Several files refer to symbols declared in headers not explicitly
included. This compiles now because libc++ tranitively includes these
headers via other libc++ headers; however, these transitive includes are
not guaranteed to exist and in Chrome, will no longer exist once libc++
is compiled with modules.
Bug: chromium:543704
Change-Id: I638bb02df3d050a48345248e80aebd2dd60956c1
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/295762
Auto-Submit: Alan Zhao <ayzhao@google.com>
Reviewed-by: Tomas Gunnarsson <tommi@webrtc.org>
Commit-Queue: Tomas Gunnarsson <tommi@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#39448}
Note that api/ code is not exempt from the “.h and .cc files come in
pairs” rule, so if you declare something in api/path/to/foo.h, it should be
defined in api/path/to/foo.cc.
Headers in api/ should, if possible, not #include headers outside api/.
It’s not always possible to avoid this, but be aware that it adds to a small
mountain of technical debt that we’re trying to shrink.
.cc files in api/, on the other hand, are free to #include headers
outside api/.
That is, the preferred way for api/ code to access non-api/ code is to call
it from a .cc file, so that users of our API headers won’t transitively
#include non-public headers.
For headers in api/ that need to refer to non-public types, forward
declarations are often a lesser evil than including non-public header files. The
usual rules still apply, though.
.cc files in api/ should preferably be kept reasonably small. If a
substantial implementation is needed, consider putting it with our non-public
code, and just call it from the api/.cc file.
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