Do not emit 100k data segments, browsers reject it (#1350)

Instead merge constant-offset segments if we must in order to stay under the limit.

If we can't - too many non-constant-offset segments - then issue a warning.

1 files changed, 8 insertions, 1 deletions

diff --git a/src/wasm-binary.h b/src/wasm-binary.h
index a407c56e4..12aecfeaa 100644
--- a/src/wasm-binary.h
+++ b/src/wasm-binary.h
@@ -37,7 +37,14 @@ namespace wasm {
 
 enum {
   // the maximum amount of bytes we emit per LEB
-  MaxLEB32Bytes = 5
+  MaxLEB32Bytes = 5,
+};
+
+// wasm VMs on the web have decided to impose some limits on what they
+// accept
+enum WebLimitations {
+  MaxDataSegments = 100 * 1000,
+  MaxFunctionBodySize = 128 * 1024
 };
 
 template<typename T, typename MiniT>