diff --git a/hawk/Makefile.in b/hawk/Makefile.in
index 420d695e..b1719b50 100644
--- a/hawk/Makefile.in
+++ b/hawk/Makefile.in
@@ -170,8 +170,8 @@ am__DIST_COMMON = $(srcdir)/Makefile.in $(top_srcdir)/ac/ar-lib \
 	$(top_srcdir)/ac/config.sub $(top_srcdir)/ac/install-sh \
 	$(top_srcdir)/ac/ltmain.sh $(top_srcdir)/ac/missing \
 	$(top_srcdir)/pkgs/hawk.spec.in ac/ar-lib ac/compile \
-	ac/config.guess ac/config.sub ac/depcomp ac/install-sh \
-	ac/ltmain.sh ac/missing
+	ac/config.guess ac/config.sub ac/install-sh ac/ltmain.sh \
+	ac/missing
 DISTFILES = $(DIST_COMMON) $(DIST_SOURCES) $(TEXINFOS) $(EXTRA_DIST)
 distdir = $(PACKAGE)-$(VERSION)
 top_distdir = $(distdir)
diff --git a/hawk/bin/Makefile.am b/hawk/bin/Makefile.am
index 00329c07..a486fea2 100644
--- a/hawk/bin/Makefile.am
+++ b/hawk/bin/Makefile.am
@@ -9,13 +9,7 @@ CPPFLAGS_COMMON = \
 	-I$(includedir)
 CFLAGS_COMMON =
 LDFLAGS_COMMON = -L$(abs_builddir)/../lib -L$(libdir)
-##
-## -lm may get omitted from dependency_libs in libhawk.la.
-## the generated libtool in the build directory may include -lm in postdeps
-## dependency_libs excludes items in postdeps.
-## specify -lm explicitly to satisfy dependency regardless of libtool behavior.
-##
-LIBADD_COMMON = -lhawk $(LIBM)
+LIBADD_COMMON = -lhawk 
 DEPENDENCIES_COMMON = ../lib/libhawk.la
 
 bin_PROGRAMS = hawk
@@ -27,6 +21,20 @@ hawk_SOURCES = main.c
 hawk_CPPFLAGS = $(CPPFLAGS_COMMON)
 hawk_CFLAGS = $(CFLAGS_COMMON)
 hawk_LDFLAGS = $(LDFLAGS_COMMON)
-hawk_LDADD = $(LIBADD_COMMON)
+##
+## -lm is omitted from dependency_libs in libhawk.la because
+## libhawk contains some C++ code and postdeps_CXX contains -lm.
+##
+## Under the default libtool configuration, postdeps is empty.
+## Under the C++ tagged libtool configuration, postdeps is set to 
+## the value of postdeps_CXX.
+##
+## libtool doesn't include -lm in dependency_libs in libhawk.la 
+## because libtool --tag=CXX is used for mixed C++ code.
+##
+## specify -lm to a C only target to satisify dependency regardless
+## of different behavior depending on the libtool tag.
+##
+hawk_LDADD = $(LIBADD_COMMON) $(LIBM)
 hawk_DEPENDENCIES = $(DEPENDENCIES_COMMON)
 
diff --git a/hawk/bin/Makefile.in b/hawk/bin/Makefile.in
index 07a6eb3e..01e8b34f 100644
--- a/hawk/bin/Makefile.in
+++ b/hawk/bin/Makefile.in
@@ -112,7 +112,6 @@ PROGRAMS = $(bin_PROGRAMS)
 am_hawk_OBJECTS = hawk-main.$(OBJEXT)
 hawk_OBJECTS = $(am_hawk_OBJECTS)
 am__DEPENDENCIES_1 =
-am__DEPENDENCIES_2 = $(am__DEPENDENCIES_1)
 AM_V_lt = $(am__v_lt_@AM_V@)
 am__v_lt_ = $(am__v_lt_@AM_DEFAULT_V@)
 am__v_lt_0 = --silent
@@ -342,7 +341,7 @@ CPPFLAGS_COMMON = \
 
