<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/83210>83210</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [libc] convert preprocessor includes to "" for other libc sources
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            code-cleanup,
            libc
      </td>
    </tr>

    <tr>
      <th>Assignees</th>
      <td>
      </td>
    </tr>

    <tr>
      <th>Reporter</th>
      <td>
          nickdesaulniers
      </td>
    </tr>
</table>

<pre>
    Forking the discussion from https://github.com/llvm/llvm-project/pull/83199#discussion_r1505142721.

> all the #includes in /include/ for things in llvm-libc-types or llvm-libc-macros currently use <>. It may be worthwhile to change this, but that should probably be one cleanup patch.

So we're pretty inconsistent in our use of `#include` preprocessor statement wrt `<>` vs `""`.  I _think_ we should move to the convention (and document it in our coding style):
- If the .h file is part of our sources, use `""`
- If the .h file is NOT part of our sources, use `<>`

https://gcc.gnu.org/onlinedocs/cpp/Search-Path.html is helpful, particularly:

> By default, the preprocessor looks for header files included by the quote form of the directive #include "file" first relative to the directory of the current file, and then in a preconfigured list of standard system directories. For example, if /usr/include/sys/stat.h contains #include "types.h", GCC looks for types.h first in /usr/include/sys, then in its usual search path.

> For the angle-bracket form #include <file>, the preprocessor’s default behavior is to look only in the standard system directories.

> The most commonly-used option is -Idir, which causes dir to be searched after the current directory (for the quote form of the directive) and ahead of the standard system directories.

Then I think that will help us refine our clang-tidy lint for this: #82695
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJyUVU-P47YP_TTKhYhhy_nnQw67mfEPc_m1wO59Ict0pI4suaKU1N--kJzMZLbbbQsECRyLFN_j46Mg0meLeGTbz2z7tBIxKOePVsvXHklEYzV6WnWun4-t86_aniEohF6TjETaWRi8G0GFMBGrPzHeMt6edVCxK6QbGW-Nudx_1pN3v6EMjLdTNIbx9lBXTcN4_Z7vm6-25bba8D2vClY-sfLT7bt-BmFMvp7xWltpYo8E2gLj7e2R8RYG5yEobc_5Xb7X6E6uwzwhgfMPf41Cekcgo_dog5khEgKrT6x-LuAlwChm6BCuzgd1VdogBAdSCXvGdAUxfoIuBghKBCDloulh8q4TncmBziJIg8LGCSYRpPqA6IuDKzK-9wiTxxBm0FY6S5oC2pCKd9HnktwAbFe-o2a7MoVM3kkkch4oiIBjirr6kM9mEOnchZZYnj67sgB4gW-Jn9dvcMV71aO7ZHCJXensBW1IzWX8IGwPvZMxZ9dvZUnXJzFQmA0y3qTeZ1BreBlylkLBkBjTBJPwIWFIceSil5iZy2Q_lPb3Cf7_y9d_SnLH-0jwd6qUsjjbWDh_Zrx11miLvZPEeCunifH2Cwov1fpXEVShwmjSzQrNNESTbkoFaBmN8GZ-g_uuzc8z9DiIaEI6nAB86JBx7pWyNhWKHn3GlhSaG9pDN-eY36MLmI6NCesyah5l0JdH1QPjPMUzzmHQngJ4NCIfuvVwiXJ-vqe5aRyWsBOktgaFNvVTpFKls4M-R489GE2ZagrC9sL3QDMFHN-SaqQCWucB_xDjtOTTQxrDSP7DMNKc6E3qLFTSVRDa0ndA8lwWKsvgBP87nR64ur27gVxG_Yd3nN7A6EAQKQoDlPuZBk_9xUnabBIIwp4Nrjsv5CuGhffH6upT5qt-_lFP2TNnh5I1Dd07Dx0qcdHOJ-kEl4GAsyZNdg7_GaPfl_hVIYyOAkg3jinJOhL24KY8mZpg_dJrnwq7Ki0VSBEJKaVMV3d4w489iCGg_6CCd3kwfhhuXPxEe4w3WTEiiff-9t-C-Zo685I9-XWxyqs2Jo8WRAKPg7a4mIoR9rwOup_BaBvuVp5mOLXlwHfNdtUf676pG7HCY7Uvm3K_P5TblTqKZl9htRn4sGuGXmJVSRR8V-6FHAZRbVf6yEu-KTnf83pblttC4G4z1F25aXhTyapmmxJHoU2RNkTyiZUming81LwqV0Z0aChvSs6l63F9s_ZFuYzztFPSw_Zp5Y95y3TxTGxTpoGi96xBB5NXbg7YPi2O68NHx3jbcMHB4pGZDxcUekiRdxtcRW-O_3kDZ2iUdzCvyj8DAAD__w7frVU">