Add upgrade logic to version-check.sh

Slightly rework config version detector to catch the case where neither
CONFIG_VERSION/CONFIG_VERSION_CURRENT is defined in the config file.

Add olddefconfig and use it after the upgrade.

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

1 files changed, 481 insertions, 2 deletions

diff --git a/scripts/version-check.sh b/scripts/version-check.sh
index c4a2bd07..0fe5c167 100644
--- a/scripts/version-check.sh
+++ b/scripts/version-check.sh
@@ -6,6 +6,11 @@ CFGFILE="${1}"
 
 . "${CT_LIB_DIR}/scripts/functions"
 . "${CFGFILE}"
+
+# If an old config does not define a version, assume it is 0. This is used
+# if we run this script on an old full .config file, not restored from a
+# defconfig.
+CT_CONFIG_VERSION="${CT_CONFIG_VERSION:-0}"
 if [ "${CT_CONFIG_VERSION_CURRENT}" == "${CT_CONFIG_VERSION}" ]; then
     # Nothing to do
     exit 0
@@ -34,5 +39,479 @@ EOF
     fi
 fi
 
-echo "TBD not implemented yet" >&2
-exit 1
+is_set()
+{
+    if [ "x${val+set}" = "xset" ]; then
+        return 0
+    else
+        return 1
+    fi
+}
+
+info()
+{
+    # $opt comes from the caller
+    echo "INFO ${opt:+:: ${opt} }:: $1" >&2
+}
+
+warning()
+{
+    # $opt comes from the caller
+    echo "WARN ${opt:+:: ${opt} }:: $1" >&2
+}
+
+warning_if_set()
+{
+    if is_set; then
+        warning "$@"
+    fi
+}
+
+# When a symbol is replaced with a newer version. If it is a choice and
+# the replacement existed in the old version as well, add a replacement_for
+# handler for the other symbol to avoid kconfig warnings.
+replace()
+{
+    local newopt="${1}"
+
+    if is_set; then
+        info "No longer supported; replacing with '${newopt}'".
+        opt="${newopt}"
+    else
+        # Wasn't set; just drop it silently
+        unset opt
+    fi
+}
+
+# Avoid multiple definitions for a symbol when multiple old symbols are folded into one
+# in a new version. If any of the variable names passed as arguments are set, skip
+# emitting this variable (which, presumably, is "not set").
+replacement_for()
+{
+    while [ -n "${1}" ]; do
+        if [ -n "${!1}" ]; then
+            unset opt
+            return
+        fi
+        shift
+    done
+}
+
+# Upgrade from v0: select Linaro as the vendor if a Linaro version was selected
+# (in v0, both GNU and Linaro versions were combined in a single list). GNU is
+# the default, leave it to olddefconfig to select it if we don't see a Linaro version.
+# We don't depend on CT_xxx_SHOW_LINARO symbols: they just enabled showing Linaro
+# versions in that list, but it may have been GNU version that was actually selected.
+select_linaro()
+{
+    if is_set; then
+        echo "# CT_${1}_USE_GNU is not set"
+        echo "CT_${1}_USE_LINARO=y"
+    fi
+}
+
+
+### Per-version upgrade drivers. Called with ${opt} and ${val} set,
+### may modify these variables
+
+# Upgrade from version 0 (which is 1.23, as released) to version 1
+# (current state of master as of 2019/01/20). Upgrades in the interim
+# versions may be broken.
