Implement flexible target specification

Removes all target-specific knowledge from rustc. Some targets have changed
during this, but none of these should be very visible outside of
cross-compilation. The changes make our targets more consistent.

iX86-unknown-linux-gnu is now only available as i686-unknown-linux-gnu. We
used to accept any value of X greater than 1. i686 was released in 1995, and
should encompass the bare minimum of what Rust supports on x86 CPUs.

The only two windows targets are now i686-pc-windows-gnu and
x86_64-pc-windows-gnu.

The iOS target has been renamed from arm-apple-ios to arm-apple-darwin.

A complete list of the targets we accept now:

arm-apple-darwin
arm-linux-androideabi
arm-unknown-linux-gnueabi
arm-unknown-linux-gnueabihf

i686-apple-darwin
i686-pc-windows-gnu
i686-unknown-freebsd
i686-unknown-linux-gnu

mips-unknown-linux-gnu
mipsel-unknown-linux-gnu

x86_64-apple-darwin
x86_64-unknown-freebsd
x86_64-unknown-linux-gnu
x86_64-pc-windows-gnu

Closes rust-lang#16093

[breaking-change]

Author: emberian

configure

@@ -350,37 +350,40 @@ case $CFG_OSTYPE in
         # instead, msys defines $MSYSTEM which is MINGW32 on i686 and
         # MINGW64 on x86_64.
         CFG_CPUTYPE=i686
-        CFG_OSTYPE=w64-mingw32
+        CFG_OSTYPE=pc-windows-gnu
         if [ "$MSYSTEM" = MINGW64 ]
         then
             CFG_CPUTYPE=x86_64
-            CFG_OSTYPE=w64-mingw32
         fi
         ;;
 
+    MSYS*)
+        CFG_OSTYPE=pc-windows-gnu
+        ;;
+
 # Thad's Cygwin identifers below
 
 #   Vista 32 bit
     CYGWIN_NT-6.0)
-        CFG_OSTYPE=pc-mingw32
+        CFG_OSTYPE=pc-windows-gnu
         CFG_CPUTYPE=i686
         ;;
 
 #   Vista 64 bit
     CYGWIN_NT-6.0-WOW64)
-        CFG_OSTYPE=w64-mingw32
+        CFG_OSTYPE=pc-windows-gnu
         CFG_CPUTYPE=x86_64
         ;;
 
 #   Win 7 32 bit
     CYGWIN_NT-6.1)
-        CFG_OSTYPE=pc-mingw32
+        CFG_OSTYPE=pc-windows-gnu
         CFG_CPUTYPE=i686
         ;;
 
 #   Win 7 64 bit
     CYGWIN_NT-6.1-WOW64)
-        CFG_OSTYPE=w64-mingw32
+        CFG_OSTYPE=pc-windows-gnu
         CFG_CPUTYPE=x86_64
         ;;
 
@@ -466,7 +469,6 @@ opt llvm-assertions 1 "build LLVM with assertions"
 opt debug 1 "build with extra debug fun"
 opt ratchet-bench 0 "ratchet benchmarks"
 opt fast-make 0 "use .gitmodules as timestamp for submodule deps"
-opt mingw-cross 0 "cross-compile for win32 using mingw"
 opt ccache 0 "invoke gcc/clang via ccache to reuse object files between builds"
 opt local-rust 0 "use an installed rustc rather than downloading a snapshot"
 opt llvm-static-stdcpp 0 "statically link to libstdc++ for LLVM"
@@ -506,7 +508,7 @@ valopt_nosave release-channel "dev" "the name of the release channel to build"
 # --libdir is used to configure the installation directory.
 # FIXME: This needs to parameterized over target triples. Do it in platform.mk
 CFG_LIBDIR_RELATIVE=lib
-if [ "$CFG_OSTYPE" = "pc-mingw32" ] || [ "$CFG_OSTYPE" = "w64-mingw32" ]
+if [ "$CFG_OSTYPE" = "pc-windows-gnu" ]
 then
     CFG_LIBDIR_RELATIVE=bin
 fi
@@ -632,7 +634,7 @@ then
 fi
 
 BIN_SUF=
-if [ "$CFG_OSTYPE" = "pc-mingw32" ] || [ "$CFG_OSTYPE" = "w64-mingw32" ]
+if [ "$CFG_OSTYPE" = "pc-windows-gnu" ]
 then
     BIN_SUF=.exe
 fi
@@ -1100,12 +1102,22 @@ do
 
     if [ ${do_reconfigure} -ne 0 ]
     then
-        msg "configuring LLVM for $t"
+        # LLVM's configure doesn't recognize the new Windows triples yet
+        case $t in
+            i686-pc-windows-gnu)
+                gnu_t="i686-w64-mingw32" ;;
+            x86_64-pc-windows-gnu)
+                gnu_t="x86_64-w64-mingw32" ;;
+            *)
+                gnu_t=$t ;;
+        esac
+
+        msg "configuring LLVM for $gnu_t"
 
