Dismec++ can be compiled with a large set of warnings enabled and treated as errors. In particular,
with disabling only a small number of selected warnings, it is possible to compile using
-Wall -Wextra -Werror.
By default, the CMake script will add -Wall and -Wextra, but not -Werror to the compile flags.
For development, it is recommended to enable warnings as errors, for example by exporting
export CXXFLAGS=-Werrorbefore the first configuration run of CMake.
The automatic adjustment of warning flags is handled in the cmake/compile-options.cmake
file, which defines a an INTERFACE target libdismec_config which is linked to all
other targets.
We know that in some situations the produced warnings are false positives. Therefore, these warnings
are never treated as errors, even if -Werror is present. The following warnings are not treated as
errors:
This warning complains about function parameters not being used in the definition of a function. In many
cases in the code, however, we have virtual functions that take a set of parameters the cover all the data
a potential implementation of this function might need. In each concrete case, though, only a subset of
these values are actually used. It would be possible to annotate all these definitions with corresponding
[[maybe_unused]] attributes, but for now we decided to make this warning ignorable instead of littering
the code with annotations.
If testing is disabled (DOCTEST_CONFIG_DISABLE is defined), then the test case macros ensure that the
test cases do not end up in the binary. Further, the assert-style macros evaluate to nothing.
However, at least Clang still parses the test cases' contents, which leads to some variables being
seemingly unused, as their only use would be in an assert macro.
Therefore, when compiling with Clang and -DDOCTEST_CONFIG_DISABLE, the warning configuration is extended
by -Wno-error=unused-variable and -Wno-error=unused-but-set-variable.
If the available boost version if less than 1.70, then boost.histogram is not available. This is not a
required component of the software, but its lack is diagnosed using a #warning preprocessor directive.
Consequently, in such cases these warnings are excluded from being treated as errors, through
-Wno-error=cpp (GCC) or -Wno-error=\#warnings.
GCC 8 seems to get confused by some part of our code, and reports an "unused static function" problem
for a non-static(!) member function when compiling objective/dense_and_sparse.cpp. Therefore, this
warning is completely disabled for this source file.