Rename TOOL-LDFLAGS to TOOL-LDLIBS, fix order and add explicit .c.o

The tool-specific flags were LDLIBS and not LDFLAGS, because we specify
the libraries we want to link in, not flags to the linker itself.
The order was broken as it didn't allow -Wl,--as-needed or other things
highly dependent on the order of arguments.

I also wanted to add an explicit .c.o suffix rule. This way, it is
clearer what is happening in the Makefile and the form of compilation
output is controllable.

2 files changed, 10 insertions, 7 deletions

diff --git a/Makefile b/Makefile
index baf2d41..27dc544 100644
--- a/Makefile
+++ b/Makefile
@@ -11,10 +11,10 @@ SCR = 2ff
 MAN1 = 2ff.1 $(BIN:=.1)
 MAN5 = farbfeld.5
 
-png2ff-LDFLAGS = $(PNG-LDFLAGS)
-ff2png-LDFLAGS = $(PNG-LDFLAGS)
-jpg2ff-LDFLAGS = $(JPG-LDFLAGS)
-ff2jpg-LDFLAGS = $(JPG-LDFLAGS)
+png2ff-LDLIBS = $(PNG-LDLIBS)
+ff2png-LDLIBS = $(PNG-LDLIBS)
+jpg2ff-LDLIBS = $(JPG-LDLIBS)
+ff2jpg-LDLIBS = $(JPG-LDLIBS)
 
 all: $(BIN)
 
@@ -23,7 +23,10 @@ $(BIN): $(REQ:=.o)
 $(BIN:=.o): config.mk $(HDR) $(REQ:=.h)
 
 .o:
-	$(CC) -o $@ $< $(REQ:=.o) $($*-LDFLAGS) $(LDFLAGS)
+	$(CC) -o $@ $(LDFLAGS) $< $(REQ:=.o) $($*-LDLIBS)
+
+.c.o:
+	$(CC) -c $(CPPFLAGS) $(CFLAGS) $<
 
 clean:
 	rm -f $(BIN) $(BIN:=.o) $(REQ:=.o)
diff --git a/config.mk b/config.mk
index 194ab86..67d5448 100644
--- a/config.mk
+++ b/config.mk
@@ -11,8 +11,8 @@ MANPREFIX = ${PREFIX}/man
 CPPFLAGS = -D_DEFAULT_SOURCE
 CFLAGS   = -std=c99 -pedantic -Wall -Wextra -Os
 LDFLAGS  = -s
-PNG-LDFLAGS = -lpng
-JPG-LDFLAGS = -ljpeg
+PNG-LDLIBS = -lpng
+JPG-LDLIBS = -ljpeg
 
 # compiler and linker
 CC = cc