 CFLAGS_COMMON = 
 LDFLAGS_COMMON = -L$(abs_builddir)/../lib -L$(libdir)
-LIBADD_COMMON = -lhawk $(LIBM)
+LIBADD_COMMON = -lhawk 
 DEPENDENCIES_COMMON = ../lib/libhawk.la
 
 ##################################################
@@ -352,7 +351,7 @@ hawk_SOURCES = main.c
 hawk_CPPFLAGS = $(CPPFLAGS_COMMON)
 hawk_CFLAGS = $(CFLAGS_COMMON)
 hawk_LDFLAGS = $(LDFLAGS_COMMON)
-hawk_LDADD = $(LIBADD_COMMON)
+hawk_LDADD = $(LIBADD_COMMON) $(LIBM)
 hawk_DEPENDENCIES = $(DEPENDENCIES_COMMON)
 all: all-am
 
diff --git a/hawk/lib/Makefile.am b/hawk/lib/Makefile.am
index c58e9869..50636abc 100644
--- a/hawk/lib/Makefile.am
+++ b/hawk/lib/Makefile.am
@@ -86,6 +86,7 @@ libhawk_la_SOURCES = \
 	hawk.c \
 	idmap-imp.h \
 	mb8.c \
+	misc-imp.h \
 	misc-prv.h \
 	misc.c \
 	parse-prv.h \
diff --git a/hawk/lib/Makefile.in b/hawk/lib/Makefile.in
index 4e6118a5..346b1046 100644
--- a/hawk/lib/Makefile.in
+++ b/hawk/lib/Makefile.in
@@ -221,8 +221,8 @@ am__libhawk_la_SOURCES_DIST = hawk.h hawk-arr.h hawk-chr.h hawk-cmn.h \
 	chr.c dir.c ecs-imp.h ecs.c err-prv.h err.c err-sys.c \
 	fmt-imp.h fmt.c fnc-prv.h fnc.c htb.c gem.c gem-skad.c \
 	gem-nwif.c gem-nwif2.c hawk-prv.h hawk.c idmap-imp.h mb8.c \
-	misc-prv.h misc.c parse-prv.h parse.c rbt.c rec.c rio-prv.h \
-	rio.c run-prv.h run.c tre-prv.h tre-ast.c tre-ast.h \
+	misc-imp.h misc-prv.h misc.c parse-prv.h parse.c rbt.c rec.c \
+	rio-prv.h rio.c run-prv.h run.c tre-prv.h tre-ast.c tre-ast.h \
 	tre-compile.c tre-compile.h tre-match-bt.c tre-match-pa.c \
 	tre-match-ut.h tre-mem.c tre-mem.h tre-parse.c tre-parse.h \
 	tre-stack.h tre-stack.c tre.c tree-prv.h tree.c uch-prop.h \
@@ -590,17 +590,17 @@ pkglib_LTLIBRARIES = libhawk.la $(am__append_15)
 libhawk_la_SOURCES = $(pkginclude_HEADERS) arr.c chr.c dir.c ecs-imp.h \
 	ecs.c err-prv.h err.c err-sys.c fmt-imp.h fmt.c fnc-prv.h \
