perform type checking of translated instructions

4 files changed, 403 insertions, 128 deletions

diff --git a/tools/parse_module.c b/tools/parse_module.c
index 155fc9c..75329f8 100644
--- a/tools/parse_module.c
+++ b/tools/parse_module.c
@@ -68,6 +68,19 @@ int leb_u32(FILE *handle, uint32_t *result)
 	return 0;
 }
 
+void deinitialize_resulttype(struct resulttype *type)
+{
+	type->count = 0;
+	free(type->types);
+	type->types = NULL;
+}
+
+void deinitialize_functype(struct functype *type)
+{
+	deinitialize_resulttype(&type->args);
+	deinitialize_resulttype(&type->results);
+}
+
 void free_module(struct module *module)
 {
 	size_t i;
@@ -76,7 +89,7 @@ void free_module(struct module *module)
 		return;
 
 	for (i = 0; i < module->functypes_count; i++)
-		free(module->functypes[i].arguments);
+		deinitialize_functype(module->functypes + i);
 
 	free(module->functypes);
 
@@ -113,37 +126,30 @@ static inline int safe_mul(size_t *factor1, uint32_t factor2)
 	return 0;
 }
 
-int parse_type_section(FILE *handle, struct module *module)
+int parse_resulttype(FILE *handle, struct resulttype *type)
 {
-	uint32_t types_count;
 	int readval;
-	size_t malloc_size;
-	struct functype *types = NULL;
-	uint32_t types_parsed = 0;
-	uint32_t args_count;
-	char *args;
 	uint32_t i;
 
-	if (leb_u32(handle, &types_count)) {
+	if (leb_u32(handle, &type->count)) {
 		PRERR(MSG_BAD_NUM);
 		goto fail;
 	}
 
-	malloc_size = sizeof(struct functype);
+	if (type->count) {
+		type->types = malloc(type->count);
 
-	if (safe_mul(&malloc_size, types_count)) {
-		PRERR(MSG_BAD_SIZE);
-		goto fail;
+		if (!type->types) {
+			PRERR(MSG_ALLOC_FAIL(type->count));
+			goto fail;
+		}
+	} else {
+		type->types = NULL;
 	}
 
-	types = malloc(malloc_size);
-
-	if (!types) {
-		PRERR(MSG_ALLOC_FAIL(malloc_size));
-		goto fail;
-	}
+	i = type->count;
 
-	while (types_parsed < types_count) {
+	while (i--) {
 		readval = fgetc(handle);
 
 		if (readval == EOF) {
@@ -151,77 +157,78 @@ int parse_type_section(FILE *handle, struct module *module)
 			goto fail;
 		}
 
-		if (readval != 0x60) {
-			PRERR(MSG_BAD("functype starting byte (0x60)",
-				      readval));
+		if (!is_valid_valtype(readval)) {
+			PRERR(MSG_BAD("value type encoding", readval));
 			goto fail;
 		}
 
-		if (leb_u32(handle, &args_count)) {
-			PRERR(MSG_BAD_NUM);
-			goto fail;
-		}
+		type->types[i] = readval;
+	}
 
-		if (args_count) {
-			args = malloc(args_count);
+	return 0;
 
-			if (!args) {
-				PRERR(MSG_ALLOC_FAIL(args_count));
-				goto fail;
-			}
-		} else {
-			args = NULL;
-		}
+fail:
+	deinitialize_resulttype(type);
 
-		types[types_parsed].arguments_count = args_count;
-		types[types_parsed].arguments = args;
-		/* Increment here, so that jump to fail: frees the args */
-		types_parsed++;
+	return -1;
+}
 
-		for (i = 0; i < args_count; i++) {
-			readval = fgetc(handle);
+int parse_functype(FILE *handle, struct functype *type)
+{
+	int readval;
 
-			if (readval == EOF) {
-				PRERR(MSG_EOF);
-				goto fail;
-			}
+	readval = fgetc(handle);
 
-			if (!is_valid_valtype(readval)) {
-				PRERR(MSG_BAD("value type encoding", readval));
-				goto fail;
-			}
+	if (readval == EOF) {
+		PRERR(MSG_EOF);
+		return -1;
+	}
 
