Autoconf: Add autogen.sh, remove configure and config.h.in

Put autoconf-generated files in the release tarball.

The minimum required version of autoconf is currently 2.69.

If version 2.69 or later is already installed and there is no
autoconf default, it may be necessary to set the AUTORECONF
environment variable to enable the one to use, like:
AUTORECONF=autoreconf-2.69 ./autogen.sh
or
AUTORECONF=autoreconf-2.71 ./autogen.sh

(backported from commit 15e642a)

.cirrus.yml

@@ -51,6 +51,7 @@ linux_task:
     - apt list --installed 'lib*-dev'
     - echo '$ git clone [...] libpcap.git'
     - git -C .. clone --depth ${CIRRUS_CLONE_DEPTH} --branch=master --quiet ${LIBPCAP_GIT}
+    - ./autogen.sh
     - ./configure --quiet # build the Makefile
     - make releasecheck
     - make whitespacecheck
@@ -90,4 +91,5 @@ coverity_task:
     - apt-get -qy install libssl-dev libsmi2-dev libcap-ng-dev libpcap-dev >/dev/null
     - apt-get -qy install git curl wget ruby rubygems ruby-json >/dev/null # for the coverity script
     - apt list --installed 'lib*-dev'
+    - ./autogen.sh
     - ./.ci-coverity-scan-build.sh

.gitignore

@@ -5,9 +5,11 @@ Makefile
 *.o
 libnetdissect.a
 config.h
+config.h.in
 config.log
 config.cache
 config.status
+configure
 .devel
 os-proto.h
 stamp-h

CHANGES

@@ -64,6 +64,8 @@ DayOfTheWeek, Month DD, YYYY / The Tcpdump Group
       Autoconf: Fix --static-pcap-only test on Solaris 10.
       autoconf: Add some warning flags for clang 13 or newer.
       Autoconf: Update config.{guess,sub}, timestamps 2024-01-01.
+      Autoconf: Add autogen.sh, remove configure and config.h.in and put
+        these generated files in the release tarball.
       configure: Apply autoupdate 2.69.
       CMake: improve the comment before project(tcpdump C).
       Do not require vsnprintf().

INSTALL.md

@@ -12,9 +12,27 @@ the generally available GNU C compiler (GCC) or Clang.
 
 After libpcap has been built (either install it with `make install` or
 make sure both the libpcap and tcpdump source trees are in the same
-directory), run `./configure` (a shell script). `configure` will
+directory), do the following steps:
+
+* If you build from a git clone rather than from a release archive,
+run `./autogen.sh` (a shell script). The autogen.sh script will
+build the `configure` and `config.h.in` files.
+
+On some system, you may need to set the `AUTORECONF` variable, like:
+`AUTORECONF=autoreconf-2.69 ./autogen.sh`
+to select the `autoreconf` version you want to use.
+
+* Run `./configure` (a shell script). The configure script will
 determine your system attributes and generate an appropriate `Makefile`
-from `Makefile.in`.  Now build tcpdump by running `make`.
+from `Makefile.in`.  The configure script has a number of options to
+control the configuration of tcpdump; `./configure --help` will show
+them.
+
+* Next, build tcpdump by running `make`.
+
+On OpenBSD, you may need to set, before the `make`, the `AUTOCONF_VERSION`
+variable like:
+`AUTOCONF_VERSION=2.69 make`
 
 If everything builds fine, `su` and type `make install`.  This will install
 tcpdump and the manual entry.  Any user will be able to use tcpdump to
@@ -62,15 +80,14 @@ ascii_strcasecmp.c - locale-independent case-independent string comparison
 		routines
 atime.awk	- TCP ack awk script
 atm.h		- ATM traffic type definitions
+autogen.sh	- build configure and config.h.in (run this first)
 bpf_dump.c	- BPF program printing routines, in case libpcap doesn't
 		  have them
 chdlc.h		- Cisco HDLC definitions
 cpack.c		- functions to extract packed data
 cpack.h		- declarations of functions to extract packed data
 config.guess	- autoconf support
-config.h.in	- autoconf input
 config.sub	- autoconf support
-configure	- configure script (run this first)
 configure.ac	- configure script source
 doc/README.*	- some building documentation
 ethertype.h	- Ethernet type value definitions

