Like most GNU software, GCC must be configured before it can be built. This document describes the recommended configuration procedure for both native and cross targets.
We use srcdir to refer to the toplevel source directory for GCC; we use objdir to refer to the toplevel build/object directory.
If you obtained the sources via SVN, srcdir must refer to the top gcc directory, the one where the MAINTAINERS file can be found, and not its gcc subdirectory, otherwise the build will fail.
If either srcdir or objdir is located on an automounted NFS
file system, the shell’s built-in pwd command will return
temporary pathnames. Using these can lead to various sorts of build
problems. To avoid this issue, set the PWDCMD environment
variable to an automounter-aware pwd command, e.g.,
pawd or ‘amq -w’, during the configuration and build
phases.
First, we highly recommend that GCC be built into a separate directory from the sources which does not reside within the source tree. This is how we generally build GCC; building where srcdir == objdir should still work, but doesn’t get extensive testing; building where objdir is a subdirectory of srcdir is unsupported.
If you have previously built GCC in the same directory for a different target machine, do ‘make distclean’ to delete all files that might be invalid. One of the files this deletes is Makefile; if ‘make distclean’ complains that Makefile does not exist or issues a message like “don’t know how to make distclean” it probably means that the directory is already suitably clean. However, with the recommended method of building in a separate objdir, you should simply use a different objdir for each target.
Second, when configuring a native system, either cc or
gcc must be in your path or you must set CC in
your environment before running configure. Otherwise the configuration
scripts may fail.
To configure GCC:
% mkdir objdir % cd objdir % srcdir/configure [options] [target]
If you will be distributing binary versions of GCC, with modifications to the source code, you should use the options described in this section to make clear that your version contains modifications.
--with-pkgversion=versionSpecify a string that identifies your package. You may wish
to include a build number or build date. This version string will be
included in the output of gcc --version. This suffix does
not replace the default version string, only the ‘GCC’ part.
The default value is ‘GCC’.
--with-bugurl=urlSpecify the URL that users should visit if they wish to report a bug. You are of course welcome to forward bugs reported to you to the FSF, if you determine that they are not bugs in your modifications.
The default value refers to the FSF’s GCC bug tracker.
Use options to override several configure time options for GCC. A list of supported options follows; ‘configure --help’ may list other options, but those not listed below may not work and should not normally be used.
Note that each --enable option has a corresponding --disable option and that each --with option has a corresponding --without option.
--prefix=dirnameSpecify the toplevel installation directory. This is the recommended way to install the tools into a directory other than the default. The toplevel installation directory defaults to /usr/local.
We highly recommend against dirname being the same or a
subdirectory of objdir or vice versa. If specifying a directory
beneath a user’s home directory tree, some shells will not expand
dirname correctly if it contains the ‘~’ metacharacter; use
$HOME instead.
The following standard autoconf options are supported. Normally you
should not need to use these options.
--exec-prefix=dirnameSpecify the toplevel installation directory for architecture-dependent files. The default is prefix.
--bindir=dirnameSpecify the installation directory for the executables called by users
(such as gcc and g++). The default is
exec-prefix/bin.
--libdir=dirnameSpecify the installation directory for object code libraries and internal data files of GCC. The default is exec-prefix/lib.
--libexecdir=dirnameSpecify the installation directory for internal executables of GCC. The default is exec-prefix/libexec.
--with-slibdir=dirnameSpecify the installation directory for the shared libgcc library. The default is libdir.
--datarootdir=dirnameSpecify the root of the directory tree for read-only architecture-independent data files referenced by GCC. The default is prefix/share.
--infodir=dirnameSpecify the installation directory for documentation in info format. The default is datarootdir/info.
--datadir=dirnameSpecify the installation directory for some architecture-independent data files referenced by GCC. The default is datarootdir.
--docdir=dirnameSpecify the installation directory for documentation files (other than Info) for GCC. The default is datarootdir/doc.
--htmldir=dirnameSpecify the installation directory for HTML documentation files. The default is docdir.
--pdfdir=dirnameSpecify the installation directory for PDF documentation files. The default is docdir.
--mandir=dirnameSpecify the installation directory for manual pages. The default is datarootdir/man. (Note that the manual pages are only extracts from the full GCC manuals, which are provided in Texinfo format. The manpages are derived by an automatic conversion process from parts of the full manual.)
--with-gxx-include-dir=dirnameSpecify the installation directory for G++ header files. The default depends on other configuration options, and differs between cross and native configurations.
--with-specs=specsSpecify additional command line driver SPECS. This can be useful if you need to turn on a non-standard feature by default without modifying the compiler’s source code, for instance --with-specs=%{!fcommon:%{!fno-common:-fno-common}}. See “Spec Files” in the main manual
--program-prefix=prefixGCC supports some transformations of the names of its programs when installing them. This option prepends prefix to the names of programs to install in bindir (see above). For example, specifying --program-prefix=foo- would result in ‘gcc’ being installed as /usr/local/bin/foo-gcc.
--program-suffix=suffixAppends suffix to the names of programs to install in bindir (see above). For example, specifying --program-suffix=-3.1 would result in ‘gcc’ being installed as /usr/local/bin/gcc-3.1.
--program-transform-name=patternApplies the ‘sed’ script pattern to be applied to the names of programs to install in bindir (see above). pattern has to consist of one or more basic ‘sed’ editing commands, separated by semicolons. For example, if you want the ‘gcc’ program name to be transformed to the installed program /usr/local/bin/myowngcc and the ‘g++’ program name to be transformed to /usr/local/bin/gspecial++ without changing other program names, you could use the pattern --program-transform-name='s/^gcc$/myowngcc/; s/^g++$/gspecial++/' to achieve this effect.
All three options can be combined and used together, resulting in more complex conversion patterns. As a basic rule, prefix (and suffix) are prepended (appended) before further transformations can happen with a special transformation script pattern.
As currently implemented, this option only takes effect for native builds; cross compiler binaries’ names are not transformed even when a transformation is explicitly asked for by one of these options.
For native builds, some of the installed programs are also installed with the target alias in front of their name, as in ‘i686-pc-linux-gnu-gcc’. All of the above transformations happen before the target alias is prepended to the name—so, specifying --program-prefix=foo- and program-suffix=-3.1, the resulting binary would be installed as /usr/local/bin/i686-pc-linux-gnu-foo-gcc-3.1.
As a last shortcoming, none of the installed Ada programs are transformed yet, which will be fixed in some time.
--with-local-prefix=dirnameSpecify the installation directory for local include files. The default is /usr/local. Specify this option if you want the compiler to search directory dirname/include for locally installed header files instead of /usr/local/include.
You should specify --with-local-prefix only if your site has a different convention (not /usr/local) for where to put site-specific files.
