Build wasm without Emscripten

3 files changed, 54 insertions, 39 deletions

diff --git a/Dockerfile b/Dockerfile
index 4b0f30f..1967156 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,6 +1,7 @@
-FROM emscripten/emsdk as build
+FROM alpine as build
+RUN apk add clang lld
 COPY reduced_system_layer.c /usr/reduced_system_layer.c
-RUN emcc -D REDUCED_SYSTEM_LAYER_EXAMPLE -s ERROR_ON_UNDEFINED_SYMBOLS=0 -s EXPORTED_FUNCTIONS=_js_main,_js_init,_js_pixels,_js_frame -o /usr/index.wasm /usr/reduced_system_layer.c
+RUN clang -D REDUCED_SYSTEM_LAYER_EXAMPLE --target=wasm32 -nostdlib -Wl,--no-entry,--allow-undefined -o /usr/index.wasm /usr/reduced_system_layer.c
 
 FROM nginx:alpine
 EXPOSE 80
diff --git a/index.htm b/index.htm
index 35fd8ca..0ffcf89 100644
--- a/index.htm
+++ b/index.htm
@@ -24,13 +24,13 @@
           fetch("index.wasm"),
           {
             "wasi_snapshot_preview1" : {
-              args_sizes_get : (...args) => { console.log(`args_sizes_get: ${args}`); },
-              args_get       : (...args) => { console.log(`args_get: ${args}`); },
-              proc_exit      : (...args) => { console.log(`proc_exit: ${args}`); },
               clock_time_get : () => { return Date.now(); },
-              fd_close       : (...args) => { console.log(`fd_close: ${args}`); },
-              fd_write       : (...args) => { console.log(`fd_write: ${args}`); },
-              fd_seek        : (...args) => { console.log(`fd_seek: ${args}`); },
+              args_sizes_get : () => { throw new Error("Unexpected args_sizes_get call"); },
+              args_get       : () => { throw new Error("Unexpected args_get call"); },
+              proc_exit      : () => { throw new Error("Unexpected proc_exit call"); },
+              fd_close       : () => { throw new Error("Unexpected fd_close call"); },
+              fd_write       : () => { throw new Error("Unexpected fd_write call"); },
+              fd_seek        : () => { throw new Error("Unexpected fd_seek call"); },
             },
             "env" : {
               p_init : () => {
@@ -60,6 +60,16 @@
               p_wait_events   : () => {},
               p_sleep_for     : (time) => {},
               p_time          : Date.now,
+              memset : (dst, val, num) => {
+                //  FIXME PERF
+                for (let i = 0; i < num; ++i)
+                  dst[i] = val;
+              },
+              memcpy : (dst, src, num) => {
+                //  FIXME PERF
+                for (let i = 0; i < num; ++i)
+                  dst[i] = src[i];
+              },
             },
           }
         );
diff --git a/reduced_system_layer.c b/reduced_system_layer.c
index 19c8a0c..5ddd3ab 100755
--- a/reduced_system_layer.c
+++ b/reduced_system_layer.c
@@ -102,17 +102,6 @@ typedef double             f64;
 #ifndef REDUCED_SYSTEM_LAYER_HEADER_GUARD_
 #define REDUCED_SYSTEM_LAYER_HEADER_GUARD_
 
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE
-#endif
-
-#include <time.h>
-#include <math.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <assert.h>
-
 //  ================================================================
 //
 //    PLATFORM API
@@ -232,6 +221,8 @@ void p_render_frame(void);
 //  User-defined proc
 void p_frame(void);
 
+void p_event_loop(void);
+
 //  Clipboard
 void p_clipboard_write(i64 size, c8 *data);
 
@@ -245,6 +236,10 @@ i64 p_send(u16 slot, IP_Address address, i64 size, u8 *data, u16 *local_port);
 
 extern Platform platform;
 
+#ifdef __wasm__
+i32 main(i32 argc, c8 **argv);
+#endif
+
 #ifdef __cplusplus
 }
 #endif
@@ -292,13 +287,8 @@ i32 main(i32 argc, c8 **argv) {
     .frame_height =  720,
   };
 