Makefile.in

@@ -344,6 +344,7 @@ EXTRA_DIST = \
 	README.md \
 	VERSION \
 	aclocal.m4 \
+	autogen.sh \
 	atime.awk \
 	bpf_dump.c \
 	cmake/Modules/FindCRYPTO.cmake \
@@ -352,9 +353,7 @@ EXTRA_DIST = \
 	cmake_uninstall.cmake.in \
 	cmakeconfig.h.in \
 	config.guess \
-	config.h.in \
 	config.sub \
-	configure \
 	configure.ac \
 	doc/README.aix.md \
 	doc/README.NetBSD.md \
@@ -386,7 +385,7 @@ EXTRA_DIST = \
 	stime.awk \
 	tcpdump.1.in
 
-TEST_DIST= `git ls-files tests | grep -v 'tests/\..*'`
+TEST_DIST= `git -C "$$DIR" ls-files tests | grep -v 'tests/\..*'`
 
 RELEASE_FILES = $(CSRC) $(HDR) $(LIBNETDISSECT_SRC) $(EXTRA_DIST) $(TEST_DIST)
 
@@ -446,7 +445,8 @@ clean:
 
 distclean:
 	rm -f $(CLEANFILES) Makefile config.cache config.log config.status \
-	    config.h os-proto.h stamp-h stamp-h.in $(PROG).1 \
+	    config.h config.h.in config.h.in~ configure configure~ configure.ac~ \
+	    os-proto.h stamp-h stamp-h.in $(PROG).1 \
 	    libnetdissect.a tests/.failed tests/.passed \
 	    tests/failure-outputs.txt
 	rm -rf autom4te.cache tests/DIFF tests/NEW
@@ -463,17 +463,52 @@ tags: $(TAGFILES)
 TAGS: $(TAGFILES)
 	etags $(TAGFILES)
 
+#
+# Use git archive piped to tar to construct a subdirectory whose name
+# is tcpdump-{release}, containing all the checked-in source files,
+# and then run autoreconf in that directory to generate the configure
+# script and other files from that source. Then remove autom4te.cache,
+# construct the release tarball from that subdirectory, and remove
+# the subdirectory.
+#
+# The --format=tar is to force git archive to write a non-compressed
+# archive, in case the platform's tar command doesn't have built-in
+# decompression.
+#
+# The ^{tree} is there to force git archive not to write out the
+# "helpful" global extended pax header with a commit ID, as not all
+# versions of tar can handle that (Solaris tar can't, for example).
+# (It turns HEAD, or a tag, both of which are apparently "tree-ish"es,
+# into a tree; apparently, unlike HEAD, or a tag, which have a commit
+# ID associated with them, the tree associated with them doesn't have
+# a commit ID, so no commit ID is available to write, and thus
+# git archive doesn't write one.)
+#
 releasetar:
 	@TAG=$(PROG)-`cat VERSION` && \
-	if git show-ref --tags --quiet --verify -- "refs/tags/$$TAG"; then \
-	    git archive --prefix="$$TAG"/ -o "$$TAG".tar.gz "$$TAG" \
-	    $(RELEASE_FILES) && \
+	if [ ! -d .git ]; then echo 'Not in a git clone, stop.'; exit 1; fi && \
+	TMPTESTFILE=`mktemp -t tmptestfile_XXXXXXXX` && \
+	rm -f "$$TMPTESTFILE" && \
+	AUTORECONF_DIR=`dirname "$$TMPTESTFILE"`/"$(PROG)"_build_autoreconf_$$$$ && \
+	DIR=`pwd` && \
+	rm -rf "$$AUTORECONF_DIR" && \
+	mkdir "$$AUTORECONF_DIR" && \
+	cd "$$AUTORECONF_DIR" && \
+	if git -C "$$DIR" show-ref --tags --quiet --verify -- "refs/tags/$$TAG"; then \
+	    (git -C "$$DIR" archive --format=tar --prefix="$$TAG"/ "$$TAG^{tree}" $(RELEASE_FILES) | \
+	     tar xf -) && \
 	    echo "Archive build from tag $$TAG."; \
 	else \
-	    git archive --prefix="$$TAG"/ -o "$$TAG".tar.gz HEAD \
-	    $(RELEASE_FILES) && \
+	    (git -C "$$DIR" archive --format=tar --prefix="$$TAG"/ "HEAD^{tree}" $(RELEASE_FILES) | \
+	     tar xf -) && \
 	    echo "No $$TAG tag. Archive build from HEAD."; \
-	fi
+	fi && \
+	(cd "$$TAG" && "$${AUTORECONF:-autoreconf}" && rm -rf autom4te.cache) && \
+	tar cf "$$DIR/$$TAG".tar "$$TAG" && \
+	rm -f "$$DIR/$$TAG".tar.gz && \
+	gzip --best "$$DIR/$$TAG".tar && \
+	cd "$$DIR" && \
+	rm -rf "$$AUTORECONF_DIR"
 