The default value for --with-local-prefix is /usr/local regardless of the value of --prefix. Specifying --prefix has no effect on which directory GCC searches for local header files. This may seem counterintuitive, but actually it is logical.
The purpose of --prefix is to specify where to install GCC. The local header files in /usr/local/include—if you put any in that directory—are not part of GCC. They are part of other programs—perhaps many others. (GCC installs its own header files in another directory which is based on the --prefix value.)
Both the local-prefix include directory and the GCC-prefix include directory are part of GCC’s “system include” directories. Although these two directories are not fixed, they need to be searched in the proper order for the correct processing of the include_next directive. The local-prefix include directory is searched before the GCC-prefix include directory. Another characteristic of system include directories is that pedantic warnings are turned off for headers in these directories.
Some autoconf macros add -I directory options to the compiler command line, to ensure that directories containing installed packages’ headers are searched. When directory is one of GCC’s system include directories, GCC will ignore the option so that system directories continue to be processed in the correct order. This may result in a search order different from what was specified but the directory will still be searched.
GCC automatically searches for ordinary libraries using
GCC_EXEC_PREFIX. Thus, when the same installation prefix is
used for both GCC and packages, GCC will automatically search for
both headers and libraries. This provides a configuration that is
easy to use. GCC behaves in a manner similar to that when it is
installed as a system compiler in /usr.
Sites that need to install multiple versions of GCC may not want to
use the above simple configuration. It is possible to use the
--program-prefix, --program-suffix and
--program-transform-name options to install multiple versions
into a single directory, but it may be simpler to use different prefixes
and the --with-local-prefix option to specify the location of the
site-specific files for each version. It will then be necessary for
users to specify explicitly the location of local site libraries
(e.g., with LIBRARY_PATH).
The same value can be used for both --with-local-prefix and --prefix provided it is not /usr. This can be used to avoid the default search of /usr/local/include.
Do not specify /usr as the --with-local-prefix!
The directory you use for --with-local-prefix must not
contain any of the system’s standard header files. If it did contain
them, certain programs would be miscompiled (including GNU Emacs, on
certain targets), because this would override and nullify the header
file corrections made by the fixincludes script.
Indications are that people who use this option use it based on mistaken ideas of what it is for. People use it as if it specified where to install part of GCC. Perhaps they make this assumption because installing GCC creates the directory.
--with-gcc-major-version-onlySpecifies that GCC should use only the major number rather than major.minor.patchlevel in filesystem paths.
--with-native-system-header-dir=dirnameSpecifies that dirname is the directory that contains native system header files, rather than /usr/include. This option is most useful if you are creating a compiler that should be isolated from the system as much as possible. It is most commonly used with the --with-sysroot option and will cause GCC to search dirname inside the system root specified by that option.
--enable-shared[=package[,…]]Build shared versions of libraries, if shared libraries are supported on the target platform. Unlike GCC 2.95.x and earlier, shared libraries are enabled by default on all platforms that support shared libraries.
If a list of packages is given as an argument, build shared libraries only for the listed packages. For other packages, only static libraries will be built. Package names currently recognized in the GCC tree are ‘libgcc’ (also known as ‘gcc’), ‘libstdc++’ (not ‘libstdc++-v3’), ‘libffi’, ‘zlib’, ‘boehm-gc’, ‘ada’, ‘libada’, ‘libgo’, and ‘libobjc’. Note ‘libiberty’ does not support shared libraries at all.
Use --disable-shared to build only static libraries. Note that --disable-shared does not accept a list of package names as argument, only --enable-shared does.
Contrast with --enable-host-shared, which affects host code.
--enable-host-sharedSpecify that the host code should be built into position-independent machine code (with -fPIC), allowing it to be used within shared libraries, but yielding a slightly slower compiler.
This option is required when building the libgccjit.so library.
Contrast with --enable-shared, which affects target libraries.
--with-gnu-asSpecify that the compiler should assume that the assembler it finds is the GNU assembler. However, this does not modify the rules to find an assembler and will result in confusion if the assembler found is not actually the GNU assembler. (Confusion may also result if the compiler finds the GNU assembler but has not been configured with --with-gnu-as.) If you have more than one assembler installed on your system, you may want to use this option in connection with --with-as=pathname or --with-build-time-tools=pathname.
The following systems are the only ones where it makes a difference whether you use the GNU assembler. On any other system, --with-gnu-as has no effect.
--with-as=pathnameSpecify that the compiler should use the assembler pointed to by pathname, rather than the one found by the standard rules to find an assembler, which are:
PATH for a tool whose name is prefixed by the
target system triple.
PATH for a tool whose name is not prefixed by the
target system triple, if the host and target system triple are
the same (in other words, we use a host tool if it can be used for
the target as well).
You may want to use --with-as if no assembler is installed in the directories listed above, or if you have multiple assemblers installed and want to choose one that is not found by the above rules.
--with-gnu-ldSame as --with-gnu-as but for the linker.
--with-ld=pathnameSame as --with-as but for the linker.
--with-stabsSpecify that stabs debugging information should be used instead of whatever format the host normally uses. Normally GCC uses the same debug format as the host system.
On MIPS based systems and on Alphas, you must specify whether you want GCC to create the normal ECOFF debugging format, or to use BSD-style stabs passed through the ECOFF symbol table. The normal ECOFF debug format cannot fully handle languages other than C. BSD stabs format can handle other languages, but it only works with the GNU debugger GDB.
Normally, GCC uses the ECOFF debugging format by default; if you prefer BSD stabs, specify --with-stabs when you configure GCC.
No matter which default you choose when you configure GCC, the user can use the -gcoff and -gstabs+ options to specify explicitly the debug format for a particular compilation.
--with-stabs is meaningful on the ISC system on the 386, also, if --with-gas is used. It selects use of stabs debugging information embedded in COFF output. This kind of debugging information supports C++ well; ordinary COFF debugging information does not.
--with-stabs is also meaningful on 386 systems running SVR4. It selects use of stabs debugging information embedded in ELF output. The C++ compiler currently (2.6.0) does not support the DWARF debugging information normally used on 386 SVR4 platforms; stabs provide a workable alternative. This requires gas and gdb, as the normal SVR4 tools can not generate or interpret stabs.
--with-tls=dialectSpecify the default TLS dialect, for systems were there is a choice.
For ARM targets, possible values for dialect are gnu or
gnu2, which select between the original GNU dialect and the GNU TLS
descriptor-based dialect.
--enable-multiarchSpecify whether to enable or disable multiarch support. The default is to check for glibc start files in a multiarch location, and enable it if the files are found. The auto detection is enabled for native builds, and for cross builds configured with --with-sysroot, and without --with-native-system-header-dir. More documentation about multiarch can be found at https://wiki.debian.org/Multiarch.
