discourage else after "noreturn" statements.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77387 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2009-07-28 22:54:04 +00:00
parent cf593a3f43
commit 9eb7e0aa57

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@ -43,6 +43,8 @@
Private</a></li>
<li><a href="#hl_earlyexit">Use Early Exits and 'continue' to Simplify
Code</a></li>
<li><a href="#hl_else_after_return">Don't use "else" after a
return</a></li>
<li><a href="#hl_predicateloops">Turn Predicate Loops into Predicate
Functions</a></li>
</ol></li>
@ -624,6 +626,88 @@ be a big understandability win.</p>
</div>
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
<a name="hl_else_after_return">Don't use "else" after a return</a>
</div>
<div class="doc_text">
<p>For similar reasons above (reduction of indentation and easier reading),
please do not use "else" or "else if" after something that interrupts
control flow like return, break, continue, goto, etc. For example, this is
"bad":</p>
<div class="doc_code">
<pre>
case 'J': {
if (Signed) {
Type = Context.getsigjmp_bufType();
if (Type.isNull()) {
Error = ASTContext::GE_Missing_sigjmp_buf;
return QualType();
} else {
break;
}
} else {
Type = Context.getjmp_bufType();
if (Type.isNull()) {
Error = ASTContext::GE_Missing_jmp_buf;
return QualType();
} else {
break;
}
}
}
}
</pre>
</div>
<p>It is better to write this something like:</p>
<div class="doc_code">
<pre>
case 'J':
if (Signed) {
Type = Context.getsigjmp_bufType();
if (Type.isNull()) {
Error = ASTContext::GE_Missing_sigjmp_buf;
return QualType();
}
} else {
Type = Context.getjmp_bufType();
if (Type.isNull()) {
Error = ASTContext::GE_Missing_jmp_buf;
return QualType();
}
}
break;
</pre>
</div>
<p>Or better yet (in this case), as:</p>
<div class="doc_code">
<pre>
case 'J':
if (Signed)
Type = Context.getsigjmp_bufType();
else
Type = Context.getjmp_bufType();
if (Type.isNull()) {
Error = Signed ? ASTContext::GE_Missing_sigjmp_buf :
ASTContext::GE_Missing_jmp_buf;
return QualType();
}
break;
</pre>
</div>
<p>The idea is to reduce indentation and the amount of code you have to keep
track of when reading the code.</p>
</div>
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">