This would have caught the issue discussed in709b1f3ddb
"Make sure VCLXPopupMenu has unique RTTI". (The commit message talks about RTTI there, while what Clang actually compared for an optimized implementation of a dynamic_cast to a final class is vtable pointers, but the overall picture remains the same. Both RTTI and vtables are emitted along the key function, and if that is missing or inline, they are emitted for each dynamic library individually, and as internal symbols on macOS.) This commit also addresses all the issues found by the improved loplugin:dyncastvisibility on Linux. See the newly added TODO in compilerplugins/clang/dyncastvisibility.cxx and86b86ac87e
"Give DocumentEventHolder (aka EventHolder<DocumentEvent>) a key function" for an issue with key functions for class template instantiations. Change-Id: Ia19155efb1d23692c92b9c97ff17f18ae7a1f3ee Reviewed-on: https://gerrit.libreoffice.org/c/core/+/176576 Reviewed-by: Stephan Bergmann <stephan.bergmann@allotropia.de> Tested-by: Jenkins
Compiler plugins
Overview
This directory contains code for compiler plugins. These are used to perform additional actions during compilation (such as additional warnings) and also to perform mass code refactoring.
Currently only the Clang compiler is supported http://wiki.documentfoundation.org/Development/Clang.
Usage
Compiler plugins are enabled automatically by --enable-dbgutil
if Clang headers
are found or explicitly using --enable-compiler-plugins
.
Functionality
There are two kinds of plugin actions:
- compile checks - these are run during normal compilation
- rewriters - these must be run manually and modify source files
Each source has a comment saying whether it's compile check or a rewriter and description of functionality.
Compile Checks
Used during normal compilation to perform additional checks. All warnings and errors are marked '[loplugin]' in the message.
Rewriters
Rewriters analyse and possibly modify given source files.
Usage: make COMPILER_PLUGIN_TOOL=<rewriter_name>
Additional optional make arguments:
-
it is possible to also pass
FORCE_COMPILE=all
to make to trigger rebuild of all source files, even those that are up to date. FORCE_COMPILE takes a list of gbuild targets specifying where to run the rewriter ('all' means everything, '-' prepended means to not enable, '/' appended means everything in the directory; there is no ordering, more specific overrides more general, and disabling takes precedence). Example: FORCE_COMPILE="all -sw/ -Library_sc" -
UPDATE_FILES=<scope>
- limits which modified files will be actually written back with the changesmainfile
- only the main.cxx
file will be modified (default)all
- all source files involved will be modified (possibly even header files from other LO modules), 3rd party header files are however never modified<module>
- only files in the given LO module (toplevel directory) will be modified (including headers)
Modifications will be written directly to the source files.
Some rewriter plugins are dual-mode and can also be used in a non-rewriting mode
in which they emit warnings for problematic code that they would otherwise
automatically rewrite. When any rewriter is enabled explicitly via make COMPILER_PLUGIN_TOOL=<rewriter_name>
it works in rewriting mode (and all other
plugins are disabled), but when no rewriter is explicitly enabled (i.e., just
make
), all dual-mode rewriters are enabled in non-rewriting mode (along with
all non-rewriter plugins; and all non--dual-mode plugins are disabled). The
typical process to use such a dual-mode rewriter X in rewriting mode is
make COMPILER_PLUGIN_WARNINGS_ONLY=X \
&& make COMPILER_PLUGIN_TOOL=X FORCE_COMPILE=all UPDATE_FILES=all
which first generates a full build without failing due to warnings from plugin
X in non-rewriting mode (in case of --enable-werror
) and then repeats the build
in rewriting mode (during which no object files are generate).