rt0_js_wasm.s

Documentation: runtime

     1// Copyright 2018 The Go Authors. All rights reserved.
     2// Use of this source code is governed by a BSD-style
     3// license that can be found in the LICENSE file.
     4
     5#include "go_asm.h"
     6#include "textflag.h"
     7
     8// _rt0_wasm_js is not used itself. It only exists to mark the exported functions as alive.
     9TEXT _rt0_wasm_js(SB),NOSPLIT,$0
    10	I32Const $wasm_export_run(SB)
    11	Drop
    12	I32Const $wasm_export_resume(SB)
    13	Drop
    14	I32Const $wasm_export_getsp(SB)
    15	Drop
    16
    17// wasm_export_run gets called from JavaScript. It initializes the Go runtime and executes Go code until it needs
    18// to wait for an event. It does NOT follow the Go ABI. It has two WebAssembly parameters:
    19// R0: argc (i32)
    20// R1: argv (i32)
    21TEXT wasm_export_run(SB),NOSPLIT,$0
    22	MOVD $runtime·wasmStack+(m0Stack__size-16)(SB), SP
    23
    24	Get SP
    25	Get R0 // argc
    26	I64ExtendI32U
    27	I64Store $0
    28
    29	Get SP
    30	Get R1 // argv
    31	I64ExtendI32U
    32	I64Store $8
    33
    34	I32Const $0 // entry PC_B
    35	Call runtime·rt0_go(SB)
    36	Drop
    37	Call wasm_pc_f_loop(SB)
    38
    39	Return
    40
    41// wasm_export_resume gets called from JavaScript. It resumes the execution of Go code until it needs to wait for
    42// an event.
    43TEXT wasm_export_resume(SB),NOSPLIT,$0
    44	I32Const $0
    45	Call runtime·handleEvent(SB)
    46	Drop
    47	Call wasm_pc_f_loop(SB)
    48
    49	Return
    50
    51// wasm_export_getsp gets called from JavaScript to retrieve the SP.
    52TEXT wasm_export_getsp(SB),NOSPLIT,$0
    53	Get SP
    54	Return
    55
    56TEXT runtime·pause(SB), NOSPLIT, $0-8
    57	MOVD newsp+0(FP), SP
    58	I32Const $1
    59	Set PAUSE
    60	RETUNWIND
    61
    62TEXT runtime·exit(SB), NOSPLIT, $0-4
    63	I32Const $0
    64	Call runtime·wasmExit(SB)
    65	I32Const $1
    66	Set PAUSE
    67	RETUNWIND
View as plain text