type section parser

src/sections.inc

@@ -47,6 +47,15 @@ parse_sections:
 	call	print_str
 	pop	esi
 
+	mov	eax, [sec_id]
+	cmp	eax, SECT_TYPE
+	je	.type
+	jmp	.skip
+
+.type:
+	call	parse_type_section
+
+.skip:
 	mov	esi, [sec_next]
 	jmp	.next
 
@@ -66,3 +75,133 @@ print_sec_name:
 .unknown:
 	pop	eax esi
 	ret
+
+MAX_TYPES	= 64
+
+parse_type_section:
+	pushad
+	mov	esi, [sec_content]
+
+	call	decode_leb128_u32
+	mov	[type_count], eax
+	mov	ecx, eax
+	xor	ebx, ebx
+
+.next_type:
+	test	ecx, ecx
+	jz	.types_done
+
+	cmp	byte [esi], 0x60
+	jne	.types_done
+	inc	esi
+
+	push	ecx
+	call	decode_leb128_u32
+	mov	[type_param_counts + ebx*4], eax
+	mov	[type_param_ptrs + ebx*4], esi
+	mov	ecx, eax
+
+	push	esi ecx
+	mov	esi, msg_indent
+	call	print_str
+	mov	esi, msg_type_word
+	call	print_str
+	mov	eax, ebx
+	call	print_dec
+	mov	esi, msg_colon
+	call	print_str
+	mov	esi, msg_oparen
+	call	print_str
+	pop	ecx esi
+
+	push	ecx
+.print_param:
+	test	ecx, ecx
+	jz	.params_printed
+	movzx	eax, byte [esi]
+	inc	esi
+	push	esi ecx
+	call	print_valtype
+	pop	ecx esi
+	dec	ecx
+	test	ecx, ecx
+	jz	.params_printed
+	push	esi
+	mov	esi, msg_comma
+	call	print_str
+	pop	esi
+	jmp	.print_param
+.params_printed:
+	pop	ecx
+
+	push	esi
+	mov	esi, msg_arrow_paren
+	call	print_str
+	pop	esi
+
+	call	decode_leb128_u32
+	mov	[type_result_counts + ebx*4], eax
+	mov	[type_result_ptrs + ebx*4], esi
+	mov	ecx, eax
+
+	push	ecx
+.print_result:
+	test	ecx, ecx
+	jz	.results_printed
+	movzx	eax, byte [esi]
+	inc	esi
+	push	esi ecx
+	call	print_valtype
+	pop	ecx esi
+	dec	ecx
+	test	ecx, ecx
+	jz	.results_printed
+	push	esi
+	mov	esi, msg_comma
+	call	print_str
+	pop	esi
+	jmp	.print_result
+.results_printed:
+	pop	ecx
+
+	push	esi
+	mov	esi, msg_cparen_nl
+	call	print_str
+	pop	esi
+	pop	ecx
+
+	inc	ebx
+	dec	ecx
+	jmp	.next_type
+
+.types_done:
+	popad
+	ret
+
+print_valtype:
+	push	esi
+	cmp	al, 0x7F
+	je	.i32
+	cmp	al, 0x7E
+	je	.i64
+	cmp	al, 0x7D
+	je	.f32
+	cmp	al, 0x7C
+	je	.f64
+	mov	esi, msg_vt_unknown
+	jmp	.vt_print
+.i32:
+	mov	esi, msg_vt_i32
+	jmp	.vt_print
+.i64:
+	mov	esi, msg_vt_i64
+	jmp	.vt_print
+.f32:
+	mov	esi, msg_vt_f32
+	jmp	.vt_print
+.f64:
+	mov	esi, msg_vt_f64
+.vt_print:
+	call	print_str
+	pop	esi
+	ret

src/wasm.asm

@@ -207,6 +207,19 @@ msg_newline	db 10, 0
 
 msg_sec_hdr	db 'Section ', 0
 msg_sec_comma_sz db ', size: ', 0
+msg_indent	db '  ', 0
+msg_type_word	db 'type ', 0
+msg_colon	db ': ', 0
+msg_comma	db ', ', 0
+msg_oparen	db '(', 0
+msg_cparen_nl	db ')', 10, 0
+msg_arrow_paren	db ') -> (', 0
+
+msg_vt_i32	db 'i32', 0
+msg_vt_i64	db 'i64', 0
+msg_vt_f32	db 'f32', 0
+msg_vt_f64	db 'f64', 0
+msg_vt_unknown	db '?', 0
 
 sec_name_tbl	dd sn_custom, sn_type, sn_import, sn_func, sn_table
 		dd sn_memory, sn_global, sn_export, sn_start, sn_element
@@ -237,4 +250,10 @@ sec_size	dd 0
 sec_content	dd 0
 sec_next	dd 0
 
+type_count	dd 0
+type_param_counts rd MAX_TYPES
+type_result_counts rd MAX_TYPES
+type_param_ptrs	rd MAX_TYPES
+type_result_ptrs rd MAX_TYPES
+
 file_buf	rb FILE_BUF_SIZE

test/run_tests.sh

@@ -29,6 +29,8 @@ check "valid wasm"      "Valid wasm file"       $WASM test/wasm/valid.wasm
 check "bad magic"       "invalid wasm magic"    $WASM test/wasm/badmagic.wasm
 check "bad version"     "unsupported wasm"      $WASM test/wasm/badver.wasm
 check "section list"    "(Type)"                $WASM test/wasm/valid.wasm
+check "type no params" "() -> (i32)"           $WASM test/wasm/valid.wasm
+check "type two params" "(i32, i32) -> (i32)"  $WASM test/wasm/add.wasm
 
 echo ""
 echo "Results: $PASS/$TESTS passed, $FAIL failed"

test/wat/add.wat

@@ -0,0 +1,6 @@
+(module
+  (func (export "add") (param i32 i32) (result i32)
+    local.get 0
+    local.get 1
+    i32.add)
+)