-			args[i] = readval;
-		}
+	if (readval != 0x60) {
+		PRERR(MSG_BAD("functype starting byte (0x60)", readval));
+		return -1;
+	}
 
-		readval = fgetc(handle);
+	if (parse_resulttype(handle, &type->args) ||
+	    parse_resulttype(handle, &type->results)) {
+		deinitialize_functype(type);
+		return -1;
+	}
 
-		if (readval == EOF) {
-			PRERR(MSG_EOF);
-			goto fail;
-		}
+	return 0;
+}
 
-		if (readval == 0x00) {
-			types[types_parsed - 1].result = 0;
-		} else if (readval == 0x01) {
+int parse_type_section(FILE *handle, struct module *module)
+{
+	uint32_t types_count;
+	size_t malloc_size;
+	struct functype *types = NULL;
+	uint32_t types_parsed = 0;
 
-			readval = fgetc(handle);
+	if (leb_u32(handle, &types_count)) {
+		PRERR(MSG_BAD_NUM);
+		goto fail;
+	}
 
-			if (readval == EOF) {
-				PRERR(MSG_EOF);
-				goto fail;
-			}
+	malloc_size = sizeof(struct functype);
 
-			if (!is_valid_valtype(readval)) {
-				PRERR(MSG_BAD("value type encoding", readval));
-				goto fail;
-			}
+	if (safe_mul(&malloc_size, types_count)) {
+		PRERR(MSG_BAD_SIZE);
+		goto fail;
+	}
 
-			types[types_parsed - 1].result = readval;
-		} else {
-			PRERR(MSG_BAD("return values count", readval));
+	types = malloc(malloc_size);
+
+	if (!types) {
+		PRERR(MSG_ALLOC_FAIL(malloc_size));
+		goto fail;
+	}
+
+	while (types_parsed < types_count) {
+		if (parse_functype(handle, types + types_parsed))
 			goto fail;
-		}
+
+		types_parsed++;
 	}
 
 	module->functypes_count = types_count;
@@ -233,10 +240,8 @@ fail:
 	PRERR("Couldn't parse function types section\n");
 
 	if (types) {
-		while (types_parsed) {
-			free(types[types_parsed - 1].arguments);
-			types_parsed--;
-		}
+		while (types_parsed--)
+			deinitialize_functype(types + types_parsed);
 
 		free(types);
 	}
@@ -282,7 +287,12 @@ int parse_function_section(FILE *handle, struct module *module)
 			goto fail;
 		}
 
-		funcs[i].type = module->functypes + i;
+		if (module->functypes[type_idx].results.count > 1) {
+			PRERR("Function returning more than one value\n");
+			goto fail;
+		}
+
+		funcs[i].type = module->functypes + type_idx;
 		funcs[i].translated_body = NULL;
 	}
 
@@ -444,7 +454,6 @@ static int parse_function_code(FILE *handle, struct function *function,
 	uint32_t locals_blocks;
 	uint32_t locals_count = 0;
 	char *locals = NULL, *tmp;
-	char *body = NULL;
 	uint32_t i;
 	uint32_t locals_in_block;
 
@@ -459,7 +468,8 @@ static int parse_function_code(FILE *handle, struct function *function,
 			goto fail;
 		}
 
-		if (locals_count + (uint64_t) locals_in_block > UINT32_MAX) {
+		if (locals_count + (uint64_t) locals_in_block +
+		    (uint64_t) function->type->args.count > UINT32_MAX) {
 			PRERR("Too many locals\n");
 			goto fail;
 		}
@@ -505,7 +515,6 @@ static int parse_function_code(FILE *handle, struct function *function,
 
 fail:
 	free(locals);
-	free(body);
 
 	return -1;
 }
@@ -565,6 +574,7 @@ fail:
 		free(module->functions[functions_parsed - 1].locals);
 		free_expr(module->functions[functions_parsed - 1]
 			  .translated_body);
+		module->functions[functions_parsed - 1].translated_body = NULL;
 
 		functions_parsed--;
 	}
diff --git a/tools/translate.c b/tools/translate.c
index 97d48f7..b3d2afd 100644
--- a/tools/translate.c
+++ b/tools/translate.c
@@ -2,20 +2,42 @@
 #include "wasm.h"
 #include "stack_machine_instruction.h"
 