--enable-sjlj-exceptionsForce use of the setjmp/longjmp-based scheme for exceptions.
‘configure’ ordinarily picks the correct value based on the platform.
Only use this option if you are sure you need a different setting.
--enable-vtable-verifySpecify whether to enable or disable the vtable verification feature. Enabling this feature causes libstdc++ to be built with its virtual calls in verifiable mode. This means that, when linked with libvtv, every virtual call in libstdc++ will verify the vtable pointer through which the call will be made before actually making the call. If not linked with libvtv, the verifier will call stub functions (in libstdc++ itself) and do nothing. If vtable verification is disabled, then libstdc++ is not built with its virtual calls in verifiable mode at all. However the libvtv library will still be built (see --disable-libvtv to turn off building libvtv). --disable-vtable-verify is the default.
--disable-multilibSpecify that multiple target libraries to support different target variants, calling conventions, etc. should not be built. The default is to build a predefined set of them.
Some targets provide finer-grained control over which multilibs are built (e.g., --disable-softfloat):
arm-*-*fpu, 26bit, underscore, interwork, biendian, nofmult.
m68*-*-*softfloat, m68881, m68000, m68020.
mips*-*-*single-float, biendian, softfloat.
powerpc*-*-*, rs6000*-*-*aix64, pthread, softfloat, powercpu, powerpccpu, powerpcos, biendian, sysv, aix.
--with-multilib-list=list--without-multilib-listSpecify what multilibs to build. list is a comma separated list of values, possibly consisting of a single value. Currently only implemented for arm*-*-*, sh*-*-* and x86-64-*-linux*. The accepted values and meaning for each target is given below.
arm*-*-*list is a comma separated list of aprofile and rmprofile
to build multilibs for A or R and M architecture profiles respectively. Note
that, due to some limitation of the current multilib framework, using the
combined aprofile,rmprofile multilibs selects in some cases a less
optimal multilib than when using the multilib profile for the architecture
targetted. The special value default is also accepted and is equivalent
to omitting the option, ie. only the default run-time library will be enabled.
The table below gives the combination of ISAs, architectures, FPUs and
floating-point ABIs for which multilibs are built for each accepted value.
The union of these options is considered when specifying both aprofile
and rmprofile.
| Option | aprofile | rmprofile |
| ISAs | -marm and -mthumb | -mthumb |
| Architectures | default architecture-march=armv7-a-march=armv7ve-march=armv8-a | default architecture-march=armv6s-m-march=armv7-m-march=armv7e-m-march=armv8-m.base-march=armv8-m.main-march=armv7 |
| FPUs | none-mfpu=vfpv3-d16-mfpu=neon-mfpu=vfpv4-d16-mfpu=neon-vfpv4-mfpu=neon-fp-armv8 | none-mfpu=vfpv3-d16-mfpu=fpv4-sp-d16-mfpu=fpv5-sp-d16-mfpu=fpv5-d16 |
| floating-point ABIs | -mfloat-abi=soft-mfloat-abi=softfp-mfloat-abi=hard | -mfloat-abi=soft-mfloat-abi=softfp-mfloat-abi=hard |
sh*-*-*list is a comma separated list of CPU names. These must be of the
form sh* or m* (in which case they match the compiler option
for that processor). The list should not contain any endian options -
these are handled by --with-endian.
If list is empty, then there will be no multilibs for extra processors. The multilib for the secondary endian remains enabled.
As a special case, if an entry in the list starts with a !
(exclamation point), then it is added to the list of excluded multilibs.
Entries of this sort should be compatible with ‘MULTILIB_EXCLUDES’
(once the leading ! has been stripped).
If --with-multilib-list is not given, then a default set of multilibs is selected based on the value of --target. This is usually the complete set of libraries, but some targets imply a more specialized subset.
Example 1: to configure a compiler for SH4A only, but supporting both endians, with little endian being the default:
--with-cpu=sh4a --with-endian=little,big --with-multilib-list=
Example 2: to configure a compiler for both SH4A and SH4AL-DSP, but with only little endian SH4AL:
--with-cpu=sh4a --with-endian=little,big \ --with-multilib-list=sh4al,!mb/m4al
x86-64-*-linux*list is a comma separated list of m32, m64 and
mx32 to enable 32-bit, 64-bit and x32 run-time libraries,
respectively. If list is empty, then there will be no multilibs
and only the default run-time library will be enabled.
If --with-multilib-list is not given, then only 32-bit and 64-bit run-time libraries will be enabled.
--with-endian=endiansSpecify what endians to use. Currently only implemented for sh*-*-*.
endians may be one of the following:
bigUse big endian exclusively.
littleUse little endian exclusively.
big,littleUse big endian by default. Provide a multilib for little endian.
little,bigUse little endian by default. Provide a multilib for big endian.
--enable-threadsSpecify that the target supports threads. This affects the Objective-C compiler and runtime library, and exception handling for other languages like C++. On some systems, this is the default.
In general, the best (and, in many cases, the only known) threading model available will be configured for use. Beware that on some systems, GCC has not been taught what threading models are generally available for the system. In this case, --enable-threads is an alias for --enable-threads=single.
--disable-threadsSpecify that threading support should be disabled for the system. This is an alias for --enable-threads=single.
--enable-threads=libSpecify that lib is the thread support library. This affects the Objective-C compiler and runtime library, and exception handling for other languages like C++. The possibilities for lib are:
aixAIX thread support.
dceDCE thread support.
lynxLynxOS thread support.
mipssdeMIPS SDE thread support.
noThis is an alias for ‘single’.
posixGeneric POSIX/Unix98 thread support.
rtemsRTEMS thread support.
singleDisable thread support, should work for all platforms.
tpfTPF thread support.
vxworksVxWorks thread support.
win32Microsoft Win32 API thread support.
--enable-tlsSpecify that the target supports TLS (Thread Local Storage). Usually configure can correctly determine if TLS is supported. In cases where it guesses incorrectly, TLS can be explicitly enabled or disabled with --enable-tls or --disable-tls. This can happen if the assembler supports TLS but the C library does not, or if the assumptions made by the configure test are incorrect.
--disable-tlsSpecify that the target does not support TLS. This is an alias for --enable-tls=no.
--with-cpu=cpu--with-cpu-32=cpu--with-cpu-64=cpuSpecify which cpu variant the compiler should generate code for by default. cpu will be used as the default value of the -mcpu= switch. This option is only supported on some targets, including ARC, ARM, i386, M68k, PowerPC, and SPARC. It is mandatory for ARC. The --with-cpu-32 and --with-cpu-64 options specify separate default CPUs for 32-bit and 64-bit modes; these options are only supported for i386, x86-64, PowerPC, and SPARC.
