libreoffice

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Stephan Bergmann cab0427cad Enable loplugin:cstylecast for some more cases

...mostly of C-style casts among arithmetic types, and automatically rewrite
those into either static_cast or a functional cast (which should have identical
semantics, but where the latter probably looks better for simple cases like
casting a literal to a specific type, as in "sal_Int32(0)" vs.
"static_cast<sal_Int32>(0)").

The main benefit of reducing the amount of C-style casts across the code base
further is so that other plugins (that have not been taught about the complex
semantics of C-style cast) can pick those up (cf. the various recent
"loplugin:redundantcast" commits, which address those findings after this
improved loplugin:cstylecast has been run).  Also, I found some places where
a C-style cast has probably been applied only to the first part of a larger
expression in error (because it's easy to forget parentheses in cases like
"(sal_uInt16)VOPT_CLIPMARKS+1"); I'll follow up on those individually.

The improved loplugin:cstylecast is careful to output either "(performs:
static_cast)" or "(performs: functional cast)", so that
compilerplugins/clang/test/cstylecast.cxx can check that the plugin would
automatically rewrite to one or the other form.

To allow fully-automatic rewriting, this also required loplugin:unnecessaryparen
to become a rewriting plugin, at least for the parens-around-cast case (where
"((foo)bar)" first gets rewritten to "(static_cast<foo>(bar))", then to
"static_cast<foo>(bar)".  Rewriting could probably be added to other cases of
loplugin:unnecessaryparen in the future, too.

(The final version of this patch would even have been able to cope with
361dd2576a09fbda83f3ce9a26ecb590c38f74e3 "Replace some C-style casts in ugly
macros with static_cast", so that manual change would not have been necessary
after all.)

Change-Id: Icd7e319cc38eb58262fcbf7643d177ac9ea0220a
Reviewed-on: https://gerrit.libreoffice.org/47798
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>

2018-01-12 20:32:32 +01:00

clang

Enable loplugin:cstylecast for some more cases

2018-01-12 20:32:32 +01:00

.gitignore

…

Makefile

…

Makefile-clang.mk

Remove CXXFLAGS_CXX11 from Clang plugin compilation

2017-12-06 07:26:14 +01:00

Makefile.mk

Revert "Revert "compilerplugins: Build them in parallel.""

2017-09-22 10:59:15 +02:00

README

…

README

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=1 to make to trigger rebuild of all source files,
    even those that are up to date.
- UPDATE_FILES=<scope> - limits which modified files will be actually written back with the changes
    - mainfile - 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=1 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).


== Code documentation / howtos ==

http://wiki.documentfoundation.org/Clang_plugins