         LLVM_TARGETS="--enable-targets=x86,x86_64,arm,mips"
-        LLVM_BUILD="--build=$t"
-        LLVM_HOST="--host=$t"
-        LLVM_TARGET="--target=$t"
+        LLVM_BUILD="--build=$gnu_t"
+        LLVM_HOST="--host=$gnu_t"
+        LLVM_TARGET="--target=$gnu_t"
 
         # Disable unused LLVM features
         LLVM_OPTS="$LLVM_DBG_OPTS $LLVM_ASSERTION_OPTS --disable-docs --enable-bindings=none"
@@ -1119,7 +1131,7 @@ do
         # (llvm's configure tries to find pthread first, so we have to disable it explicitly.)
         # Also note that pthreads works badly on mingw-w64 systems: #8996
         case "$CFG_BUILD" in
-            (*-mingw32)
+            (*-windows-*)
             LLVM_OPTS="$LLVM_OPTS --disable-pthreads"
             ;;
         esac
@@ -1269,6 +1281,7 @@ putvar CFG_HOST
 putvar CFG_TARGET
 putvar CFG_LIBDIR_RELATIVE
 putvar CFG_DISABLE_MANAGE_SUBMODULES
+putvar CFG_ANDROID_CROSS_PATH
 putvar CFG_MANDIR
 
 # Avoid spurious warnings from clang by feeding it original source on

mk/cfg/arm-apple-ios

@@ -3,7 +3,7 @@ CFG_SDK_NAME_arm-apple-ios = iphoneos
 CFG_SDK_ARCHS_arm-apple-ios = armv7
 ifneq ($(findstring darwin,$(CFG_OSTYPE)),)
 CFG_IOS_SDK = $(shell xcrun --show-sdk-path -sdk iphoneos 2>/dev/null)
-CFG_IOS_FLAGS = -target armv7-apple-darwin -isysroot $(CFG_IOS_SDK) -mios-version-min=7.0
+CFG_IOS_FLAGS = -target armv7-apple-ios -isysroot $(CFG_IOS_SDK) -mios-version-min=7.0
 CC_arm-apple-ios = $(shell xcrun -find -sdk iphoneos clang)
 CXX_arm-apple-ios = $(shell xcrun -find -sdk iphoneos clang++)
 CPP_arm-apple-ios = $(shell xcrun -find -sdk iphoneos clang++)
@@ -32,3 +32,4 @@ CFG_RUN_arm-apple-ios = $(2)
 CFG_RUN_TARG_arm-apple-ios = $(call CFG_RUN_arm-apple-ios,,$(2))
 RUSTC_FLAGS_arm-apple-ios := -C relocation_model=pic
 RUSTC_CROSS_FLAGS_arm-apple-ios :=-C relocation_model=pic
+CFG_GNU_TRIPLE_arm-apple-ios := arm-apple-ios

mk/cfg/arm-linux-androideabi

@@ -26,3 +26,4 @@ CFG_RUN_arm-linux-androideabi=
 CFG_RUN_TARG_arm-linux-androideabi=
 RUSTC_FLAGS_arm-linux-androideabi :=
 RUSTC_CROSS_FLAGS_arm-linux-androideabi :=
+CFG_GNU_TRIPLE_arm-linux-androideabi := arm-linux-androideabi

mk/cfg/arm-unknown-linux-gnueabi

@@ -27,3 +27,4 @@ CFG_RUN_arm-unknown-linux-gnueabi=$(2)
 CFG_RUN_TARG_arm-unknown-linux-gnueabi=$(call CFG_RUN_arm-unknown-linux-gnueabi,,$(2))
 RUSTC_FLAGS_arm-unknown-linux-gnueabi :=
 RUSTC_CROSS_FLAGS_arm-unknown-linux-gnueabi :=
+CFG_GNU_TRIPLE_arm-unknown-linux-gnueabi := arm-unknown-linux-gnueabi

mk/cfg/arm-unknown-linux-gnueabihf

@@ -27,3 +27,4 @@ CFG_RUN_arm-unknown-linux-gnueabihf=$(2)
 CFG_RUN_TARG_arm-unknown-linux-gnueabihf=$(call CFG_RUN_arm-unknown-linux-gnueabihf,,$(2))
 RUSTC_FLAGS_arm-unknown-linux-gnueabihf := -C target-feature=+v6,+vfp2
 RUSTC_CROSS_FLAGS_arm-unknown-linux-gnueabihf :=
+CFG_GNU_TRIPLE_arm-unknown-linux-gnueabihf := arm-unknown-linux-gnueabihf

