The uunf package stackoverflows with flambda

[vicuna]

Original bug ID: 7501
Reporter: @dbuenzli
Assigned to: @chambart
Status: closed (set by @alainfrisch on 2017-06-30T07:51:10Z)
Resolution: fixed
Priority: normal
Severity: minor
Version: 4.04.0
Fixed in version: 4.04.1
Category: middle end (typedtree to clambda)
Monitored by: @dbuenzli

Bug description

mshinwell told me the backtrace is useless so I elided it.

The source file is a generated one and only available in distributions do:

opam source uunf --dir /tmp/uunf
cat /tmp/uunf/src/uunf_data.ml

to consult it.

Steps to reproduce

ulimit -s
8192
opam switch 4.04.0+flambda
opam install uunf -v -v
[...]

• ocamlfind ocamlopt -c -g -bin-annot -safe-string -package bytes -package uchar -I src -I test -o src/uunf_data.cmx src/uunf_data.ml

• Fatal error: exception Stack overflow

[vicuna]

Comment author: @dbuenzli

Forgot to add seems to happen both on linux and osx.

[vicuna]

Comment author: @chambart

I could reproduced it on trunk.
The stack overflow happens during CSE.
The failing code is a large generated file containing arrays.
The entry function initializing the arrays is very large.

[vicuna]

Comment author: @dbuenzli

FTR easy repro instructions without going through ocamlfind (as requested by Mark)

opam source uunf --dir /tmp/uunf
cd /tmp/uunf
ocaml pkg/pkg.ml build
cd _build/src
ocamlopt -c -g -o uunf_data.cmx uunf_data.ml
Raised by primitive operation at file "asmcomp/CSEgen.ml", line 298, characters 22-58
Called from file "asmcomp/CSEgen.ml", line 330, characters 24-32

[vicuna]

Comment author: @chambart

Potential fix: #1089
This reduces the size of the code, hence preventing the stack overflow on that file. This does not prevent it on a much larger one.

[vicuna]

Comment author: @dbuenzli

This can be closed. It was fixed in 4.04.1.