configure.host revision 1.6 
1# configure.host
2#
3# This shell script handles all host based configuration for libstdc++.
4# It sets various shell variables based on the the host and the
5# configuration options.  You can modify this shell script without needing
6# to rerun autoconf/aclocal/etc.  This file is "sourced" not executed.
7#
8# You should read docs/html/17_intro/porting.* to make sense of this file.
9#
10#
11# It uses the following shell variables as set by config.guess:
12#   host                The configuration host (full CPU-vendor-OS triplet)
13#   host_cpu            The configuration host CPU
14#   host_os             The configuration host OS
15#
16#
17# It sets the following shell variables:
18#
19#   cpu_include_dir        CPU-specific directory, defaults to cpu/generic
20#                          if cpu/host_cpu doesn't exist.  This is not used
21#                          directly, but sets the default for others.
22#
23#   os_include_dir         OS-specific directory, defaults to os/generic.
24#
25#   c_model                the "C" header model, defaults to c_global.
26#
27#   c_compatibility        if "C" compatibility headers are necessary,
28#                          defaults to no.
29#
30#   abi_baseline_pair      directory name for ABI compat testing,
31#                          defaults to host_cpu-host_os (as per config.guess)
32#
33#   abi_baseline_subdir_switch
34#			   g++ switch to determine ABI baseline subdir for
35#			   multilibbed targets,
36#			   defaults to --print-multi-directory
37#
38#   abi_tweaks_dir         location of cxxabi_tweaks.h,
39#                          defaults to cpu_include_dir
40#
41#   atomicity_dir          location of atomicity.h,
42#                          defaults to cpu_include_dir
43#
44#   atomic_word_dir        location of atomic_word.h
45#                          defaults to generic.
46#
47#   atomic_flags           extra flags to pass to use atomic instructions
48#                          defaults to nothing.
49#
50#   cpu_defines_dir        location of cpu_defines.h
51#                          defaults to generic.
52#
53#   cpu_opt_bits_random    path name of random.h containing CPU-specific
54#                          optimizations
55#
56#   cpu_opt_ext_random     path name of random.h containing CPU-specific
57#                          optimizations for extensions
58#
59#   error_constants_dir    location of error_constants.h
60#                          defaults to os/generic.
61#
62# It possibly modifies the following variables:
63#
64#   OPT_LDFLAGS            extra flags to pass when linking the library, of
65#                          the form '-Wl,blah'
66#                          (defaults to empty in acinclude.m4)
67#
68#   port_specific_symbol_files
69#                          whitespace-separated list of files containing
70#                          additional symbols to export from the shared
71#                          library, when symbol versioning is in use
72#
73#
74# If the defaults will not work for your platform, you need only change the
75# variables that won't work, i.e., you do not need to explicitly set a
76# working variable to its default.  Most hosts only need to change the two
77# *_include_dir variables.
78
79
80# DEFAULTS
81# Try to guess a default cpu_include_dir based on the name of the CPU.  We
82# cannot do this for os_include_dir; there are too many portable operating
83# systems out there.  :-)
84c_model=c_global
85c_compatibility=no
86atomic_word_dir=cpu/generic
87atomic_flags=""
88atomicity_dir="cpu/generic"
89cpu_defines_dir="cpu/generic"
90try_cpu=generic
91abi_baseline_subdir_switch=--print-multi-directory
92abi_tweaks_dir="cpu/generic"
93error_constants_dir="os/generic"
94
95# HOST-SPECIFIC OVERRIDES
96# Set any CPU-dependent bits.
97
98# Provide a way to funnel exotic flavors and prefixed/postfixed chip
99# variants into the established source config/cpu/* sub-directories.
100# THIS TABLE IS SORTED.  KEEP IT THAT WAY.
101case "${host_cpu}" in
102  alpha*)
103    try_cpu=alpha
104    ;;
105  arm*)
106    try_cpu=arm
107    ;;
108  crisv32)
109    try_cpu=cris
110    ;;
111  i[567]86 | x86_64)
112    try_cpu=i486
113    ;;
114  hppa*)
115    try_cpu=hppa
116    ;;
117  mep*)
118    EXTRA_CXX_FLAGS=-mm
119    try_cpu=generic
120    ;;
121  mips*)
122    try_cpu=mips
123    ;;
124  powerpc* | rs6000)
125    try_cpu=powerpc
126    ;;
127  sparc* | ultrasparc)
128    try_cpu=sparc
129    ;;
130  *)
131    if test -d ${glibcxx_srcdir}/config/cpu/${host_cpu}; then
132      try_cpu=${host_cpu}
133    fi
134esac
135
136
137# Now look for the file(s) usually tied to a CPU model, and make
138# default choices for those if they haven't been explicitly set
139# already.  
140cpu_include_dir=cpu/${try_cpu}
141
142
143# Set specific CPU overrides for cpu_defines_dir. Most can just use generic.