mk/cfg/i386-apple-ios

@@ -31,3 +31,4 @@ CFG_LDPATH_i386-apple-ios =
 CFG_RUN_i386-apple-ios = $(2)
 CFG_RUN_TARG_i386-apple-ios = $(call CFG_RUN_i386-apple-ios,,$(2))
 CFG_JEMALLOC_CFLAGS_i386-apple-ios = -target i386-apple-ios -Wl,-syslibroot $(CFG_IOSSIM_SDK) -Wl,-no_compact_unwind
+CFG_GNU_TRIPLE_i386-apple-ios := i386-apple-ios

mk/cfg/i586-mingw32msvc

@@ -24,4 +24,4 @@ CFG_PATH_MUNGE_i686-apple-darwin := true
 CFG_LDPATH_i686-apple-darwin :=
 CFG_RUN_i686-apple-darwin=$(2)
 CFG_RUN_TARG_i686-apple-darwin=$(call CFG_RUN_i686-apple-darwin,,$(2))
-
+CFG_GNU_TRIPLE_i686-apple-darwin := i686-apple-darwin

mk/cfg/i686-apple-darwin

@@ -0,0 +1,28 @@
+# i686-pc-windows-gnu configuration
+CROSS_PREFIX_i686-pc-windows-gnu=i686-pc-windows-gnu-
+CC_i686-pc-windows-gnu=gcc
+CXX_i686-pc-windows-gnu=g++
+CPP_i686-pc-windows-gnu=gcc -E
+AR_i686-pc-windows-gnu=ar
+CFG_LIB_NAME_i686-pc-windows-gnu=$(1).dll
+CFG_STATIC_LIB_NAME_i686-pc-windows-gnu=$(1).lib
+CFG_LIB_GLOB_i686-pc-windows-gnu=$(1)-*.dll
+CFG_LIB_DSYM_GLOB_i686-pc-windows-gnu=$(1)-*.dylib.dSYM
+CFG_CFLAGS_i686-pc-windows-gnu := -march=i686 -m32 -D_WIN32_WINNT=0x0600 $(CFLAGS)
+CFG_GCCISH_CFLAGS_i686-pc-windows-gnu := -Wall -Werror -g -m32 -D_WIN32_WINNT=0x0600 $(CFLAGS)
+CFG_GCCISH_CXXFLAGS_i686-pc-windows-gnu := -fno-rtti $(CXXFLAGS)
+CFG_GCCISH_LINK_FLAGS_i686-pc-windows-gnu := -shared -g -m32
+CFG_GCCISH_DEF_FLAG_i686-pc-windows-gnu :=
+CFG_GCCISH_PRE_LIB_FLAGS_i686-pc-windows-gnu :=
+CFG_GCCISH_POST_LIB_FLAGS_i686-pc-windows-gnu :=
+CFG_DEF_SUFFIX_i686-pc-windows-gnu := .windows.def
+CFG_LLC_FLAGS_i686-pc-windows-gnu :=
+CFG_INSTALL_NAME_i686-pc-windows-gnu =
+CFG_EXE_SUFFIX_i686-pc-windows-gnu := .exe
+CFG_WINDOWSY_i686-pc-windows-gnu := 1
+CFG_UNIXY_i686-pc-windows-gnu :=
+CFG_PATH_MUNGE_i686-pc-windows-gnu :=
+CFG_LDPATH_i686-pc-windows-gnu :=$(CFG_LDPATH_i686-pc-windows-gnu):$(PATH)
+CFG_RUN_i686-pc-windows-gnu=PATH="$(CFG_LDPATH_i686-pc-windows-gnu):$(1)" $(2)
+CFG_RUN_TARG_i686-pc-windows-gnu=$(call CFG_RUN_i686-pc-windows-gnu,$(HLIB$(1)_H_$(CFG_BUILD)),$(2))
+CFG_GNU_TRIPLE_i686-pc-windows-gnu := i686-w64-mingw32

mk/cfg/i686-pc-windows-gnu

@@ -24,4 +24,4 @@ CFG_PATH_MUNGE_i686-unknown-linux-gnu := true
 CFG_LDPATH_i686-unknown-linux-gnu :=
 CFG_RUN_i686-unknown-linux-gnu=$(2)
 CFG_RUN_TARG_i686-unknown-linux-gnu=$(call CFG_RUN_i686-unknown-linux-gnu,,$(2))
-
+CFG_GNU_TRIPLE_i686-unknown-linux-gnu := i686-unknown-linux-gnu