[PATCH] D57909: [WebAssembly] Don't generate invalid modules when function signatures mismatch

[Rui Ueyama via Phabricator via llvm-commits]

ruiu added inline comments.


================
Comment at: wasm/SymbolTable.cpp:571-572
+
+// Remove any variant symbols that were created due to function signature
+// mismatches.
+void SymbolTable::handleSymbolVariants() {
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sbc100 wrote:
> ruiu wrote:
> > It looks like you are trying to reduce the number of stub functions, by generating only one stub for each function type. But is this necessary? Given that no production code will contain a stub, no one cares if a binary with type mismatch contains many duplicated stubs?
> Yes, I create one stub for each variant of each symbol by encoding the signature into a string and appending it to the symbol name.
> 
> Are you suggesting that createFunctionVariant not even use the symbol table at all and just unconditionally create a new Symbol outside the symbol table?  I guess it might work, but I'm not sure how much simpler it would make the code.
> 
> Finally I'm not sure this won't end up happening somewhat in production code, especially if we implement the more useful stubs that coerce rather than trap.
> 
I don't have a clear idea what I was suggesting, but feels like there's room to simplify the way how we creates stub functions. Currently the code for creating stub functions somewhat scatters over many places in this file.

I wonder if you can create a vector to which we store all (undefined?) symbols that we find type mismatch, and scan that vector at some point to create stubs?


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  rLLD LLVM Linker

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  https://reviews.llvm.org/D57909/new/

https://reviews.llvm.org/D57909