--with-schedule=cpu--with-arch=cpu--with-arch-32=cpu--with-arch-64=cpu--with-tune=cpu--with-tune-32=cpu--with-tune-64=cpu--with-abi=abi--with-fpu=type--with-float=typeThese configure options provide default values for the -mschedule=, -march=, -mtune=, -mabi=, and -mfpu= options and for -mhard-float or -msoft-float. As with --with-cpu, which switches will be accepted and acceptable values of the arguments depend on the target.
--with-mode=modeSpecify if the compiler should default to -marm or -mthumb. This option is only supported on ARM targets.
--with-stack-offset=numThis option sets the default for the -mstack-offset=num option, and will thus generally also control the setting of this option for libraries. This option is only supported on Epiphany targets.
--with-fpmath=isaThis options sets -mfpmath=sse by default and specifies the default ISA for floating-point arithmetics. You can select either ‘sse’ which enables -msse2 or ‘avx’ which enables -mavx by default. This option is only supported on i386 and x86-64 targets.
--with-fp-32=modeOn MIPS targets, set the default value for the -mfp option when using the o32 ABI. The possibilities for mode are:
32Use the o32 FP32 ABI extension, as with the -mfp32 command-line option.
xxUse the o32 FPXX ABI extension, as with the -mfpxx command-line option.
64Use the o32 FP64 ABI extension, as with the -mfp64 command-line option.
In the absence of this configuration option the default is to use the o32 FP32 ABI extension.
--with-odd-spreg-32On MIPS targets, set the -modd-spreg option by default when using the o32 ABI.
--without-odd-spreg-32On MIPS targets, set the -mno-odd-spreg option by default when using the o32 ABI. This is normally used in conjunction with --with-fp-32=64 in order to target the o32 FP64A ABI extension.
--with-nan=encodingOn MIPS targets, set the default encoding convention to use for the special not-a-number (NaN) IEEE 754 floating-point data. The possibilities for encoding are:
legacyUse the legacy encoding, as with the -mnan=legacy command-line option.
2008Use the 754-2008 encoding, as with the -mnan=2008 command-line option.
To use this configuration option you must have an assembler version installed that supports the -mnan= command-line option too. In the absence of this configuration option the default convention is the legacy encoding, as when neither of the -mnan=2008 and -mnan=legacy command-line options has been used.
--with-divide=typeSpecify how the compiler should generate code for checking for division by zero. This option is only supported on the MIPS target. The possibilities for type are:
trapsDivision by zero checks use conditional traps (this is the default on systems that support conditional traps).
breaksDivision by zero checks use the break instruction.
--with-llscOn MIPS targets, make -mllsc the default when no -mno-llsc option is passed. This is the default for Linux-based targets, as the kernel will emulate them if the ISA does not provide them.
--without-llscOn MIPS targets, make -mno-llsc the default when no -mllsc option is passed.
--with-synciOn MIPS targets, make -msynci the default when no -mno-synci option is passed.
--without-synciOn MIPS targets, make -mno-synci the default when no -msynci option is passed. This is the default.
--with-lxc1-sxc1On MIPS targets, make -mlxc1-sxc1 the default when no -mno-lxc1-sxc1 option is passed. This is the default.
--without-lxc1-sxc1On MIPS targets, make -mno-lxc1-sxc1 the default when no
-mlxc1-sxc1 option is passed. The indexed load/store
instructions are not directly a problem but can lead to unexpected
behaviour when deployed in an application intended for a 32-bit address
space but run on a 64-bit processor. The issue is seen because all
known MIPS 64-bit Linux kernels execute o32 and n32 applications
with 64-bit addressing enabled which affects the overflow behaviour
of the indexed addressing mode. GCC will assume that ordinary
32-bit arithmetic overflow behaviour is the same whether performed
as an addu instruction or as part of the address calculation
in lwxc1 type instructions. This assumption holds true in a
pure 32-bit environment and can hold true in a 64-bit environment if
the address space is accurately set to be 32-bit for o32 and n32.
--with-madd4On MIPS targets, make -mmadd4 the default when no -mno-madd4 option is passed. This is the default.
--without-madd4On MIPS targets, make -mno-madd4 the default when no
-mmadd4 option is passed. The madd4 instruction
family can be problematic when targeting a combination of cores that
implement these instructions differently. There are two known cores
that implement these as fused operations instead of unfused (where
unfused is normally expected). Disabling these instructions is the
only way to ensure compatible code is generated; this will incur
a performance penalty.
--with-mips-pltOn MIPS targets, make use of copy relocations and PLTs. These features are extensions to the traditional SVR4-based MIPS ABIs and require support from GNU binutils and the runtime C library.
--enable-__cxa_atexitDefine if you want to use __cxa_atexit, rather than atexit, to register C++ destructors for local statics and global objects. This is essential for fully standards-compliant handling of destructors, but requires __cxa_atexit in libc. This option is currently only available on systems with GNU libc. When enabled, this will cause -fuse-cxa-atexit to be passed by default.
--enable-gnu-indirect-functionDefine if you want to enable the ifunc attribute. This option is
currently only available on systems with GNU libc on certain targets.
--enable-target-optspaceSpecify that target libraries should be optimized for code space instead of code speed. This is the default for the m32r platform.
--with-cpp-install-dir=dirnameSpecify that the user visible cpp program should be installed
in prefix/dirname/cpp, in addition to bindir.
--enable-comdatEnable COMDAT group support. This is primarily used to override the automatically detected value.
--enable-initfini-arrayForce the use of sections .init_array and .fini_array
(instead of .init and .fini) for constructors and
destructors. Option --disable-initfini-array has the
opposite effect. If neither option is specified, the configure script
will try to guess whether the .init_array and
.fini_array sections are supported and, if they are, use them.
--enable-link-mutexWhen building GCC, use a mutex to avoid linking the compilers for multiple languages at the same time, to avoid thrashing on build systems with limited free memory. The default is not to use such a mutex.
--enable-maintainer-modeThe build rules that regenerate the Autoconf and Automake output files as
well as the GCC master message catalog gcc.pot are normally
disabled. This is because it can only be rebuilt if the complete source
tree is present. If you have changed the sources and want to rebuild the
catalog, configuring with --enable-maintainer-mode will enable
this. Note that you need a recent version of the gettext tools
to do so.
--disable-bootstrapFor a native build, the default configuration is to perform a 3-stage bootstrap of the compiler when ‘make’ is invoked, testing that GCC can compile itself correctly. If you want to disable this process, you can configure with --disable-bootstrap.
