sfgraph/wasm/test00/0m.sh

#/bin/sh -x
echo "tested with clang-7"
clang --version
clang --target=wasm32 --no-standard-libraries -Wl,--export-all -Wl,--no-entry -o add.wasm add.c
echo "adding memory support with -Wl,--import-memory for lenstr.c"
clang --target=wasm32 --no-standard-libraries -Wl,--export-all -Wl,--import-memory -Wl,--no-entry -o lenstr.wasm lenstr.c
exit 0

on debian with clang version 7, lld-7 as separate package installed
missing link to /usr/bin/ldd added to /usr/bin/ldd-7

The options passed to clang are:

    --target=wasm32 Set the build target to wasm.
    --no-standard-libraries Do not use libc (more on this later).
    -Wl,--export-all Export all symbols (i.e., add) from the compiled wasm file so that they can be used from JavaScript.
    -Wl,--no-entry Don't check for a main function.
    -o Set the output destination.

Options preceded by -Wl, are passed from the LLVM compiler to the linker.

The webserver to use is:
pythom -m SimpleHTTPServer

Then the page is on localhost at port 8000 and in console log file is "the answer is 3"