vlib: add a wasm module, implementing a pure V webassembly seralisation library (#17909)

examples/wasm_codegen/add.v

@@ -0,0 +1,13 @@
+import wasm
+
+fn main() {
+	mut m := wasm.Module{}
+	mut func := m.new_function('add', [.i32_t, .i32_t], [.i32_t])
+	{
+		func.local_get(0)
+		func.local_get(1)
+		func.add(.i32_t)
+	}
+	m.commit(func, true) // `export: true`
+	print(m.compile().bytestr())
+}

examples/wasm_codegen/control_flow.v

@@ -0,0 +1,43 @@
+import wasm
+
+fn main() {
+	mut m := wasm.Module{}
+	mut bif := m.new_function('block_if', [.i32_t], [.i32_t])
+	{
+		loc := bif.new_local(.i32_t)
+
+		// loc = i32.const 10
+		bif.i32_const(10)
+		bif.local_set(loc)
+
+		blk := bif.c_block([], [])
+		{
+			// if argument[0], break
+			bif.local_get(0)
+			bif.c_br_if(blk)
+			// loc = i32.const 11
+			bif.i32_const(11)
+			bif.local_set(loc)
+		}
+		bif.c_end(blk)
+
+		// return loc
+		bif.local_get(loc)
+	}
+	m.commit(bif, true)
+	mut ifexpr := m.new_function('if_expr', [.i32_t], [.i64_t])
+	{
+		ifexpr.local_get(0)
+		ifexpr.c_if([], [.i64_t])
+		{
+			ifexpr.i64_const(5000)
+		}
+		ifexpr.c_else()
+		{
+			ifexpr.i64_const(-5000)
+		}
+		ifexpr.c_end_if()
+	}
+	m.commit(ifexpr, true)
+	print(m.compile().bytestr())
+}

examples/wasm_codegen/factorial.v

@@ -0,0 +1,33 @@
+import wasm
+
+fn main() {
+	mut m := wasm.Module{}
+	mut fac := m.new_function('fac', [.i64_t], [.i64_t])
+	{
+		fac.local_get(0)
+		fac.eqz(.i64_t)
+		fac.c_if([], [.i64_t])
+		{
+			fac.i64_const(1)
+		}
+		fac.c_else()
+		{
+			{
+				fac.local_get(0)
+			}
+			{
+				fac.local_get(0)
+				fac.i64_const(1)
+				fac.sub(.i64_t)
+				fac.call('fac')
+			}
+			fac.mul(.i64_t)
+		}
+		fac.c_end_if()
+	}
+	m.commit(fac, true)
+	print(m.compile().bytestr())
+
+	// v run factorial.v > a.wasm
+	// wasmer a.wasm -i fac 5
+}

examples/wasm_codegen/functions.v

@@ -0,0 +1,29 @@
+import wasm
+
+fn main() {
+	mut m := wasm.Module{}
+	mut pyth := m.new_function('pythagoras', [.f32_t, .f32_t], [
+		.f32_t,
+	])
+	{
+		pyth.local_get(0)
+		pyth.local_get(0)
+		pyth.mul(.f32_t)
+		pyth.local_get(1)
+		pyth.local_get(1)
+		pyth.mul(.f32_t)
+		pyth.add(.f32_t)
+		pyth.sqrt(.f32_t)
+		pyth.cast(.f32_t, true, .f64_t)
+	}
+	m.commit(pyth, true)
+	mut test := m.new_function('test', [.f32_t], [.f64_t])
+	{
+		test.local_get(0)
+		test.f32_const(10.0)
+		test.call('pythagoras')
+		test.cast(.f32_t, true, .f64_t)
+	}
+	m.commit(test, true)
+	print(m.compile().bytestr())
+}

examples/wasm_codegen/hello_wasi.v

@@ -0,0 +1,28 @@
+import wasm
+
+fn main() {
+	mut m := wasm.Module{}
+	m.new_function_import('wasi_unstable', 'proc_exit', [.i32_t], [])
+	m.new_function_import('wasi_unstable', 'fd_write', [.i32_t, .i32_t, .i32_t, .i32_t],
+		[.i32_t])
+	m.assign_memory('memory', true, 1, none)
+
+	m.new_data_segment(0, [u8(8), 0, 0, 0]) // pointer to string
+	m.new_data_segment(4, [u8(13), 0, 0, 0]) // length of string
+	m.new_data_segment(8, 'Hello, WASI!\n'.bytes())
+
+	mut func := m.new_function('_start', [], [])
+	{
+		func.i32_const(1) // stdout
+		func.i32_const(0) // *iovs
+		func.i32_const(1) // 1 iov
+		func.i32_const(-1) // *retptrs
+		func.call_import('wasi_unstable', 'fd_write')
+		func.drop()
+		func.i32_const(0)
+		func.call_import('wasi_unstable', 'proc_exit')
+	}
+	m.commit(func, true)
+
+	print(m.compile().bytestr())
+}

examples/wasm_codegen/memory.v

@@ -0,0 +1,12 @@
+import wasm
+
+fn main() {
+	mut m := wasm.Module{}
+	mut mtest := m.new_function('mload', [.i32_t], [.i32_t])
+	{
+		mtest.local_get(0)
+		mtest.load(.i32_t, 2, 0)
+	}
+	m.commit(mtest, false)
+	print(m.compile().bytestr())
+}