Re: Emacs on QNX

[Elad Lahav <elahav@blackberry.com>]

On Thu, 2017-11-09 at 19:23 +0200, Eli Zaretskii wrote:
> I think you definitely need to increase the stack.  Emacs needs at
> least 2MB of stack space; on MS-Windows we use 8MB, and for a good
> reason.  So 512K is definitely too little.

Sorry, it took me a while to get back to this.
The following patch fixes the problem, and emacs/HEAD now builds and
runs on QNX:

=====
diff --git a/configure.ac b/configure.ac
index 469ad00eaa..e0944dd12b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -702,7 +702,11 @@ AC_DEFUN
   ## QNX Neutrino
   *-nto-qnx* )
     opsys=qnxnto
+    ## Need to use qcc and the -N flag to increase the default stack
+    ## size for the main thread.
+    CC=qcc
     CFLAGS="$CFLAGS -D__NO_EXT_QNX"
+    LDFLAGS=-N2MB
   ;;
 
   ## Intel 386 machines where we don't care about the manufacturer.
=====

qcc is a simple wrapper around gcc. It takes some extra arguments,
including -N, which sets the stack size of the main thread.

For the record, this is the command line I used to configure emacs:

# LIBXML2_CFLAGS=-I/usr/include LIBXML2_LIBS=-lxml2 -lm ./configure 
  --without-makeinfo --with-gnutls=no --with-x-toolkit=no

The LIBXML2_CFLAGS variable is bogus, as no special flags are required.
However, unless this variable being is set to a non-empty string the
configure script tries to use pkg-config for libxml2, which doesn't
work.

--Elad