Fix up the sysroot issue for sh4 in a different way

(see the comments in the code for details on the issue)

Old workaround in 100-gcc.sh stopped working (probably, due to one
of GCC version upgrades), so switch to the other approach originally
described there: adjust the list of multilibs to not include the
default target explicitly.

Signed-off-by: Alexey Neyman <stilor@att.net>

samples/sh4-multilib-linux-gnu/crosstool.config

@@ -3,7 +3,7 @@ CT_ARCH_SH_SH4=y
 CT_TARGET_VENDOR="multilib"
 CT_KERNEL_linux=y
 CT_BINUTILS_PLUGINS=y
-CT_CC_GCC_MULTILIB_LIST="m4,m4a"
+CT_CC_GCC_MULTILIB_LIST="m4a"
 CT_CC_LANG_CXX=y
 CT_DEBUG_gdb=y
 # CT_GDB_CROSS_PYTHON is not set

samples/sh4-multilib-linux-uclibc/crosstool.config

@@ -5,7 +5,7 @@ CT_KERNEL_linux=y
 CT_BINUTILS_PLUGINS=y
 CT_LIBC_uClibc=y
 CT_CC_GCC_V_4_9_4=y
-CT_CC_GCC_MULTILIB_LIST="m4,m4a,m3"
+CT_CC_GCC_MULTILIB_LIST="m4a,m3"
 CT_CC_LANG_CXX=y
 CT_DEBUG_gdb=y
 # CT_GDB_CROSS_PYTHON is not set

scripts/build/arch.sh

@@ -5,6 +5,11 @@ CT_DoArchTupleValues() {
     :;
 }
 
+# Adjust the list of multilibs for the target
+CT_DoArchMultilibList() {
+    :;
+}
+
 # Multilib: change the target triplet according to CFLAGS
 # Usage: CT_DoArchGlibcAdjustTuple <variable-name> <CFLAGS>
 CT_DoArchMultilibTarget() {
@@ -43,7 +48,7 @@ CT_DoArchUClibcCflags() {
 
     # Likely, any non-default cflags need to be reflected into the config.
     # It may work if we just pass them into EXTRA_CFLAGS, but we have no
-    # idea as they might interact with the CFLAGS inferred by uClibc from
+    # idea how they might interact with the CFLAGS inferred by uClibc from
     # the configuration file.
     if [ "${cflags}" != "" ]; then
         CT_DoLog WARN "Multilib configuration not supported for uClibc/${CT_ARCH}"

scripts/build/arch/sh.sh

@@ -36,6 +36,29 @@ CT_DoArchTupleValues () {
     CT_ARCH_FLOAT_CFLAG=
 }
 
+CT_DoArchMultilibList() {
+    local save_ifs="${IFS}"
+    local new
+    local x
+
+    # In a configuration for SuperH, GCC list of multilibs shall not include
+    # the default CPU. E.g. if configuring for sh4-*-*, we need to remove
+    # "sh4" or "m4" from the multilib list. Otherwise, the resulting compiler
+    # will fail when that CPU is selected explicitly "sh4-multilib-linux-gnu-gcc -m4 ..."
+    # as it will fail to find the sysroot with that suffix.
+    IFS=,
+    for x in ${CT_CC_GCC_MULTILIB_LIST}; do
+        if [ "${x}" = "${CT_ARCH_SH_VARIANT}" -o "sh${x#m}" = "${CT_ARCH_SH_VARIANT}" ]; then
+            CT_DoLog WARN "Ignoring '${x}' in multilib list: it is the default multilib"
+            continue
+        fi
+        new="${new:+${new},}${x}"
+    done
+    IFS="${save_ifs}"
+    CT_CC_GCC_MULTILIB_LIST="${new}"
+    CT_DoLog DEBUG "Adjusted CT_CC_GCC_MULTILIB_LIST to '${CT_CC_GCC_MULTILIB_LIST}'"
+}
+
 CT_DoArchUClibcConfig() {
     local cfg="${1}"
 

