gh-115028: Add support for relocatable installations using $ORIGIN in RPATH

Makefile.pre.in

@@ -1,4 +1,4 @@
-# Top-level Makefile for Python
+# Top-level Makeile for Python
 #
 # As distributed, this file is called Makefile.pre.in; it is processed
 # into the real Makefile by running the script ./configure, which
@@ -58,6 +58,9 @@ DTRACE_HEADERS= @DTRACE_HEADERS@
 DTRACE_OBJS=    @DTRACE_OBJS@
 DSYMUTIL=       @DSYMUTIL@
 DSYMUTIL_PATH=  @DSYMUTIL_PATH@
+PY_RPATH_EXEC=  @PY_RPATH_EXEC@
+PY_RPATH_LIB=   @PY_RPATH_LIB@
+PY_RPATH_MOD=   @PY_RPATH_MOD@
 
 GNULD=		@GNULD@
 
@@ -915,7 +918,8 @@ clinic-tests: check-clean-src $(srcdir)/Lib/test/clinic.test.c
 
 # Build the interpreter
 $(BUILDPYTHON):	Programs/python.o $(LINK_PYTHON_DEPS)
-	$(LINKCC) $(PY_CORE_LDFLAGS) $(LINKFORSHARED) -o $@ Programs/python.o $(LINK_PYTHON_OBJS) $(LIBS) $(MODLIBS) $(SYSLIBS)
+	$(LINKCC) $(PY_CORE_LDFLAGS) $(LINKFORSHARED) $(PY_RPATH_EXEC) -o $@ Programs/python.o $(LINK_PYTHON_OBJS) $(LIBS) $(MODLIBS) $(SYSLIBS)
+
 
 platform: $(PYTHON_FOR_BUILD_DEPS) pybuilddir.txt
 	$(RUNSHARED) $(PYTHON_FOR_BUILD) -c 'import sys ; from sysconfig import get_platform ; print("%s-%d.%d" % (get_platform(), *sys.version_info[:2]))' >platform
@@ -945,7 +949,7 @@ $(LIBRARY): $(LIBRARY_OBJS)
 	$(AR) $(ARFLAGS) $@ $(LIBRARY_OBJS)
 
 libpython$(LDVERSION).so: $(LIBRARY_OBJS) $(DTRACE_OBJS)
-	$(BLDSHARED) -Wl,-h$(INSTSONAME) -o $(INSTSONAME) $(LIBRARY_OBJS) $(MODLIBS) $(SHLIBS) $(LIBC) $(LIBM)
+	$(BLDSHARED) -Wl,-h$(INSTSONAME) $(PY_RPATH_LIB) -o $(INSTSONAME) $(LIBRARY_OBJS) $(MODLIBS) $(SHLIBS) $(LIBC) $(LIBM)
 	if test $(INSTSONAME) != $@; then \
 		$(LN) -f $(INSTSONAME) $@; \
 	fi

Misc/NEWS.d/next/Build/2025-03-26-23-34-17.gh-issue-115028.-jEZA-.rst

@@ -0,0 +1,4 @@
+Add a new ``--with-relative-rpath`` configure option that sets $ORIGIN-based
+RPATHs for Python binaries when enabled. This is a first step towards making
+Python installations more relocatable on Linux by allowing shared libraries
+to be found relative to their binary locations. Currently Linux-only.

Modules/makesetup

@@ -274,7 +274,7 @@ sed -e 's/[ 	]*#.*//' -e '/^[ 	]*$/d' |
 				;;
 			esac
 			rule="$file: $objs"
-			rule="$rule; \$(BLDSHARED) $objs $libs \$(LIBPYTHON) -o $file"
+			rule="$rule; \$(BLDSHARED) \$(PY_RPATH_MOD) $objs $libs \$(LIBPYTHON) -o $file"
 			echo "$rule" >>$rulesf
 		done
 	done

configure.ac

@@ -3356,6 +3356,38 @@ AC_MSG_RESULT([no])
 with_tsan="no"
 ])
 
+# Check for --with-relative-rpath
+AC_MSG_CHECKING([for --with-relative-rpath])
+AC_ARG_WITH([relative-rpath],
+  [AS_HELP_STRING([--with-relative-rpath],
+    [use relative rpath with $ORIGIN for binaries (Linux only)])],
+  [], [with_relative_rpath=no])
+
+# Initialize empty RPATH variables
+PY_RPATH_EXEC=""
+PY_RPATH_LIB=""
+PY_RPATH_MOD=""
+
+if test "$with_relative_rpath" = "yes"; then
+  if test "$ac_sys_system" = "Linux"; then
+    # Define the RPATH settings for each binary type
+    PY_RPATH_EXEC="-Wl,-rpath,\\\$\$ORIGIN/../\$(PLATLIBDIR)"
+    PY_RPATH_LIB="-Wl,-rpath,\\\$\$ORIGIN"
+    PY_RPATH_MOD="-Wl,-rpath,\\\$\$ORIGIN/../../"
+    AC_MSG_RESULT([yes])
+  else
+    AC_MSG_RESULT([no - only supported on Linux])
+    with_relative_rpath=no
+  fi
+else
+  AC_MSG_RESULT([no])
+fi
+
+# Export these variables for the Makefile
+AC_SUBST([PY_RPATH_EXEC])
+AC_SUBST([PY_RPATH_LIB])
+AC_SUBST([PY_RPATH_MOD])
+
 # Set info about shared libraries.
 AC_SUBST([SHLIB_SUFFIX])
 AC_SUBST([LDSHARED])