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      <base href="https://llvm.org/bugs/" />
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    <body><table border="1" cellspacing="0" cellpadding="8">
        <tr>
          <th>Bug ID</th>
          <td><a class="bz_bug_link 
          bz_status_NEW "
   title="NEW --- - r287138 causes -MP output to be incorrect"
   href="https://llvm.org/bugs/show_bug.cgi?id=31644">31644</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>r287138 causes -MP output to be incorrect
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>new-bugs
          </td>
        </tr>

        <tr>
          <th>Version</th>
          <td>trunk
          </td>
        </tr>

        <tr>
          <th>Hardware</th>
          <td>PC
          </td>
        </tr>

        <tr>
          <th>OS</th>
          <td>All
          </td>
        </tr>

        <tr>
          <th>Status</th>
          <td>NEW
          </td>
        </tr>

        <tr>
          <th>Severity</th>
          <td>normal
          </td>
        </tr>

        <tr>
          <th>Priority</th>
          <td>P
          </td>
        </tr>

        <tr>
          <th>Component</th>
          <td>new bugs
          </td>
        </tr>

        <tr>
          <th>Assignee</th>
          <td>unassignedbugs@nondot.org
          </td>
        </tr>

        <tr>
          <th>Reporter</th>
          <td>dimitry@andric.com
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>llvm-bugs@lists.llvm.org
          </td>
        </tr>

        <tr>
          <th>Classification</th>
          <td>Unclassified
          </td>
        </tr></table>
      <p>
        <div>
        <pre>Before r287138:

$ cat a.c
int main(void) { return 0; }
$ clang -MD -MP -c a.c
$ cat a.d
a.o: a.c

After r287138:

$ clang -MD -MP -c a.c
$ cat a.d
a.o: a.c

a.c:

E.g. one additional dependency for the main source file itself is printed,
while it should not be.

The relevant piece of code is in DFGImpl::OutputDependencyFile():

  // Create phony targets if requested.
  if (PhonyTarget && !Files.empty()) {
    // Skip the first entry, this is always the input file itself.
    for (StringRef File : Files) {
      OS << '\n';
      PrintFilename(OS, File, OutputFormat);
      OS << ":\n";
    }
  }

Unfortunately the comment does not match the range-based for loop anymore, as
this does *not* skip the first entry.  The code used to do:

    for (std::vector<std::string>::iterator I = Files.begin() + 1,
           E = Files.end(); I != E; ++I) {

I am unsure how to achieve this effect with range-based for loops though, it
may be best to just revert that part.</pre>
        </div>
      </p>
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