+upgrade_v0()
+{
+    case "${opt}" in
+    CT_ARCH_alpha|CT_ARCH_arm|CT_ARCH_avr|CT_ARCH_m68k|CT_ARCH_microblaze|\
+    CT_ARCH_mips|CT_ARCH_nios2|CT_ARCH_powerpc|CT_ARCH_s390|CT_ARCH_sh|\
+    CT_ARCH_sparc|CT_ARCH_x86|CT_ARCH_xtensa|\
+    CT_BINUTILS_binutils|\
+    CT_CC_gcc|\
+    CT_COMP_TOOLS_autoconf|CT_COMP_TOOLS_automake|CT_COMP_TOOLS_libtool|\
+    CT_COMP_TOOLS_m4|CT_COMP_TOOLS_make|\
+    CT_DEBUG_duma|CT_DEBUG_gdb|CT_DEBUG_ltrace|CT_DEBUG_strace|\
+    CT_KERNEL_bare_metal|CT_KERNEL_linux|CT_KERNEL_windows|\
+    CT_LIBC_avr_libc|CT_LIBC_glibc|CT_LIBC_musl|CT_LIBC_newlib|CT_LIBC_none|\
+    CT_LIBC_uClibc)
+        # Renamed to upper-case
+        opt=${opt^^}
+        ;;
+    CT_ARCH_XTENSA_CUSTOM_NAME)
+        replace CT_OVERLAY_NAME
+        ;;
+    CT_ARCH_XTENSA_CUSTOM_OVERLAY_LOCATION)
+        replace CT_OVERLAY_LOCATION
+        ;;
+    CT_LIBC_mingw)
+        # Renamed to MINGW_W64
+        opt=CT_LIBC_MINGW_W64
+        ;;
+    CT_ARCH_*_AVAILABLE|CT_KERNEL_*_AVAILABLE|CT_LIBC_*_AVAILABLE)
+        # Previously used "backend selectors". Autogenerated, no warning
+        unset opt
+        ;;
+    CT_CONFIGURE_has_*)
+        # Configure-detected build machine options. Drop, will use current.
+        unset opt
+        ;;
+    CT_*_or_later)
+        # Automatically selected version constraints. Drop, will auto-select current ones.
+        unset opt
+        ;;
+    CT_BACKEND_ARCH|CT_BACKEND_KERNEL|CT_BACKEND_LIBC|CT_IS_A_BACKEND)
+        warning "Option ${opt} is no longer supported, dropping"
+        unset opt
+        ;;
+    CT_*_SHOW_LINARO)
+        # Used to just include Linaro versions into the list. We'll infer whether Linaro is
+        # actually used from the actual version selected, below.
+        unset opt
+        ;;
+    CT_CC_GCC_4_8|CT_CC_GCC_4_9|CT_CC_GCC_5|CT_CC_GCC_6|\
+    CT_LIBC_NEWLIB_2_0|CT_LIBC_NEWLIB_2_1|CT_LIBC_NEWLIB_2_2|CT_LIBC_NEWLIB_2_3|CT_LIBC_NEWLIB_2_4|CT_LIBC_NEWLIB_2_5)
+        # In 1.23.0, each package had its own ad-hoc version constraints. Drop, new ones
+        # will be autoselected.
+        unset opt
+        ;;
+    # Custom location: translate to the new framework. No generic way to interpret the version
+    # string user may have configured; just warn him to select it manually.
+    CT_BINUTILS_CUSTOM)
+        warning_if_set "Assuming custom location contains GNU sources; edit the configuration if it was Linaro version"
+        replace CT_BINUTILS_SRC_CUSTOM
+        ;;
+    CT_CC_GCC_CUSTOM)
+        warning_if_set "Assuming custom location contains GNU sources; edit the configuration if it was Linaro version"
+        replace CT_GCC_SRC_CUSTOM
+        ;;
+    CT_CC_GCC_CUSTOM_LOCATION)
+        replace CT_GCC_CUSTOM_LOCATION
+        ;;
+    CT_ELF2FLT_CUSTOM)
+        replace CT_ELF2FLT_SRC_CUSTOM
+        ;;
+    CT_ELF2FLT_GIT)
+        if is_set; then
+            echo "CT_ELF2FLT_SRC_DEVEL=y"
+        fi
+        replace CT_ELF2FLT_DEVEL_VCS_git
+        ;;
+    CT_ELF2FLT_GIT_CSET)
+        replace CT_ELF2FLT_DEVEL_REVISION
+        ;;
