MT#58307 build: Normalize variable handling

Make it conform to common expectations, where:

- Use DESTDIR for the staged installation directory.
- Use PREFIX to set the installation prefix for all pathnames,
  and include it in the other DIR variables.
- Rename LIBSOVER to LIBSONAME.
- Rename HDR to HDRDIR to make the variable more clear.
- Add LIBSONAME for lib<name>.so.<version>.
- Do not specify the target name if it matches the source.
- Add spaces around Makefile variable assignments.
- Make VERSION parsing more robust against coding style changes.
- Pass PREFIX from the environment to «make install», which avoids a
  debhelper override.

Change-Id: I6d5181dd34cd076966ed02e7ae9701286e4673cf

Makefile

@@ -1,12 +1,12 @@
-export LIBNAME=libtcap
-export VERSION=1
-export LIBSO=$(LIBNAME).so
-export LIBSOVER=$(LIBNAME).so.$(VERSION)
+export LIBNAME = libtcap
+export VERSION = 1
+export LIBSO = $(LIBNAME).so
+export LIBSONAME = $(LIBSO).$(VERSION)
 
-LIBDIR=lib
-HDR=include/tcap
+PREFIX ?= /usr/local
+HDRDIR ?= $(PREFIX)/include/tcap
+LIBDIR ?= $(PREFIX)/lib
 
-DESTDIR?=/usr/local
 
 all:
 	$(MAKE) -C asn1
@@ -26,10 +26,10 @@ clean:
 	$(MAKE) -C tests clean
 
 install: all
-	mkdir -p $(DESTDIR)/$(HDR)
-	cp include/*.h $(DESTDIR)/$(HDR)
-	mkdir -p $(DESTDIR)/$(LIBDIR)
-	cp src/$(LIBSOVER) $(DESTDIR)/$(LIBDIR)/$(LIBSOVER)
-	ln -s $(LIBSOVER) $(DESTDIR)/$(LIBDIR)/$(LIBSO)
+	mkdir -p $(DESTDIR)$(HDRDIR)
+	cp include/*.h $(DESTDIR)$(HDRDIR)
+	mkdir -p $(DESTDIR)$(LIBDIR)
+	cp src/$(LIBSONAME) $(DESTDIR)$(LIBDIR)
+	ln -s $(LIBSONAME) $(DESTDIR)$(LIBDIR)/$(LIBSO)
 
 .PHONY: all regenerate-asn1 clean install

debian/ngcp-libtcap-dev.install

@@ -1,2 +1,2 @@
-debian/tmp/include/tcap /usr/include/
-debian/tmp/lib/*.so /usr/lib/
+debian/tmp/usr/include/tcap /usr/include/
+debian/tmp/usr/lib/*.so /usr/lib/

debian/ngcp-libtcap1.install

@@ -1 +1 @@
-debian/tmp/lib/*.so.* /usr/lib/
+debian/tmp/usr/lib/*.so.* /usr/lib/

debian/rules

@@ -2,5 +2,7 @@
 # Uncomment this to turn on verbose mode.
 # export DH_VERBOSE=1
 
+export PREFIX = /usr
+
 %:
 	dh $@

src/Makefile

@@ -4,7 +4,7 @@ CPPFLAGS += -I../asn1 -I../include
 CFLAGS := -g -Wall -O3
 CFLAGS += -fPIC -D_DEFAULT_SOURCE
 LDFLAGS := -O3
-LDFLAGS += -shared -fPIC -Wl,-soname,$(LIBNAME).so.$(VERSION)
+LDFLAGS += -shared -fPIC -Wl,-soname,$(LIBSONAME)
 LDFLAGS += -Wl,--version-script=libtcap.map
 
 OBJS=tcap.o
@@ -15,13 +15,13 @@ OBJS=tcap.o
 
 all: $(LIBSO)
 
-$(LIBSOVER): $(OBJS) ../asn1/libtcap-asn.a
+$(LIBSONAME): $(OBJS) ../asn1/libtcap-asn.a
 	$(CC) $(CFLAGS) -o $@ $(OBJS) ../asn1/libtcap-asn.a $(LDFLAGS)
 
-$(LIBSO): $(LIBSOVER)
-	ln -fs $(LIBSOVER) $(LIBSO)
+$(LIBSO): $(LIBSONAME)
+	ln -fs $(LIBSONAME) $(LIBSO)
 
 clean:
 	rm -f $(OBJS)
 	rm -f $(LIBSO)
-	rm -f $(LIBSOVER)
+	rm -f $(LIBSONAME)

t/abi-check.sh

@@ -44,8 +44,8 @@ cp -r "${source_path}"/.git "${CHECK_DIR}/source.$new_version_norm"
   make
 )
 
-old_soversion="$(grep VERSION= "${CHECK_DIR}/source.$old_version_norm/Makefile")"
-new_soversion="$(grep VERSION= "${CHECK_DIR}/source.$new_version_norm/Makefile")"
+old_soversion="$(sed -ne 's/^VERSION *= *//p' "${CHECK_DIR}/source.$old_version_norm/Makefile")"
+new_soversion="$(sed -ne 's/^VERSION *= *//p' "${CHECK_DIR}/source.$new_version_norm/Makefile")"
 
 if [ "${old_soversion}" != "${new_soversion}" ]; then
   echo "The SOVERSION is different, skipping API/ABI tests."