What do the makefile symbols $@ and $

Question

``` CC=g++ CFLAGS=-c -Wall LDFLAGS= SOURCES=main.cpp hello.cpp factorial.cpp OBJECTS=$(SOURCES:.cpp=.o) EXECUTABLE=hello all: $(SOURCES) $(EXECUTABLE) $(EXECUTABLE): $(OBJECTS) $(CC) $(LDFLAGS) $(OBJECTS) -o $@ .cpp.o: $(CC) $(CFLAGS) $< -o $@ ``` What do the `$@` and `$<` do exactly?

Accepted Answer

`$@` is the name of the target being generated, and `$<` the first prerequisite (usually a source file). You can find a list of all these special variables in the GNU Make manual.

For example, consider the following declaration:

```
all: library.cpp main.cpp
```

In this case:

- `$@` evaluates to `all`

- `$<` evaluates to `library.cpp`

- `$^` evaluates to `library.cpp main.cpp`

What do the makefile symbols $@ and $< mean?

Solution

Problem