+    CT_GDB_CUSTOM)
+        warning_if_set "Assuming custom location contains GNU sources; edit the configuration if it was Linaro version"
+        replace CT_GDB_SRC_CUSTOM
+        ;;
+    CT_KERNEL_LINUX_CUSTOM)
+        replace CT_LINUX_SRC_CUSTOM
+        ;;
+    CT_KERNEL_LINUX_CUSTOM_LOCATION)
+        replace CT_LINUX_CUSTOM_LOCATION
+        ;;
+    CT_LIBC_AVR_LIBC_CUSTOM)
+        replace CT_AVR_LIBC_SRC_CUSTOM
+        ;;
+    CT_LIBC_AVR_LIBC_CUSTOM_LOCATION)
+        replace CT_AVR_LIBC_CUSTOM_LOCATION
+        ;;
+    CT_LIBC_GLIBC_CUSTOM)
+        warning_if_set "Assuming custom location contains GNU sources; edit the configuration if it was Linaro version"
+        replace CT_GLIBC_SRC_CUSTOM
+        ;;
+    CT_LIBC_GLIBC_CUSTOM_LOCATION)
+        replace CT_GLIBC_CUSTOM_LOCATION
+        ;;
+    CT_LIBC_MUSL_CUSTOM)
+        replace CT_MUSL_SRC_CUSTOM
+        ;;
+    CT_LIBC_MUSL_CUSTOM_LOCATION)
+        replace CT_MUSL_CUSTOM_LOCATION
+        ;;
+    CT_LIBC_NEWLIB_CUSTOM)
+        warning_if_set "Assuming custom location contains GNU sources; edit the configuration if it was Linaro version"
+        replace CT_NEWLIB_SRC_CUSTOM
+        ;;
+    CT_LIBC_NEWLIB_CUSTOM_LOCATION)
+        replace CT_NEWLIB_CUSTOM_LOCATION
+        ;;
+    CT_LIBC_UCLIBC_CUSTOM)
+        if [ "${CT_LIBC_UCLIBC_CUSTOM_UCLIBC}" = "y" ]; then
+            replace CT_UCLIBC_SRC_CUSTOM
+        else
+            replace CT_UCLIBC_NG_SRC_CUSTOM
+        fi
+        ;;
+    CT_LIBC_UCLIBC_CUSTOM_UCLIBC)
+        replace CT_UCLIBC_SRC_CUSTOM
+        ;;
+    CT_LIBC_UCLIBC_CUSTOM_UCLIBC_NG)
+        replace CT_UCLIBC_NG_SRC_CUSTOM
+        ;;
+    CT_LIBC_UCLIBC_CUSTOM_UCLIBC_NG_OLD)
+        warning_if_set "uClibc-NG versions before 1.0.15 no longer supported"
+        replace CT_UCLIBC_NG_SRC_CUSTOM
+        ;;
+    CT_LIBC_UCLIBC_CUSTOM_LOCATION)
+        if [ "${CT_LIBC_UCLIBC_CUSTOM_UCLIBC}" = "y" ]; then
+            replace CT_UCLIBC_CUSTOM_LOCATION
+        else
+            replace CT_UCLIBC_NG_CUSTOM_LOCATION
+        fi
+        ;;
+    CT_WINAPI_V_DEVEL)
+        replace CT_MINGW_W64_SRC_DEVEL
+        ;;
+    CT_WINAPI_V_select)
+        # Internal selector
+        unset opt
+        ;;
+    CT_BINUTILS_CUSTOM_VERSION|CT_CC_GCC_CUSTOM_VERSION|CT_ELF2FLT_CUSTOM_VERSION|CT_KERNEL_LINUX_CUSTOM_VERSION|\
+    CT_LIBC_AVR_LIBC_CUSTOM_VERSION|CT_LIBC_GLIBC_CUSTOM_VERSION|CT_LIBC_MUSL_CUSTOM_VERSION|\
+    CT_LIBC_NEWLIB_CUSTOM_VERSION|CT_LIBC_UCLIBC_CUSTOM_VERSION|CT_GDB_CUSTOM_VERSION)
+        warning_if_set "Cannot automatically convert custom version; edit configuration to select it"
+        unset opt
+        ;;
+    CT_CC_GCC_VERSION|CT_CC_VERSION|CT_KERNEL_VERSION|CT_WINAPI_VERSION|CT_LIBC_VERSION)
+        # Auto-selected; the symbol was just renamed
+        unset opt
+        ;;
+    CT_LIBC_glibc_family)
+        # Internal selector, not user-visible
+        unset opt
+        ;;
+    CT_LIBC_ADDONS_LIST)
+        warning_if_set "Support for custom add-ons has been removed. If using libidn add-on, edit the configuration."
