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| <h4 class="subsection">3.10.7 Newlines in Arguments</h4> |
| |
| <p><a name="index-newlines-in-macro-arguments-82"></a> |
| The invocation of a function-like macro can extend over many logical |
| lines. However, in the present implementation, the entire expansion |
| comes out on one line. Thus line numbers emitted by the compiler or |
| debugger refer to the line the invocation started on, which might be |
| different to the line containing the argument causing the problem. |
| |
| <p>Here is an example illustrating this: |
| |
| <pre class="smallexample"> #define ignore_second_arg(a,b,c) a; c |
| |
| ignore_second_arg (foo (), |
| ignored (), |
| syntax error); |
| </pre> |
| <p class="noindent">The syntax error triggered by the tokens <code>syntax error</code> results in |
| an error message citing line three—the line of ignore_second_arg— |
| even though the problematic code comes from line five. |
| |
| <p>We consider this a bug, and intend to fix it in the near future. |
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