Replace Makefile with configure script

Since libweb depends on dynstr, this dependency can be already available
on the system, and therefore the CFLAGS and LDFLAGS should be updated
according to pkg-config(1), rather than hardcoding them to the source
tree.

4 files changed, 199 insertions, 76 deletions

diff --git a/.gitignore b/.gitignore
index a9aba1d..b8e0d43 100644
--- a/.gitignore
+++ b/.gitignore
@@ -9,3 +9,4 @@ examples/headers/headers
 examples/hello/hello
 examples/html/html
 examples/put/put
+/Makefile
diff --git a/Makefile b/Makefile
deleted file mode 100644
index af79de3..0000000
--- a/Makefile
+++ /dev/null
@@ -1,73 +0,0 @@
-.POSIX:
-
-PROJECT = libweb
-PROJECT_A = $(PROJECT).a
-MAJOR_VERSION = 0
-MINOR_VERSION = 1
-PATCH_VERSION = 0
-VERSION = $(MAJOR_VERSION).$(MINOR_VERSION).$(PATCH_VERSION)
-PROJECT_SO = $(PROJECT).so.$(VERSION)
-PROJECT_SO_FQ = $(PROJECT).so.$(MAJOR_VERSION)
-PROJECT_SO_NV = $(PROJECT).so
-prefix = /usr/local
-exec_prefix = $(prefix)
-includedir = $(prefix)/include
-datarootdir = $(prefix)/share
-mandir = $(datarootdir)/man
-libdir = $(exec_prefix)/lib
-pkgcfgdir = $(libdir)/pkgconfig
-O = -O1
-CDEFS = -D_FILE_OFFSET_BITS=64 # Required for large file support on 32-bit.
-CFLAGS = $(O) $(CDEFS) -g -Iinclude -Idynstr/include -fPIC -MD -MF $(@:.o=.d)
-LDFLAGS = -shared
-DEPS = $(OBJECTS:.o=.d)
-OBJECTS = \
-	form.o \
-	handler.o \
-	html.o \
-	http.o \
-	server.o \
-	wildcard_cmp.o
-
-all: $(PROJECT_A) $(PROJECT_SO)
-
-install: all $(pkgcfgdir)/libweb.pc
-	mkdir -p $(DESTDIR)$(includedir)
-	cp -R include/libweb $(DESTDIR)$(includedir)
-	chmod 0644  $(DESTDIR)$(includedir)/libweb/*.h
-	mkdir -p $(DESTDIR)$(libdir)
-	cp $(PROJECT_A) $(PROJECT_SO) $(DESTDIR)$(libdir)
-	chmod 0755 $(libdir)/$(PROJECT_A) $(DESTDIR)$(libdir)/$(PROJECT_SO)
-	ln -fs $(libdir)/$(PROJECT_SO) $(DESTDIR)$(libdir)/$(PROJECT_SO_FQ)
-	ln -fs $(libdir)/$(PROJECT_SO) $(DESTDIR)$(libdir)/$(PROJECT_SO_NV)
-	+cd doc && $(MAKE) install \
-		DESTDIR=$(DESTDIR) \
-		prefix=$(prefix) \
-		datarootdir=$(datarootdir) \
-		mandir=$(mandir)
-
-clean:
-	rm -f $(OBJECTS) $(DEPS)
-	+cd examples && $(MAKE) clean
-
-distclean: clean
-	rm -f $(PROJECT_A) $(PROJECT_SO)
-	+cd examples && $(MAKE) distclean
-
-FORCE:
-
-examples: FORCE
-	+cd examples && $(MAKE)
-
-$(PROJECT_A): $(OBJECTS)
-	$(AR) $(ARFLAGS) $@ $(OBJECTS)
-
-$(PROJECT_SO): $(OBJECTS)
-	$(CC) $(LDFLAGS) $(OBJECTS) -o $@
-
-$(pkgcfgdir)/libweb.pc: libweb.pc
-	mkdir -p $(pkgcfgdir)
-	sed -e 's,/usr/local,$(prefix),' $< > $@
-	chmod 0644 $@
-
--include $(DEPS)
diff --git a/README.md b/README.md
index d522bcf..a57fe0d 100644
--- a/README.md
+++ b/README.md
@@ -76,14 +76,23 @@ apk add cmake
 Two build environments are provided for `libweb` - feel free to choose any of
 them:
 
-- A mostly POSIX-compliant [`Makefile`](Makefile).
+- A [`configure`](configure) POSIX shell and mostly POSIX-compliant
+[`Makefile`](Makefile).
 - A [`CMakeLists.txt`](CMakeLists.txt).
 