+        ;;
+    CT_LIBC_DISABLE_VERSIONING)
+        replace CT_GLIBC_DISABLE_VERSIONING
+        ;;
+    CT_LIBC_ENABLE_FORTIFIED_BUILD)
+        replace CT_GLIBC_ENABLE_FORTIFIED_BUILD
+        ;;
+    CT_LIBC_GLIBC_CONFIGPARMS|CT_LIBC_GLIBC_EXTRA_CFLAGS|CT_LIBC_GLIBC_EXTRA_CONFIG_ARRAY|\
+    CT_LIBC_GLIBC_FORCE_UNWIND|CT_LIBC_GLIBC_KERNEL_VERSION_AS_HEADERS|CT_LIBC_GLIBC_KERNEL_VERSION_CHOSEN|\
+    CT_LIBC_GLIBC_KERNEL_VERSION_NONE|CT_LIBC_GLIBC_MIN_KERNEL|CT_LIBC_GLIBC_MIN_KERNEL_VERSION)
+        replace CT_GLIBC_${opt#CT_LIBC_GLIBC_}
+        ;;
+    CT_LIBC_LOCALES)
+        replace CT_GLIBC_LOCALES
+        ;;
+    CT_LIBC_OLDEST_ABI)
+        replace CT_GLIBC_OLDEST_ABI
+        ;;
+    CT_LIBC_GLIBC_NEEDS_PORTS|CT_LIBC_GLIBC_PORTS_EXTERNAL|CT_LIBC_GLIBC_USE_PORTS)
+        # Auto-selected
+        unset opt
+        ;;
+    CT_LIBC_UCLIBC_LOCALES_PREGEN_DATA)
+        warning_if_set "Support for pregenerated locales in uClibc has been removed"
+        unset opt
+        ;;
+    # Trivial version replacements
+    CT_AUTOMAKE_V_1_11_1)           replace CT_AUTOMAKE_V_1_11_6;;
+    CT_AUTOMAKE_V_1_11_6)           replacement_for CT_AUTOMAKE_V_1_11_1;;
+    CT_AUTOMAKE_V_1_14)             replace CT_AUTOMAKE_V_1_14_1;;
+    CT_AUTOMAKE_V_1_15)             replace CT_AUTOMAKE_V_1_15_1;;
+    CT_BINUTILS_V_2_26)             replace CT_BINUTILS_V_2_26_1;;
+    CT_BINUTILS_V_2_28)             replace CT_BINUTILS_V_2_28_1;;
+    CT_BINUTILS_LINARO_V_2_23_2)    select_linaro BINUTILS; replace CT_BINUTILS_LINARO_V_2_23_2_2013_10_4;;
+    CT_BINUTILS_LINARO_V_2_24)      select_linaro BINUTILS; replace CT_BINUTILS_LINARO_V_2_24_0_2014_11_2;;
+    CT_BINUTILS_LINARO_V_2_25)      select_linaro BINUTILS; replace CT_BINUTILS_LINARO_V_2_25_0_2015_01_2;;
+    CT_CC_GCC_V_4_8_5)              replace CT_GCC_V_4_8_5;;
+    CT_CC_GCC_V_4_9_4)              replace CT_GCC_V_4_9_4;;
+    CT_CC_GCC_V_5_4_0)              replace CT_GCC_V_5_5_0;;
+    CT_CC_GCC_V_6_3_0)              replace CT_GCC_V_6_5_0;;
+    CT_CC_GCC_V_linaro_4_8)         select_linaro GCC; replace CT_GCC_LINARO_V_4_8_2015_06;;
+    CT_CC_GCC_V_linaro_4_9)         select_linaro GCC; replace CT_GCC_LINARO_V_4_9_2017_01;;
+    CT_CC_GCC_V_linaro_5_4)         select_linaro GCC; replace CT_GCC_LINARO_V_5_5_2017_10;;
+    CT_CC_GCC_V_linaro_6_3)         select_linaro GCC; replace CT_GCC_LINARO_V_6_4_2018_05;;
+    CT_CLOOG_V_0_18_0)              replace CT_CLOOG_V_0_18_1;;
+    CT_CLOOG_V_0_18_1)              replacement_for CT_CLOOG_V_0_18_0;;