+struct types {
+	struct types *prev;
+	char type; /* should be one of VALTYPE_* constants from wasm.h */
+};
+
 struct translation {
 	FILE *handle;
 	struct function *function;
 	struct module *module;
+	struct types *types_stack;
 };
 
-/* All functions, that go into function pointer array, start with _ */
+void free_types_stack(struct types *top)
+{
+	struct types *tmp;
+
+	while (top) {
+		tmp = top->prev;
+		free(top);
+		top = tmp;
+	}
+}
+
+/* All functions, that go into one of function pointer arrays, start with _ */
+
+/** DEFINE TRANSLATION FUNCTIONS **/
 
 /* Translate complex - those routines have to be defined manually */
-#define TC(wasm_opcode, name)
+#define TC(wasm_opcode, name, argtypes, restype)
+
+static int typecheck_call(struct translation *data, struct function *callee);
 
 static int _translate_call(struct translation *data)
 {
 	uint32_t funcidx;
+	struct function *func;
 	struct instruction **target;
 
 	if (leb_u32(data->handle, &funcidx)) {
@@ -28,15 +50,22 @@ static int _translate_call(struct translation *data)
 		return -1;
 	}
 
-	target = &data->module->functions[funcidx].translated_body;
+	func = data->module->functions + funcidx;
+
+	if (typecheck_call(data, func))
+		return -1;
+
+	target = &func->translated_body;
 
 	return i_call(ptr(target), &data->function->translated_body);
 }
 
+static int typecheck_local_get(struct translation *data, uint32_t localidx);
+
 static int _translate_local_get(struct translation *data)
 {
 	uint32_t localidx;
-	uint32_t args_count = data->function->type->arguments_count;
+	uint32_t args_count = data->function->type->args.count;
 	uint32_t locals_count = data->function->locals_count;
 	uint32_t all_locals_count = args_count + locals_count;
 	uint64_t offset_on_frame;
@@ -52,14 +81,19 @@ static int _translate_local_get(struct translation *data)
 		return -1;
 	}
 
+	if (typecheck_local_get(data, localidx))
+		return -1;
+
 	offset_on_frame = all_locals_count - localidx + 1;
 
 	if (localidx >= args_count)
 		offset_on_frame -= 1;
 
-	return
-		i_load  (im(STACK_FRAME_BACKUP_ADDR), expr) ||
-		i_load_p(im(4 * offset_on_frame),     expr);
+	if (i_load  (im(STACK_FRAME_BACKUP_ADDR), expr) ||
+	    i_load_p(im(4 * offset_on_frame),     expr))
+		return -1;
+
+	return 0;
 }
 
 static int _translate_const(struct translation *data)
@@ -75,7 +109,7 @@ static int _translate_const(struct translation *data)
 }
 
 /* Translate Simple */
-#define TS(wasm_opcode, sm_instr)					\
+#define TS(wasm_opcode, sm_instr, argtypes, restype)			\
 	static int _translate_##sm_instr(struct translation *data)	\
 	{								\
 		return i_##sm_instr(&data->function->translated_body);	\
@@ -99,7 +133,7 @@ static int translate_load_store(struct translation *data,
 	return instr_routine(im(offset), &data->function->translated_body);
 }
 
-#define TLS(wasm_opcode, sm_instr)					\
+#define TLS(wasm_opcode, sm_instr, argtypes, restype)			\
 	static int _translate_##sm_instr(struct translation *data)	\
 	{								\
 		return translate_load_store(data, i_##sm_instr);	\
@@ -112,14 +146,19 @@ static int translate_load_store(struct translation *data,
 #undef TLS
 #undef TC
 
+/** DEFINE TRANSLATION FUNCTIONS POINTER ARRAY **/
+
 /* Translate complex */
-#define TC(wasm_opcode, name) [wasm_opcode] = _translate_##name,
+#define TC(wasm_opcode, name, argtypes, restype) \
+	[wasm_opcode] = _translate_##name,
 
