Editing GNU Compiler Collection (section)

=== Other features ===
Some features of GCC include:

; Link-time optimization
: [[Link-time optimization]] optimizes across object file boundaries to directly improve the linked binary. Link-time optimization relies on an intermediate file containing the serialization of some ''Gimple'' representation included in the object file.{{Citation needed|date=January 2016}} The file is generated alongside the object file during source compilation. Each source compilation generates a separate object file and link-time helper file. When the object files are linked, the compiler is executed again and uses the helper files to optimize code across the separately compiled object files.
; Plugins
: [[Plug-in (computing)|Plugins]] extend the GCC compiler directly.<ref>{{cite web |title= Plugins |url= https://gcc.gnu.org/onlinedocs/gccint/Plugins.html |work= GCC online documentation |access-date= July 8, 2013 |archive-date= April 30, 2013 |archive-url= https://web.archive.org/web/20130430223330/http://gcc.gnu.org/onlinedocs/gccint/Plugins.html |url-status= live }}</ref> Plugins allow a stock compiler to be tailored to specific needs by external code loaded as plugins. For example, plugins can add, replace, or even remove middle-end passes operating on ''Gimple'' representations.<ref>{{cite web|last=Starynkevitch|first=Basile|title=GCC plugins thru the MELT example|url=http://gcc-melt.org/gcc-plugin-MELT-LinuxCollabSummit2014.pdf |archive-url=https://web.archive.org/web/20140413124801/http://gcc-melt.org/gcc-plugin-MELT-LinuxCollabSummit2014.pdf |archive-date=2014-04-13 |url-status=live|access-date=2014-04-10}}</ref> Several GCC plugins have already been published, notably:
:* The Python plugin, which links against libpython, and allows one to invoke arbitrary Python scripts from inside the compiler. The aim is to allow GCC plugins to be written in Python.
:* The MELT plugin provides a high-level [[Lisp (programming language)|Lisp]]-like language to extend GCC.<ref>{{cite web|title=About GCC MELT|url=http://gcc-melt.org/|access-date=July 8, 2013|archive-url= https://archive.today/20130704015544/http://gcc-melt.org/|archive-date=July 4, 2013|url-status=live}}</ref>
: The support of plugins was once a contentious issue in 2007.<ref>{{cite web |title=GCC unplugged [LWN.net] |url=https://lwn.net/Articles/259157/ |website=lwn.net |access-date=March 28, 2021 |archive-date=November 9, 2020 |archive-url=https://web.archive.org/web/20201109001410/https://lwn.net/Articles/259157/ |url-status=live }}</ref>
; C++ [[Software transactional memory|transactional memory]]
: The C++ language has an active proposal for transactional memory. It can be enabled in GCC 6 and newer when compiling with <code>-fgnu-tm</code>.<ref name="gcc6"/><ref>{{Cite web|url=https://gcc.gnu.org/wiki/TransactionalMemory|title=TransactionalMemory - GCC Wiki|website=gcc.gnu.org|access-date=September 19, 2016|archive-date=August 19, 2016|archive-url=https://web.archive.org/web/20160819055121/http://gcc.gnu.org/wiki/TransactionalMemory|url-status=live}}</ref>
; Unicode identifiers
: Although the C++ language requires support for non-ASCII [[Unicode characters]] in [[Identifier (computer languages)|identifiers]], the feature has only been supported since GCC 10. As with the existing handling of string literals, the source file is assumed to be encoded in [[UTF-8]]. The feature is optional in C, but has been made available too since this change.<ref>{{Cite web|url=https://gcc.gnu.org/legacy-ml/gcc-patches/2020-01/msg01667.html|title=Lewis Hyatt - [PATCH] wwwdocs: Document support for extended identifiers added to GCC|website=gcc.gnu.org|access-date=2020-03-27|archive-date=March 27, 2020|archive-url=https://web.archive.org/web/20200327153559/https://gcc.gnu.org/legacy-ml/gcc-patches/2020-01/msg01667.html|url-status=live}}</ref><ref>{{Cite web|url=http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2010/n3146.html|title=Recommendations for extended identifier characters for C and C++|website=www.open-std.org|access-date=2020-03-27|archive-date=September 30, 2020|archive-url=https://web.archive.org/web/20200930152408/http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2010/n3146.html|url-status=live}}</ref>
; C extensions
: GNU C extends the C programming language with several non-standard-features, including [[nested function]]s.<ref>{{Cite web|title=C Extensions (Using the GNU Compiler Collection (GCC))|url=https://gcc.gnu.org/onlinedocs/gcc/C-Extensions.html|access-date=2022-01-12|website=gcc.gnu.org|archive-date=January 12, 2022|archive-url=https://web.archive.org/web/20220112203037/https://gcc.gnu.org/onlinedocs/gcc/C-Extensions.html|url-status=live}}</ref>