[PATCH] Makefile: warn user when libxml and/or libgtk2 are not available

[Florian Fainelli <f.fainelli@gmail.com>]

From: Florian Fainelli <f.fainelli@gmail.com>

Since sparse's c2xml is not always packaged by modern distributions, it can be
built as a host package in build systems, finding out why c2xml was not
compiled turned out to be easier if a warning was emitted, add two for libxml
and libgtk2 presence/absence.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
diff --git a/Makefile b/Makefile
index 74905df..e9ae26f 100644
--- a/Makefile
+++ b/Makefile
@@ -45,6 +45,8 @@ ifeq ($(HAVE_LIBXML),yes)
 PROGRAMS+=c2xml
 INST_PROGRAMS+=c2xml
 c2xml_EXTRA_OBJS = `pkg-config --libs libxml-2.0`
+else
+$(info Your system does not have libxml, disabling c2xml)
 endif

 ifeq ($(HAVE_GTK2),yes)
@@ -55,6 +57,8 @@ INST_PROGRAMS += test-inspect
 test-inspect_EXTRA_DEPS := ast-model.o ast-view.o ast-inspect.o
 test-inspect.o $(test-inspect_EXTRA_DEPS): CFLAGS += $(GTK2_CFLAGS)
 test-inspect_EXTRA_OBJS := $(GTK2_LIBS)
+else
+$(info Your system does not have libgtk2, disabling test-inspect)
 endif

 LIB_H=    token.h parse.h lib.h symbol.h scope.h expression.h target.h \
--