From e58629b990ee8ca2dc8fde0703fc7ca2b4b2a809 Mon Sep 17 00:00:00 2001 From: Alex Crichton Date: Thu, 19 Apr 2018 14:51:59 -0700 Subject: [PATCH] wasm: Increase default stack size to 1MB This commit increases the dfeault stack size allocated to the wasm32-unknown-unknown target to 1MB by default. Currently the default stack size is one wasm page, or 64 kilobytes. This default stack is quite small and has caused a stack overflow or two in the wild by accident. The current "best practice" for fixing this is to pass `-Clink-args='-z stack-size=$bigger'` but that's not great nor always easy to do. A default of 1MB matches more closely with other platforms where it's "pretty big" by default. Note that it was tested and if the users uses `-C link-args` to pass a custom stack size that's still resepected as lld seems to take the first argument, and where rustc is passing it will always be last. --- src/librustc_trans/back/linker.rs | 1 + 1 file changed, 1 insertion(+) diff --git a/src/librustc_trans/back/linker.rs b/src/librustc_trans/back/linker.rs index ebcf06d63be26..e001e809ee5f0 100644 --- a/src/librustc_trans/back/linker.rs +++ b/src/librustc_trans/back/linker.rs @@ -960,6 +960,7 @@ impl Linker for WasmLd { fn finalize(&mut self) -> Command { self.cmd.arg("--threads"); + self.cmd.arg("-z").arg("stack-size=1048576"); // FIXME we probably shouldn't pass this but instead pass an explicit // whitelist of symbols we'll allow to be undefined. Unfortunately