Handling file names with space with GNU Make - makefile

Question

I am using GNU Make (v3.80) and I must deal with file names with space. (There is nothing that I can do about the file names per se.) My makefile includes "normal" rules as well as static pattern rules. How can I deal with these files without changing too much my makefile?
I have read and studied previous related questions (here, here, here, and there) but none handle static pattern rules.

Answer 1

A solution combines the "question mark" trick by Mecklenburg combined with shell commands (find and sed) and not using the automatic variable $< but rather $*.
Imagine that you want to copy any files found in a data directory into a target directory, here are the rules (including a static pattern rule). Below is the complete makefile, here are the interesting bits:
EXEDIR = bin/vbcc-classic/AmiModRadio/
DATADIR = $(EXEDIR)data/
DATA = $(addprefix $(DATADIR), $(shell find data/ -mindepth 1 -maxdepth 1 -printf "%f\n" | sed 's/ /?/g'))
In the above, the last variable declaration, DATA contains the set of file names available in data/ with any space in their file names replaced by a ?. Each file name is prefixed by the target directory DATADIR and delimited by spaces.
space :=
space +=
replaceQuestionBySpace = $(subst ?,$(space),$1)
replaceSpaceByQuestion = $(subst $(space),?,$1)
In the above, following Mecklenburg, two functions are defined to replace spaces with question marks and vice-versa.
$(DATA) : $(DATADIR)% : $(wildcard data/%)
cp -f -R "$(call replaceQuestionBySpace,data/$*)" "$(call replaceQuestionBySpace,$#)"
The above is the important static pattern rule: the prerequisite of the rule $(wildcard data/%) ensures that Make will not copy the files in data at each call, but only if they have changed or disappeared from $(DATADIR).
$(wildcard data/%) works because % is replaced by the stem built by $(DATA) : $(DATADIR)% and because $(DATA) contains a set of file names without space (but question marks) and prefixed by $(DATADIR).
In the recipe, question marks are replaced by spaces to get the original file names back. $< cannot be used because it would match to $(wildcard data/%), which would result in an empty string. But, because the target contains $(DATADIR) and the file names, $* can be used (the file names) at the cost of adding data/ in front.
The complete makefile for example.
#
# AmiModRadio
# All of Aminet modules at your fingertips
#
#
#
# Copyright 2015, 2016 Tygre <tygre#chingu.asia>
#
# This file is part of AmiModRadio.
#
# AmiModRadio is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# AmiModRadio is distributed in the hope fthat it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with AmiModRadio. If not, see <http://www.gnu.org/licenses/>.
#
#
#
# Entirely developed on an Amiga!
# (Except for source code versioning...)
# tygre#chingu.asia
#
# Main paths
EXEDIR = bin/vbcc-classic/debug/
OBJECTSDIR = o/vbcc-classic/debug/
# Main paths for release ONLY
ifeq "$(strip $(filter dist, $(MAKECMDGOALS)))" "dist"
EXEDIR = bin/vbcc-classic/AmiModRadio/
OBJECTSDIR = o/vbcc-classic/release/
endif
# Secondary paths
EXE = $(EXEDIR)AmiModRadio
DATADIR = $(EXEDIR)data/
ICONSDIR = $(EXEDIR)icons/
IMAGESDIR = $(EXEDIR)images/
MODULESDIR = $(EXEDIR)modules/
# (Re)Source files
SOURCES = $(wildcard *.c)
OBJECTS = $(addprefix $(OBJECTSDIR), $(SOURCES:.c=.o))
DATA = $(addprefix $(DATADIR), $(shell find data/ -mindepth 1 -maxdepth 1 -printf "%f\n" | sed 's/ /?/g'))
ICONS = $(addprefix $(ICONSDIR), $(shell find icons/ -mindepth 1 -maxdepth 1 -printf "%f\n" | sed 's/ /?/g'))
IMAGES = $(addprefix $(IMAGESDIR), $(shell find images/ -mindepth 1 -maxdepth 1 -printf "%f\n" -type d | sed 's/ /?/g'))
# compiler and linker
CC = vbcc:bin/vc
LD = vbcc:bin/vc
# Because Make does not support spaces properly...
space :=
space +=
replaceQuestionBySpace = $(subst ?,$(space),$1)
replaceSpaceByQuestion = $(subst $(space),?,$1)
# ----------------------------------------
# target 'all' (default target, for debug)
all : CFLAGS += -DFORTIFY
all : $(EXEDIR)\
$(OBJECTSDIR)\
$(EXE)\
data\
images
# target 'dist' for release
dist : mostlyclean\
$(EXEDIR)\
$(OBJECTSDIR)\
$(EXE)\
data\
icons\
images\
modules\
$(EXEDIR:/=).lha
# target 'mostlyclean'
mostlyclean :
-rm $(EXE)
-rm $(OBJECTSDIR)*
# target 'clean'
clean : mostlyclean
-rm $(DATADIR)*
-rm $(ICONSDIR)*
-rm $(IMAGESDIR)*
-rm $(MODULESDIR)*
# ----------------------------------------
# Directories
$(EXEDIR) :
mkdir "$#"
$(OBJECTSDIR) :
mkdir "$#"
# Objects and executable
$(OBJECTS) : $(OBJECTSDIR)%.o : %.c
$(CC) $(shell vbccprefs) $(CFLAGS) -c $< -o $#
$(EXE) : $(OBJECTS)
$(LD) $(shell vbccprefs) -o $(EXE) $(OBJECTS)
# Data
data : $(DATADIR)\
$(DATA)\
$(DATADIR) :
mkdir "$#"
$(DATA) : $(DATADIR)% : $(wildcard data/%)
cp -f -R "$(call replaceQuestionBySpace,data/$*)" "$(call replaceQuestionBySpace,$#)"
# Icons
icons : $(ICONSDIR)\
$(ICONS)\
$(EXE).info\
$(EXEDIR:/=).info
$(ICONSDIR) :
mkdir "$#"
$(ICONS) : $(ICONSDIR)% : $(wildcard icons/%)
cp -f -R "$(call replaceQuestionBySpace,icons/$*)" "$(call replaceQuestionBySpace,$#)"
$(EXE).info :
cp -f -R "$(ICONSDIR)AmiModRadio2.tool.info" "$#"
$(EXEDIR:/=).info :
cp -f -R "$(ICONSDIR)AmiModRadio3.drawer.info" "$#"
# Images
images : $(IMAGESDIR)\
$(IMAGES)\
$(IMAGESDIR) :
mkdir "$#"
$(IMAGES) : $(IMAGESDIR)% : $(wildcard images/%)
cp -f -R "$(call replaceQuestionBySpace,images/$*)" "$(call replaceQuestionBySpace,$#)"
# Modules
modules : $(MODULESDIR)
$(MODULESDIR) :
mkdir "$#"
# LHA archive of 'dist'
$(EXEDIR:/=).lha : PARENTDIR = $(dir $(patsubst %/,%,$(EXEDIR)))
$(EXEDIR:/=).lha : EXENAME = $(notdir $(patsubst %/,%,$(EXEDIR)))
$(EXEDIR:/=).lha :
rm -f RAM:$(EXENAME).lha
/C/LHA -r -e a RAM:$(EXENAME).lha $(PARENTDIR) $(EXENAME).info $(EXENAME)/*