--enable-bootstrapIn special cases, you may want to perform a 3-stage build even if the target and host triplets are different. This is possible when the host can run code compiled for the target (e.g. host is i686-linux, target is i486-linux). Starting from GCC 4.2, to do this you have to configure explicitly with --enable-bootstrap.
--enable-generated-files-in-srcdirNeither the .c and .h files that are generated from Bison and flex nor the info manuals and man pages that are built from the .texi files are present in the SVN development tree. When building GCC from that development tree, or from one of our snapshots, those generated files are placed in your build directory, which allows for the source to be in a readonly directory.
If you configure with --enable-generated-files-in-srcdir then those generated files will go into the source directory. This is mainly intended for generating release or prerelease tarballs of the GCC sources, since it is not a requirement that the users of source releases to have flex, Bison, or makeinfo.
--enable-version-specific-runtime-libsSpecify that runtime libraries should be installed in the compiler specific subdirectory (libdir/gcc) rather than the usual places. In addition, ‘libstdc++’’s include files will be installed into libdir unless you overruled it by using --with-gxx-include-dir=dirname. Using this option is particularly useful if you intend to use several versions of GCC in parallel. This is currently supported by ‘libgfortran’, ‘libstdc++’, and ‘libobjc’.
--with-aix-soname=‘aix’, ‘svr4’ or ‘both’Traditional AIX shared library versioning (versioned Shared Object
files as members of unversioned Archive Library files named
‘lib.a’) causes numerous headaches for package managers. However,
Import Files as members of Archive Library files allow for
filename-based versioning of shared libraries as seen on Linux/SVR4,
where this is called the "SONAME". But as they prevent static linking,
Import Files may be used with Runtime Linking only, where the
linker does search for ‘libNAME.so’ before ‘libNAME.a’ library
filenames with the ‘-lNAME’ linker flag.
For detailed information please refer to the AIX ld Command reference.
As long as shared library creation is enabled, upon:
--with-aix-soname=aix--with-aix-soname=bothA (traditional AIX) Shared Archive Library file is created:
Shared Object file as archive member named
‘libNAME.so.V’ (except for ‘libgcc_s’, where the Shared
Object file is named ‘shr.o’ for backwards compatibility), which
dlopen("libNAME.a(libNAME.so.V)", RTLD_MEMBER)
Static Archive
Library file is needed
--with-aix-soname=both--with-aix-soname=svr4A (second) Shared Archive Library file is created:
Shared Object file as archive member named
‘shr.o’, which
-G linker flag
F_LOADONLY flag set
dlopen("libNAME.so.V(shr.o)",
RTLD_MEMBER)
Import File as archive member named ‘shr.imp’,
which
Loader Section of subsequent binaries
‘weak’ Keyword
A symbolic link using the ‘libNAME.so’ filename scheme is created:
Shared Archive Library file
ld Command to find ‘lib.so.V(shr.imp)’ via
the ‘-lNAME’ argument (requires Runtime Linking to be enabled)
dlopen("libNAME.so(shr.o)",
RTLD_MEMBER)
As long as static library creation is enabled, upon:
--with-aix-soname=svr4A Static Archive Library is created:
Static Object files as archive members, which
While the aix-soname=‘svr4’ option does not create Shared Object
files as members of unversioned Archive Library files any more, package
managers still are responsible to
transfer Shared Object files
found as member of a previously installed unversioned Archive Library
file into the newly installed Archive Library file with the same
filename.
WARNING: Creating Shared Object files with Runtime Linking
enabled may bloat the TOC, eventually leading to TOC overflow errors,
requiring the use of either the -Wl,-bbigtoc linker flag (seen to
break with the GDB debugger) or some of the TOC-related compiler flags,
see “RS/6000 and PowerPC Options” in the main manual.
--with-aix-soname is currently supported by ‘libgcc_s’ only, so this option is still experimental and not for normal use yet.
Default is the traditional behavior --with-aix-soname=‘aix’.
--enable-languages=lang1,lang2,…Specify that only a particular subset of compilers and
their runtime libraries should be built. For a list of valid values for
langN you can issue the following command in the
gcc directory of your GCC source tree:
grep ^language= */config-lang.in
Currently, you can use any of the following:
all, default, ada, c, c++, fortran,
go, jit, lto, objc, obj-c++.
Building the Ada compiler has special requirements, see below.
If you do not pass this flag, or specify the option default, then the
default languages available in the gcc sub-tree will be configured.
Ada, Go, Jit, and Objective-C++ are not default languages. LTO is not a
default language, but is built by default because --enable-lto is
enabled by default. The other languages are default languages. If
all is specified, then all available languages are built. An
exception is jit language, which requires
--enable-host-shared to be included with all.
--enable-stage1-languages=lang1,lang2,…Specify that a particular subset of compilers and their runtime
libraries should be built with the system C compiler during stage 1 of
the bootstrap process, rather than only in later stages with the
bootstrapped C compiler. The list of valid values is the same as for
--enable-languages, and the option all will select all
of the languages enabled by --enable-languages. This option is
primarily useful for GCC development; for instance, when a development
version of the compiler cannot bootstrap due to compiler bugs, or when
one is debugging front ends other than the C front end. When this
option is used, one can then build the target libraries for the
specified languages with the stage-1 compiler by using make
stage1-bubble all-target, or run the testsuite on the stage-1 compiler
for the specified languages using make stage1-start check-gcc.
--disable-libadaSpecify that the run-time libraries and tools used by GNAT should not be built. This can be useful for debugging, or for compatibility with previous Ada build procedures, when it was required to explicitly do a ‘make -C gcc gnatlib_and_tools’.
--disable-libsanitizerSpecify that the run-time libraries for the various sanitizers should not be built.
--disable-libsspSpecify that the run-time libraries for stack smashing protection should not be built.
--disable-libquadmathSpecify that the GCC quad-precision math library should not be built. On some systems, the library is required to be linkable when building the Fortran front end, unless --disable-libquadmath-support is used.
--disable-libquadmath-supportSpecify that the Fortran front end and libgfortran do not add
support for libquadmath on systems supporting it.
--disable-libgompSpecify that the GNU Offloading and Multi Processing Runtime Library should not be built.
--disable-libvtvSpecify that the run-time libraries used by vtable verification should not be built.
--with-dwarf2Specify that the compiler should use DWARF 2 debugging information as the default.
--with-advance-toolchain=atOn 64-bit PowerPC Linux systems, configure the compiler to use the header files, library files, and the dynamic linker from the Advance Toolchain release at instead of the default versions that are provided by the Linux distribution. In general, this option is intended for the developers of GCC, and it is not intended for general use.