 /* Translate Simple */
-#define TS(wasm_opcode, sm_instr) TC(wasm_opcode, sm_instr)
+#define TS(wasm_opcode, sm_instr, argtypes, restype) \
+	TC(wasm_opcode, sm_instr, dummy, dummy)
 
 /* Translate load/store */
-#define TLS(wasm_opcode, sm_instr) TC(wasm_opcode, sm_instr)
+#define TLS(wasm_opcode, sm_instr, argtypes, restype)	\
+	TC(wasm_opcode, sm_instr, dummy, dummy)
 
 /* The actual array of function pointers is defined here */
 static int (*translation_routines[256]) (struct translation *) = {
@@ -130,42 +169,262 @@ static int (*translation_routines[256]) (struct translation *) = {
 #undef TLS
 #undef TC
 
-static int translate_expr(struct translation *data, struct functype *exprtype)
+/** DEFINE ARGUMENT TYPECHECK FUNCTIONS **/
+
+static int _argcheck_empty(struct types **types_stack)
+{
+	return 0;
+}
+
+static int argcheck_generic_noremove(struct types *types_stack, char expected)
+{
+	char *name;
+
+	name =
+		expected == VALTYPE_F64 ? "f64" :
+		expected == VALTYPE_F32 ? "f32" :
+		expected == VALTYPE_I64 ? "i64" :
+		"i32";
+
+	if (!types_stack) {
+		PRERR("Expected %s on stack, got nothing\n", name);
+		return -1;
+	}
+
+	if (types_stack->type != VALTYPE_I32) {
+		PRERR("Expected %s (0x%02hhx) on stack, got 0x%02hhx\n",
+		      name, expected, types_stack->type);
+		return -1;
+	}
+
+	return 0;
+}
+
+static int argcheck_generic(struct types **types_stack, char expected)
+{
+	struct types *top_type;
+
+	if (argcheck_generic_noremove(*types_stack, expected))
+		return -1;
+
+	top_type = *types_stack;
+	*types_stack = top_type->prev;
+	free(top_type);
+
+	return 0;
+}
+
+static int _argcheck_i32(struct types **types_stack)
+{
+	return argcheck_generic(types_stack, VALTYPE_I32);
+}
+
+static int _argcheck_i32_i32(struct types **types_stack)
+{
+	int i;
+
+	for (i = 0; i < 2; i++) {
+		if (argcheck_generic(types_stack, VALTYPE_I32))
+			return -1;
+	}
+
+	return 0;
+}
+
+static int _argcheck_custom(struct types **types_stack)
+{
+	return 0; /* Translation function will handle argument checks */
+}
+
+/** DEFINE RESULT TYPECHECK FUNCTIONS **/
+
+static int _rescheck_empty(struct types **types_stack)
+{
+	return 0;
+}
+
+static int rescheck_generic(struct types **types_stack, char returned)
+{
+	struct types *top;
+
+	top = malloc(sizeof(struct types));
+
+	if (!top) {
+		PRERR(MSG_ALLOC_FAIL(sizeof(struct types)));
+		return -1;
+	}
+
+	*top = (struct types) {.prev = *types_stack, .type = returned};
+	*types_stack = top;
+
+	return 0;
+}
+
+static int _rescheck_i32(struct types **types_stack)
+{
+	return rescheck_generic(types_stack, VALTYPE_I32);
+}
+
+static int _rescheck_custom(struct types **types_stack)
+{
+	return 0;
+}
+
+/** DEFINE TYPECHECK FUNCTION POINTER ARRAY **/
+
+/* Translate complex */
+#define TC(wasm_opcode, name, argtypes, restype)		\
+	[wasm_opcode] = {.argcheck = _argcheck_##argtypes,	\
+			 .rescheck = _rescheck_##restype},
+
+/* Translate Simple */
+#define TS(wasm_opcode, sm_instr, argtypes, restype)	\
+	TC(wasm_opcode, dummy, argtypes, restype)
+
+/* Translate load/store */
+#define TLS(wasm_opcode, sm_instr, argtypes, restype)	\
+	TC(wasm_opcode, dummy, argtypes, restype)
+
+struct typecheck {
+	int (*argcheck) (struct types **), (*rescheck) (struct types **);
+};
+
+/*static*/ struct typecheck typecheck_routines[256] = {
+#include "translate_xmacro.h"
+};
+
+#undef TS
+#undef TLS
+#undef TC
+
+/** DEFINE CUSTOM TYPECHECK FUNCTIONS **/
+
+static int typecheck_call(struct translation *data, struct function *callee)
+{
+	uint32_t i;
+
+	i = callee->type->args.count;
+
+	while (i--) {
+		if (argcheck_generic(&data->types_stack,
+				     callee->type->args.types[i]))
+			return -1;
+	}
+
+	for (i = 0; i < callee->type->results.count; i++) {
+		if (rescheck_generic(&data->types_stack,
+				     callee->type->results.types[i]))
+			return -1;
+	}
+
+	return 0;
+}
+
+static int typecheck_local_get(struct translation *data, uint32_t localidx)
+{
+	uint32_t args_count = data->function->type->args.count;
+	char type = localidx < args_count ?
+		data->function->type->args.types[localidx] :
+		data->function->locals[localidx - args_count];
+
+	if (rescheck_generic(&data->types_stack, type))
+		return -1;
+
+	return 0;
+}
+
+/** REST OF THE CODE **/
+
+static int translate_instr(struct translation *data, uint8_t wasm_opcode)
 {
+	struct typecheck *tc_routines;
+
+	if (!translation_routines[wasm_opcode]) {
+		PRERR("Unknown Wasm opcode: 0x%02x\n", wasm_opcode);
+		return -1;
+	}
+
+	tc_routines = typecheck_routines + wasm_opcode;
+
+	if (tc_routines->argcheck(&data->types_stack) ||
+	    tc_routines->rescheck(&data->types_stack) ||
+	    translation_routines[wasm_opcode](data))
+		return -1;
+
+	return 0;
+}
+
+static int translate_expr(struct translation *data, struct resulttype *args,
+			  struct resulttype *results)
+{
+	struct types **tmp, *types_stack_rest;
+	uint32_t i;
 	int wasm_opcode;
 
