diff options
Diffstat (limited to 'gcc/doc')
| -rw-r--r-- | gcc/doc/install.texi | 48 |
1 files changed, 25 insertions, 23 deletions
diff --git a/gcc/doc/install.texi b/gcc/doc/install.texi index 8411f44..9569f9b 100644 --- a/gcc/doc/install.texi +++ b/gcc/doc/install.texi @@ -1762,33 +1762,35 @@ same described above, but object files from the stage1 and stage2 of the 3-stage bootstrap of the compiler are deleted as soon as they are no longer needed. -If you want to save additional space during the bootstrap and in -the final installation as well, you can build the compiler binaries -without debugging information as in the following example. This will save -roughly 40% of disk space both for the bootstrap and the final installation. -(Libraries will still contain debugging information.) +If you wish to use non-default GCC flags when compiling the stage2 +and stage3 compilers, set @code{BOOT_CFLAGS} on the command line when +doing @samp{make}. For example, if you want to save additional space +during the bootstrap and in the final installation as well, you can +build the compiler binaries without debugging information as in the +following example. This will save roughly 40% of disk space both for +the bootstrap and the final installation. (Libraries will still contain +debugging information.) @smallexample - make CFLAGS='-O' LIBCFLAGS='-g -O2' \ - LIBCXXFLAGS='-g -O2 -fno-implicit-templates' bootstrap + make BOOT_CFLAGS='-O' bootstrap @end smallexample -If you wish to use non-default GCC flags when compiling the stage2 and -stage3 compilers, set @code{BOOT_CFLAGS} on the command line when doing -@samp{make}. Non-default optimization flags are less well -tested here than the default of @samp{-g -O2}, but should still work. -In a few cases, you may find that you need to specify special flags such -as @option{-msoft-float} here to complete the bootstrap; or, if the -native compiler miscompiles the stage1 compiler, you may need to work -around this, by choosing @code{BOOT_CFLAGS} to avoid the parts of the -stage1 compiler that were miscompiled, or by using @samp{make +You can place non-default optimization flags into @code{BOOT_CFLAGS}; they +are less well tested here than the default of @samp{-g -O2}, but should +still work. In a few cases, you may find that you need to specify special +flags such as @option{-msoft-float} here to complete the bootstrap; or, +if the native compiler miscompiles the stage1 compiler, you may need +to work around this, by choosing @code{BOOT_CFLAGS} to avoid the parts +of the stage1 compiler that were miscompiled, or by using @samp{make bootstrap4} to increase the number of stages of bootstrap. -Note that using non-standard @code{CFLAGS} can cause bootstrap to fail -if these trigger a warning with the new compiler. For example using -@samp{-O2 -g -mcpu=i686} on @code{i686-pc-linux-gnu} will cause bootstrap -failure as @option{-mcpu=} is deprecated in 3.4.0 and above. - +@code{BOOT_CFLAGS} does not apply to bootstrapped target libraries. +Since these are always compiled with the compiler currently being +bootstrapped, you can use @code{CFLAGS_FOR_TARGET} to modify their +compilation flags, as for non-bootstrapped target libraries. +Again, if the native compiler miscompiles the stage1 compiler, you may +need to work around this by avoiding non-working parts of the stage1 +compiler. Use @code{STAGE1_LIBCFLAGS} to this end. If you used the flag @option{--enable-languages=@dots{}} to restrict the compilers to be built, only those you've actually enabled will be @@ -2679,8 +2681,8 @@ cross-compilers on the Alpha for 32-bit machines has only been tested in a few cases and may not work properly. @samp{make compare} may fail on old versions of DEC Unix unless you add -@option{-save-temps} to @code{CFLAGS}. On these systems, the name of the -assembler input file is stored in the object file, and that makes +@option{-save-temps} to @code{BOOT_CFLAGS}. On these systems, the name +of the assembler input file is stored in the object file, and that makes comparison fail if it differs between the @code{stage1} and @code{stage2} compilations. The option @option{-save-temps} forces a fixed name to be used for the assembler input file, instead of a |