+    CT_EXPAT_V_2_2_0)               replace CT_EXPAT_V_2_2_6;; # 2.2.6 was not available in ct-ng 1.23.0 - no replacement_for
+    CT_GDB_V_6_8a)                  replace CT_GDB_V_6_8A;;
+    CT_GDB_V_7_0a)                  replace CT_GDB_V_7_0_1A;;
+    CT_GDB_V_7_0_1a)                replace CT_GDB_V_7_0_1A;;
+    CT_GDB_V_7_1a)                  replace CT_GDB_V_7_1A;;
+    CT_GDB_V_7_2a)                  replace CT_GDB_V_7_2A;;
+    CT_GDB_V_7_3a)                  replace CT_GDB_V_7_3A;;
+    CT_GDB_V_7_4)                   replace CT_GDB_V_7_4_1;;
+    CT_GDB_V_7_7)                   replace CT_GDB_V_7_7_1;;
+    CT_GDB_V_7_8|CT_GDB_V_7_8_1)    replace CT_GDB_V_7_8_2;;
+    CT_GDB_V_7_8_2)                 replacement_for CT_GDB_V_7_8 CT_GDB_V_7_8_1;;
+    CT_GDB_V_7_9)                   replace CT_GDB_V_7_9_1;;
+    CT_GDB_V_7_10)                  replace CT_CT_GDB_V_7_10_1;;
+    CT_GDB_V_linaro_7_3)            select_linaro GDB; replace CT_GDB_LINARO_V_7_3_2011_12;;
+    CT_GDB_V_linaro_7_4)            select_linaro GDB; replace CT_GDB_LINARO_V_7_4_2012_06;;
+    CT_GDB_V_linaro_7_5)            select_linaro GDB; replace CT_GDB_LINARO_V_7_5_2012_12;;
+    CT_GDB_V_linaro_7_6)            select_linaro GDB; replace CT_GDB_LINARO_V_7_6_1_2013_10;;
+    CT_GDB_V_linaro_7_7)            select_linaro GDB; replace CT_GDB_LINARO_V_7_7_1_2014_06_1;;
+    CT_GDB_V_linaro_7_7_1)          select_linaro GDB; replace CT_GDB_LINARO_V_7_7_1_2014_06_1;;
+    CT_GDB_V_linaro_7_8)            select_linaro GDB; replace CT_GDB_LINARO_V_7_8_2014_09;;
+    CT_GMP_V_4_3_0|CT_GMP_V_4_3_1)  replace CT_GMP_V_4_3_2;;
+    CT_GMP_V_4_3_2)                 replacement_for CT_GMP_V_4_3_0 CT_GMP_V_4_3_1;;
+    CT_GMP_V_5_0_1|CT_GMP_V_5_0_2)  replace CT_GMP_V_5_0_5;; # 5.0.5 not in ct-ng 1.23.0
+    CT_GMP_V_5_1_1)                 replace CT_GMP_V_5_1_3;;
+    CT_GMP_V_5_1_3)                 replacement_for CT_GMP_V_5_1_1;;
+    CT_GMP_V_6_0_0)                 replace CT_GMP_V_6_0_0A;; # 6.0.0a not in ct-ng 1.23.0
+    CT_GMP_V_6_1_0)                 replace CT_GMP_V_6_1_2;;
+    CT_GMP_V_6_1_2)                 replacement_for CT_GMP_V_6_1_0;;
+    CT_ISL_V_0_11_1)                replace CT_ISL_V_0_11_2;;
+    CT_ISL_V_0_14)                  replace CT_ISL_V_0_14_1;;
+    CT_KERNEL_V_2_6_32|CT_KERNEL_V_2_6_33|CT_KERNEL_V_2_6_34|CT_KERNEL_V_2_6_35|\
+    CT_KERNEL_V_2_6_36|CT_KERNEL_V_2_6_37|CT_KERNEL_V_2_6_38|CT_KERNEL_V_2_6_39|\
+    CT_KERNEL_V_3_0|CT_KERNEL_V_3_1|CT_KERNEL_V_3_2|CT_KERNEL_V_3_3|CT_KERNEL_V_3_4|CT_KERNEL_V_3_5|\
+    CT_KERNEL_V_3_6|CT_KERNEL_V_3_7|CT_KERNEL_V_3_8|CT_KERNEL_V_3_9|CT_KERNEL_V_3_10|CT_KERNEL_V_3_11|\