+	tmp = &data->types_stack;
+	i = args ? args->count : 0;
+
+	while (i--) {
+		if (argcheck_generic_noremove(*tmp, args->types[i]))
+			return -1;
+
+		tmp = &(*tmp)->prev;
+	}
+
+	types_stack_rest = *tmp;
+	*tmp = NULL;
+
 	while (1) {
 		wasm_opcode = fgetc(data->handle);
 
 		if (wasm_opcode == EOF) {
 			PRERR(MSG_EOF);
-			return -1;
+			goto fail;
 		}
 
-		if (wasm_opcode == WASM_END) {
-			return 0;
-		}
+		if (wasm_opcode == WASM_END)
+			break;
 
-		if (!translation_routines[wasm_opcode]) {
-			PRERR("Unknown Wasm opcode: 0x%02x\n", wasm_opcode);
-			return -1;
-		}
+		if (translate_instr(data, wasm_opcode))
+			goto fail;
+	}
 
-		if (translation_routines[wasm_opcode](data))
-			return -1;
+	tmp = &data->types_stack;
+	i = results ? results->count : 0;
+
+	while (i--) {
+		if (argcheck_generic_noremove(*tmp, results->types[i]))
+			goto fail;
+
+		tmp = &(*tmp)->prev;
 	}
+
+	if (*tmp) {
+		PRERR("Expression produces too many result values\n");
+		goto fail;
+	}
+
+	*tmp = types_stack_rest;
+	return 0;
+
+fail:
+	free_types_stack(data->types_stack);
+	data->types_stack = types_stack_rest;
+
+	return -1;
 }
 
 int translate(FILE *handle, struct function *function, struct module *module)
 {
 	struct instruction **expr = &function->translated_body;
-	uint32_t args_count = function->type->arguments_count;
+	uint32_t args_count = function->type->args.count;
 	uint32_t locals_count = function->locals_count;
 	uint32_t all_locals_count = args_count + locals_count;
 	size_t i;
 	struct translation data = {.handle = handle,
 				   .function = function,
-				   .module = module};
+				   .module = module,
+				   .types_stack = NULL};
 
 	if (locals_count + (uint64_t) args_count > STACK_TOP_ADDR * 4) {
 		PRERR("Too many locals in a function\n");
@@ -186,11 +445,11 @@ int translate(FILE *handle, struct function *function, struct module *module)
 		goto fail;
 
