codeblocks-ep/help/html/programmerHelp/make/Reference.html at master · maifeeulasad/codeblocks-ep · GitHub

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<title>GNU `make'</title>
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Node:<a name="Reference">Reference</a>,
Next:<a rel="next" accesskey="n" href="Flavors.html#Flavors">Flavors</a>,
Previous:<a rel="previous" accesskey="p" href="Using-Variables.html#Using%20Variables">Using Variables</a>,
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<h3 class="section">Basics of Variable References</h3>

   <p>To substitute a variable's value, write a dollar sign followed by the name
of the variable in parentheses or braces: either <code>$(foo)</code> or
<code>${foo}</code> is a valid reference to the variable <code>foo</code>.  This
special significance of <code>$</code> is why you must write <code>$$</code> to have
the effect of a single dollar sign in a file name or command.

   <p>Variable references can be used in any context: targets, prerequisites,
commands, most directives, and new variable values.  Here is an
example of a common case, where a variable holds the names of all the
object files in a program:

<pre class="example">     objects = program.o foo.o utils.o
     program : $(objects)
             cc -o program $(objects)

     $(objects) : defs.h
     </pre>

   <p>Variable references work by strict textual substitution.  Thus, the rule

<pre class="example">     foo = c
     prog.o : prog.$(foo)
             $(foo)$(foo) -$(foo) prog.$(foo)
     </pre>

<p>could be used to compile a C program <code>prog.c</code>.  Since spaces before
the variable value are ignored in variable assignments, the value of
<code>foo</code> is precisely <code>c</code>.  (Don't actually write your makefiles
this way!)

   <p>A dollar sign followed by a character other than a dollar sign,
open-parenthesis or open-brace treats that single character as the
variable name.  Thus, you could reference the variable <code>x</code> with
<code>$x</code>.  However, this practice is strongly discouraged, except in
the case of the automatic variables (see <a href="Automatic.html#Automatic">Automatic Variables</a>).

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