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<base href="https://bugs.llvm.org/">
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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - clang-format not idempotent with long comment containing tabs"
href="https://bugs.llvm.org/show_bug.cgi?id=52466">52466</a>
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<th>Summary</th>
<td>clang-format not idempotent with long comment containing tabs
</td>
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<th>Product</th>
<td>clang
</td>
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<th>Version</th>
<td>13.0
</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>normal
</td>
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<th>Priority</th>
<td>P
</td>
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<th>Component</th>
<td>Formatter
</td>
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<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
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<th>Reporter</th>
<td>felix.widmaier@tue.mpg.de
</td>
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<th>CC</th>
<td>djasper@google.com, klimek@google.com, llvm-bugs@lists.llvm.org
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<pre>Created <span class=""><a href="attachment.cgi?id=25437" name="attach_25437" title="Example file for which the described issue occurs.">attachment 25437</a> <a href="attachment.cgi?id=25437&action=edit" title="Example file for which the described issue occurs.">[details]</a></span>
Example file for which the described issue occurs.
The output of `clang-format` changes multiple times on this example containing
a long comment with tabs (this is extracted from a real-world example, reduced
to the offending line):
<span class="quote">> // // for(auto const& value: sze) cout << value<<" ";</span >
(the file is also added as attachment).
I am testing with version "13.0.0 (<a href="https://github.com/llvm/llvm-project">https://github.com/llvm/llvm-project</a>
d7b669b3a30345cfcdb2fde2af6f48aa4b94845d)".
Expected behaviour
==================
Calling `clang-format` a second time on any file should not result in any
additional changes, i.e. the output of
$ clang-format file.cpp | clang-format --dry-run
should always be empty.
Actual behaviour
================
On the given example,
$ clang-format file.cpp | clang-format --dry-run
results in the following output:
<span class="quote">> <stdin>:1:37: warning: code should be clang-formatted [-Wclang-format-violations]
> // // for(auto const& value: sze)
> ^
> <stdin>:1:42: warning: code should be clang-formatted [-Wclang-format-violations]
> // // for(auto const& value: sze)
> ^
> <stdin>:2:1: warning: code should be clang-formatted [-Wclang-format-violations]
> // cout << value<<" ";
> ^</span >
Actually, I have to call it four times until there are no changes anymore.
One run
-------
$ clang-format file.cpp
// //
for(auto const& value: sze)
// cout << value<<" ";
Two runs
--------
$ clang-format file.cpp | clang-format
// //
for(auto const& value:
// sze) cout << value<<" ";
Three runs
----------
$ clang-format file.cpp | clang-format | clang-format
// //
for(auto const&
// value: sze) cout << value<<" ";
Four runs
---------
$ clang-format file.cpp | clang-format | clang-format | clang-format
// //
for(auto
// const& value: sze) cout << value<<" ";
>From here there are no more changes.
I noticed that when I replace the tabs with spaces, I don't have this issue.</pre>
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