1. g++ features, better makefiles
Recitation 1 cop4530
g++ features, better makefiles

2. Compiling C++ programs
Single-file programs
g++ prog1.cpp
Multiple-file programs
To invoke the compile stage:
g++ -c <file_name>
Example: g++ -c frac.cpp g++ -c main.cpp
To invoke the linking stage:
g++ -o <target_name> <object_files> example: g++ -o frac frac.o main.o (run the program: frac)

3. Some useful flags -std=c++11 (flag for using c++11 standard features)
-std=c++11 (flag for using c++11 standard features) 
-Wall (all warnings about construction and some language- specific warnings) 
-pedantic (Enables warnings demanded by ISO C/C++)
-I (including directories to search for header files) 
-c (compile only) 
-o <filename> (output rename) 

4. Makefiles Filename: makefile or Makefile
It consists of several sections:
<target_name>: <dependency list> <TAB><commands>
Any line that starts with a # character is a comment.

5. Make file example
# This is a comment line frac: main.o frac.o g++ -o frac main.o frac.o main.o: main.cpp frac.h g++ -c main.cpp frac.o: frac.cpp frac.h g++ -c frac.cpp clean: rm *.o frac

6. Two ways to invoke commands:
make : only the first target
make <target_name>
Clean section:
Removing the old object files
To invoke: make clean

7. More advanced makefile
HOME = /home/courses/cop4530/recitation CC = g++ -Wall -pedantic PROJ = $(HOME)/rect2/makeutil  INCL = -I $(PROJ)  all: main.x  main.x: largest.o print.o main.o  $(CC) -o main.x print.o largest.o main.o  largest.o: $(PROJ)/largest.h $(PROJ)/largest.cpp  $(CC) -c $(INCL) $(PROJ)/largest.cpp  print.o: $(PROJ)/print.h $(PROJ)/print.cpp  $(CC) -c $(INCL) $(PROJ)/print.cpp  main.o: $(PROJ)/main.cpp  $(CC) -c $(INCL) $(PROJ)/main.cpp  clean:  rm -rf *.o *~ *.x