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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW --- - -Wpadded may be split in two options"
href="http://llvm.org/bugs/show_bug.cgi?id=22442">22442</a>
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<th>Summary</th>
<td>-Wpadded may be split in two options
</td>
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<th>Product</th>
<td>clang
</td>
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<th>Version</th>
<td>unspecified
</td>
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<th>Hardware</th>
<td>PC
</td>
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<th>OS</th>
<td>Linux
</td>
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<th>Status</th>
<td>NEW
</td>
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<th>Severity</th>
<td>enhancement
</td>
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<th>Priority</th>
<td>P
</td>
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<th>Component</th>
<td>Frontend
</td>
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<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
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<th>Reporter</th>
<td>guillaum.bouchard@gmail.com
</td>
</tr>
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<th>CC</th>
<td>llvmbugs@cs.uiuc.edu
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<th>Classification</th>
<td>Unclassified
</td>
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<p>
<div>
<pre>Hello.
-Wpadded warns about two issues, padding a struct field and padding at the end
(i.e: the whole struct). See the example:
-------------------
struct Bidule
{
char b;
int a;
char c;
};
--->
test.cpp:4:6: warning: padding struct 'Bidule' with 3 bytes to align 'a'
[-Wpadded]
int a;
^
test.cpp:1:8: warning: padding size of 'Bidule' with 3 bytes to alignment
boundary [-Wpadded]
struct Bidule
--------------------------
Usually padding in the middle is a bad thing because the struct can be "easily"
organized differently to reduce the memory footprint. On the other hand,
padding at the end of a structure is common and there is usually no trivial
fix.
As an example, I ran -Wpadded on a large code base, I found 3 padding of field
which I fixed, and more than one thousand warning messages about padding of
struct for which I cannot do something without complex code refactoring.
It may be possible to split -Wpadding in two options, one which warns about
padding fields (which I found really useful 100% of the time) and the other
which warns about padding the whole struct, which IMHO only need to be
activated when needed.
Thank you.</pre>
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