From 91a68b5f61db50344c6a5df497f55370d54a7b15 Mon Sep 17 00:00:00 2001 From: Eli Zaretskii Date: Fri, 4 May 2018 18:12:32 +0300 Subject: ; * msdos/INSTALL: Add info about GCC versions. --- msdos/INSTALL | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) (limited to 'msdos') diff --git a/msdos/INSTALL b/msdos/INSTALL index 3b343f14563..3707f436625 100644 --- a/msdos/INSTALL +++ b/msdos/INSTALL @@ -19,6 +19,15 @@ the necessary utilities; search for "MS-DOS". The configuration step (see below) will test for these utilities and will refuse to continue if any of them isn't found. +You should carefully choose the version of GCC you use to build Emacs, +because recent versions of GCC don't support building Emacs very well. +The main issue is the debug info: the DJGPP build of Emacs must use +the COFF debug info. GCC support for COFF debug info was steadily +deteriorating since GCC 5, and GCC 8.1 officially stopped supporting +the -gcoff switch, which the Emacs build process needs. We recommend +using GCC 3.4.X and Binutils 2.26; GDB 7.2 is capable to debug an +Emacs binary built by this combination. + Bootstrapping Emacs or recompiling Lisp files in the `lisp' subdirectory using the various targets in the lisp/Makefile file requires additional utilities: `find' (from Findutils), GNU `echo' and @@ -70,15 +79,15 @@ Running "config msdos" checks for several programs that are required to configure and build Emacs; if one of those programs is not found, CONFIG.BAT stops and prints an error message. -On Windows NT and Windows 2000/XP/Vista/7, running "config msdos" +On Windows NT and Windows 2000/XP and later, running "config msdos" might print an error message like "VDM has been already loaded". This is because those systems have a program called `redir.exe' which is incompatible with a program by the same name supplied with DJGPP, which is used by config.bat. To resolve this, move the DJGPP's `bin' subdirectory to the front of your PATH environment variable. -Windows Vista/7 has several bugs in its DPMI server related to memory -allocation: it fails DPMI resize memory block function, and it +Windows Vista and later has several bugs in its DPMI server related to +memory allocation: it fails DPMI resize memory block function, and it arbitrarily limits the default amount of DPMI memory to 32MB. To work around these bugs, first configure Emacs to use the `malloc' function from the DJGPP library. To this end, run CONFIG.BAT with the -- cgit v1.2.3