;
- struct callframe *frame;
struct cursor instrs;
- fns = functions_count(interp->module);
- frame = top_callframe(&interp->callframes);
-
- assert(frame);
- assert(frame->fn < fns);
-
- label = index_label(&interp->labels, frame->fn, 0);
- assert(label);
-
- if (label_is_resolved(label)) {
- frame->code.p = frame->code.start + label->jump;
- assert(frame->code.p < frame->code.end);
- return 1;
- }
-
- instr_pos = frame->code.p - frame->code.start;
- if (!upsert_label(interp, frame->fn, instr_pos, &ind)) {
- interp_error(interp, "upsert label");
- return 0;
- }
-
- if (!cursor_push_u16(&interp->resolver_stack, ind)) {
- interp_error(interp, "push label index to resolver stack oob");
+ if (!label_checkpoint(interp)) {
+ interp_error(interp, "label checkpoint");
return 0;
}
diff --git a/src/wasm.h b/src/wasm.h
@@ -349,9 +349,15 @@ struct block {
struct cursor instrs;
};
+struct memarg {
+ unsigned int offset;
+ unsigned int align;
+};
+
struct instr {
enum instr_tag tag;
union {
+ struct memarg memarg;
struct block block;
struct block blocks[2];
unsigned int integer;