-  p_init();
-
-  while (!platform.done) {
-    p_frame();
-  }
+  p_event_loop();
 
-  p_cleanup();
   return 0;
 }
 
@@ -316,6 +306,12 @@ i32 main(i32 argc, c8 **argv) {
 
 Platform platform = {0};
 
+void p_event_loop(void) {
+  p_init();
+  while (!platform.done) p_frame();
+  p_cleanup();
+}
+
 //  ================================================================
 //
 //  Utilities
@@ -394,8 +390,13 @@ i32 utf8_write(c32 c, c8 *buffer) {
 //
 //  ================================================================
 
-#ifdef __unix__
+#if defined(__unix__)
+
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
 
+#include <time.h>
 #include <sched.h>
 #include <unistd.h>
 
@@ -424,7 +425,7 @@ void p_sleep_for(i64 duration) {
     usleep((duration % 1000) * 1000);
 }
 
-#endif
+#endif // defined(__unix__)
 
 //  ================================================================
 //
@@ -432,8 +433,11 @@ void p_sleep_for(i64 duration) {
 //
 //  ================================================================
 
-#ifdef __unix__
+#if defined(__unix__)
 
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
 #include <errno.h>
 #include <signal.h>
 #include <netinet/in.h>
@@ -651,7 +655,7 @@ i64 p_send(u16 slot, IP_Address address, i64 size, u8 *data, u16 *local_port) {
   return sent;
 }
 
-#endif
+#endif // defined(__unix__)
 
 //  ================================================================
 //
@@ -659,7 +663,7 @@ i64 p_send(u16 slot, IP_Address address, i64 size, u8 *data, u16 *local_port) {
 //
 //  ================================================================
 
-#ifdef __linux__
+#if defined(__linux__)
 
 #include <X11/Xlib.h>
 #include <X11/Xutil.h>
@@ -1169,7 +1173,7 @@ void p_clipboard_write(i64 size, c8 *data) {
     memcpy(platform.clipboard, data, platform.clipboard_size);
 }
 
-#endif
+#endif // defined(__linux__)
 
 //  ================================================================
 //
@@ -1177,7 +1181,7 @@ void p_clipboard_write(i64 size, c8 *data) {
 //
 //  ================================================================
 
-#ifdef __linux__
+#if defined(__linux__)
 
 void p_handle_audio(i64 time_elapsed) {
   (void) time_elapsed;
@@ -1191,7 +1195,7 @@ void p_queue_sound(i64 delay, i64 num_samples, f32 *samples) {
   assert(0);
 }
 
-#endif
+#endif // defined(__linux__)
 
 //  ================================================================
 //
@@ -1199,7 +1203,7 @@ void p_queue_sound(i64 delay, i64 num_samples, f32 *samples) {
 //
 //  ================================================================
 
-#ifdef __EMSCRIPTEN__
+#ifdef __wasm__
 
 static u32 _buffer[MAX_NUM_PIXELS] = {0};
 
@@ -1214,27 +1218,27 @@ void p_render_frame(void) {
   p_render_frame_impl();
 }
 
-void js_main(c8 *href) {
+__attribute__((export_name("js_main"))) void js_main(c8 *href) {
   main(1, &href);
 }
 
-void js_init(void) {
+__attribute__((export_name("js_init"))) void js_init(void) {
   platform.pixels = _buffer;
   platform.done   = 1;
 }
 
-void *js_pixels(void) {
+__attribute__((export_name("js_pixels"))) void *js_pixels(void) {
   return platform.pixels;
 }
 
-void js_frame(i32 frame_width, i32 frame_height) {
+__attribute__((export_name("js_frame"))) void js_frame(i32 frame_width, i32 frame_height) {
   platform.frame_width  = frame_width;
   platform.frame_height = frame_height;
 
   p_frame();
 }
 
-#endif // __EMSCRIPTEN__
+#endif // __wasm__
 
 //  ================================================================