+    CT_KERNEL_V_3_12|CT_KERNEL_V_3_13|CT_KERNEL_V_3_14|CT_KERNEL_V_3_15|CT_KERNEL_V_3_16|\
+    CT_KERNEL_V_3_17|CT_KERNEL_V_3_18|CT_KERNEL_V_3_19|\
+    CT_KERNEL_V_4_0|CT_KERNEL_V_4_1|CT_KERNEL_V_4_2|CT_KERNEL_V_4_3|CT_KERNEL_V_4_4|\
+    CT_KERNEL_V_4_5|CT_KERNEL_V_4_6|CT_KERNEL_V_4_7|CT_KERNEL_V_4_8|CT_KERNEL_V_4_9|CT_KERNEL_V_4_10)
+                                    replace CT_LINUX_${opt#CT_KERNEL_};;
+    CT_LIBC_AVR_LIBC_V_1_8_0)       replace CT_AVR_LIBC_V_1_8_1;;
+    CT_LIBC_AVR_LIBC_V_1_8_1)       replace CT_AVR_LIBC_V_1_8_1;;
+    CT_LIBC_AVR_LIBC_V_2_0_0)       replace CT_AVR_LIBC_V_2_0_0;;
+    CT_LIBC_GLIBC_V_2_12_1|CT_LIBC_GLIBC_V_2_12_2|CT_LIBC_GLIBC_V_2_13|CT_LIBC_GLIBC_V_2_14|\
+    CT_LIBC_GLIBC_V_2_14_1|CT_LIBC_GLIBC_V_2_15|CT_LIBC_GLIBC_V_2_16_0|CT_LIBC_GLIBC_V_2_17|\
+    CT_LIBC_GLIBC_V_2_18|CT_LIBC_GLIBC_V_2_19|CT_LIBC_GLIBC_V_2_20|CT_LIBC_GLIBC_V_2_21|\
+    CT_LIBC_GLIBC_V_2_22|CT_LIBC_GLIBC_V_2_23|CT_LIBC_GLIBC_V_2_24|CT_LIBC_GLIBC_V_2_25)
+                                    replace CT_GLIBC_${opt#CT_LIBC_GLIBC_};;
+    CT_LIBC_GLIBC_LINARO_V_2_20)    replace CT_GLIBC_LINARO_V_2_20_2014_11;;
+    CT_LIBC_MUSL_V_1_1_15|CT_LIBC_MUSL_V_1_1_16)
+                                    replace CT_MUSL_${opt#CT_LIBC_MUSL_};;
+    CT_LIBC_NEWLIB_V_1_17_0|CT_LIBC_NEWLIB_V_1_18_0|CT_LIBC_NEWLIB_V_1_19_0|CT_LIBC_NEWLIB_V_1_20_0|\
+    CT_LIBC_NEWLIB_V_2_0_0|CT_LIBC_NEWLIB_V_2_1_0|CT_LIBC_NEWLIB_V_2_2_0|CT_LIBC_NEWLIB_V_2_3_0|\
+    CT_LIBC_NEWLIB_V_2_4_0|CT_LIBC_NEWLIB_V_2_5_0)
+                                    replace CT_NEWLIB_${opt#CT_LIBC_NEWLIB_};;
+    CT_LIBC_NEWLIB_LINARO_V_2_1_0)  select_linaro NEWLIB; replace CT_NEWLIB_LINARO_V_2_1_0_2014;;
+    CT_LIBC_NEWLIB_LINARO_V_2_2_0)  select_linaro NEWLIB; replace CT_NEWLIB_LINARO_V_2_2_0_2015;;
+    CT_LIBELF_V_0_8_12)             replace CT_LIBELF_V_0_8_13;;
+    CT_LIBELF_V_0_8_13)             replacement_for CT_LIBELF_V_0_8_12;;
+    CT_M4_V_1_4_13|CT_M4_V_1_4_17)  replace CT_CT_M4_V_1_4_18;;
+    CT_M4_V_1_4_18)                 replacement_for CT_M4_V_1_4_13 CT_M4_V_1_4_17;;
+    CT_MPC_V_0_8_1)                 replace CT_MPC_V_0_8_2;;
+    CT_MPC_V_0_8_2)                 replacement_for CT_MPC_V_0_8_1;;
+    CT_MPC_V_1_0|CT_MPC_V_1_0_1|CT_MPC_V_1_0_2)
+                                    replace CT_MPC_V_1_0_3;;
+    CT_MPC_V_1_0_3)                 replacement_for CT_MPC_V_1_0 CT_MPC_V_1_0_1 CT_MPC_V_1_0_2;;
+    CT_MPFR_V_2_4_0|CT_MPFR_V_2_4_1)
+                                    replace CT_MPFR_V_2_4_2;;