 	fnc.c htb.c gem.c gem-skad.c gem-nwif.c gem-nwif2.c hawk-prv.h \
-	hawk.c idmap-imp.h mb8.c misc-prv.h misc.c parse-prv.h parse.c \
-	rbt.c rec.c rio-prv.h rio.c run-prv.h run.c tre-prv.h \
-	tre-ast.c tre-ast.h tre-compile.c tre-compile.h tre-match-bt.c \
-	tre-match-pa.c tre-match-ut.h tre-mem.c tre-mem.h tre-parse.c \
-	tre-parse.h tre-stack.h tre-stack.c tre.c tree-prv.h tree.c \
-	uch-prop.h uch-case.h utf16.c utf8.c utl-ass.c utl-skad.c \
-	utl-skad.h utl-sort.c utl-str.c utl-sys.c utl.c val-prv.h \
-	val.c xma.c hawk-cli.h hawk-fio.h hawk-mtx.h hawk-pio.h \
-	hawk-sio.h hawk-tio.h cli-imp.h cli.c fio.c mtx.c pio.c sio.c \
-	syscall.h tio.c std-prv.h std.c $(am__append_8) \
-	$(am__append_9)
+	hawk.c idmap-imp.h mb8.c misc-imp.h misc-prv.h misc.c \
+	parse-prv.h parse.c rbt.c rec.c rio-prv.h rio.c run-prv.h \
+	run.c tre-prv.h tre-ast.c tre-ast.h tre-compile.c \
+	tre-compile.h tre-match-bt.c tre-match-pa.c tre-match-ut.h \
+	tre-mem.c tre-mem.h tre-parse.c tre-parse.h tre-stack.h \
+	tre-stack.c tre.c tree-prv.h tree.c uch-prop.h uch-case.h \
+	utf16.c utf8.c utl-ass.c utl-skad.c utl-skad.h utl-sort.c \
+	utl-str.c utl-sys.c utl.c val-prv.h val.c xma.c hawk-cli.h \
+	hawk-fio.h hawk-mtx.h hawk-pio.h hawk-sio.h hawk-tio.h \
+	cli-imp.h cli.c fio.c mtx.c pio.c sio.c syscall.h tio.c \
+	std-prv.h std.c $(am__append_8) $(am__append_9)
 libhawk_la_CPPFLAGS = $(CPPFLAGS_ALL_COMMON) $(CPPFLAGS_PFMOD) \
 	$(am__append_3)
 libhawk_la_CFLAGS = $(CFLAGS_ALL_COMMON)
diff --git a/hawk/samples/Makefile.am b/hawk/samples/Makefile.am
index 27eb3d18..e89dd69a 100644
--- a/hawk/samples/Makefile.am
+++ b/hawk/samples/Makefile.am
@@ -10,7 +10,7 @@ CPPFLAGS_COMMON = \
 CFLAGS_COMMON =
 CXXFLAGS_COMMON =
 LDFLAGS_COMMON = -L$(abs_builddir)/../lib -L$(libdir)
-LIBADD_COMMON = -lhawk $(LIBM)
+LIBADD_COMMON = -lhawk 
 DEPENDENCIES_COMMON = ../lib/libhawk.la
 
