ecl build with Xcode 12

[jhpalmieri]

The configure script for ecl fails with Xcode 12, with this kind of error in config.log:

conftest.c:4:3: error: implicitly declaring library function 'exit' with type 'void (int) __attribute__((noreturn))' [-Werror,-Wimplicit-function-declaration]
  exit(0);
  ^
conftest.c:4:3: note: include the header <stdlib.h> or explicitly provide a declaration for 'exit'
1 error generated.

upstream, in the develop branch, this is fixed in https://gitlab.com/embeddable-common-lisp/ecl/-/merge_requests/231

Upstream: Fixed upstream, but not in a stable release.

CC: @dimpase @spaghettisalat

Component: packages: standard

Author: John Palmieri

Branch/Commit: e5aeb62

Reviewer: Dima Pasechnik

Issue created by migration from https://trac.sagemath.org/ticket/30594

[jhpalmieri]

comment:1

We can imitate the changes in #30593. Here is a patch to do that. It works, but is there a better way?

[jhpalmieri]

Branch: u/jhpalmieri/ecl-vs-xcode12

[jhpalmieri]

Commit: e5aeb62

[jhpalmieri]

New commits:

e5aeb62

trac 30594: allow ecl to build with Xcode 12.

[jhpalmieri]

Author: John Palmieri

[dimpase]

comment:5

this seems to come from an autoconf macro, not from configure.ac itself, but which one needs to be dug up.

aclocal.m4 has hand-written macros with C/C++ programs calling exit(), and not including stdlib.h (which, by right, must be done, according to man 3 exit) - I suppose it is from there.

Once Apple in its infinite wisdom allows the download of Xcode 12 on my machine to complete, I'll have a look (assuming it is reproducible on macOS 10).

[dimpase]

comment:6

Is this on macOS 10, or only on Big Sur?

[dimpase]

comment:7

should not be a blocker, as only beta tools are affected.