+    CT_MPFR_V_2_4_2)                replacement_for CT_MPFR_V_2_4_0 CT_MPFR_V_2_4_1;;
+    CT_MPFR_V_3_0_0)                replace CT_MPFR_V_3_0_1;;
+    CT_MPFR_V_3_0_1)                replacement_for CT_MPFR_V_3_0_0;;
+    CT_MPFR_V_3_1_0|CT_MPFR_V_3_1_2|CT_MPFR_V_3_1_3|CT_MPFR_V_3_1_5)
+                                    replace CT_MPFR_V_3_1_6;;
+    CT_MPFR_V_3_1_6)                replacement_for CT_MPFR_V_3_1_0 CT_MPFR_V_3_1_2 CT_MPFR_V_3_1_3 CT_MPFR_V_3_1_5;;
+    CT_STRACE_V_4_5_18|CT_STRACE_V_4_5_19)
+                                    replace CT_STRACE_V_4_5_20;;
+    CT_STRACE_V_4_5_20)             replacement_for CT_STRACE_V_4_5_18 CT_STRACE_V_4_5_19;;
+    CT_LIBC_UCLIBC_NG_V_1_0_20|CT_LIBC_UCLIBC_NG_V_1_0_21|CT_LIBC_UCLIBC_NG_V_1_0_22)
+                                    is_set && echo "CT_UCLIBC_USE_UCLIBC_NG_ORG=y"
+                                    replace CT_UCLIBC_NG_V_1_0_25
+                                    ;;
+    CT_LIBC_UCLIBC_V_0_9_33_2)
+                                    is_set && echo "CT_UCLIBC_USE_UCLIBC_ORG=y"
+                                    replace CT_UCLIBC_V_0_9_33_2
+                                    ;;
+    CT_WINAPI_V_2_0_7|CT_WINAPI_V_2_0_7|CT_WINAPI_V_2_0_9)
+                                    replace CT_MINGW_W64_V_V2_0_10;;
+    CT_WINAPI_V_3_0_0)              replace CT_MINGW_W64_V_V3_0_0;;
+    CT_WINAPI_V_3_1_0)              replace CT_MINGW_W64_V_V3_1_0;;
+    CT_WINAPI_V_3_2_0)              replace CT_MINGW_W64_V_V3_2_0;;
+    CT_WINAPI_V_3_3_0)              replace CT_MINGW_W64_V_V3_3_0;;
+    CT_WINAPI_V_4_0_0|CT_WINAPI_V_4_0_1|CT_WINAPI_V_4_0_2|CT_WINAPI_V_4_0_3|\
+    CT_WINAPI_V_4_0_4|CT_WINAPI_V_4_0_5|CT_WINAPI_V_4_0_6)
+                                    replace CT_MINGW_W64_V_V4_0_6;;
+    CT_WINAPI_V_5_0_0|CT_WINAPI_V_5_0_1)
+                                    replace CT_MINGW_W64_V_V5_0_3;;
+
+    # Misc
+    CT_CLOOG_NEEDS_AUTORECONF)
+        # Was unused in 1.23, just drop
+        unset opt
+        ;;
+    CT_PATCH_SINGLE)
+        # Internal selector in 1.23
+        unset opt
+        ;;
+    CT_PATCH_BUNDLED_FALLBACK_LOCAL|CT_PATCH_LOCAL_FALLBACK_BUNDLED)
+        warning_if_set "Fallback patch order has been removed"
+        ;;
+    CT_CC_GCC_TARGET_FINAL)
+        warning_if_set "Option removed"
+        ;;
+    CT_COMPLIBS|CT_COMPLIBS_NEEDED|CT_CC_GCC_latest)
+        # Internal selectors
+        unset opt
+        ;;
+    esac
+
+}
+
+# Main upgrade driver. One version at a time, read line by line, interpret
+# the options and replace anything that needs replacing.
