INITIAL_MEMORY error when trying to set MAXIMUM_MEMORY

[mzukovec]

Version of emscripten/emsdk:
emcc (Emscripten gcc/clang-like replacement + linker emulating GNU ld) 3.1.73 (ac676d5)

Issue
When trying to allocate maximal initial memory, there is an error:
em++: error: MAXIMUM_MEMORY cannot be less than INITIAL_MEMORY

As I've inspected the code behind, it's due to the fact that INITIAL_MEMORY can be incremented withing the link.py -> inc_initial_memory which is quite a big increment in case of -phtread and -fsanitize=address, which is my case.

Can we make this more user friendly? Maybe some kind of check that it's capped to MAXIMUM_MEMORY.

Failing command line in full:

// cat main.cpp
int main() {
  return 0;
}

em++ main.cpp -o main.html -stdlib=libc++ -fsanitize=address -pthread -sSHARED_MEMORY=1 -sINITIAL_MEMORY=4288413696 -sMAXIMUM_MEMORY=4294967296 -sALLOW_MEMORY_GROWTH=1


em++: warning: -pthread + ALLOW_MEMORY_GROWTH may run non-wasm code slowly, see https://github.com/WebAssembly/design/issues/1271 [-Wpthreads-mem-growth]
(print from link.py) INITIAL_MEMORY 4902027264
(print from link.py) MAXIMUM_MEMORY 4294967296
em++: error: MAXIMUM_MEMORY cannot be less than INITIAL_MEMORY

[sbc100]

Yes, its certainly looks like we got at least give a better error here. ASAN requires a lot of extra memory but that way we calculate this and inject it into the exiting memory is pretty delicate/hairy.