Author :
Sergei Trofimovich
Date :
2021-06-27 16:50:20
Hash :132699b9 Message :configure.ac: add --disable-exec-static-tramp flag (#647)
Some projects like GHC (Glasgow Haskell Compiler) and
gobject-introspection use `ffi_closure_alloc()` as a way
to allocate executable memory. exec static tramp
interferes with it (unclear how exactly yet).
GHC symptom: ffi closure freeing cimplains about unexpected
trampoline (GHC manually fills one):
```
$ ghci
GHCi, version 8.10.5: https://www.haskell.org/ghc/ :? for help
ghc: freeHaskellFunctionPtr: not for me, guv! 0x7f0417a1efe8
ghc: freeHaskellFunctionPtr: not for me, guv! 0x7f0417a1efc8
```
gobject-introspection symptom:
```
$ meld
Segmentation fault (core dumped)
$ gdb --args /usr/bin/python3.9 /usr/bin/meld
(gdb) run
...
Thread 1 "python3.9" received signal SIGSEGV, Segmentation fault.
0x00007fffe9ac1ae8 in g_callable_info_free_closure (
callable_info=0x555555d45990, closure=0x7fffe9e70c20)
at ../gobject-introspection-1.68.0/girepository/girffi.c:428
428 g_free (wrapper->ffi_closure.cif->arg_types);
(gdb) bt
callable_info=0x555555d45990, closure=0x7fffe9e70c20)
at ../gobject-introspection-1.68.0/girepository/girffi.c:428
data=0x555555d252d0)
at ../pygobject-3.40.1/gi/pygi-closure.c:635
...
```
To ease downstreams narrowing down the actual problem let's
provide a knob to disable exec static trampolines.
The change for not affect current default.
Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>