Instead of markGlobals calling markRoots unconditionally (which doesn't
make sense for -gc=none and -gc=leaking), provide markRoots as a
callback function.
This is in preparation for -gc=boehm, where the previous design is even
more awkward and a callback makes far more sense.
I've tested the size impact using `make smoketest XTENSA=0`. There is
none, except for two cases:
* One with `-opt=0` so const-propagation for the callback didn't take
place.
* One other on AVR, I don't know why but as it's only 16 bytes in a
very specific case I'm going to assume it's just a random change in
compiler output that caused a size difference.
We don't support these yet so let's just put them in a central location.
Once these functions are supported we can think about how to structure
the code again.
This reverts commit 0b3a7280fa and updates
the documentation a little bit to explain the purpose of -gc=none. (I'm
thinking about the attiny10 by the way where defaulting to -gc=none
makes sense).
Scan globals conservatively by reading writable sections from the PE
header.
I'd like to get rid of needing to precisely scan globals eventually, and
this brings us one step closer. It also avoids a bug with ThinLTO on
Windows.
Do it all at once in preparation for Go 1.18 support.
To make this commit, I've simply modified the `fmt-check` Makefile
target to rewrite files instead of listing the differences. So this is a
fully mechanical change, it should not have introduced any errors.
When using the latest wasi-libc I experienced a
panic on an attempt to call realloc. My first attempt to
add it to arch_tinygowasm.go was obviously not good (PR #2194). So here
is another suggestion.
This layout parameter is currently always nil and ignored, but will
eventually contain a pointer to a memory layout.
This commit also adds module verification to the transform tests, as I
found out that it didn't (and therefore didn't initially catch all
bugs).
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.