 bin_PROGRAMS = 
@@ -22,9 +22,8 @@ bin_PROGRAMS += hawk02 hawk51
 hawk02_SOURCES = hawk02.c
 hawk02_CPPFLAGS = $(CPPFLAGS_COMMON)
 hawk02_CFLAGS = $(CFLAGS_COMMON)
-hawk02_CXXFLAGS = $(CXXFLAGS_COMMON)
 hawk02_LDFLAGS = $(LDFLAGS_COMMON)
-hawk02_LDADD = $(LIBADD_COMMON)
+hawk02_LDADD = $(LIBADD_COMMON) $(LIBM)
 hawk02_DEPENDENCIES = $(DEPENDENCIES_COMON)
 
 hawk51_SOURCES = hawk51.cpp
diff --git a/hawk/samples/Makefile.in b/hawk/samples/Makefile.in
index e1cbc25f..8f3d7876 100644
--- a/hawk/samples/Makefile.in
+++ b/hawk/samples/Makefile.in
@@ -115,7 +115,6 @@ am__hawk02_SOURCES_DIST = hawk02.c
 @ENABLE_CXX_TRUE@am_hawk02_OBJECTS = hawk02-hawk02.$(OBJEXT)
 hawk02_OBJECTS = $(am_hawk02_OBJECTS)
 am__DEPENDENCIES_1 =
-am__DEPENDENCIES_2 = $(am__DEPENDENCIES_1)
 AM_V_lt = $(am__v_lt_@AM_V@)
 am__v_lt_ = $(am__v_lt_@AM_DEFAULT_V@)
 am__v_lt_0 = --silent
@@ -371,14 +370,13 @@ CPPFLAGS_COMMON = \
 CFLAGS_COMMON = 
 CXXFLAGS_COMMON = 
 LDFLAGS_COMMON = -L$(abs_builddir)/../lib -L$(libdir)
-LIBADD_COMMON = -lhawk $(LIBM)
+LIBADD_COMMON = -lhawk 
 DEPENDENCIES_COMMON = ../lib/libhawk.la
 @ENABLE_CXX_TRUE@hawk02_SOURCES = hawk02.c
 @ENABLE_CXX_TRUE@hawk02_CPPFLAGS = $(CPPFLAGS_COMMON)
 @ENABLE_CXX_TRUE@hawk02_CFLAGS = $(CFLAGS_COMMON)
-@ENABLE_CXX_TRUE@hawk02_CXXFLAGS = $(CXXFLAGS_COMMON)
 @ENABLE_CXX_TRUE@hawk02_LDFLAGS = $(LDFLAGS_COMMON)
-@ENABLE_CXX_TRUE@hawk02_LDADD = $(LIBADD_COMMON)
+@ENABLE_CXX_TRUE@hawk02_LDADD = $(LIBADD_COMMON) $(LIBM)
 @ENABLE_CXX_TRUE@hawk02_DEPENDENCIES = $(DEPENDENCIES_COMON)
 @ENABLE_CXX_TRUE@hawk51_SOURCES = hawk51.cpp
 @ENABLE_CXX_TRUE@hawk51_CPPFLAGS = $(CPPFLAGS_COMMON)
diff --git a/hawk/t/Makefile.am b/hawk/t/Makefile.am
index 931e2dca..6aff1ee2 100644
--- a/hawk/t/Makefile.am
+++ b/hawk/t/Makefile.am
@@ -8,12 +8,15 @@ CPPFLAGS_COMMON = \
 	-I$(includedir)
 CFLAGS_COMMON =
 LDFLAGS_COMMON=-L$(abs_builddir)/../lib  -L$(libdir)
+## place $(LIBM)  here as all programs below are C only programs linked
+## against the C/C++ hybrid library. Read comments in ../bin/Makefile.am
+## for more information.
 LIBADD_COMMON = -lhawk $(LIBM)
 DEPENDENCIES_COMMON = ../lib/libhawk.la
 
 check_SCRIPTS = h-001.hawk h-002.hawk
 ##noinst_SCRIPTS = $(check_SCRIPTS)
-EXTRA_DIST = $(check_SCRIPTS)
+EXTRA_DIST = $(check_SCRIPTS) ensure.inc
 
 check_PROGRAMS = t-001 t-002 t-003 t-004 t-005 t-006
 
diff --git a/hawk/t/Makefile.in b/hawk/t/Makefile.in
index e13e836f..47bc265c 100644
--- a/hawk/t/Makefile.in
+++ b/hawk/t/Makefile.in
@@ -575,7 +575,7 @@ LDFLAGS_COMMON = -L$(abs_builddir)/../lib  -L$(libdir)
 LIBADD_COMMON = -lhawk $(LIBM)
 DEPENDENCIES_COMMON = ../lib/libhawk.la
 check_SCRIPTS = h-001.hawk h-002.hawk
-EXTRA_DIST = $(check_SCRIPTS)
+EXTRA_DIST = $(check_SCRIPTS) ensure.inc
 t_001_SOURCES = t-001.c t.h
 t_001_CPPFLAGS = $(CPPFLAGS_COMMON)
 t_002_SOURCES = t-002.c t.h