On WebAssembly it is possible to grow the heap with the memory.grow
instruction. This commit implements this feature and with that also
removes the -heap-size flag that was reportedly broken (I haven't
verified that). This should make it easier to use TinyGo for
WebAssembly, where there was no good reason to use a fixed heap size.
This commit has no effect on baremetal targets with optimizations
enabled.
For example, for running tests with -target=wasm or
-target=cortex-m-qemu. It looks at the output to determine whether tests
were successful in the absence of a status code.
This is the same problem as in
https://github.com/tinygo-org/tinygo/pull/605, but other targets also
suffer from it.
Discovered with the GBA target, but as pointed out in
https://bugs.llvm.org/show_bug.cgi?id=42881#c1 this appears to be a bug
in the way external globals are declared, not in LLVM. Therefore I
decided that fixing it everywhere would be the best thing to do.
Ayke van Laethem
Jaden Weiss
BCG