scripts/build/cc/100-gcc.sh

@@ -72,23 +72,6 @@ cc_gcc_lang_list() {
     printf "%s" "${lang_list}"
 }
 
-#------------------------------------------------------------------------------
-# Return a value of a requested GCC spec
-cc_gcc_get_spec() {
-    local spec=$1
-    local cc_and_cflags=$2
-
-    # GCC does not provide a facility to request a value of a spec string.
-    # The only way to do that I found was to augment the spec file with
-    # some dummy suffix handler that does nothing except printing it.
-    touch temp-input.spec_eval
-    {
-        echo ".spec_eval:"
-        echo "echo %(${spec})"
-    } > "tmp-specs-${spec}"
-    ${cc_and_cflags} -specs="tmp-specs-${spec}" -E temp-input.spec_eval
-}
-
 #------------------------------------------------------------------------------
 # Report the type of a GCC option
 cc_gcc_classify_opt() {
@@ -168,30 +151,16 @@ evaluate_multilib_cflags()
 # is disabled - so that it lists the default GCC/OS directory, which may differ
 # from the default 'lib'). It then performs a few multilib checks/quirks:
 #
-# 1. On SuperH target, configuring with default CPU (e.g. by supplying the target
+# 1. On MIPS target, gcc (or rather, ld, which it invokes under the hood) chokes
-# name as 'sh4', which is what CT-NG does) results in the compiler being unable to
-# run if that same switch is passed to the resulting gcc (e.g. 'gcc -m4'). The reason
-# for this behavior is that the script that determines the sysroot suffix is not
-# aware of the default multilib selection, so it generates <sysroot>/m4 as the
-# suffixed sysroot. But the main driver, knowing that -m4 is the default, does not
-# even attempt to fall back to the non-suffixed sysroot (as it does with non-default
-# multilibs) - as a result, gcc fails to find any library if invoked with -m4.
-# The right solution would be to drop the default CPU from the multilib list
-# completely, or make the print-sysroot-suffix.sh script aware of the defaults
-# (which is not easy, as the defaults are not in tmake_file, but rather in tm_file...)
-#
-# 2. On MIPS target, gcc (or rather, ld, which it invokes under the hood) chokes
 # if supplied with two -mabi=* options. I.e., 'gcc -mabi=n32' and 'gcc -mabi=32' both
 # work, but 'gcc -mabi=32 -mabi=n32' produces an internal error in ld. Thus we do
 # not supply target's CFLAGS in multilib builds - and after compiling pass-1 gcc,
 # attempt to determine which CFLAGS need to be filtered out.
 #
-# 3. If "demultilibing" is in effect, create top-level directories for any
+# 2. If "demultilibing" is in effect, create top-level directories for any
 # multilibs not in lib/ as symlinks to lib.
 cc_gcc_multilib_housekeeping() {
     local cc host
-    local multilib_defaults
-    local suffix sysroot base lnk
     local ml_arch ml_abi ml_cpu ml_tune ml_fpu ml_float ml_endian ml_mode ml_unknown ml
     local new_cflags
 
@@ -207,10 +176,6 @@ cc_gcc_multilib_housekeeping() {
         cc="${CT_BUILDTOOLS_PREFIX_DIR}/bin/${CT_TARGET}-${CT_CC}"
     fi
 
-    # sed: prepend dashes or do nothing if default is empty string
-    multilib_defaults=( $( cc_gcc_get_spec multilib_defaults "${cc}" | \
-        sed 's/\(^\|[[:space:]]\+\)\([^[:space:]]\)/ -\2/g' ) )
-    CT_DoLog EXTRA "gcc default flags: '${multilib_defaults}'"
     CT_IterateMultilibs evaluate_multilib_cflags evaluate_cflags
 
     # Filtering out some of the options provided in CT-NG config. Then *prepend*
@@ -236,21 +201,6 @@ cc_gcc_multilib_housekeeping() {
         CT_EnvModify CT_ARCH_TARGET_LDFLAGS_MULTILIB ""
     fi
     CT_DoLog DEBUG "Filtered target LDFLAGS: '${CT_ARCH_TARGET_LDFLAGS_MULTILIB}'"
-
-    # Sysroot suffix fixup for the multilib default.
-    suffix=$( cc_gcc_get_spec sysroot_suffix_spec "${cc} ${multilib_defaults}" )
-    if [ -n "${suffix}" ]; then
-        base=${suffix%/*}
-        sysroot=$( "${cc}" -print-sysroot )
-        if [ -n "${base}" ]; then
-            CT_DoExecLog ALL mkdir -p "${sysroot}${base}"
-            lnk=$( echo "${base#/}" | sed -e 's,[^/]*,..,g' )
-        else
-            lnk=.
-        fi
-        CT_DoExecLog ALL rm -f "${sysroot}${suffix}"
-        CT_DoExecLog ALL ln -sfv "${lnk}" "${sysroot}${suffix}"
-    fi
 }
 
 #------------------------------------------------------------------------------

scripts/crosstool-NG.sh.in

@@ -231,6 +231,9 @@ CT_SYS_GCC=$(${CT_BUILD_PREFIX}gcc${CT_BUILD_SUFFIX} -dumpversion)
 CT_SYS_TARGET=$(CT_DoConfigGuess)
 CT_TOOLCHAIN_ID="crosstool-${CT_VERSION} build ${CT_STAR_DATE_HUMAN} by ${CT_SYS_USER}@${CT_SYS_HOSTNAME}"
 
+# Adjust the list of multilibs, if needed
+CT_DoArchMultilibList
+
 CT_DoLog EXTRA "Preparing working directories"
 
 # Ah! The build directory shall be eradicated, even if we restart!