CODEWITHSUNDEEP
bashmakefile
smilingbuddha
smilingbuddha

Reputation: 14670

Checking for existence of a directory with GNU make

I am dumping all the object files of my compilation into a separate directory called objfiles

While compiling I want to check for the existence of the directory objfiles and if it does not exist (indicating re-compilation of the whole project) I want to create it.

Here is my Makefile and an attempt at the problem

    SHELL := /bin/zsh
    #All object files are dumped into OBJDIR
    OBJDIR=objfiles
    OBJECTS=$(OBJDIR)/main.o \
            $(OBJDIR)/printdata.o \
            #...
            #...

   COMPILER=nvcc -arch=sm_20

   exec: objdir_exist $(OBJECTS)
        $(COMPILER) $(OBJECTS) -o exec
        @printf "\nExecutable updated!\n\n"

    $(OBJDIR)/main.o: main.cu octree.h
        $(COMPILER) -c $< -o $@

    $(OBJDIR)/printdata.o: printdata.cu  
        $(COMPILER) -c $< -o $@
    ...    


    #Clean-up executables and object files
    .PHONY=clean objdir_exist
    clean:
        rm exec 
        rm -r $(OBJDIR)

    # Check for the existence of object files. 
    # If it does not exist, then create another object_file directory to dump data to.
    # If it exists do nothing
   objdir_exist: 
        if [ ! -d "$(OBJDIR)" ] then mkdir $(OBJDIR)  fi

I get the following error.

if [ ! -d "objfiles" ] then mkdir objfiles  fi
zsh:[:1: ']' expected
nvcc -arch=sm_20 -c main.cu -o objfiles/main.o
Assembler messages:
Fatal error: can't create objfiles/main.o: No such file or directory
make: *** [objfiles/main.o] Error 1

Where am I going wrong?

Upvotes: 0

Views: 7084

Answers (3)

mondaugen
mondaugen

Reputation: 454

The solution I found goes something like this

BIN=exec
OBJSDIR=objs

all: $(OBJSDIR) $(BIN)

$(OBJSDIR):
    if [ ! -d $(OBJSDIR) ]; then mkdir $(OBJSDIR); fi

$(OBJSDIR)/obj1.o: obj1.c header1.h
    # $< expands only to first prerequisite
    $(COMPILER) -c $< -o $@

$(OBJSDIR)/obj2.o: obj2.c header2.h
    $(COMPILER) -c $< -o $@

$(BIN): $(OBJSDIR)/obj1.o $(OBJSDIR)/obj2.o
    # $^ expands to all prerequisites
    $(COMPILER) $^ -o $@

all depends on both $(OBJSDIR) and $(BIN). If $(OBJSDIR) doesn't exist, it creates it. Then it goes on to check $(BIN) and builds that if it doesn't exist or its prerequisites have changed.

Upvotes: 0

stark
stark

Reputation: 13189

Simpler is:

mkdir -p $(OBJDIR)

Upvotes: 3

Slava Semushin
Slava Semushin

Reputation: 15214

The problem is because when you write if in one line you should use ; as line-delimiter.

So, replace

if [ ! -d "$(OBJDIR)" ] then mkdir $(OBJDIR)  fi

by

if [ ! -d "$(OBJDIR)" ]; then mkdir $(OBJDIR);  fi

Upvotes: 5

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