Pattern rules and targets with no extension

[Haavard Skinnemoen]

Hi everyone,

I have a question regarding a pattern rule with a target consisting of
only a stem, no extension. Please consider the following (simplified)
Makefile:

all: hello_world.srec hello_world

%: %.o
        gcc -o $@ $<

%.srec: %
        cp $< $@

When running make 3.81, it fails completely:

address@hidden:~/make-test$ make
make: *** No rule to make target `hello_world.srec', needed by `all'.
Stop.

However, with make 3.80, it manages to build hello_world.srec, but in
an unexpected way:

cat2:~/make-test$ make
cc     hello_world.c   -o hello_world
cp hello_world hello_world.srec

Also, u-boot uses essentially the same kind of makefile constructs in
its examples subdirectory (see below), but it actually works correctly
with make 3.80. It still fails with make 3.81. This is actually the
case I tried (and failed) to recreate.

If I move "hello_world" before "hello_world.srec" in the list of
prerequisites to "all", make 3.81 behaves the same way as make 3.80.

Can someone please explain the behaviour I'm seeing here?

Best regards,
Haavard Skinnemoen

#
# (C) Copyright 2000-2004
# Wolfgang Denk, DENX Software Engineering, address@hidden
#
# See file CREDITS for list of people who contributed to this
# project.
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License as
# published by the Free Software Foundation; either version 2 of
# the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston,
# MA 02111-1307 USA
#

ifeq ($(ARCH),ppc)
LOAD_ADDR = 0x40000
endif

ifeq ($(ARCH),i386)
LOAD_ADDR = 0x40000
endif

ifeq ($(ARCH),arm)
LOAD_ADDR = 0xc100000
endif

ifeq ($(ARCH),mips)
LOAD_ADDR = 0x80200000 -T mips.lds
endif

ifeq ($(ARCH),nios)
LOAD_ADDR = 0x00800000 -L $(gcclibdir)/m32 -T nios.lds
endif

ifeq ($(ARCH),nios2)
LOAD_ADDR = 0x02000000 -L $(gcclibdir) -T nios2.lds
endif

ifeq ($(ARCH),m68k)
LOAD_ADDR = 0x20000  -L $(clibdir)
endif

ifeq ($(ARCH),microblaze)
LOAD_ADDR = 0x80F00000
endif

ifeq ($(ARCH),blackfin)
LOAD_ADDR = 0x1000
endif

include $(TOPDIR)/config.mk

SREC    = hello_world.srec
BIN     = hello_world.bin hello_world

ifeq ($(CPU),mpc8xx)
SREC    = test_burst.srec
BIN     = test_burst.bin test_burst
endif

ifeq ($(ARCH),i386)
SREC   += 82559_eeprom.srec
BIN    += 82559_eeprom.bin 82559_eeprom
endif

ifeq ($(ARCH),ppc)
SREC   += sched.srec
BIN    += sched.bin sched
endif

ifeq ($(ARCH),blackfin)
SREC    += smc91111_eeprom.srec
BIN     += smc91111_eeprom.bin smc91111_eeprom
endif

# The following example is pretty 8xx specific...
ifeq ($(CPU),mpc8xx)
SREC   += timer.srec
BIN    += timer.bin timer
endif

# The following example is 8260 specific...
ifeq ($(CPU),mpc8260)
SREC   += mem_to_mem_idma2intr.srec
BIN    += mem_to_mem_idma2intr.bin mem_to_mem_idma2intr
endif

# Utility for resetting i82559 EEPROM
ifeq ($(BOARD),oxc)
SREC   += eepro100_eeprom.srec
BIN    += eepro100_eeprom.bin eepro100_eeprom
endif

ifeq ($(BIG_ENDIAN),y)
EX_LDFLAGS += -EB
endif

OBJS    = $(SREC:.srec=.o)

LIB     = libstubs.a
LIBAOBJS=
ifeq ($(ARCH),ppc)
LIBAOBJS+= $(ARCH)_longjmp.o $(ARCH)_setjmp.o
endif
ifeq ($(CPU),mpc8xx)
LIBAOBJS+= test_burst_lib.o
endif
LIBCOBJS= stubs.o
LIBOBJS = $(LIBAOBJS) $(LIBCOBJS)

gcclibdir := $(shell dirname `$(CC) -print-libgcc-file-name`)
clibdir := $(shell dirname `$(CC) $(CFLAGS) -print-file-name=libc.a`)

CPPFLAGS += -I..

all:    .depend $(OBJS) $(LIB) $(SREC) $(BIN)

#########################################################################
$(LIB): .depend $(LIBOBJS)
        $(AR) crv $@ $(LIBOBJS)

%:      %.o $(LIB)
        $(LD) -g $(EX_LDFLAGS) -Ttext $(LOAD_ADDR) \
                -o $@ -e $(<:.o=) $< $(LIB) \
                -L$(gcclibdir) -lgcc
%.srec: %
        $(OBJCOPY) -O srec $< $@ 2>/dev/null

%.bin:  %
        $(OBJCOPY) -O binary $< $@ 2>/dev/null

#########################################################################

.depend:        Makefile $(OBJS:.o=.c) $(LIBCOBJS:.o=.c)
$(LIBAOBJS:.o=.S) $(CC) -M $(CFLAGS) $(OBJS:.o=.c) $(LIBCOBJS:.o=.c)
$(LIBAOBJS:.o=.S) > $@

sinclude .depend

#########################################################################