--enable-targets=all--enable-targets=target_listSome GCC targets, e.g. powerpc64-linux, build bi-arch compilers. These are compilers that are able to generate either 64-bit or 32-bit code. Typically, the corresponding 32-bit target, e.g. powerpc-linux for powerpc64-linux, only generates 32-bit code. This option enables the 32-bit target to be a bi-arch compiler, which is useful when you want a bi-arch compiler that defaults to 32-bit, and you are building a bi-arch or multi-arch binutils in a combined tree. On mips-linux, this will build a tri-arch compiler (ABI o32/n32/64), defaulted to o32. Currently, this option only affects sparc-linux, powerpc-linux, x86-linux, mips-linux and s390-linux.
--enable-default-pieTurn on -fPIE and -pie by default.
--enable-securepltThis option enables -msecure-plt by default for powerpc-linux. See “RS/6000 and PowerPC Options” in the main manual
--enable-default-sspTurn on -fstack-protector-strong by default.
--enable-cldThis option enables -mcld by default for 32-bit x86 targets. See “i386 and x86-64 Options” in the main manual
--enable-win32-registry--enable-win32-registry=key--disable-win32-registryThe --enable-win32-registry option enables Microsoft Windows-hosted GCC to look up installations paths in the registry using the following key:
HKEY_LOCAL_MACHINE\SOFTWARE\Free Software Foundation\key
key defaults to GCC version number, and can be overridden by the --enable-win32-registry=key option. Vendors and distributors who use custom installers are encouraged to provide a different key, perhaps one comprised of vendor name and GCC version number, to avoid conflict with existing installations. This feature is enabled by default, and can be disabled by --disable-win32-registry option. This option has no effect on the other hosts.
--nfpSpecify that the machine does not have a floating point unit. This option only applies to ‘m68k-sun-sunosn’. On any other system, --nfp has no effect.
--enable-werror--disable-werror--enable-werror=yes--enable-werror=noWhen you specify this option, it controls whether certain files in the compiler are built with -Werror in bootstrap stage2 and later. If you don’t specify it, -Werror is turned on for the main development trunk. However it defaults to off for release branches and final releases. The specific files which get -Werror are controlled by the Makefiles.
--enable-checking--enable-checking=listWhen you specify this option, the compiler is built to perform internal consistency checks of the requested complexity. This does not change the generated code, but adds error checking within the compiler. This will slow down the compiler and may only work properly if you are building the compiler with GCC. This is ‘yes,extra’ by default when building from SVN or snapshots, but ‘release’ for releases. The default for building the stage1 compiler is ‘yes’. More control over the checks may be had by specifying list. The categories of checks available are ‘yes’ (most common checks ‘assert,misc,tree,gc,rtlflag,runtime’), ‘no’ (no checks at all), ‘all’ (all but ‘valgrind’), ‘release’ (cheapest checks ‘assert,runtime’) or ‘none’ (same as ‘no’). Individual checks can be enabled with these flags ‘assert’, ‘df’, ‘fold’, ‘gc’, ‘gcac’, ‘misc’, ‘rtl’, ‘rtlflag’, ‘runtime’, ‘tree’, ‘extra’ and ‘valgrind’. ‘extra’ adds for ‘misc’ checking extra checks that might affect code generation and should therefore not differ between stage1 and later stages.
The ‘valgrind’ check requires the external valgrind
simulator, available from http://valgrind.org/. The
‘df’, ‘rtl’, ‘gcac’ and ‘valgrind’ checks are very expensive.
To disable all checking, ‘--disable-checking’ or
‘--enable-checking=none’ must be explicitly requested. Disabling
assertions will make the compiler and runtime slightly faster but
increase the risk of undetected internal errors causing wrong code to be
generated.
--disable-stage1-checking--enable-stage1-checking--enable-stage1-checking=listIf no --enable-checking option is specified the stage1 compiler will be built with ‘yes’ checking enabled, otherwise the stage1 checking flags are the same as specified by --enable-checking. To build the stage1 compiler with different checking options use --enable-stage1-checking. The list of checking options is the same as for --enable-checking. If your system is too slow or too small to bootstrap a released compiler with checking for stage1 enabled, you can use ‘--disable-stage1-checking’ to disable checking for the stage1 compiler.
--enable-coverage--enable-coverage=levelWith this option, the compiler is built to collect self coverage information, every time it is run. This is for internal development purposes, and only works when the compiler is being built with gcc. The level argument controls whether the compiler is built optimized or not, values are ‘opt’ and ‘noopt’. For coverage analysis you want to disable optimization, for performance analysis you want to enable optimization. When coverage is enabled, the default level is without optimization.
--enable-gather-detailed-mem-statsWhen this option is specified more detailed information on memory allocation is gathered. This information is printed when using -fmem-report.
--enable-valgrind-annotationsMark selected memory related operations in the compiler when run under valgrind to suppress false positives.
--enable-nls--disable-nlsThe --enable-nls option enables Native Language Support (NLS), which lets GCC output diagnostics in languages other than American English. Native Language Support is enabled by default if not doing a canadian cross build. The --disable-nls option disables NLS.
--with-included-gettextIf NLS is enabled, the --with-included-gettext option causes the build
procedure to prefer its copy of GNU gettext.
--with-catgetsIf NLS is enabled, and if the host lacks gettext but has the
inferior catgets interface, the GCC build procedure normally
ignores catgets and instead uses GCC’s copy of the GNU
gettext library. The --with-catgets option causes the
build procedure to use the host’s catgets in this situation.
--with-libiconv-prefix=dirSearch for libiconv header files in dir/include and libiconv library files in dir/lib.
--enable-obsoleteEnable configuration for an obsoleted system. If you attempt to configure GCC for a system (build, host, or target) which has been obsoleted, and you do not specify this flag, configure will halt with an error message.
All support for systems which have been obsoleted in one release of GCC is removed entirely in the next major release, unless someone steps forward to maintain the port.
--enable-decimal-float--enable-decimal-float=yes--enable-decimal-float=no--enable-decimal-float=bid--enable-decimal-float=dpd--disable-decimal-floatEnable (or disable) support for the C decimal floating point extension that is in the IEEE 754-2008 standard. This is enabled by default only on PowerPC, i386, and x86_64 GNU/Linux systems. Other systems may also support it, but require the user to specifically enable it. You can optionally control which decimal floating point format is used (either ‘bid’ or ‘dpd’). The ‘bid’ (binary integer decimal) format is default on i386 and x86_64 systems, and the ‘dpd’ (densely packed decimal) format is default on PowerPC systems.
--enable-fixed-point--disable-fixed-pointEnable (or disable) support for C fixed-point arithmetic. This option is enabled by default for some targets (such as MIPS) which have hardware-support for fixed-point operations. On other targets, you may enable this option manually.
