configure: Remove --build detection

This commit removes detection of CFG_OSTYPE and CFG_CPUTYPE from the configure
script, which means that the default value of `--build` is no longer present in
the configure script. All this logic is now available in rustbuild itself, so
there's no need to duplicate it.

Author: alexcrichton

configure

@@ -384,207 +384,6 @@ need_cmd sed
 need_cmd file
 need_cmd make
 
-msg "inspecting environment"
-
-CFG_OSTYPE=$(uname -s)
-CFG_CPUTYPE=$(uname -m)
-
-if [ $CFG_OSTYPE = Darwin -a $CFG_CPUTYPE = i386 ]
-then
-    # Darwin's `uname -s` lies and always returns i386. We have to use sysctl
-    # instead.
-    if sysctl hw.optional.x86_64 | grep -q ': 1'
-    then
-        CFG_CPUTYPE=x86_64
-    fi
-fi
-
-# The goal here is to come up with the same triple as LLVM would,
-# at least for the subset of platforms we're willing to target.
-
-case $CFG_OSTYPE in
-
-    Linux)
-        CFG_OSTYPE=unknown-linux-gnu
-        ;;
-
-    FreeBSD)
-        CFG_OSTYPE=unknown-freebsd
-        ;;
-
-    DragonFly)
-        CFG_OSTYPE=unknown-dragonfly
-        ;;
-
-    Bitrig)
-        CFG_OSTYPE=unknown-bitrig
-        ;;
-
-    OpenBSD)
-        CFG_OSTYPE=unknown-openbsd
-       ;;
-
-    NetBSD)
-	    CFG_OSTYPE=unknown-netbsd
-	    ;;
-
-    Darwin)
-        CFG_OSTYPE=apple-darwin
-        ;;
-
-    SunOS)
-        CFG_OSTYPE=sun-solaris
-        CFG_CPUTYPE=$(isainfo -n)
-        ;;
-
-    Haiku)
-        CFG_OSTYPE=unknown-haiku
-        ;;
-
-    MINGW*)
-        # msys' `uname` does not print gcc configuration, but prints msys
-        # configuration. so we cannot believe `uname -m`:
-        # msys1 is always i686 and msys2 is always x86_64.
-        # instead, msys defines $MSYSTEM which is MINGW32 on i686 and
-        # MINGW64 on x86_64.
-        CFG_CPUTYPE=i686
-        CFG_OSTYPE=pc-windows-gnu
-        if [ "$MSYSTEM" = MINGW64 ]
-        then
-            CFG_CPUTYPE=x86_64
-        fi
-        ;;
-
-    MSYS*)
-        CFG_OSTYPE=pc-windows-gnu
-        ;;
-
-# Thad's Cygwin identifiers below
-
-#   Vista 32 bit
-    CYGWIN_NT-6.0)
-        CFG_OSTYPE=pc-windows-gnu
-        CFG_CPUTYPE=i686
-        ;;
-
-#   Vista 64 bit
-    CYGWIN_NT-6.0-WOW64)
-        CFG_OSTYPE=pc-windows-gnu
-        CFG_CPUTYPE=x86_64
-        ;;
-
-#   Win 7 32 bit
-    CYGWIN_NT-6.1)
-        CFG_OSTYPE=pc-windows-gnu
-        CFG_CPUTYPE=i686
-        ;;
-
-#   Win 7 64 bit
-    CYGWIN_NT-6.1-WOW64)
-        CFG_OSTYPE=pc-windows-gnu
-        CFG_CPUTYPE=x86_64
-        ;;
-
-#   Win 8 # uname -s on 64-bit cygwin does not contain WOW64, so simply use uname -m to detect arch (works in my install)
-    CYGWIN_NT-6.3)
-    	CFG_OSTYPE=pc-windows-gnu
-    	;;
-# We do not detect other OS such as XP/2003 using 64 bit using uname.
-# If we want to in the future, we will need to use Cygwin - Chuck's csih helper in /usr/lib/csih/winProductName.exe or alternative.
-    *)
-        err "unknown OS type: $CFG_OSTYPE"
-        ;;
-esac
-
-
-case $CFG_CPUTYPE in
-
-    i386 | i486 | i686 | i786 | x86)
-        CFG_CPUTYPE=i686
-        ;;
-
-    xscale | arm)
-        CFG_CPUTYPE=arm
-        ;;
-
-    armv6l)
-        CFG_CPUTYPE=arm
-        CFG_OSTYPE="${CFG_OSTYPE}eabihf"
-        ;;
-
-    armv7l)
-        CFG_CPUTYPE=armv7
-        CFG_OSTYPE="${CFG_OSTYPE}eabihf"
-        ;;
-
-    aarch64 | arm64)
-        CFG_CPUTYPE=aarch64
-        ;;
-
-    powerpc | ppc)
-        CFG_CPUTYPE=powerpc
-        ;;
-
-    powerpc64 | ppc64)
-        CFG_CPUTYPE=powerpc64
-        ;;
-
-    powerpc64le | ppc64le)
-        CFG_CPUTYPE=powerpc64le
-        ;;
-
-    s390x)
-        CFG_CPUTYPE=s390x
-        ;;
-
-    x86_64 | x86-64 | x64 | amd64)
-        CFG_CPUTYPE=x86_64
-        ;;
-
-    mips | mips64)
-        if [ "$CFG_CPUTYPE" = "mips64" ]; then
-            CFG_OSTYPE="${CFG_OSTYPE}abi64"
-        fi
-        ENDIAN=$(printf '\1' | od -dAn)
-        if [ "$ENDIAN" -eq 1 ]; then
-            CFG_CPUTYPE="${CFG_CPUTYPE}el"
-        elif [ "$ENDIAN" -ne 256 ]; then
-            err "unknown endianness: $ENDIAN (expecting 1 for little or 256 for big)"
-        fi
-        ;;
-
-    BePC)
-        CFG_CPUTYPE=i686
-        ;;
-
-    *)
-        err "unknown CPU type: $CFG_CPUTYPE"
-esac
-
-# Detect 64 bit linux systems with 32 bit userland and force 32 bit compilation
-if [ $CFG_OSTYPE = unknown-linux-gnu -a $CFG_CPUTYPE = x86_64 ]
-then
-    # $SHELL does not exist in standard 'sh', so probably only exists
-    # if configure is running in an interactive bash shell. /usr/bin/env
-    # exists *everywhere*.
-    BIN_TO_PROBE="$SHELL"
-    if [ ! -r "$BIN_TO_PROBE" ]; then
-        if [ -r "/usr/bin/env" ]; then
-            BIN_TO_PROBE="/usr/bin/env"
-        else
-            warn "Cannot check if the userland is i686 or x86_64"
-        fi
-    fi
-    file -L "$BIN_TO_PROBE" | grep -q "x86[_-]64"
-    if [ $? != 0 ]; then
-        msg "i686 userland on x86_64 Linux kernel"
-        CFG_CPUTYPE=i686
-    fi
-fi
-
-
-DEFAULT_BUILD="${CFG_CPUTYPE}-${CFG_OSTYPE}"
-
 CFG_SRC_DIR="$(abs_path $(dirname $0))/"
 CFG_SRC_DIR_RELATIVE="$(dirname $0)/"
 CFG_BUILD_DIR="$(pwd)/"
@@ -672,7 +471,7 @@ valopt infodir "${CFG_PREFIX}/share/info" "install additional info"
 valopt llvm-root "" "set LLVM root"
 valopt python "" "set path to python"
 valopt jemalloc-root "" "set directory where libjemalloc_pic.a is located"
-valopt build "${DEFAULT_BUILD}" "GNUs ./configure syntax LLVM build triple"
+valopt build "" "GNUs ./configure syntax LLVM build triple"
 valopt android-cross-path "" "Android NDK standalone path (deprecated)"
 valopt i686-linux-android-ndk "" "i686-linux-android NDK standalone path"
 valopt arm-linux-androideabi-ndk "" "arm-linux-androideabi NDK standalone path"

