Implement automatic relocation of previously compiled-in paths.

With the exception of the env variables in src/bin/gnucash we're
fully relocatable now.



git-svn-id: svn+ssh://svn.gnucash.org/repo/gnucash/trunk@14862 57a11ea4-9604-0410-9ed3-97b8803252fd

macros/binreloc.m4

@@ -0,0 +1,77 @@
+# Check for binary relocation support.
+# Written by Hongli Lai
+# http://autopackage.org/
+
+AC_DEFUN([AM_BINRELOC],
+[
+	AC_ARG_ENABLE(binreloc,
+		[  --enable-binreloc       compile with binary relocation support
+                          (default=enable when available)],
+		enable_binreloc=$enableval,enable_binreloc=auto)
+
+	AC_ARG_ENABLE(binreloc-threads,
+		[  --enable-binreloc-threads      compile binary relocation with threads support
+	                         (default=yes)],
+		enable_binreloc_threads=$enableval,enable_binreloc_threads=yes)
+
+	BINRELOC_CFLAGS=
+	BINRELOC_LIBS=
+	if test "x$enable_binreloc" = "xauto"; then
+		AC_CHECK_FILE([/proc/self/maps])
+		AC_CACHE_CHECK([whether everything is installed to the same prefix],
+			       [br_cv_valid_prefixes], [
+				if test "$bindir" = '${exec_prefix}/bin' -a "$sbindir" = '${exec_prefix}/sbin' -a \
+					"$datadir" = '${prefix}/share' -a "$libdir" = '${exec_prefix}/lib' -a \
+					"$libexecdir" = '${exec_prefix}/libexec' -a "$sysconfdir" = '${prefix}/etc'
+				then
+					br_cv_valid_prefixes=yes
+				else
+					br_cv_valid_prefixes=no
+				fi
+				])
+	fi
+	AC_CACHE_CHECK([whether binary relocation support should be enabled],
+		       [br_cv_binreloc],
+		       [if test "x$enable_binreloc" = "xyes"; then
+		       	       br_cv_binreloc=yes
+		       elif test "x$enable_binreloc" = "xauto"; then
+			       if test "x$br_cv_valid_prefixes" = "xyes" -a \
+			       	       "x$ac_cv_file__proc_self_maps" = "xyes"; then
+				       br_cv_binreloc=yes
+			       else
+				       br_cv_binreloc=no
+			       fi
+		       else
+			       br_cv_binreloc=no
+		       fi])
+
+	if test "x$br_cv_binreloc" = "xyes"; then
+		BINRELOC_CFLAGS="-DENABLE_BINRELOC"
+		AC_DEFINE(ENABLE_BINRELOC,,[Use binary relocation?])
+		if test "x$enable_binreloc_threads" = "xyes"; then
+			AC_CHECK_LIB([pthread], [pthread_getspecific])
+		fi
+
+		AC_CACHE_CHECK([whether binary relocation should use threads],
+			       [br_cv_binreloc_threads],
+			       [if test "x$enable_binreloc_threads" = "xyes"; then
+					if test "x$ac_cv_lib_pthread_pthread_getspecific" = "xyes"; then
+						br_cv_binreloc_threads=yes
+					else
+						br_cv_binreloc_threads=no
+					fi
+			        else
+					br_cv_binreloc_threads=no
+				fi])
+
+		if test "x$br_cv_binreloc_threads" = "xyes"; then
+			BINRELOC_LIBS="-lpthread"
+			AC_DEFINE(BR_PTHREAD,1,[Include pthread support for binary relocation?])
+		else
+			BINRELOC_CFLAGS="$BINRELOC_CFLAGS -DBR_PTHREADS=0"
+			AC_DEFINE(BR_PTHREAD,0,[Include pthread support for binary relocation?])
+		fi
+	fi
+	AC_SUBST(BINRELOC_CFLAGS)
+	AC_SUBST(BINRELOC_LIBS)
+])