[PATCH] maint: modernize README-{hacking,prereq}

[Paul Eggert]

---
 README-hacking | 60 +++++++++++++++++--------------
 README-prereq  | 96 +++++++++++++++++++-------------------------------
 2 files changed, 70 insertions(+), 86 deletions(-)

diff --git a/README-hacking b/README-hacking
index be9ea3766..44cb75b98 100644
--- a/README-hacking
+++ b/README-hacking
@@ -1,34 +1,45 @@
--*- outline -*-
+Building from a Git repository                         -*- outline -*-
 
 These notes intend to help people working on the checked-out sources.
 These requirements do not apply when building from a distribution tarball.
-See also HACKING for more detailed contribution guidelines.
+If this package has a file HACKING, please also read that file for
+more detailed contribution guidelines.
 
 * Requirements
 
-We've opted to keep only the highest-level sources in the GIT repository.
-This eases our maintenance burden, (fewer merges etc.), but imposes more
+We've opted to keep only the highest-level sources in the Git repository.
+This eases our maintenance burden (fewer merges etc.), but imposes more
 requirements on anyone wishing to build from the just-checked-out sources.
-Note the requirements to build the released archive are much less and
-are just the requirements of the standard ./configure && make procedure.
+(The requirements to build from a release are much less and are just
+the requirements of the standard './configure && make' procedure.)
 Specific development tools and versions will be checked for and listed by
 the bootstrap script.  See README-prereq for specific notes on obtaining
 these prerequisite tools.
 
 Valgrind <http://valgrind.org/> is also highly recommended, if
-Valgrind supports your architecture. See also README-valgrind.
+Valgrind supports your architecture.  See also README-valgrind
+(if present).
 
 While building from a just-cloned source tree may require installing a
-few prerequisites, later, a plain 'git pull && make' should be sufficient.
+few prerequisites, later, a plain 'git pull && make' typically suffices.
 
-* First GIT checkout
+* First Git checkout
 
 You can get a copy of the source repository like this:
 
-        $ git clone git://git.sv.gnu.org/coreutils
-        $ cd coreutils
+        $ git clone git://git.sv.gnu.org/<packagename>
+        $ cd <packagename>
 
-As an optional step, if you already have a copy of the gnulib git
+where '<packagename>' stands for 'coreutils' or whatever other package
+you are building.
+
+To use the most-recent Gnulib (as opposed to the Gnulib version that
+the package last synchronized to), do this next:
+
+        $ git submodule foreach git pull origin master
+        $ git commit -m 'build: update gnulib submodule to latest' gnulib
+
+As an optional step, if you already have a copy of the Gnulib Git
 repository, then you can use it as a reference to reduce download
 time and file system space requirements:
 
@@ -39,20 +50,14 @@ which are extracted from other source packages:
 
         $ ./bootstrap
 
-To use the most-recent gnulib (as opposed to the gnulib version that
-the package last synchronized to), do this next:
-
-        $ git submodule foreach git pull origin master
-        $ git commit -m 'build: update gnulib submodule to latest' gnulib
-
 And there you are!  Just
 
-        $ ./configure --quiet #[--enable-gcc-warnings] [*]
+        $ ./configure --quiet #[--disable-gcc-warnings] [*]
         $ make
         $ make check
 
 At this point, there should be no difference between your local copy,
-and the GIT master copy:
+and the Git master copy:
 
         $ git diff
 
@@ -60,12 +65,15 @@ should output no difference.
 
 Enjoy!
 
-[*] The --enable-gcc-warnings option is useful only with glibc
-and with a very recent version of gcc.  You'll probably also have
-to use recent system headers.  If you configure with this option,
-and spot a problem, please be sure to send the report to the bug
-reporting address of this package, and not to that of gnulib, even
-if the problem seems to originate in a gnulib-provided file.
+[*] By default GCC warnings are enabled when building from Git.
+If you get warnings with recent GCC and Glibc with default
+configure-time options, please report the warnings to the bug
+reporting address of this package instead of to bug-gnulib,
+even if the problem seems to originate in a Gnulib-provided file.
+If you get warnings with other configurations, you can run
+'./configure --disable-gcc-warnings' or 'make WERROR_CFLAGS='
+to build quietly or verbosely, respectively.
+-----
 
