fpc/utils/wasmbin

wasmbin

Collection of WebAssembly binary utils

wasmtool

wasmtool is an utility that allows to modify wasm binary linking information. wat2wasm util is capable of generating binaries with relocation information. However the symbol flags are setup in the manner that final binaries cannot be linked by wasm-ld utility. (i.e. non setting weak symbols).

command

Only one command should be specified per call

exportrename

--exportrename inputfile

The option allow to change the export name. The reasoning for that is wasm-ld behavior of renaming the export from the declared name to the symbol name.

The input file can be either a text file, containing a list of oldname new name values:

OldExportName=NewExportName

or the input file can point to an object file. The object file's export section is parsed for the desired export names.

symbolflag

--symbolflag inputfile

The action allows to modify flags for the specified symbols. The input file specified must contain the pairs of symbolname + desired flags.

$TESTUNIT_$$_ADD$LONGINT$LONGINT$$LONGINT=WH

The desired flag is a string (or a character) that should consists of the following characters. Each character corresponds to a certain symbol linking flag:

• W - WASM_SYM_BINDING_WEAK

• H - WASM_SYM_VISIBILITY_HIDDEN

• L - WASM_SYM_BINDING_LOCAL

• D - removes flag WASM_SYM_BINDING_LOCAL

Multiple characters can be specified per flag.

symbolauto

 --symbolauto

The flags for each symbol updated and is determined based of the symbol use: if a function is a stub function (the only code is "unreachable"), the status given "weak" (it's a reference function elsewhere)

if a function is located in the function table, then the status given is
"hidden" (do not add to the final linked executable)

if a function is not located in the function table, the status given is:
"hidden"+"local" (local means the function can be used only in this object file)

Imported and exported functions are left unmodified.