144# THIS TABLE IS SORTED.  KEEP IT THAT WAY.
145case "${host_cpu}" in
146  arm*)
147    cpu_defines_dir=cpu/arm
148    ;;
149  powerpc* | rs6000)
150    cpu_defines_dir=cpu/powerpc
151    ;;
152esac
153
154
155# Set specific CPU overrides for atomic_word_dir and atomic_flags. 
156# Most can just use generic.
157# THIS TABLE IS SORTED.  KEEP IT THAT WAY.
158case "${host_cpu}" in
159  cris*)
160    atomic_word_dir=cpu/cris
161    ;;
162  i[4567]86 | x86_64)
163    atomic_flags="-march=native"
164    ;;
165  sparc* | ultrasparc)
166    atomic_word_dir=cpu/sparc
167    atomic_flags="-mcpu=v9"
168    ;;
169esac
170
171
172# Set specific CPU overrides for atomicity_dir.
173# This can be over-ridden in GLIBCXX_ENABLE_ATOMIC_BUILTINS.
174# THIS TABLE IS SORTED.  KEEP IT THAT WAY.
175if test -f ${glibcxx_srcdir}/config/${cpu_include_dir}/atomicity.h ; then
176# The sh atomicity.h is unusable
177if test ${cpu_include_dir} != "cpu/sh"; then
178  atomicity_dir=$cpu_include_dir
179fi
180fi
181
182
183if test -f ${glibcxx_srcdir}/config/${cpu_include_dir}/cxxabi_tweaks.h ; then
184  abi_tweaks_dir=$cpu_include_dir
185fi
186
187
188# Set directory with CPU-specific optimization
189cpu_opt_dir=${cpu_include_dir}/opt
190test -d ${glibcxx_srcdir}/config/${cpu_include_dir}/opt ||
191cpu_opt_dir=cpu/generic/opt
192# For each header with CPU-specific optimizations check whether it
193# exists in ${cpu_opt_dir}.  If not, point the variable at the
194# appropriate file in the generic directory.
195cpu_opt_ext_random=${cpu_opt_dir}/ext/opt_random.h
196test -f ${glibcxx_srcdir}/config/${cpu_opt_ext_random} ||
197cpu_opt_ext_random=cpu/generic/opt/ext/opt_random.h
198
199cpu_opt_bits_random=${cpu_opt_dir}/bits/opt_random.h
200test -f ${glibcxx_srcdir}/config/${cpu_opt_ext_random} ||
201cpu_opt_ext_random=cpu/generic/opt/bits/opt_random.h
202
203
204# Set any OS-dependent bits.
205# Set the os_include_dir.
206# Set the error_costants_dir.
207# Set c_model, c_compatibility here.
208# If atomic ops and/or numeric limits are OS-specific rather than
209# CPU-specifc, set those here too.
210# THIS TABLE IS SORTED.  KEEP IT THAT WAY.
211case "${host_os}" in
212  aix[56789]*)
213    # Newer versions of AIX only support PowerPC architecture, so use
214    # atomic instructions directly.
215    os_include_dir="os/aix"
216    ;;
217  aix4.[3456789]*)
218    # We set os_include_dir to os/aix only on AIX 4.3 and newer, but
219    # os/aix/atomicity.h works on earlier versions of AIX 4.*, so we
220    # explicitly duplicate the directory for 4.[<3].
221    os_include_dir="os/aix"
222    atomicity_dir="os/aix"
223    ;;
224  aix4.*)
225    os_include_dir="os/generic"
226    atomicity_dir="os/aix"
227    ;;
228  aix*)
229    os_include_dir="os/generic"
230    atomicity_dir="cpu/generic"
231    ;;
232  bsd*)
233    # Plain BSD attempts to share FreeBSD files.
234    os_include_dir="os/bsd/freebsd"
235    ;;
236  cygwin*)
237    os_include_dir="os/newlib"
238    OPT_LDFLAGS="${OPT_LDFLAGS} \$(lt_host_flags)"
239    ;;
240  darwin | darwin[1-7] | darwin[1-7].*)
241    # On Darwin, performance is improved if libstdc++ is single-module.
242    # Up to at least 10.3.7, -flat_namespace is required for proper
243    # treatment of coalesced symbols.
244    OPT_LDFLAGS="${OPT_LDFLAGS} -Wl,-single_module -Wl,-flat_namespace"
245    os_include_dir="os/bsd/darwin"
246    ;;
247  darwin[89] | darwin[89].* | darwin[1-9][0-9]* )
248    # On Darwin, performance is improved if libstdc++ is single-module,
249    # and on 8+ compatibility is better if not -flat_namespace.