 `libweb` can be built using the standard build process:
 
 #### Make
 
+First, generate the `Makefile` via the `configure` script:
+
 ```sh
+$ ./configure
+```
+
+Then:
+
+```
 $ make
 ```
 
@@ -93,12 +102,20 @@ the use of recursive `make`. For example, assuming `libweb` is contained on a
 subdirectory:
 
 ```make
-libweb/libweb.a:
+libweb/Makefile:
+    cd libweb && ./configure
+libweb/libweb.a: libweb/Makefile
     +cd libweb && $(MAKE)
 ```
 
 Additionally, `libweb` can be installed using the `install` target. A
-custom prefix can be assigned via the `PREFIX` variable:
+custom prefix can be assigned via the `configure` script:
+
+```sh
+$ ./configure --prefix=$HOME/libweb-prefix
+```
+
+Or, directly from the generated `Makefile`:
 
 ```sh
 $ make PREFIX=$HOME/libweb-prefix install
diff --git a/configure b/configure
new file mode 100755
index 0000000..4d055f9
--- /dev/null
+++ b/configure
@@ -0,0 +1,178 @@
+#! /bin/sh
+
+set -e
+
+default_prefix=/usr/local
+prefix=$default_prefix
+default_CC='c99'
+# FILE_OFFSET_BITS=64 is required for large file support on 32-bit platforms.
+default_CFLAGS='-O1 -D_FILE_OFFSET_BITS=64 -MD -Iinclude -fPIC'
+default_LDFLAGS="-shared"
+
+CC=${CC:-$default_CC}
+
+help()
+{
+	cat <<-EOF
+$0 [OPTION ...]
+
+--prefix      Set installation directory [$default_prefix]
+
+Some influential environment variables:
+  CC                  C compiler [$default_CC]
+  CFLAGS              C compiler flags [$default_CFLAGS]
+  LDFLAGS             Link-time flags [$default_LDFLAGS]
+EOF
+}
+
+while true; do
+	split_arg=0
+
+	if printf "%s" "$1" | grep -e '=' > /dev/null
+	then
+		key="$(printf "%s" "$1" | cut -d '=' -f1)"
+		value="$(printf "%s" "$1" | cut -d '=' -f2)"
+		split_arg=1
+	else
+		key="$1"
+		value="$2"
+	fi
+
+	case "$key" in
+		--prefix ) prefix="$value"; shift; test $split_arg -eq 0 && shift ;;
+		-h | --help ) help; exit 0 ;;
+		* ) test "$1" != "" && help && exit 1 || break ;;
+	esac
+done
+
+if pkg-config dynstr
+then
+	in_tree_dynstr=0
+	proj_CFLAGS="$(pkg-config --cflags dynstr) $proj_CFLAGS"
+	proj_LDFLAGS="$(pkg-config --libs dynstr) $proj_LDFLAGS"
+else
+	echo "Info: dynstr not found. Using in-tree copy" >&2
+	in_tree_dynstr=1
+	proj_CFLAGS="-Idynstr/include $proj_CFLAGS"
+	proj_LDFLAGS="-Ldynstr -ldynstr $proj_LDFLAGS"
+fi
+
+proj_CFLAGS="$proj_CFLAGS $default_CFLAGS $CFLAGS"