+cp "${CFGFILE}" "${CFGFILE}.before-upgrade"
+v=${CT_CONFIG_VERSION}
+input="${CFGFILE}"
+while [ "${v}" -lt "${CT_CONFIG_VERSION_CURRENT}" ]; do
+    vn=$[ v + 1 ]
+    info "Upgrading v${v} to v${vn}"
+    {
+        while read ln; do
+            unset val
+            q=
+            case "${ln}" in
+                CT_CONFIG_VERSION_CURRENT=*|CT_CONFIG_VERSION=*)
+                    continue
+                    ;;
+                CT_*=*)
+                    opt=${ln%%=*}
+                    val=${ln#*=}
+                    case "${val}" in
+                    \"*\")
+                        val="${val%\"}"
+                        val="${val#\"}"
+                        q=\"
+                        ;;
+                    esac
+                    ;;
+                "# CT_"*" is not set")
+                    opt=${ln#* }
+                    opt=${opt%% *}
+                    ;;
+                *)
+                    echo "${ln}"
+                    continue
+                    ;;
+            esac
+            upgrade_v${v}
+            # Emit the option(s)
+            if [ x${opt+set} = x ]; then
+                continue
+            elif [ x${val+set} = x ]; then
+                echo "# ${opt} is not set"
+            else
+                echo "${opt}=${q}${val}${q}"
+            fi
+        done
+        echo "CT_CONFIG_VERSION=\"${vn}\""
+        echo "CT_CONFIG_VERSION_CURRENT=\"${CT_CONFIG_VERSION_CURRENT}\""
+    } < "${input}" > "${CFGFILE}.${vn}"
+    v=${vn}
+    rm -f "${input}"
+    input="${CFGFILE}.${vn}"
+    # Reload the next input so that the upgrade function can rely on other CT_xxx variables,
+    # not just the currently processed variable.
+    # TBD clean the environment first to avoid any stale values
+    . "${input}"
+    # Ideally, we'd do 'ct-ng olddefconfig' after each step with the appropriate
+    # Kconfig so that the next step would be able to use auto-set values from the
+    # previous step. However, that would require us to keep archived config/ trees
+    # from every config file version, which is not practical. So, I decided to defer
+    # this until it is actually needed. Even then, it is probably sufficient to only
+    # keep the versions where there is such a dependency.
+done
+mv "${CFGFILE}.${CT_CONFIG_VERSION_CURRENT}" "${CFGFILE}"
+cp "${CFGFILE}" "${CFGFILE}.before-olddefconfig"
+cat >&2 <<EOF
+
+Done. The original '${CFGFILE}' has been saved as '${CFGFILE}.before-upgrade'.
+Will now run through 'ct-ng olddefconfig'.  The intermediate configuration (after the upgrade script,
+but before running 'ct-ng olddefconfig') has been saved as '${CFGFILE}.before-olddefconfig'.
+EOF