[PATCH 3/4] * config.sub: Properly recognise configs with 4 components

[John Ericson]

---
 ChangeLog  | 27 +++++++++++++++++++++++++++
 config.sub | 46 +++++++++++++++++++++++++++++++---------------
 2 files changed, 58 insertions(+), 15 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 0655aad..7e675c9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,30 @@
+2018-04-24  John Ericson  <address@hidden>
+
+       * config.sub: Properly recognise configs with 4 components.
+
+       The old logic was a bit hard to follow due to lots of sed and
+       unintuitive collapsing of cases. The code now works like this
+
+               * 4 components is always parsed as
+                 CPU_TYPE-MANUFACTURER-KERNEL-OPERATING_SYSTEM
+
+               * 2 components is always parsed as
+                 CPU_TYPE-OPERATING_SYSTEM
+
+               * 1 component is always parsed as
+                 CPU_TYPE
+
+               * 3 components is ambiguous and parsed as either
+                 CPU_TYPE-MANUFACTURER-OPERATING_SYSTEM
+                 CPU_TYPE-KERNEL-OPERATING_SYSTEM
+
+       The old code differed semantically in that
+
+               * The 4-case was awkwardly folded into the 3-case disambiguation
+
+               * The "android-linux" ad-hoc fixdup did something different in
+                 the non-3 cases, but isn't intended to apply in those cases.
+
 2018-05-01  John Ericson  <address@hidden>
 
        * config.sub (os, maybe_os): Normalize indentation to match rest of
diff --git a/config.sub b/config.sub
index 5e5eac2..06c755b 100755
--- a/config.sub
+++ b/config.sub
@@ -110,33 +110,49 @@ case $# in
     exit 1;;
 esac
 
-# Separate what the user gave into CPU-COMPANY and OS or KERNEL-OS (if any).
-# Here we must recognize all the valid KERNEL-OS combinations.
-maybe_os=`echo "$1" | sed 's/^\(.*\)-\([^-]*-[^-]*\)$/\2/'`
-case $maybe_os in
+# Physical components of config
+comp1=`echo "$1" | sed 's/^\([^-]*\).*$/\1/'`
+comp2=`echo "$1" | sed 's/^[^-]*-\([^-]*\).*$/\1/'`
+comp3=`echo "$1" | sed 's/^[^-]*-[^-]*-\([^-]*\).*$/\1/'`
+comp4=`echo "$1" | sed 's/^[^-]*-[^-]*-[^-]*-\([^-]*\).*$/\1/'`
+
+# Separate into logical components for further validation
+case $1 in
+       *-*-*-*)
+               basic_machine=$comp1-$comp2
+               os=-$comp3-$comp4
+               ;;
+       *-*-*)
+               # Ambiguous whether COMPANY is present, or skipped and 
KERNEL-OS is two
+               # parts
+               maybe_os=$comp2-$comp3
+               case $maybe_os in
                        nto-qnx* | linux-gnu* | linux-android* | linux-dietlibc 
\
                        | linux-newlib* | linux-musl* | linux-uclibc* | 
uclinux-uclibc* \
                        | uclinux-gnu* | kfreebsd*-gnu* | knetbsd*-gnu* | 
netbsd*-gnu* \
                        | netbsd*-eabi* | kopensolaris*-gnu* | cloudabi*-eabi* \
                        | storm-chaos* | os2-emx* | rtmk-nova*)
+                               basic_machine=$comp1
                                os=-$maybe_os
-                               basic_machine=`echo "$1" | sed 
's/^\(.*\)-\([^-]*-[^-]*\)$/\1/'`
                                ;;
                        android-linux)
+                               basic_machine=$comp1-unknown
                                os=-linux-android
-                               basic_machine=`echo "$1" | sed 
's/^\(.*\)-\([^-]*-[^-]*\)$/\1/'`-unknown
                                ;;
                        *)
-                               basic_machine=`echo "$1" | sed 's/-[^-]*$//'`
-                               case $1 in
-                               *-*)
-                                       os=`echo "$1" | sed 's/.*-/-/'`
-                                       ;;
-                               *)
-                                       os=
-                                       ;;
-                               esac
+                               basic_machine=$comp1-$comp2
+                               os=-$comp3
                                ;;
+               esac
+               ;;
+       *-*)
+               basic_machine=$comp1
+               os=-$comp2
+               ;;
+       *)
+               basic_machine=$1
+               os=
+               ;;
 esac
 
 ### Let's recognize common machines as not being operating systems so
-- 
2.16.3