When classifying generated sources, we were treating gir/typelib files
generated by gobject-introspection as headers. This is bad because it
serializes the build by adding order-only dependencies to every target
even though sources will never actually use them for anything.
Treat them as libraries, which is somewhat more accurate.
We do not need to *always* rebuild generated sources when a generated
header changes. We will get that information from the compiler's
dependency file, and ninja will track it for us. This is exactly the
same as static sources.
However, we do need an order-only dependency on all generated headers,
because we cannot know what headers will be needed at compile time
(which is when the compiler's dependency file is generated).
This fixes spurious rebuilds and relinking in many cases.
A current rather untyped storage of options is one of the things that
contributes to the options code being so complex. This takes a small
step in synching down by storing the compiler options in dicts per
language.
Future work might be replacing the langauge strings with an enum, and
defaultdict with a custom struct, just like `PerMachine` and
`MachineChoice`.
This make relative pathes shorter an too give a chance to
de-duplicate -isystem flags just like -I flags.
Fix common test case 203 for OSX build host too
When a source file for a library is changed without adding new extern
symbols, only that library should be rebuilt. Nothing that uses it
should be relinked.
Along the way, also remove trailing `.` in all Ninja rule
descriptions. It's very confusing to see messages like:
```
Linking target mylib.dll.
```
It's confusing that the period at the end of that is not part of the
filename. Instead of removing that period manually in the tests (which
feels wrong!) just don't print it at all.
We actually use this while linking on Windows, and hence we need to
extract symbols from this file, and not the DLL.
However, we cannot pass it instead of the DLL because it's an optional
output of the compiler. It will not be written out at all if there are
no symbols in the DLL, and we cannot know that at configure time. This
means we cannot describe it as an output of any ninja target, or the
input of any ninja target. We must pass it as an argument without
semantic meaning.
This is more correct, and forces the target(s) to be rebuilt if the
PDB files are missing. Increases the minimum required Ninja to 1.7,
which is available in Ubuntu 16.04 under backports.
We can't do the same for import libraries, because it is impossible
for us to know at configure time whether or not an import library will
be generated for a given DLL.
This is similar to what we currently do for scan-build except there is
no environment variable to choose a specific clang-format to run. If an
environment variable is needed for better control, we can add it later.
Detect scan-build the same way when trying to launch it and when
generating the target.
The detection method is:
1. look within SCANBUILD env variable
2. shutil.which('scan-build')
3. *on non-linux platforms only*: go through all the possible
name candidates and test them individually.
The third step is added following this comment
https://github.com/mesonbuild/meson/pull/5857#issuecomment-528305788
However, going through a list of all the possible candidates is neither
easily maintainable nor performant, and is therefore skipped on
platforms that should not require such a step (currently, only Linux
platforms).
This is a follow-up to the issue raised by @lantw44 during PR:
https://github.com/mesonbuild/meson/pull/5857
as what was done with clang-format, test the presence of the tool before
generating a dedicated target. Pass silently if scan-build is not found.
Signed-off-by: Gabriel Ganne <gabriel.ganne@mindmaze.ch>
Return the command line from serialize_executable, which is then
renamed to as_meson_exe_cmdline. This avoids repeating code that
is common to custom targets and generators.
georgev93