regression: "panic: runtime error: out of memory" error on some tests on target cortex-m-qemu

[dkegel-fastly]

Using the command

tinygo test -v -target=cortex-m-qemu $foo

the following tests pass on both 0.21 and 0.23-dev:

container/heap
container/list
container/ring
encoding
hash/fnv
internal/itoa
reflect
testing/iotest
unicode/utf16

but the following tests pass on 0.21 and fail on 0.23-dev:

crypto/des
encoding/ascii85
encoding/hex
math/cmplx
net/mail
text/scanner
unicode/utf8

In all cases, the log shows "panic: runtime error: out of memory".

[dgryski]

The biggest pain I've had with trying to bisect between release and dev is the llvm version change. Maybe start with 3a4e0c9 and narrow down from there? I can maybe take a look this evening once I get qemu set up.

[aykevl]

TinyGo still supports LLVM 11, so that shouldn't be a problem. Just compile with go install -tags=llvm11.

[dgryski]

Unsurprisingly, bisecting gives a536ddc which brought in the regexp package to testing.

[dkegel-fastly]

Bleah. Dropping support for -run on small platforms doesn't sound great, but neither does switching to some other sort of matching than regexp...

[dgryski]

We could build a string matcher that just uses strings.Contains on "small" platforms. That way we still have some sort of matching behaviour, but it's not a full regexp engine..

[dankegel]

Probably the best option.

[dkegel-fastly]

OK, I'll bite. Who calls MainStart?

[aykevl]

I already replied on Slack, but for anybody reading this: try tinygo list -deps -test -json <package> to get the path to the generated file (the generated main package is the last package in the output).