250    OPT_LDFLAGS="${OPT_LDFLAGS} -Wl,-single_module"
251    case "${host_cpu}" in
252      i[34567]86 | x86_64)
253        OPTIMIZE_CXXFLAGS="${OPTIMIZE_CXXFLAGS} -fvisibility-inlines-hidden"
254        ;;
255    esac
256    os_include_dir="os/bsd/darwin"
257    ;;
258  *djgpp*)      # leading * picks up "msdosdjgpp"
259    os_include_dir="os/djgpp"
260    error_constants_dir="os/djgpp"
261    ;;
262  dragonfly*)
263    os_include_dir="os/bsd/dragonfly"
264    ;;
265  freebsd*)
266    os_include_dir="os/bsd/freebsd"
267    ;;
268  linux-musl*)
269    os_include_dir="os/generic"
270    ;;
271  gnu* | linux* | kfreebsd*-gnu | knetbsd*-gnu)
272    if [ "$uclibc" = "yes" ]; then
273      os_include_dir="os/uclibc"
274    elif [ "$bionic" = "yes" ]; then
275      os_include_dir="os/bionic"
276    else
277      os_include_dir="os/gnu-linux"
278    fi
279    ;;
280  hpux*)
281    os_include_dir="os/hpux"
282    ;;
283  mingw32*)
284    case "$host" in
285      *-w64-*)
286        os_include_dir="os/mingw32-w64"
287        error_constants_dir="os/mingw32-w64"
288        ;;
289      *)
290        os_include_dir="os/mingw32"
291        error_constants_dir="os/mingw32"
292        ;;
293    esac
294    OPT_LDFLAGS="${OPT_LDFLAGS} \$(lt_host_flags)"
295    ;;
296  netbsd*)
297    os_include_dir="os/bsd/netbsd"
298    ;;
299  openbsd*)
300    os_include_dir="os/bsd/openbsd"
301    ;;
302  qnx6.[12]*)
303    os_include_dir="os/qnx/qnx6.1"
304    c_model=c
305    ;;
306  rtems*)
307    # Use libatomic if necessary and avoid libstdc++ specific atomicity support
308    atomicity_dir="cpu/generic/atomicity_builtins"
309    ;;
310  solaris2)
311    # This too-vague configuration does not provide enough information
312    # to select a ctype include, and thus os_include_dir is a crap shoot.
313    echo "Please specify the full version of Solaris, ie. solaris2.10 " 1>&2
314    exit 1
315    ;;
316  solaris2.1[0-9])
317    os_include_dir="os/solaris/solaris2.10"
318    ;;
319  tpf)
320    os_include_dir="os/tpf"
321    ;;
322  vxworks)
323    os_include_dir="os/vxworks"
324    ;;
325  *)
326    os_include_dir="os/generic"
327    ;;
328esac
329
330
331# Set any OS-dependent and CPU-dependent bits.
332# THIS TABLE IS SORTED.  KEEP IT THAT WAY.
333case "${host}" in
334  *-*-linux*)
335    case "${host_cpu}" in
336      i[567]86)
337        abi_baseline_pair=i486-linux-gnu
338        ;;
339      mips64*)
340	abi_baseline_pair=mips64-linux-gnu
341	;;
342      powerpc64*)
343        abi_baseline_pair=powerpc64-linux-gnu
344        ;;
345      s390)
346        abi_baseline_pair=s390-linux-gnu
347        ;;
348      s390x)
349        abi_baseline_pair=s390x-linux-gnu
350        ;;
351      x86_64)
352        abi_baseline_pair=x86_64-linux-gnu
353        ;;
354      *)
355        if test $try_cpu = generic; then
356          try_abi_cpu=$host_cpu
357        else
358          try_abi_cpu=$try_cpu
359        fi
360        if test -d ${glibcxx_srcdir}/config/abi/post/${try_abi_cpu}-linux-gnu; then
361          abi_baseline_pair=${try_abi_cpu}-linux-gnu
362        fi
363    esac
364    case "${host}" in
365      arm*-*-linux-*)
366	port_specific_symbol_files="\$(srcdir)/../config/os/gnu-linux/arm-eabi-extra.ver"
367	;;
368    esac
369    ;;
370  arm*-*-freebsd*)
371     port_specific_symbol_files="\$(srcdir)/../config/os/gnu-linux/arm-eabi-extra.ver"
372     ;;
373  powerpc*-*-darwin*)
374    port_specific_symbol_files="\$(srcdir)/../config/os/bsd/darwin/ppc-extra.ver"
375    ;;
376  *-*-solaris2.1[0-9])
377    # On Solaris 10 with Solaris ld, there's no COMDAT support.  GNU ld always
378    # provides it, as does Solaris ld since Solaris 11, leading to different
379    # baselines.
380    case "${host_os}:${with_gnu_ld}" in
381      # with_gnu_ld may either be unset (default) or no (with --without-gnu-ld).
382      solaris2.10: | solaris2.10:no)
383        abi_baseline_pair=solaris2.10
384	;;
385      *)
386        abi_baseline_pair=solaris2.11
387	;;
388    esac
389    abi_baseline_subdir_switch=--print-multi-os-directory
390    ;;
391esac
392