dbdac49b81
autotools projects commonly should include "config.h" as first header. Also, commonly we need more headers, like glib.h or our nm_auto macros. Hence, almost all our sources should as first include "nm-default.h". However, as we build different parts, "nm-default.h" gets controlled by the NETWORKMANAGER_COMPILATION define which autotools/meson needs to specify in the build options. That is confusing. One advantage of that was, that theoretically the same sources can be built twice, with different behavior. However, we should avoid doing that altogether and build static libraries (once) that we link multiple times. Another advantage was that if NETWORKMANAGER_COMPILATION is for example set to build a DAEMON source, there is a check that we don't include private headers from libnm-core. However, that should be better solved by not having public, internal and private headers in the same directory. Instead, introduce different "nm-default-*.h" headers that don't require special defines and behave in a consistent way. This way, we require fewer CFLAGS and it's immediately clear by looking at the source alone which headers are included. Also, you will be easier see when a wrong nm-default-*.h header gets included. Introduce the first replacement. The others will follow. |
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|---|---|---|
| .. | ||
| c-list | ||
| c-rbtree | ||
| c-siphash | ||
| c-stdaux | ||
| n-acd | ||
| n-dhcp4 | ||
| nm-base | ||
| nm-glib-aux | ||
| nm-log-core | ||
| nm-platform | ||
| nm-std-aux | ||
| nm-udev-aux | ||
| nm-utils | ||
| systemd | ||
| meson.build | ||
| nm-default.h | ||
| nm-gassert-patch.h | ||
| nm-meta-setting.c | ||
| nm-meta-setting.h | ||
| nm-test-libnm-utils.h | ||
| nm-test-utils-impl.c | ||
| nm-version-macros.h.in | ||
| README.md | ||
The "shared/" Directory
For NetworkManager we place helper/utility code under "shared/" in static libraries. The idea is to avoid code duplication but also provide high quality helper functions that simplify the higher layers. In NetworkManager there are complicated parts, for example "src/nm-manager.c" is huge. On the other hand, this helper code should be simple and easy to understand, so that we can build more complex code on top of it.
As we statically link them into our binaries, they are all inherently internal API, that means they cannot be part of libnm's (libnm-core's) public API. It also means that their API/ABI is not stable.
We don't care these libraries to be minimal and contain only symbols that are
used by all users. Instead, we expect the linker to throw away unused symbols.
We achieve this by having a symbol versioning file to hide internal symbols
(which gives the linker a possibility to remove them if they are unused) and
compiling with LTO or "-Wl,--gc-sections". Let the tool solve this and not
manual organization.
Hence these libraries (and their content) are structured this way to satisfy the following questions:
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which dependencies (libraries) do they have? That determines which other libraries can use it. For example:
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"shared/nm-std-aux" and "shared/nm-glib-aux" both provide general purpose helpers, the difference is that the former has no dependency on glib2 library. Both these libraries are a basic dependency for many other parts of the code.
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"shared/nm-udev-aux" has a dependency on libudev, it thus cannot be in "shared/nm-glib-aux".
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client code also has a glib2 dependency. That means it can link with "shared/nm-std-aux" and "shared/nm-glib-aux", but must not link with "shared/nm-udev-aux" (as it has no direct udev dependenct -- although clients get it indirectly because libnm already requires it).
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what is their overall purpose? As said, we rely on the linker to prune unused symbols. But in a few cases we avoid to merge different code in the same library. For example:
- "shared/nm-glib-aux" and "shared/nm-base" both only have a glib2 dependency. Hence, they could be merged. However we don't do that because "shared/nm-base" is more about NetworkManager specific code, while "shared/nm-glib-aux" is about general purpose helpers.
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some of these libraries are forked from an upstream. They are kept separate so that we can re-import future upstream versions.
Detail
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shared/c-list -
shared/c-rbtree -
shared/c-siphash -
shared/c-stdoux -
shared/n-acd -
shared/n-dhcp4These are forked from upstream and imported with git-subtree. They in general only have a libc dependency (or dependencies between each other).
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shared/nm-std-auxThis contains helper code with only a libc dependency. Almost all C code depends on this library.
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shared/nm-glib-auxLike "shared/nm-std-aux" but also has a glib2 dependency. Almost all glib2 code depends on this library.
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shared/nm-udev/auxLike "shared/nm-glib-aux" but also has a libudev dependency. It has code related to libudev.
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shared/systemdThese are forked from upstream systemd and imported with a script. Under "shared/systemd/src" we try to keep the sources as close to the original as possible. There is also some adapter code to make it useable for us. It has a dependency on "shared/nm-glib-aux" and will need a logging implementation for "shared/nm-glib-aux/nm-logging-fwd.h".
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shared/nm-baseDepends on "shared/nm-glib-aux" and glib2 but it provides helper code that more about NetworkManager specifc things.
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shared/nm-log-coreThis is the logging implementation as used by NetworkManager core ("src/"). It is also a dependency for "shared/nm-platform".
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shared/nm-platformPlatform implementation. It depends on "shared/nm-log-core", "shared/nm-base" and "shared/nm-glib-aux".
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Other than that, there are still a few unorganized files/directories here. These should be cleaned up.