Merge pull request #2507 from ziglang/wasm-libs

improvements to build-lib use case of WebAssembly

2 files changed, 18 insertions, 11 deletions

diff --git a/std/special/bootstrap.zig b/std/special/bootstrap.zig
index e6505c836b..b389c03c8c 100644
--- a/std/special/bootstrap.zig
+++ b/std/special/bootstrap.zig
@@ -8,34 +8,41 @@ const assert = std.debug.assert;
 
 var argc_ptr: [*]usize = undefined;
 
+const is_wasm = switch (builtin.arch) { .wasm32, .wasm64 => true, else => false};
+
 comptime {
-    const strong_linkage = builtin.GlobalLinkage.Strong;
     if (builtin.link_libc) {
-        @export("main", main, strong_linkage);
-    } else if (builtin.os == builtin.Os.windows) {
-        @export("WinMainCRTStartup", WinMainCRTStartup, strong_linkage);
+        @export("main", main, .Strong);
+    } else if (builtin.os == .windows) {
+        @export("WinMainCRTStartup", WinMainCRTStartup, .Strong);
+    } else if (is_wasm and builtin.os == .freestanding) {
+        @export("_start", wasm_freestanding_start, .Strong);
     } else {
-        @export("_start", _start, strong_linkage);
+        @export("_start", _start, .Strong);
     }
 }
 
+extern fn wasm_freestanding_start() void {
+    _ = callMain();
+}
+
 nakedcc fn _start() noreturn {
     if (builtin.os == builtin.Os.wasi) {
         std.os.wasi.proc_exit(callMain());
     }
 
     switch (builtin.arch) {
-        builtin.Arch.x86_64 => {
+        .x86_64 => {
             argc_ptr = asm ("lea (%%rsp), %[argc]"
                 : [argc] "=r" (-> [*]usize)
             );
         },
-        builtin.Arch.i386 => {
+        .i386 => {
             argc_ptr = asm ("lea (%%esp), %[argc]"
                 : [argc] "=r" (-> [*]usize)
             );
         },
-        builtin.Arch.aarch64, builtin.Arch.aarch64_be => {
+        .aarch64, .aarch64_be => {
             argc_ptr = asm ("mov %[argc], sp"
                 : [argc] "=r" (-> [*]usize)
             );
diff --git a/std/special/c.zig b/std/special/c.zig
index d5de52a6a3..6332d9a12e 100644
--- a/std/special/c.zig
+++ b/std/special/c.zig
@@ -11,14 +11,14 @@ const maxInt = std.math.maxInt;
 const is_wasm = switch (builtin.arch) { .wasm32, .wasm64 => true, else => false};
 const is_freestanding = switch (builtin.os) { .freestanding => true, else => false };
 comptime {
-    if (is_freestanding and is_wasm) {
+    if (is_freestanding and is_wasm and builtin.link_libc) {
         @export("_start", wasm_start, .Strong);
     }
 }
 
 extern fn main(argc: c_int, argv: [*][*]u8) c_int;
-extern fn wasm_start() c_int {
-    return main(0, undefined);
+extern fn wasm_start() void {
+    _ = main(0, undefined);
 }
 
 // Avoid dragging in the runtime safety mechanisms into this .o file,