build: Add DESTDIR to make

Add the variable DESTDIR that allows a user to install into
a directory that will later be moved to another host. This
facilitates the creation of distribution packages.

  make DESTDIR=/tmp/build prefix=/usr install

Will install the program files into /tmp/build/usr/..
but the program will expect to find itself in the /usr/..
directories.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

2 files changed, 31 insertions, 21 deletions

diff --git a/Documentation/Makefile b/Documentation/Makefile
index d161703..b7c17e7 100644
--- a/Documentation/Makefile
+++ b/Documentation/Makefile
@@ -12,7 +12,7 @@ else
   Q = @
   print_asciidoc =              echo '      ASCIIDOC            '`basename $@`;
   print_xsltproc =              echo '      XSLTPROC            '`basename $@`;
-  print_install =               echo '      INSTALL             '`basename $1`' to      '$2;
+  print_install =               echo '      INSTALL             '`basename $1`' to      $(DESTDIR_SQ)'$2;
   hide_xsltproc_output = 2> /dev/null
 endif
 
@@ -69,21 +69,23 @@ MAN5 = $(patsubst %.5.txt,$(obj)/%.5, ${TEXT5})
 
 all: $(MAN1) $(MAN5)
 
+# Need to find out how to export a macro instead of
+# copying this from the main Makefile.
 define do_install
-        $(print_install)                        \
-        if [ ! -d $2 ]; then                    \
-                $(INSTALL) -d -m 755 $2 ;       \
-        fi;                                     \
-        $(INSTALL) $1 $2;
+        $(print_install)                                \
+        if [ ! -d '$(DESTDIR_SQ)$2' ]; then             \
+                $(INSTALL) -d -m 755 '$(DESTDIR_SQ)$2'; \
+        fi;                                             \
+        $(INSTALL) $1 '$(DESTDIR_SQ)$2'
 endef
 
 MAN1_INSTALL = $(MAN1:%.1=%.1.install)
 MAN5_INSTALL = $(MAN5:%.5=%.5.install)
 
 $(MAN1_INSTALL): %.1.install : %.1 force
-        $(Q)$(call do_install, $<, '$(man_dir_SQ)/man1')
+        $(Q)$(call do_install,$<,$(man_dir_SQ)/man1)
 $(MAN5_INSTALL): %.5.install : %.5 force
-        $(Q)$(call do_install, $<, '$(man_dir_SQ)/man5')
+        $(Q)$(call do_install,$<,$(man_dir_SQ)/man5)
 
 install: $(MAN1_INSTALL) $(MAN5_INSTALL)
 
diff --git a/Makefile b/Makefile
index a358f82..fb06e26 100644
--- a/Makefile
+++ b/Makefile
@@ -18,6 +18,13 @@ AR = $(CROSS_COMPILE)ar
 EXT = -std=gnu99
 INSTALL = install
 
+# Use DESTDIR for installing into a different root directory.
+# This is useful for building a package. The program will be
+# installed in this directory as if it was the root directory.
+# Then the build tool can move it later.
+DESTDIR ?=
+DESTDIR_SQ = '$(subst ','\'',$(DESTDIR))'
+
 prefix ?= /usr/local
 bindir_relative = bin
 bindir = $(prefix)/$(bindir_relative)
@@ -25,6 +32,7 @@ man_dir = $(prefix)/share/man
 man_dir_SQ = '$(subst ','\'',$(man_dir))'
 
 export man_dir man_dir_SQ INSTALL
+export DESTDIR DESTDIR_SQ
 
 ifeq ($(prefix),$(HOME))
 plugin_dir = $(HOME)/.trace-cmd/plugins
@@ -186,7 +194,7 @@ else
   print_plugin_obj_compile =    echo '  $(GUI)COMPILE PLUGIN OBJ '$(GOBJ);
   print_plugin_build =          echo '  $(GUI)BUILD PLUGIN       '$(GOBJ);
   print_static_lib_build =      echo '  $(GUI)BUILD STATIC LIB   '$(GOBJ);
-  print_install =               echo '  $(GUI)INSTALL     '$(GSPACE)$1' to      '$2;
+  print_install =               echo '  $(GUI)INSTALL     '$(GSPACE)$1' to      $(DESTDIR_SQ)$2';
 endif
 
 do_fpic_compile =                                       \
@@ -419,36 +427,36 @@ TAGS:	force
 PLUGINS_INSTALL = $(subst .so,.install,$(PLUGINS)) $(subst .so,.install,$(PYTHON_PLUGINS))
 
 define do_install
-        $(print_install)                        \
-        if [ ! -d $2 ]; then                    \
-                $(INSTALL) -d -m 755 $2 ;       \
-        fi;                                     \
-        $(INSTALL) $1 $2;
+        $(print_install)                                \
+        if [ ! -d '$(DESTDIR_SQ)$2' ]; then             \
+                $(INSTALL) -d -m 755 '$(DESTDIR_SQ)$2'; \
+        fi;                                             \
+        $(INSTALL) $1 '$(DESTDIR_SQ)$2'
 endef
 
 $(PLUGINS_INSTALL): %.install : %.so force
-        $(Q)$(call do_install, $<, '$(plugin_dir_SQ)')
+        $(Q)$(call do_install,$<,$(plugin_dir_SQ))
 
 install_plugins: $(PLUGINS_INSTALL)
 
 $(PYTHON_SO_INSTALL): %.install : %.so force
-        $(Q)$(call do_install, $<, '$(python_dir_SQ)')
+        $(Q)$(call do_install,$<,$(python_dir_SQ))
 
 $(PYTHON_PY_INSTALL): %.install : %.py force
-        $(Q)$(call do_install, $<, '$(python_dir_SQ)')
+        $(Q)$(call do_install,$<,$(python_dir_SQ))
 
 install_python: $(PYTHON_SO_INSTALL) $(PYTHON_PY_INSTALL)
 
 install_cmd: all_cmd install_plugins install_python
-        $(Q)$(call do_install, trace-cmd, '$(bindir_SQ)')
+        $(Q)$(call do_install,trace-cmd,$(bindir_SQ))
 
 install: install_cmd
         @echo "Note: to install the gui, type \"make install_gui\""
 
 install_gui: install_cmd gui
-        $(Q)$(call do_install, trace-view, '$(bindir_SQ)')
-        $(Q)$(call do_install, trace-graph, '$(bindir_SQ)')
-        $(Q)$(call do_install, kernelshark, '$(bindir_SQ)')
+        $(Q)$(call do_install,trace-view,$(bindir_SQ))
+        $(Q)$(call do_install,trace-graph,$(bindir_SQ))
+        $(Q)$(call do_install,kernelshark,$(bindir_SQ))
 
 doc:
         $(MAKE) -C $(src)/Documentation all