Makefile: use $PKGCONFIG, use += and ?= BSD extensions

Allows to use cross-compilation for ${triple}-pkg-config on systems
like Exherbo without special handling.

The BSD extensions += and ?= for variable extension is used to avoid having
to explicitely pass a list of variables to make, thus making build recipies
simpler.
Only issue is when CC is unset, you will get CC=c99, which doesn't works as c11
is used. Consider doing something like the following in your build recipes:

	make CC=${CC:-cc}

Reported-by: danyspin97

2 files changed, 25 insertions, 17 deletions

diff --git a/Makefile b/Makefile
index 024eb56..d8e9195 100644
--- a/Makefile
+++ b/Makefile
@@ -1,15 +1,26 @@
 .POSIX:
+# POSIX Makefile with extensions common to *BSD and GNU such as:
+# - Usage of backticks for shell evaluation
+# - Usage of ?= for defining variables when not already defined
+# - Usage of += for appending to a variable
 
+PACKAGE  = Badwolf
 VERSION = 0.4.0
-VERSION_FULL = $(VERSION)$(shell ./version.sh)
+VERSION_FULL = $(VERSION)`./version.sh`
 
-PREFIX  = /usr/local
-BINDIR  = $(PREFIX)/bin
-MANDIR  = $(PREFIX)/share/man
-DOCDIR  = $(PREFIX)/share/doc/badwolf-$(VERSION)
-DATADIR = $(PREFIX)/share/badwolf
-APPSDIR = $(PREFIX)/share/applications
-PACKAGE = Badwolf
+PREFIX  ?= /usr/local
+BINDIR  ?= $(PREFIX)/bin
+MANDIR  ?= $(PREFIX)/share/man
+DOCDIR  ?= $(PREFIX)/share/doc/badwolf-$(VERSION)
+DATADIR ?= $(PREFIX)/share/badwolf
+APPSDIR ?= $(PREFIX)/share/applications
+
+CC        ?= cc
+DBG       ?=
+PKGCONFIG ?= pkg-config
+MSGFMT    ?= msgfmt
+
+CFLAGS ?= -g -Wall -Wextra -Wconversion -Wsign-conversion -O2
 
 DEPS  = gtk+-3.0 webkit2gtk-4.0 libsoup-2.4
 SRCS  = uri.c uri_test.c keybindings.c badwolf.c
@@ -20,12 +31,9 @@ EXE_test = uri_test
 TRANS = fr.mo pt_BR.mo
 DOCS  = usr.bin.badwolf README.md KnowledgeBase.md
 
-CC     = cc
-DBG    =
-CFLAGS = -g -Wall -Wextra -Wconversion -Wsign-conversion -O2
-CDEPS  = `pkg-config --cflags $(DEPS)` -DDATADIR=\"$(DATADIR)\" -DPACKAGE=\"$(PACKAGE)\" -D_POSIX_C_SOURCE=200809L -DVERSION=\"$(VERSION_FULL)\"
-LIBS   = `pkg-config --libs $(DEPS)`
-MSGFMT = msgfmt
+CFLAGS += -DDATADIR=\"$(DATADIR)\" -DPACKAGE=\"$(PACKAGE)\" -D_POSIX_C_SOURCE=200809L -DVERSION=\"$(VERSION_FULL)\"
+CFLAGS += `$(PKGCONFIG) --cflags $(DEPS)`
+LIBS    = `$(PKGCONFIG) --libs $(DEPS)`
 
 all: $(EXE) $(TRANS)
 
@@ -43,10 +51,10 @@ badwolf: $(OBJS)
 	$(CC) -std=c11 -o $@ $(OBJS) $(LDFLAGS) $(LIBS)
 
 .c:
-	$(CC) -std=c11 $(CFLAGS) $(CDEPS) $(LDFLAGS) $(LIBS) -o $@ $<
+	$(CC) -std=c11 $(CFLAGS) $(LDFLAGS) $(LIBS) -o $@ $<
 
 .c.o:
-	$(CC) -std=c11 $(CFLAGS) $(CDEPS) -c -o $@ $<
+	$(CC) -std=c11 $(CFLAGS) -c -o $@ $<
 
 uri_test: uri.o uri_test.o
 	$(CC) -std=c11 -o $@ uri.o uri_test.o $(LDFLAGS) $(LIBS)
diff --git a/README.md b/README.md
index 75752b0..6ce8eef 100644
--- a/README.md
+++ b/README.md
@@ -54,7 +54,7 @@ Dependencies are:
 - A pkg-config implementation (pkgconf is recommended)
 - (optionnal) gettext implementation (such as GNU Gettext)
 
-Compilation is done with `make`, install with `make install`. An example AppArmor profile is provided at `usr.bin.badwolf`, please do runtime checks before deploying.
+Compilation is done with `make CC=${CC:-cc}`, install with `make install`. An example AppArmor profile is provided at `usr.bin.badwolf`, please do runtime checks before deploying.
 
 ## Notes
 Most of the privacy/security stuff will be done with patches against WebKit as quite a lot isn’t into [WebKitSettings](https://webkitgtk.org/reference/webkit2gtk/stable/WebKitSettings.html) and with generic WebKit extensions that should be resuseable.