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

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Node:<a name="Override%20Directive">Override Directive</a>,
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<h3 class="section">The <code>override</code> Directive</h3>

   <p>If a variable has been set with a command argument
(see <a href="Overriding.html#Overriding">Overriding Variables</a>),
then ordinary assignments in the makefile are ignored.  If you want to set
the variable in the makefile even though it was set with a command
argument, you can use an <code>override</code> directive, which is a line that
looks like this:

<pre class="example">     override <var>variable</var> = <var>value</var>
     </pre>

<p>or

<pre class="example">     override <var>variable</var> := <var>value</var>
     </pre>

   <p>To append more text to a variable defined on the command line, use:

<pre class="example">     override <var>variable</var> += <var>more text</var>
     </pre>

<p>See <a href="Appending.html#Appending">Appending More Text to Variables</a>.

   <p>The <code>override</code> directive was not invented for escalation in the war
between makefiles and command arguments.  It was invented so you can alter
and add to values that the user specifies with command arguments.

   <p>For example, suppose you always want the <code>-g</code> switch when you run the
C compiler, but you would like to allow the user to specify the other
switches with a command argument just as usual.  You could use this
<code>override</code> directive:

<pre class="example">     override CFLAGS += -g
     </pre>

   <p>You can also use <code>override</code> directives with <code>define</code> directives.
This is done as you might expect:

<pre class="example">     override define foo
     bar
     endef
     </pre>

<p>See <a href="Defining.html#Defining">Defining Variables Verbatim</a>.

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