--with-long-double-128Specify if long double type should be 128-bit by default on selected
GNU/Linux architectures. If using --without-long-double-128,
long double will be by default 64-bit, the same as double type.
When neither of these configure options are used, the default will be
128-bit long double when built against GNU C Library 2.4 and later,
64-bit long double otherwise.
--enable-fdpicOn SH Linux systems, generate ELF FDPIC code.
--with-gmp=pathname--with-gmp-include=pathname--with-gmp-lib=pathname--with-mpfr=pathname--with-mpfr-include=pathname--with-mpfr-lib=pathname--with-mpc=pathname--with-mpc-include=pathname--with-mpc-lib=pathnameIf you want to build GCC but do not have the GMP library, the MPFR
library and/or the MPC library installed in a standard location and
do not have their sources present in the GCC source tree then you
can explicitly specify the directory where they are installed
(‘--with-gmp=gmpinstalldir’,
‘--with-mpfr=mpfrinstalldir’,
‘--with-mpc=mpcinstalldir’). The
--with-gmp=gmpinstalldir option is shorthand for
--with-gmp-lib=gmpinstalldir/lib and
--with-gmp-include=gmpinstalldir/include. Likewise the
--with-mpfr=mpfrinstalldir option is shorthand for
--with-mpfr-lib=mpfrinstalldir/lib and
--with-mpfr-include=mpfrinstalldir/include, also the
--with-mpc=mpcinstalldir option is shorthand for
--with-mpc-lib=mpcinstalldir/lib and
--with-mpc-include=mpcinstalldir/include. If these
shorthand assumptions are not correct, you can use the explicit
include and lib options directly. You might also need to ensure the
shared libraries can be found by the dynamic linker when building and
using GCC, for example by setting the runtime shared library path
variable (LD_LIBRARY_PATH on GNU/Linux and Solaris systems).
These flags are applicable to the host platform only. When building a cross compiler, they will not be used to configure target libraries.
--with-isl=pathname--with-isl-include=pathname--with-isl-lib=pathnameIf you do not have the isl library installed in a standard location and you want to build GCC, you can explicitly specify the directory where it is installed (‘--with-isl=islinstalldir’). The --with-isl=islinstalldir option is shorthand for --with-isl-lib=islinstalldir/lib and --with-isl-include=islinstalldir/include. If this shorthand assumption is not correct, you can use the explicit include and lib options directly.
These flags are applicable to the host platform only. When building a cross compiler, they will not be used to configure target libraries.
--with-stage1-ldflags=flagsThis option may be used to set linker flags to be used when linking stage 1 of GCC. These are also used when linking GCC if configured with --disable-bootstrap. If --with-stage1-libs is not set to a value, then the default is ‘-static-libstdc++ -static-libgcc’, if supported.
--with-stage1-libs=libsThis option may be used to set libraries to be used when linking stage 1 of GCC. These are also used when linking GCC if configured with --disable-bootstrap.
--with-boot-ldflags=flagsThis option may be used to set linker flags to be used when linking stage 2 and later when bootstrapping GCC. If –with-boot-libs is not is set to a value, then the default is ‘-static-libstdc++ -static-libgcc’.
--with-boot-libs=libsThis option may be used to set libraries to be used when linking stage 2 and later when bootstrapping GCC.
--with-debug-prefix-map=mapConvert source directory names using -fdebug-prefix-map when building runtime libraries. ‘map’ is a space-separated list of maps of the form ‘old=new’.
--enable-linker-build-idTells GCC to pass --build-id option to the linker for all final links (links performed without the -r or --relocatable option), if the linker supports it. If you specify --enable-linker-build-id, but your linker does not support --build-id option, a warning is issued and the --enable-linker-build-id option is ignored. The default is off.
--with-linker-hash-style=choiceTells GCC to pass --hash-style=choice option to the linker for all final links. choice can be one of ‘sysv’, ‘gnu’, and ‘both’ where ‘sysv’ is the default.
--enable-gnu-unique-object--disable-gnu-unique-objectTells GCC to use the gnu_unique_object relocation for C++ template static data members and inline function local statics. Enabled by default for a toolchain with an assembler that accepts it and GLIBC 2.11 or above, otherwise disabled.
--with-diagnostics-color=choiceTells GCC to use choice as the default for -fdiagnostics-color=
option (if not used explicitly on the command line). choice
can be one of ‘never’, ‘auto’, ‘always’, and ‘auto-if-env’
where ‘auto’ is the default. ‘auto-if-env’ means that
-fdiagnostics-color=auto will be the default if GCC_COLORS
is present and non-empty in the environment, and
-fdiagnostics-color=never otherwise.
--enable-lto--disable-ltoEnable support for link-time optimization (LTO). This is enabled by default, and may be disabled using --disable-lto.
--enable-linker-plugin-configure-flags=FLAGS--enable-linker-plugin-flags=FLAGSBy default, linker plugins (such as the LTO plugin) are built for the host system architecture. For the case that the linker has a different (but run-time compatible) architecture, these flags can be specified to build plugins that are compatible to the linker. For example, if you are building GCC for a 64-bit x86_64 (‘x86_64-unknown-linux-gnu’) host system, but have a 32-bit x86 GNU/Linux (‘i686-pc-linux-gnu’) linker executable (which is executable on the former system), you can configure GCC as follows for getting compatible linker plugins:
% srcdir/configure \
--host=x86_64-unknown-linux-gnu \
--enable-linker-plugin-configure-flags=--host=i686-pc-linux-gnu \
--enable-linker-plugin-flags='CC=gcc\ -m32\ -Wl,-rpath,[...]/i686-pc-linux-gnu/lib'
--with-plugin-ld=pathnameEnable an alternate linker to be used at link-time optimization (LTO) link time when -fuse-linker-plugin is enabled. This linker should have plugin support such as gold starting with version 2.20 or GNU ld starting with version 2.21. See -fuse-linker-plugin for details.
--enable-canonical-system-headers--disable-canonical-system-headersEnable system header path canonicalization for libcpp. This can produce shorter header file paths in diagnostics and dependency output files, but these changed header paths may conflict with some compilation environments. Enabled by default, and may be disabled using --disable-canonical-system-headers.
--with-glibc-version=major.minorTell GCC that when the GNU C Library (glibc) is used on the target it will be version major.minor or later. Normally this can be detected from the C library’s header files, but this option may be needed when bootstrapping a cross toolchain without the header files available for building the initial bootstrap compiler.
If GCC is configured with some multilibs that use glibc and some that do not, this option applies only to the multilibs that use glibc. However, such configurations may not work well as not all the relevant configuration in GCC is on a per-multilib basis.
--enable-as-accelerator-for=targetBuild as offload target compiler. Specify offload host triple by target.