 	/* actual function body */
-	if (translate_expr(&data, function->type))
+	if (translate_expr(&data, NULL, &function->type->results))
 		goto fail;
 
         /* function epilogue */
-	if (function->type->result) {
+	if (function->type->results.count) {
 		if (i_load   (im(STACK_FRAME_BACKUP_ADDR),        expr) ||
 		    i_swap   (                                    expr) ||
 		    i_store_p(im(4 * (2 + all_locals_count - 1)), expr) ||
@@ -215,7 +474,10 @@ int translate(FILE *handle, struct function *function, struct module *module)
 
 	}
 
-	i = locals_count + args_count + 2 + (function->type->result ? 0 : 1);
+	i = locals_count + args_count + 2;
+
+	if (!function->type->results.count)
+		i++;
 
 	while (i--) {
 		if (i_drop(expr))
diff --git a/tools/translate_xmacro.h b/tools/translate_xmacro.h
index 2fc4558..5e5bd79 100644
--- a/tools/translate_xmacro.h
+++ b/tools/translate_xmacro.h
@@ -1,19 +1,20 @@
 /* X-macro-like definition of translation routines for each webasm opcode */
 
-TS(WASM_I32_ADD,   add)
-TS(WASM_I32_SUB,   sub)
-TS(WASM_I32_DIV_U, div)
-TS(WASM_I32_MUL,   mul)
+/*  wasm_opcode_______**translation_routine**argument_types**result_type*/
+TS (WASM_I32_ADD,      add,                 i32_i32,        i32)
+TS (WASM_I32_SUB,      sub,                 i32_i32,        i32)
+TS (WASM_I32_DIV_U,    div,                 i32_i32,        i32)
+TS (WASM_I32_MUL,      mul,                 i32_i32,        i32)
 
-TLS(WASM_I32_LOAD,     load_p)
-TLS(WASM_I32_LOAD8_S,  loadbsx_p)
-TLS(WASM_I32_LOAD8_U,  loadbzx_p)
-TLS(WASM_I32_LOAD16_S, loadwsx_p)
-TLS(WASM_I32_LOAD16_U, loadwzx_p)
-TLS(WASM_I32_STORE,    store_p)
-TLS(WASM_I32_STORE8,   storeb_p)
-TLS(WASM_I32_STORE16,  storew_p)
+TLS(WASM_I32_LOAD,     load_p,              i32,            i32)
+TLS(WASM_I32_LOAD8_S,  loadbsx_p,           i32,            i32)
+TLS(WASM_I32_LOAD8_U,  loadbzx_p,           i32,            i32)
+TLS(WASM_I32_LOAD16_S, loadwsx_p,           i32,            i32)
+TLS(WASM_I32_LOAD16_U, loadwzx_p,           i32,            i32)
+TLS(WASM_I32_STORE,    store_p,             i32_i32,        empty)
+TLS(WASM_I32_STORE8,   storeb_p,            i32_i32,        empty)
+TLS(WASM_I32_STORE16,  storew_p,            i32_i32,        empty)
 
-TC(WASM_CALL,      call)
-TC(WASM_LOCAL_GET, local_get)
-TC(WASM_I32_CONST, const)
+TC (WASM_CALL,         call,                custom,         custom)
+TC (WASM_LOCAL_GET,    local_get,           empty,          custom)
+TC (WASM_I32_CONST,    const,               empty,          i32)
diff --git a/tools/wasm_compile.h b/tools/wasm_compile.h
index 3412b2d..e223ec6 100644
--- a/tools/wasm_compile.h
+++ b/tools/wasm_compile.h
@@ -24,11 +24,13 @@
 
 #define PRERR(...) fprintf(stderr, __VA_ARGS__)
 
-struct functype {
-	uint32_t arguments_count;
-	char *arguments;
+struct resulttype {
+	uint32_t count;
+	char *types;
+};
 
-	char result;
+struct functype {
+	struct resulttype args, results;
 };
 
 struct function {