 * Submitting patches
 
diff --git a/README-prereq b/README-prereq
index 16684a8b8..176fb2199 100644
--- a/README-prereq
+++ b/README-prereq
@@ -1,65 +1,41 @@
 This gives some notes on obtaining the tools required for development.
-I.e., the tools checked for by the bootstrap script and include:
-
-- Autoconf  <https://www.gnu.org/software/autoconf/>
-- Automake  <https://www.gnu.org/software/automake/>
-- Bison     <https://www.gnu.org/software/bison/>
-- Gettext   <https://www.gnu.org/software/gettext/>
-- Git       <https://git-scm.com/>
-- Gperf     <https://www.gnu.org/software/gperf/>
-- Gzip      <https://www.gnu.org/software/gzip/>
-- Perl      <https://www.cpan.org/>
-- Rsync     <https://rsync.samba.org/>
-- Tar       <https://www.gnu.org/software/tar/>
-- Texinfo   <https://www.gnu.org/software/texinfo/>
-
-Note please try to install/build official packages for your system.
-If these programs are not available use the following instructions
-to build them and install the results into a directory that you will
-then use when building this package.
-
-Even if the official version of a package for your system is too old,
-please install it, as it may be required to build the newer versions.
-The examples below install into $HOME/coreutils/deps/, so if you are
-going to follow these instructions, first ensure that your $PATH is
-set correctly by running this command:
-
-  prefix=$HOME/coreutils/deps
+These tools can be used by the 'bootstrap' and 'configure' scripts,
+as well as by 'make'.  They include:
+
+- Autoconf   <https://www.gnu.org/software/autoconf/>
+- Automake   <https://www.gnu.org/software/automake/>
+- Bison      <https://www.gnu.org/software/bison/>
+- Gettext    <https://www.gnu.org/software/gettext/>
+- Git        <https://git-scm.com/>
+- Gperf      <https://www.gnu.org/software/gperf/>
+- Gzip       <https://www.gnu.org/software/gzip/>
+- Help2man   <https://www.gnu.org/software/help2man/>
+- M4         <https://www.gnu.org/software/m4/>
+- Make       <https://www.gnu.org/software/make/>
+- Perl       <https://www.cpan.org/>
+- Tar        <https://www.gnu.org/software/tar/>
+- Texinfo    <https://www.gnu.org/software/texinfo/>
+- Wget       <http://www.gnu.org/software/wget/>
+- XZ Utils   <https://tukaani.org/xz/>
+
+It is generally better to use official packages for your system.
+If a package is not officially available you can build it from source
+and install it into a directory that you can then use to build this
+package.  If some packages are available but are too old, install the
+too-old versions first as they may be needed to build newer versions.
+
+Here is an example of how to build a program from source.  This
+example is for Autoconf; a similar approach should work for the other
+developer prerequisites.  This example assumes Autoconf 2.71; it
+should be OK to use a later version of Autoconf, if available.
+
+  prefix=$HOME/prefix   # (or wherever else you choose)
   export PATH=$prefix/bin:$PATH
-
-* autoconf *
-
-  # Note Autoconf 2.62 or newer is needed to build automake-1.11.2
-  # but we specify 2.64 here as that's what coreutils requires.
-  # Please use the latest stable release version as indicated by git tags.
-  git clone --depth=1 git://git.sv.gnu.org/autoconf.git
-  cd autoconf
-  git pull --tags
-  git checkout v2.64
-  autoreconf -vi
-  ./configure --prefix=$prefix
-  make install
-
-* automake *
-
-  # Note help2man is required to build automake fully
-  git clone git://git.sv.gnu.org/automake.git
-  cd automake
-  git checkout v1.11.2
-  ./bootstrap
-  ./configure --prefix=$prefix
-  make install
-
-This package uses XZ utils (successor to LZMA) to create
-a compressed distribution tarball.  Using this feature of Automake
-requires version 1.10a or newer, as well as the xz program itself.
-
-* xz *
-
-  git clone https://git.tukaani.org/xz.git
-  cd xz
-  ./autogen.sh
+  wget https://ftp.gnu.org/pub/gnu/autoconf/autoconf-2.71.tar.gz
+  gzip -d <autoconf-2.71.tar.gz | tar xf -
+  cd autoconf-2.71
   ./configure --prefix=$prefix
   make install
 
-Now you can build this package as described in README-hacking.
+Once the prerequisites are installed, you can build this package as
+described in README-hacking.
-- 
2.32.0