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+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE pkgmetadata SYSTEM "https://www.gentoo.org/dtd/metadata.dtd">
+<pkgmetadata>
+ <maintainer type="project">
+ <email>toolchain@gentoo.org</email>
+ <name>Gentoo Toolchain Project</name>
+ </maintainer>
+ <use>
+ <flag name="ada">Build the ADA language (GNAT) frontend</flag>
+ <flag name="cet" restrict="&gt;=sys-devel/gcc-10">
+ Enable support for Intel Control Flow Enforcement Technology (CET).
+
+ Only effective on amd64/x86.
+
+ Only provides benefits on newer CPUs. For Intel, the CPU
+ must be at least as new as Tiger Lake. For AMD, it must be
+ at least as new as Zen 3. This is harmless on older CPUs,
+ but provides no benefit either.
+
+ When combined with USE=hardened, GCC will set -fcf-protection
+ by default when building software. The effect is minimal
+ on systems which do not support it, other than a possible
+ small increase in codesize for the NOPs. The generated
+ code is therefore compatible with i686 at the earliest.
+ </flag>
+ <flag name="d">Enable support for the D programming language</flag>
+ <flag name="debug">
+ Enables GCC's 'checking' facility via --enable-checking=yes,extra,rtl.
+
+ This adds checks to various compiler passes for integrity and input
+ validation. This can help catch possible miscompilations early as
+ well as latent bugs which could become real problems in future, but
+ at the cost of slower compile times when using GCC.
+
+ Unrelated to backtraces.
+ </flag>
+ <flag name="default-stack-clash-protection">
+ Build packages with stack clash protection on by default as
+ a hardening measure.
+
+ This enables -fstack-clash-protection by default which protects against
+ large memory allocations allowing stack smashing.
+
+ May cause slightly increased codesize, but modern compilers
+ have been adapted to optimize well for this case, as
+ this mitigation is now quite common.
+
+ See https://developers.redhat.com/blog/2020/05/22/stack-clash-mitigation-in-gcc-part-3
+ and https://www.qualys.com/2017/06/19/stack-clash/stack-clash.txt.
+ </flag>
+ <flag name="default-znow">
+ Request full relocation on start from ld.so by default.
+
+ This sets the -z,now (BIND_NOW) flag by default on all linker invocations. By
+ resolving all dynamic symbols at application startup, parts of the program
+ can be made read-only as a hardening measure.
+
+ This is closely related to RELRO which is also separately
+ enabled by default.
+
+ In some applications with many unresolved symbols (heavily plugin based,
+ for example), startup time may be impacted.
+ </flag>
+ <flag name="fixed-point">Enable fixed-point arithmetic support for MIPS targets in gcc (Warning: significantly increases compile time!)</flag>
+ <flag name="go">Build the GCC Go language frontend.</flag>
+ <flag name="graphite">Add support for the framework for loop optimizations based on a polyhedral intermediate representation</flag>
+ <flag name="ieee-long-double">Use accelerated 128-bit IEEE long double ABI (ppc64le only)</flag>
+ <flag name="jit">Enable libgccjit so other applications can embed gcc for Just-In-Time compilation.</flag>
+ <flag name="libssp">Build SSP support into a dedicated library rather than use the code in the C library (DO NOT ENABLE THIS IF YOU DON'T KNOW WHAT IT DOES)</flag>
+ <flag name="lto">
+ Build using Link Time Optimizations (LTO).
+
+ Note that GCC is always built with support for building
+ other programs with LTO. This USE flag is for whether
+ GCC itself is built and optimized with LTO.
+ </flag>
+ <flag name="modula2">Build the GCC Modula-2 language frontend.</flag>
+ <flag name="nptl">Enable support for Native POSIX Threads Library, the new threading module (requires linux-2.6 or better usually)</flag>
+ <flag name="objc">Build support for the Objective C code language</flag>
+ <flag name="objc++">Build support for the Objective C++ language</flag>
+ <flag name="objc-gc">Build support for the Objective C code language Garbage Collector</flag>
+ <flag name="pgo">
+ Build GCC using Profile Guided Optimization (PGO).
+
+ GCC will build itself and then analyze the just-built
+ binary and then rebuild itself using the data obtained
+ from analysis of codepaths taken.
+
+ It does not affect whether GCC itself supports PGO
+ when building other software.
+
+ This substantially increases the build time needed for
+ building GCC itself.
+ </flag>
+ <flag name="sanitize">
+ Build support for various sanitizer functions (ASAN/TSAN/etc...)
+ to find runtime problems in applications.
+ </flag>
+ <flag name="ssp">Build packages with stack smashing protection on by default</flag>
+ <flag name="systemtap">enable systemtap static probe points</flag>
+ <flag name="vtv">
+ Build support for virtual table verification (a C++ hardening feature).
+
+ This does not control whether GCC defaults to using VTV>
+
+ Note that actually using VTV breaks ABI and hence the whole
+ system must be built with -fvtable-verify.
+ </flag>
+ </use>
+ <upstream>
+ <remote-id type="cpe">cpe:/a:gnu:gcc</remote-id>
+ </upstream>
+</pkgmetadata>