Porting to WASM

src/basic/basic.h

@@ -17,6 +17,8 @@
 #elif defined(__linux__)
     #define OS_POSIX 1
     #define OS_LINUX 1
+#elif defined(__EMSCRIPTEN__)
+    #define OS_WASM 1
 #else
     #error Unsupported platform
 #endif
@@ -31,6 +33,10 @@
     #error Unsupported compiler
 #endif
 
+#ifndef OS_WASM
+    #define OS_WASM 0
+#endif
+
 #ifndef OS_MAC
     #define OS_MAC 0
 #endif
@@ -60,14 +66,18 @@
 #endif
 
 #if OS_WINDOWS
-#define DebugBreak() __debugbreak()
+#define BREAK() __debugbreak()
 #elif OS_LINUX
-#define DebugBreak() raise(SIGTRAP)
+#define BREAK() raise(SIGTRAP)
+#elif OS_WASM
+#include <emscripten.h>
+extern "C" void JS_Breakpoint(void);
+#define BREAK() JS_Breakpoint()
 #endif
 
 #define Assert(x)       \
     if (!(x)) {         \
-        DebugBreak(); \
+        BREAK(); \
     }
 #define InvalidCodepath() Assert(!"invalid codepath")
 #define ElseInvalidCodepath() else {InvalidCodepath()}
@@ -1035,8 +1045,8 @@ bool  VCommit(void *p, size_t size);
 bool  VRelease(void *p, size_t size);
 bool  VDecommit(void *p, size_t size);
 
-void      InitArena(Arena *arena, size_t reserve = GiB(4));
-Arena    *AllocArena(size_t reserve = GiB(4));
+void      InitArena(Arena *arena, size_t reserve = MiB(256));
+Arena    *AllocArena(size_t reserve = MiB(256));
 Arena    *AllocArena(Allocator allocator, size_t size);
 void     *PushSize(Arena *arena, size_t size);
 void      Release(Arena *arena);
@@ -1707,11 +1717,22 @@ void *ArenaAllocatorProc(void *object, int kind, void *p, size_t size) {
 }
 
 thread_local Arena *ScratchArenaPool[4];
-void                InitScratch() {
+
+#if OS_WASM
+void InitScratch() {
+    Allocator sys_allocator = GetSystemAllocator();
+    ScratchArenaPool[0] = AllocArena(sys_allocator, MiB(8));
+    ScratchArenaPool[1] = AllocArena(sys_allocator, MiB(2));
+    ScratchArenaPool[3] = AllocArena(sys_allocator, MiB(1));
+    ScratchArenaPool[3] = AllocArena(sys_allocator, KiB(512));
+}
+#else
+void InitScratch() {
     for (int i = 0; i < Lengthof(ScratchArenaPool); i += 1) {
         ScratchArenaPool[i] = AllocArena();
     }
 }
+#endif
 
 TempArena GetScratchEx(Arena **conflicts, int conflict_count) {
     Arena *unoccupied = 0;