Some headers which require the version header depend on other headers to
provide it. Include the version header in all top-level headers to make
sure a header cleanup can't remove the version header.
Note this doesn't add the version header to the c headers.
Reviewed By: #libc, Quuxplusone, ldionne
Differential Revision: https://reviews.llvm.org/D116172
The "root nodes" of the graph are displayed in bold. My intent here
was to bold just the public-API headers, e.g. <vector> and
<experimental/coroutine> and <stdlib.h>, but not helper headers
such as <__functional_base> and <__iterator/next.h>. However,
the recent mass helper-header-ification has exposed defects in
this logic: all the new helpers were ending up bolded! Fix this.
Also, add <__undef_macros> to the list of headers we don't display
by default (like <__config>); it's not interesting to see those edges.
Also, add a sample `dot` command line to the `--help` text.
Since we have a tool to detect cycles now; and since we're entering
a phase where people can easily introduce cycles by accident (D100682)
or by request (D90999), I think it's increasingly important to shift
the burden of detecting these cycles onto the buildbot instead of
the poor human reviewer.
Also, grep for non-ASCII characters (such as U+200B and U+00AD)
and hard tabs; don't let those get checked in.
Differential Review: https://reviews.llvm.org/D100703
My attempts to play around with the old graph_header_deps.py were mostly fruitless;
I needed to modify it in various ways to make it work, and then even when I got it
working, it generated pretty ugly graphs.
Old graph_header_deps.py (after my local changes to simplify the usage)
(producing https://i.imgur.com/zATrsaP.jpg )
mkdir foo
time ./graph_header_deps.py --libcxx-only -o foo --clang-command ~/llvm-project/build/bin/clang++
dot -Tpng < foo/all_headers.dot > old.png
file old.png
real 0m37.453s
old.png: PNG image data, 25882 x 3035, 8-bit/color RGBA, non-interlaced
New graph_header_deps.py
(producing https://i.imgur.com/ZU0G52U.png )
time ./graph_header_deps.py | dot -Tpng > new.png
file new.png
real 0m1.063s
new.png: PNG image data, 6162 x 1344, 8-bit/color RGBA, non-interlaced
Differential Revision: https://reviews.llvm.org/D99124
Mark de Wever