src/bootstrap/bootstrap.py

@@ -295,8 +295,10 @@ def get_toml(self, key):
 
     def get_mk(self, key):
         for line in iter(self.config_mk.splitlines()):
-            if line.startswith(key):
-                return line[line.find(':=') + 2:].strip()
+            if line.startswith(key + ' :='):
+                var = line[line.find(':=') + 2:].strip()
+                if var != '':
+                    return var
         return None
 
     def cargo(self):
@@ -437,6 +439,8 @@ def build_triple(self):
                 sys.exit(err)
         elif ostype == 'Darwin':
             ostype = 'apple-darwin'
+        elif ostype == 'Haiku':
+            ostype = 'unknown-haiku'
         elif ostype.startswith('MINGW'):
             # msys' `uname` does not print gcc configuration, but prints msys
             # configuration. so we cannot believe `uname -m`:
@@ -464,9 +468,12 @@ def build_triple(self):
             cputype = 'i686'
         elif cputype in {'xscale', 'arm'}:
             cputype = 'arm'
-        elif cputype == 'armv7l':
+        elif cputype == 'armv6l':
             cputype = 'arm'
             ostype += 'eabihf'
+        elif cputype == 'armv7l':
+            cputype = 'armv7'
+            ostype += 'eabihf'
         elif cputype == 'aarch64':
             cputype = 'aarch64'
         elif cputype == 'arm64':
@@ -487,12 +494,20 @@ def build_triple(self):
                 raise ValueError('unknown byteorder: ' + sys.byteorder)
             # only the n64 ABI is supported, indicate it
             ostype += 'abi64'
-        elif cputype in {'powerpc', 'ppc', 'ppc64'}:
+        elif cputype in {'powerpc', 'ppc'}:
             cputype = 'powerpc'
+        elif cputype in {'powerpc64', 'ppc64'}:
+            cputype = 'powerpc64'
+        elif cputype in {'powerpc64le', 'ppc64le'}:
+            cputype = 'powerpc64le'
         elif cputype == 'sparcv9':
             pass
         elif cputype in {'amd64', 'x86_64', 'x86-64', 'x64'}:
             cputype = 'x86_64'
+        elif cputype == 's390x':
+            cputype = 's390x'
+        elif cputype == 'BePC':
+            cputype = 'i686'
         else:
             err = "unknown cpu type: " + cputype
             if self.verbose:

src/bootstrap/config.rs

@@ -456,12 +456,12 @@ impl Config {
             }
 
             match key {
-                "CFG_BUILD" => self.build = value.to_string(),
-                "CFG_HOST" => {
+                "CFG_BUILD" if value.len() > 0 => self.build = value.to_string(),
+                "CFG_HOST" if value.len() > 0 => {
                     self.host = value.split(" ").map(|s| s.to_string())
                                      .collect();
                 }
-                "CFG_TARGET" => {
+                "CFG_TARGET" if value.len() > 0 => {
                     self.target = value.split(" ").map(|s| s.to_string())
                                        .collect();
                 }