--enable-offload-targets=target1[=path1],…,targetN[=pathN]Enable offloading to targets target1, …, targetN. Offload compilers are expected to be already installed. Default search path for them is exec-prefix, but it can be changed by specifying paths path1, …, pathN.
% srcdir/configure \
--enable-offload-target=i686-unknown-linux-gnu=/path/to/i686/compiler,x86_64-pc-linux-gnu
If ‘hsa’ is specified as one of the targets, the compiler will be built with support for HSA GPU accelerators. Because the same compiler will emit the accelerator code, no path should be specified.
--with-hsa-runtime=pathname--with-hsa-runtime-include=pathname--with-hsa-runtime-lib=pathnameIf you configure GCC with HSA offloading but do not have the HSA run-time library installed in a standard location then you can explicitly specify the directory where they are installed. The --with-hsa-runtime=hsainstalldir option is a shorthand for --with-hsa-runtime-lib=hsainstalldir/lib and --with-hsa-runtime-include=hsainstalldir/include.
The following options only apply to building cross compilers.
--with-sysroot--with-sysroot=dirTells GCC to consider dir as the root of a tree that contains (a subset of) the root filesystem of the target operating system. Target system headers, libraries and run-time object files will be searched for in there. More specifically, this acts as if --sysroot=dir was added to the default options of the built compiler. The specified directory is not copied into the install tree, unlike the options --with-headers and --with-libs that this option obsoletes. The default value, in case --with-sysroot is not given an argument, is ${gcc_tooldir}/sys-root. If the specified directory is a subdirectory of ${exec_prefix}, then it will be found relative to the GCC binaries if the installation tree is moved.
This option affects the system root for the compiler used to build
target libraries (which runs on the build system) and the compiler newly
installed with make install; it does not affect the compiler which is
used to build GCC itself.
If you specify the --with-native-system-header-dir=dirname option then the compiler will search that directory within dirname for native system headers rather than the default /usr/include.
--with-build-sysroot--with-build-sysroot=dirTells GCC to consider dir as the system root (see --with-sysroot) while building target libraries, instead of the directory specified with --with-sysroot. This option is only useful when you are already using --with-sysroot. You can use --with-build-sysroot when you are configuring with --prefix set to a directory that is different from the one in which you are installing GCC and your target libraries.
This option affects the system root for the compiler used to build target libraries (which runs on the build system); it does not affect the compiler which is used to build GCC itself.
If you specify the --with-native-system-header-dir=dirname option then the compiler will search that directory within dirname for native system headers rather than the default /usr/include.
--with-headers--with-headers=dirDeprecated in favor of --with-sysroot.
Specifies that target headers are available when building a cross compiler.
The dir argument specifies a directory which has the target include
files. These include files will be copied into the gcc install
directory. This option with the dir argument is required when
building a cross compiler, if prefix/target/sys-include
doesn’t pre-exist. If prefix/target/sys-include does
pre-exist, the dir argument may be omitted. fixincludes
will be run on these files to make them compatible with GCC.
--without-headersTells GCC not use any target headers from a libc when building a cross compiler. When crossing to GNU/Linux, you need the headers so GCC can build the exception handling for libgcc.
--with-libs--with-libs="dir1 dir2 … dirN"Deprecated in favor of --with-sysroot. Specifies a list of directories which contain the target runtime libraries. These libraries will be copied into the gcc install directory. If the directory list is omitted, this option has no effect.
--with-newlibSpecifies that ‘newlib’ is
being used as the target C library. This causes __eprintf to be
omitted from libgcc.a on the assumption that it will be provided by
‘newlib’.
--with-avrlibcSpecifies that ‘AVR-Libc’ is
being used as the target C library. This causes float support
functions like __addsf3 to be omitted from libgcc.a on
the assumption that it will be provided by libm.a. For more
technical details, cf. PR54461.
This option is only supported for the AVR target. It is not supported for
RTEMS configurations, which currently use newlib. The option is
supported since version 4.7.2 and is the default in 4.8.0 and newer.
--with-nds32-lib=librarySpecifies that library setting is used for building libgcc.a. Currently, the valid library is ‘newlib’ or ‘mculib’. This option is only supported for the NDS32 target.
--with-build-time-tools=dirSpecifies where to find the set of target tools (assembler, linker, etc.) that will be used while building GCC itself. This option can be useful if the directory layouts are different between the system you are building GCC on, and the system where you will deploy it.
For example, on an ‘ia64-hp-hpux’ system, you may have the GNU assembler and linker in /usr/bin, and the native tools in a different path, and build a toolchain that expects to find the native tools in /usr/bin.
When you use this option, you should ensure that dir includes
ar, as, ld, nm,
ranlib and strip if necessary, and possibly
objdump. Otherwise, GCC may use an inconsistent set of
tools.
configure test resultsSometimes, it might be necessary to override the result of some
configure test, for example in order to ease porting to a new
system or work around a bug in a test. The toplevel configure
script provides three variables for this:
build_configargsThe contents of this variable is passed to all build configure
scripts.
host_configargsThe contents of this variable is passed to all host configure
scripts.
target_configargsThe contents of this variable is passed to all target configure
scripts.
In order to avoid shell and make quoting issues for complex
overrides, you can pass a setting for CONFIG_SITE and set
variables in the site file.
The following options apply to the build of the Objective-C runtime library.
--enable-objc-gcSpecify that an additional variant of the GNU Objective-C runtime library is built, using an external build of the Boehm-Demers-Weiser garbage collector (http://www.hboehm.info/gc/). This library needs to be available for each multilib variant, unless configured with --enable-objc-gc=‘auto’ in which case the build of the additional runtime library is skipped when not available and the build continues.
--with-target-bdw-gc=list--with-target-bdw-gc-include=list--with-target-bdw-gc-lib=listSpecify search directories for the garbage collector header files and libraries. list is a comma separated list of key value pairs of the form ‘multilibdir=path’, where the default multilib key is named as ‘.’ (dot), or is omitted (e.g. ‘--with-target-bdw-gc=/opt/bdw-gc,32=/opt-bdw-gc32’).
The options --with-target-bdw-gc-include and --with-target-bdw-gc-lib must always be specified together for each multilib variant and they take precedence over --with-target-bdw-gc. If --with-target-bdw-gc-include is missing values for a multilib, then the value for the default multilib is used (e.g. ‘--with-target-bdw-gc-include=/opt/bdw-gc/include’ ‘--with-target-bdw-gc-lib=/opt/bdw-gc/lib64,32=/opt-bdw-gc/lib32’). If none of these options are specified, the library is assumed in default locations.
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These pages are maintained by the GCC team. Last modified 2017-05-30.