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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - -MP argument not working properly"
href="https://bugs.llvm.org/show_bug.cgi?id=48878">48878</a>
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<th>Summary</th>
<td>-MP argument not working properly
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<th>Product</th>
<td>clang
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<th>Version</th>
<td>unspecified
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<th>Hardware</th>
<td>PC
</td>
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<th>OS</th>
<td>Linux
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<th>Status</th>
<td>NEW
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<th>Severity</th>
<td>normal
</td>
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<th>Priority</th>
<td>P
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<th>Component</th>
<td>C++
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<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
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<th>Reporter</th>
<td>joao@overdrivepizza.com
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<th>CC</th>
<td>blitzrakete@gmail.com, dgregor@apple.com, erik.pilkington@gmail.com, llvm-bugs@lists.llvm.org, richard-llvm@metafoo.co.uk
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<pre>The following bug was noticed when compiling glibc (grte branch) with clang. It
seems that -MP does not output the path to cstdlib when the input is not a
file.
Glibc's configure (line 5488) file tries to run the following line as an
attempt to retrieve the path to cstdlib ($1 expands to cstdlib):
echo "#include <$1>" | $CXX -M -MP -x c++ - 2>/dev/null \
| sed -n "\,$1:,{s/:\$//;p}"
But this doesn't return a path to cstdlib. This was verified to work properly
with GCC.
If the configure is changed to something like:
echo "#include <$1>" &> tmp.cpp
$CXX -M -MP -x c++ tmp.cpp 2>/dev/null | sed -n "\,$1:,{s/:\$//;p}"
The path to cstdlib is properly found.
This behavior was observed on fedora 33.</pre>
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