Error when using make file.

Linux and Unix-Like Linux
1

hello,

i want to execute hello world using cross compiler ppc_4xx-gcc. i have this makefile:

 CC=    $(shell which ppc_4xx-gcc) 
#CC=g++    
CXXFLAGS=-cpp -Wall    
LDFLAGS=    
SOURCES=main.cpp hello.h    
OBJECTS=$(SOURCES:.cpp=.o)    
EXECUTABLE=hello    

all: $(SOURCES) $(EXECUTABLE)    
    
$(EXECUTABLE): $(OBJECTS)    
    $(CC) $(LDFLAGS) $(OBJECTS) -o $@    

.cpp.o:
    $(CC) $(CXXFLAGS) $< -o $@

and the hello.h and main.cpp developped using visuel c++:
main.cpp:

#include <iostream.h>
#include "hello.h"
using namespace std;
int main(){
    hello();
    cout << endl;
    
    return 0;
}

hello.h:

#include <iostream.h>
using namespace std;

void hello(){
   cout << "Hello World!";
}

i get many errors of this kind:

main.cpp:(.text+0x21a): undefined reference to `std::cout'

can any one help me

thank you

2

gcc will happily compile c++ objects but can't tell the difference between C .o files and c++ .o files. So when you try and link a c++ program with gcc, it won't link in the C++ libraries and things will be missing. link with g++.

3

i make this change:

CC=    $(shell which ppc_4xx-g++) 
#CC=g++    
CXXFLAGS=-cpp -Wall    
LDFLAGS=-arch ppc    
SOURCES=main.cpp hello.h    
OBJECTS=$(SOURCES:.cpp=.o)    
EXECUTABLE=hello    

all: $(SOURCES) $(EXECUTABLE)    
    
$(EXECUTABLE): $(OBJECTS)    
    $(CC) $(LDFLAGS) $(OBJECTS) -o $@    

.cpp.o:
    $(CC) $(CXXFLAGS) $< -o $@

a new errors like that:

ppc_4xx-g++: unrecognized option '-cpp'
In file included from /home/opt/eldk_4.2/ppc_4xx/usr/include/c++/4.2.2/backward/iostream.h:31,
                 from main.cpp:1:
4

So don't give it -cpp.

5

thank you,

i change makefile and also i just keep #include <iostream> without "h":

CC= $(shell which ppc_4xx-g++)
CXXFLAGS=-c++ -Wall
LDFLAGS=
SOURCES=main.cpp hello.h
OBJECTS=$(SOURCES:.c++=.o)
EXECUTABLE=hello

all: $(SOURCES) $(EXECUTABLE)

$(EXECUTABLE): $(OBJECTS)
$(CC) $(LDFLAGS) $(OBJECTS) -o $@

.cpp.o:
$(CC) $(CXXFLAGS) $< -o $@

and i obtain this result :/opt/eldk_4.2/usr/bin/ppc_4xx-g++ main.cpp hello.h -o hello

i obtain two files: main.o and hello

is it ok?

because it's the first time that i use the make file.

why i didn't see hello world?

thanks an advance

6

This is correct, it compiled main.cpp file into an object file, main.o, then linked it into an executable file, 'hello'.

It didn't print "hello world" because you didn't actually run ./hello