 releasecheck: releasetar
 	@TAG=$(PROG)-`cat VERSION` && \

autogen.sh

@@ -0,0 +1,25 @@
+#!/bin/sh -e
+
+: "${AUTORECONF:=autoreconf}"
+
+AUTORECONFVERSION=`$AUTORECONF --version 2>&1 | grep "^autoreconf" | sed 's/.*) *//'`
+
+maj=`echo "$AUTORECONFVERSION" | cut -d. -f1`
+min=`echo "$AUTORECONFVERSION" | cut -d. -f2`
+# The minimum required version of autoconf is currently 2.69.
+if [ "$maj" = "" ] || [ "$min" = "" ] || \
+   [ "$maj" -lt 2 ] || [ "$maj" -eq 2 -a "$min" -lt 69 ]; then
+	cat >&2 <<-EOF
+	Please install the 'autoconf' package version 2.69 or later.
+	If version 2.69 or later is already installed and there is no
+	autoconf default, it may be necessary to set the AUTORECONF
+	environment variable to enable the one to use, like:
+	AUTORECONF=autoreconf-2.69 ./autogen.sh
+	or
+	AUTORECONF=autoreconf-2.71 ./autogen.sh
+	EOF
+	exit 1
+fi
+
+echo "$AUTORECONF identification: $AUTORECONFVERSION"
+"$AUTORECONF" -f

build.sh

@@ -52,11 +52,13 @@ esac
 if [ "$CMAKE" = no ]; then
     if [ "$BUILD_LIBPCAP" = yes ]; then
         echo "Using PKG_CONFIG_PATH=$PKG_CONFIG_PATH"
+        run_after_echo ./autogen.sh
         run_after_echo ./configure --with-crypto="$CRYPTO" \
             --enable-smb="$SMB" --prefix="$PREFIX"
         LD_LIBRARY_PATH="$PREFIX/lib"
         export LD_LIBRARY_PATH
     else
+        run_after_echo ./autogen.sh
         run_after_echo ./configure --with-crypto="$CRYPTO" \
             --enable-smb="$SMB" --prefix="$PREFIX" --disable-local-libpcap
     fi

build_matrix.sh

@@ -62,14 +62,12 @@ build_tcpdump() {
                 fi
                 run_after_echo rm -rf "$PREFIX"/bin/tcpdump*
                 run_after_echo git status -suall
-                # Cancel changes in configure
-                run_after_echo git checkout configure
             done
         done
     done
 }
 
-touch .devel configure
+touch .devel
 for CC in $MATRIX_CC; do
     export CC
     discard_cc_cache