test/nosplit: apply stack limit adjustment in the right place
The nosplit test was originally written when the stack limit was a
mere 128 bytes. Now it's much larger, but rather than rewriting all of
the tests, we apply a hack to just add the extra space into the stack
frames of the existing tests.
Unfortunately, we add it in the wrong place. The extra space should be
added just once per chain of nosplit functions, but instead we add it
to every frame that appears first on a line in the test's little
script language. This means that for tests like
start 0 call f1
f1 16 nosplit call f2
f2 16 nosplit call f3
f3 16 nosplit call f4
f4 16 nosplit call f5
f5 16 nosplit call f6
f6 16 nosplit call f7
f7 16 nosplit call f8
f8 16 nosplit call end
end 1000
REJECT
we add 672 bytes to *every* frame, meaning that we wind up way over
the stack limit by the end of the stanza, rather than just a little as
originally intended.
Fix this by instead adding the extra space to the first nosplit
function in a stanza. This isn't perfect either, since we could have a
nosplit -> split -> nosplit chain, but it's the best we can do without
a graph analysis.
Change-Id: Ibf156c68fe3eb1b64a438115f4a17f1a6c7e2bd1
Reviewed-on: https://go-review.googlesource.com/c/go/+/398174
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>