build: Error out on implicit function declarations.

[lopsub.git] / Makefile

diff --git a/Makefile b/Makefile
index c0057a38b89119897044caa0a1eaa705877989ca..548c96ff0e6298e29d8f247940a4f446e6757d35 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -9,6 +9,13 @@ endif
 .ONESHELL:
 .SHELLFLAGS := -ec
 
+# Recipes which redirect stdout to the target of the rule (i.e., constructs
+# like cmd > $@) create empty or incomplete output files if the command fails,
+# for example when cmd was not found. Since the target exists and is uptodate
+# in this case, this may lead to all sorts of problems. The following target
+# makes sure that such files are removed.
+.DELETE_ON_ERROR:
+
 PREFIX ?= /usr/local
 M4 := m4
 LN := ln -f
@@ -88,13 +95,17 @@ lsg_objs := lopsubgen.o lsg.o lopsubgen.lsg.o lopsub.o version.o
 liblopsub_objs := config_file.o lopsub.o version.o
 lopsubex_objs := lopsubex.o lopsubex.lsg.o $(liblopsub_objs)
 
+LLS_CFLAGS := -g -fPIC
+STRICT_CFLAGS := -Wall
+STRICT_CFLAGS += -Werror-implicit-function-declaration
+
 $(lsg_objs) $(liblopsub_objs) $(lopsubex_objs): %.o: %.c
 lopsubgen.o config_file.o:
-       $(CC) -g -c -fPIC -o $@ ${@:.o=.c}
+       $(CC) $(CPPFLAGS) $(LLS_CFLAGS) $(CFLAGS) -c -o $@ ${@:.o=.c}
 lsg1.o: lsg.c lsg.h
-       $(CC) -g -DSTAGE1 -Wall -c $< -o $@
+       $(CC) $(CPPFLAGS) $(LLS_CFLAGS) $(STRICT_CFLAGS) $(CFLAGS) -DSTAGE1 -c -o $@ $<
 %.o: %.c
-       $(CC) -Wall -I. -g -c -fPIC -o $@ $<
+       $(CC) -I. $(CPPFLAGS) $(LLS_CFLAGS) $(STRICT_CFLAGS) $(CFLAGS) -c -o $@ $<
 
 # linking
 lopsubgen-stage1: $(lsg1_objs)