+if(WIN32)
+ #
+ # We need 3.12 or later, so that we can set policy CMP0074; see
+ # below.
+ #
+ cmake_minimum_required(VERSION 3.12)
+else(WIN32)
+ #
+ # For now, require only 2.8.12, just in case somebody is
+ # configuring with CMake on a "long-term support" version
+ # of some OS and that version supplies an older version of
+ # CMake.
+ #
+ # If this is ever updated to CMake 3.1 or later, remove the
+ # stuff in cmake/Modules/FindPCAP.cmake that appends subdirectories
+ # of directories from CMAKE_PREFIX_PATH to the PKG_CONFIG_PATH
+ # environment variable when running pkg-config, to make sure
+ # it finds any .pc file from there.
+ #
+ cmake_minimum_required(VERSION 2.8.12)
+endif(WIN32)
+
+#
+# We want find_path() and find_library() to honor {packagename}_ROOT,
+# as that appears to be the standard way to say "hey, look here for
+# this package" from the command line.
+#
+if(POLICY CMP0074)
+ cmake_policy(SET CMP0074 NEW)
+endif()
+
+#
+# OK, this is a pain.
+#
+# When building on NetBSD, with a libpcap installed from pkgsrc,
+# a -Wl,-rpath,/usr/pkg/lib option is added to the options when
+# linking tcpdump. This puts /usr/pkg/lib into the run-time path.
+#
+# However, by default, CMake adds a rule to the install CMake script
+# a CMake command (using an undocumented subcommand of file()) that
+# strips /usr/pkg/lib *out* of the run-time path; the message in the
+# output for the "install" target is
+#
+# -- Set runtime path of "{target-directory}/tcpdump" to ""
+#
+# I am not certain what the rationale is for doing this, but a
+# *consequence* of this is that, when you run the installed tcpdump,
+# it fails to find libpcap.so:
+#
+# $ {target-directory}/tcpdump -h
+# {target-directory}/tcpdump: Shared object "libpcap.so.0" not found
+#
+# It also appears to be the case that, on Ubuntu 22.04, FreeBSD 12,
+# DragonFly BSD 5.8, OpenBSD 6.6, and Solaris 11.4,
+#
+# On Ubuntu and Solaris, even if you have a libpcap in /usr/local, you
+# have to provide not only -I/usr/local/include and -L/usr/local/lib,
+# you also must provide -Wl,-rpath,/usr/local/lib in order to have
+# the run-time linker look in /usr/local/lib for libpcap. If it's not
+# specified, then, if the shared library major version number of the
+# libpcap in /usr/lib is the same as the shared major version number
+# of the libpcap in /usr/local/lib, the run-time linker will find the
+# libpcap in /usr/lib; if the versions are different, the run-time
+# linker will fail to find the libpcap in /usr/lib, so the program will
+# fail to run.
+#
+# We suppress this by setting CMAKE_INSTALL_RPATH_USE_LINK_PATH to TRUE;
+# as the documentation for that variable says:
+#
+# Add paths to linker search and installed rpath.
+#
+# CMAKE_INSTALL_RPATH_USE_LINK_PATH is a boolean that if set to True
+# will append to the runtime search path (rpath) of installed
+# binaries any directories outside the project that are in the linker
+# search path or contain linked library files. The directories are
+# appended after the value of the INSTALL_RPATH target property.
+#
+# If, for whatever reason, directories in which we search for external
+# libraries, other than the standard system library directories, are
+# added to the executable's rpath in the build process, we most
+# defintely want them in the installed image's rpath if they are
+# necessary in order to find the libraries at run time.
+#
+set(CMAKE_INSTALL_RPATH_USE_LINK_PATH TRUE)
projects / tcpdump / blobdiff