+proj_LDFLAGS="$proj_LDFLAGS $default_LDFLAGS $LDFLAGS"
+
+cleanup()
+{
+	rm -f $F
+}
+
+F=/tmp/Makefile.libweb
+trap cleanup EXIT
+
+cat <<EOF > $F
+.POSIX:
+
+CC = ${CC}
+CFLAGS = $CFLAGS
+PROJ_CFLAGS = $proj_CFLAGS
+PROJ_LDFLAGS = $proj_LDFLAGS
+prefix = $prefix
+EOF
+
+cat <<"EOF" >> $F
+PROJECT = libweb
+PROJECT_A = $(PROJECT).a
+MAJOR_VERSION = 0
+MINOR_VERSION = 1
+PATCH_VERSION = 0
+VERSION = $(MAJOR_VERSION).$(MINOR_VERSION).$(PATCH_VERSION)
+PROJECT_SO = $(PROJECT).so.$(VERSION)
+PROJECT_SO_FQ = $(PROJECT).so.$(MAJOR_VERSION)
+PROJECT_SO_NV = $(PROJECT).so
+exec_prefix = $(prefix)
+includedir = $(prefix)/include
+datarootdir = $(prefix)/share
+mandir = $(datarootdir)/man
+libdir = $(exec_prefix)/lib
+pkgcfgdir = $(libdir)/pkgconfig
+O = -O1
+DEPS = $(OBJECTS:.o=.d)
+OBJECTS = \
+	form.o \
+	handler.o \
+	html.o \
+	http.o \
+	server.o \
+	wildcard_cmp.o
+
+all: $(PROJECT_A) $(PROJECT_SO)
+
+install: all $(pkgcfgdir)/libweb.pc
+	mkdir -p $(DESTDIR)$(includedir)
+	cp -R include/libweb $(DESTDIR)$(includedir)
+	chmod 0644  $(DESTDIR)$(includedir)/libweb/*.h
+	mkdir -p $(DESTDIR)$(libdir)
+	cp $(PROJECT_A) $(PROJECT_SO) $(DESTDIR)$(libdir)
+	chmod 0755 $(libdir)/$(PROJECT_A) $(DESTDIR)$(libdir)/$(PROJECT_SO)
+	ln -fs $(libdir)/$(PROJECT_SO) $(DESTDIR)$(libdir)/$(PROJECT_SO_FQ)
+	ln -fs $(libdir)/$(PROJECT_SO) $(DESTDIR)$(libdir)/$(PROJECT_SO_NV)
+	+cd doc && $(MAKE) install \
+		DESTDIR=$(DESTDIR) \
+		prefix=$(prefix) \
+		datarootdir=$(datarootdir) \
+		mandir=$(mandir)
+
+FORCE:
+
+.c.o:
+	$(CC) $(PROJ_CFLAGS) -c $< -o $@
+
+examples: FORCE
+	+cd examples && $(MAKE)
+
+$(PROJECT_A): $(OBJECTS)
+	$(AR) $(ARFLAGS) $@ $(OBJECTS)
+
+$(PROJECT_SO): $(OBJECTS)
+	$(CC) $(PROJ_LDFLAGS) $(OBJECTS) -o $@
+
+$(pkgcfgdir)/libweb.pc: libweb.pc
+	mkdir -p $(pkgcfgdir)
+	sed -e 's,/usr/local,$(prefix),' $< > $@
+	chmod 0644 $@
+EOF
+
+if [ $in_tree_dynstr -ne 0 ]
+then
+cat <<"EOF" >> $F
+DYNSTR = dynstr/libdynstr.a
+$(PROJECT): $(DYNSTR)
+$(DYNSTR): FORCE
+	+cd dynstr && $(MAKE) CC=$(CC)
+EOF
+fi
+
+cat <<"EOF" >> $F
+clean:
+	rm -f $(OBJECTS) $(DEPS)
+	+cd examples && $(MAKE) clean
+EOF
+
+if [ $in_tree_dynstr -ne 0 ]
+then
+cat <<"EOF" >> $F
+	+cd dynstr && $(MAKE) clean
+EOF
+fi
+
+cat <<"EOF" >> $F
+distclean: clean
+	rm -f $(PROJECT_A) $(PROJECT_SO)
+	+cd examples && $(MAKE) distclean
+	rm Makefile
+EOF
+
+cat <<"EOF" >> $F
+-include $(DEPS)
+EOF
+
+mv $F Makefile