compiling *.C and *.S sources from same directory 'make' - makefile

Question

I have been working with a project that only compiles C sources but I've found I need some assembler too, I'm reticent to inline the asm code in a C file as GCC may not interpret it correctly.
My predecesor created the makefile for the project (apologies, it's fairly long):
# Compiler and options
CC := sparc-rtems-gcc
# The application software binary
TARGET := icu_asw
# Source and build directories
SRCDIR := src
BUILDDIR := obj
TARGETDIR := bin
HDSWROOT := ../../hdsw
BSWTOOLS := ../../bsw/sw/tools
SRCEXT := c
DEPEXT := d
OBJEXT := o
MRAMEXT := img.elf
# Flags, libraries and includes
CFLAGS := -std=gnu99 -Wall -Wextra -g
LIBDRV := $(HDSWROOT)/lib/libdrv.a
INCFLAGS := -I$(HDSWROOT)/include -I$(HDSWROOT)/osal/rtems
# Debug flags
DEBUGFLAGS = -DLOGERROR=1 -DLOGWARN=1 -DLOGDEBUG=1 -DLOGINFO=1 -DMAKECHECKS=1
NODEBUGFLAGS = -DLOGERROR=1 -DLOGWARN=0 -DLOGDEBUG=0 -DLOGINFO=0 -DMAKECHECKS=1
#-----------------------------------------------------------------------
# Build instructions
#-----------------------------------------------------------------------
SOURCES := $(shell find $(SRCDIR) -type f -name *.$(SRCEXT))
OBJECTS := $(patsubst $(SRCDIR)/%,$(BUILDDIR)/%,$(SOURCES:.$(SRCEXT)=.$(OBJEXT)))
# Default make
all: $(TARGET)
# Remake
remake: cleaner all
# Clean only objects
clean:
#$(RM) -rf $(BUILDDIR)
# Full clean (objects and binaries)
cleaner: clean
#$(RM) -rf $(TARGETDIR)
# Pull in dependency info for *existing* .o files
-include $(OBJECTS:.$(OBJEXT)=.$(DEPEXT))
# Link (uses an order-only prerequisite for the directories so that they
# don't affect the use of the $^)
$(TARGET): $(OBJECTS) | directories
$(CC) -o $(TARGETDIR)/$(TARGET) $^ $(LIBDRV)
# Make the build and target directories
directories:
#mkdir -p $(TARGETDIR)
#mkdir -p $(BUILDDIR)
# Compile
$(BUILDDIR)/%.$(OBJEXT): $(SRCDIR)/%.$(SRCEXT)
#mkdir -p $(dir $#)
$(CC) $(CFLAGS) $(INCFLAGS) $(NODEBUGFLAGS) -c -o $# $<
#$(CC) $(CFLAGS) $(INCDEP) -MM $(SRCDIR)/$*.$(SRCEXT) > $(BUILDDIR)/$*.$(DEPEXT)
#cp -f $(BUILDDIR)/$*.$(DEPEXT) $(BUILDDIR)/$*.$(DEPEXT).tmp
#sed -e 's|.*:|$(BUILDDIR)/$*.$(OBJEXT):|' < $(BUILDDIR)/$*.$(DEPEXT).tmp > $(BUILDDIR)/$*.$(DEPEXT)
#sed -e 's/.*://' -e 's/\\$$//' < $(BUILDDIR)/$*.$(DEPEXT).tmp | fmt -1 | sed -e 's/^ *//' -e 's/$$/:/' >> $(BUILDDIR)/$*.$(DEPEXT)
#rm -f $(BUILDDIR)/$*.$(DEPEXT).tmp
# Non-File Targets
.PHONY: all remake clean cleaner
I want to also bring in and compile two .S files, so, I edited the following line
SOURCES := $(shell find $(SRCDIR) -type f -name *.$(SRCEXT) -or -name *.$(ASMEXT))
To bring in the .S files, then I edited the OBJECTS to also include the ASM sources ("*.S")
OBJECTS := $(patsubst $(SRCDIR)/%,$(BUILDDIR)/%,$(SOURCES:.$(SRCEXT)=.$(OBJEXT)),$(SOURCES:.$(ASMEXT)=.$(OBJEXT)))
But when recompiling with 'make all' I'm getting:
$ make all
make: *** No rule to make target `obj/asi_access.S', needed by `icu_asw'. Stop.
I don't suppose someone could spot where I am going wrong? I think I have not correctly added to the OBJECTS line!
Thanks

Answer 1

The expression $(var:.ext1=.ext2) does not filter by .ext1, i.e.
$(SOURCES:.$(SRCEXT)=.$(OBJEXT)) $(SOURCES:.$(ASMEXT)=.$(OBJEXT))
gives for a test source list the following result
a.o b.o c.S a.c b.c c.o
I.e. you duplicated your files and you have source files in the OBJECTS definition.
The following would be a correct approach:
OBJECTS := $(patsubst $(SRCDIR)/%,$(BUILDDIR)/%, \
$(patsubst %.$(SRCEXT),%.$(OBJEXT), \
$(patsubst %.$(ASMEXT),%.$(OBJEXT),$(SOURCES)) \
) \
)
UPDATE: you should consider to use 2 separate object lists, so that you can apply different rules for them, e.g.
SOURCES_C := $(filter %.$(SRCEXT),$(SOURCES))
OBJECTS_C := $(patsubst $(SRCDIR)/%,$(BUILDDIR)/%,$(SOURCES_C:%.$(SRCEXT)=%.$(OBJEXT)))
SOURCES_ASM := $(filter %.$(ASMEXT),$(SOURCES))
OBJECTS_ASM := $(patsubst $(SRCDIR)/%,$(BUILDDIR)/%,$(SOURCES_ASM:%.$(ASMEXT)=%.$(OBJEXT)))
$(OBJECTS_C): $(BUILDDIR)/%.$(OBJEXT): $(SRCDIR)/%.$(SRCEXT)
.... C compiler recipe ....
$(OBJECTS_ASM): $(BUILDDIR)/%.$(OBJEXT): $(SRCDIR)/%.$(ASMEXT)
.... assembler recipe ....
$(TARGET): $(OBJECTS_C) $(OBJECTS_ASM) | directories