Set GCC 4.8 as the default for 32-bit ABIs

Add get_first_gcc_version_for_arch and set to GCC 4.6 for 32-bit ABIs
while it's still around (deprecated but will be removed in 1-2 release)

Change-Id: I035c3b46ffb6c5aacf92893b920623acbae1719c

6 files changed, 33 insertions, 18 deletions

diff --git a/build/core/default-build-commands.mk b/build/core/default-build-commands.mk
index ee88037cb..34653307c 100644
--- a/build/core/default-build-commands.mk
+++ b/build/core/default-build-commands.mk
@@ -148,12 +148,12 @@ TARGET_ASMFLAGS =
 TARGET_LD       = $(TOOLCHAIN_PREFIX)ld
 TARGET_LDFLAGS :=
 
-TARGET_AR       = $(TOOLCHAIN_PREFIX)ar
-# Use *-gcc-ar instead of *-ar for better LTO support
-ifneq (,$(NDK_TOOLCHAIN_VERSION))
+# Use *-gcc-ar instead of *-ar for better LTO support, except for
+# gcc4.6 which doesn't have gcc-ar
 ifneq (4.6,$(NDK_TOOLCHAIN_VERSION))
 TARGET_AR       = $(TOOLCHAIN_PREFIX)gcc-ar
-endif
+else
+TARGET_AR       = $(TOOLCHAIN_PREFIX)ar
 endif
 
 TARGET_ARFLAGS := crsD
diff --git a/build/core/init.mk b/build/core/init.mk
index 06d49da26..56e5f300e 100644
--- a/build/core/init.mk
+++ b/build/core/init.mk
@@ -513,7 +513,7 @@ $(call ndk_log,Found max platform level: $(NDK_MAX_PLATFORM_LEVEL))
 # in build/toolchains/<name>/ that will be included here.
 #
 # Each one of these files should define the following variables:
-#   TOOLCHAIN_NAME   toolchain name (e.g. arm-linux-androideabi-4.6)
+#   TOOLCHAIN_NAME   toolchain name (e.g. arm-linux-androideabi-4.9)
 #   TOOLCHAIN_ABIS   list of target ABIs supported by the toolchain.
 #
 # Then, it should include $(ADD_TOOLCHAIN) which will perform
@@ -597,13 +597,13 @@ endif
 # version number. Unlike NDK_TOOLCHAIN, this only changes the suffix of
 # the toolchain path we're using.
 #
-# For example, if GCC 4.6 is the default, defining NDK_TOOLCHAIN_VERSION=4.8
+# For example, if GCC 4.8 is the default, defining NDK_TOOLCHAIN_VERSION=4.9
 # will ensure that ndk-build uses the following toolchains, depending on
 # the target architecture:
 #
-#    arm -> arm-linux-androideabi-4.8
-#    x86 -> x86-android-linux-4.8
-#    mips -> mipsel-linux-android-4.8
+#    arm -> arm-linux-androideabi-4.9
+#    x86 -> x86-android-linux-4.9
+#    mips -> mipsel-linux-android-4.9
 #
 # This is used in setup-toolchain.mk
 #
diff --git a/build/core/setup-toolchain.mk b/build/core/setup-toolchain.mk
index 93fa85770..243df3fbf 100644
--- a/build/core/setup-toolchain.mk
+++ b/build/core/setup-toolchain.mk
@@ -36,8 +36,8 @@ ifndef NDK_TOOLCHAIN
             $(filter-out %-clang$(_ver),$(TARGET_TOOLCHAIN_LIST))))
 
     ifeq (,$(findstring 64,$(TARGET_ARCH_ABI)))
-      # Filter out 4.7, 4.8 and 4.9 which are newer than the defaultat this moment
-      __filtered_toolchain_list := $(filter-out %4.7 %4.8 %4.8l %4.9 %4.9l,$(TARGET_TOOLCHAIN_LIST))
+      # Filter out 4.6 and 4.7 which are deprecated
+      __filtered_toolchain_list := $(filter-out %4.6 %4.7,$(TARGET_TOOLCHAIN_LIST))
       ifdef __filtered_toolchain_list
           TARGET_TOOLCHAIN_LIST := $(__filtered_toolchain_list)
       endif
diff --git a/build/tools/build-gnu-libstdc++.sh b/build/tools/build-gnu-libstdc++.sh
index 48a313d64..aa23fae08 100755
--- a/build/tools/build-gnu-libstdc++.sh
+++ b/build/tools/build-gnu-libstdc++.sh
@@ -390,10 +390,10 @@ copy_gnustl_libs ()
 GCC_VERSION_LIST=$(commas_to_spaces $GCC_VERSION_LIST)
 for ABI in $ABIS; do
     ARCH=$(convert_abi_to_arch $ABI)
-    DEFAULT_GCC_VERSION=$(get_default_gcc_version_for_arch $ARCH)
+    FIRST_GCC_VERSION=$(get_first_gcc_version_for_arch $ARCH)
     for VERSION in $GCC_VERSION_LIST; do
         # Only build for this GCC version if it on or after DEFAULT_GCC_VERSION
-        if [ -z "$EXPLICIT_COMPILER_VERSION" ] && ! version_is_greater_than "${VERSION%%l}" "$DEFAULT_GCC_VERSION"; then
+        if [ -z "$EXPLICIT_COMPILER_VERSION" ] && version_is_greater_than "${VERSION%%l}" "$FIRST_GCC_VERSION"; then
             continue
         fi
 
diff --git a/build/tools/dev-defaults.sh b/build/tools/dev-defaults.sh
index 025b4c697..8078e3f84 100644
--- a/build/tools/dev-defaults.sh
+++ b/build/tools/dev-defaults.sh
@@ -49,8 +49,10 @@ TOOLCHAIN_GIT_DATE=now
 # The space-separated list of all GCC versions we support in this NDK
 DEFAULT_GCC_VERSION_LIST="4.6 4.8 4.9"
 
-DEFAULT_GCC32_VERSION=4.6
+DEFAULT_GCC32_VERSION=4.8
 DEFAULT_GCC64_VERSION=4.9
+FIRST_GCC32_VERSION=4.6
+FIRST_GCC64_VERSION=4.9
 DEFAULT_LLVM_GCC32_VERSION=4.8
 DEFAULT_LLVM_GCC64_VERSION=4.9
 
@@ -121,6 +123,17 @@ get_default_gcc_version_for_arch ()
     esac
 }
 
+# Return the first gcc version for a given architecture
+# $1: Architecture name (e.g. 'arm')
+# Out: default arch-specific gcc version
+get_first_gcc_version_for_arch ()
+{
+    case $1 in
+       *64) echo $FIRST_GCC64_VERSION ;;
+       *) echo $FIRST_GCC32_VERSION ;;
+    esac
+}
+
 # Return default NDK ABI for a given architecture name
 # $1: Architecture name
 # Out: ABI name
@@ -210,13 +223,13 @@ get_default_toolchain_prefix_for_arch ()
 # Return empty for unknown arch
 get_toolchain_name_list_for_arch ()
 {
-    local PREFIX VERSION RET ADD DEFAULT_GCC_VERSION VERSIONS
+    local PREFIX VERSION RET ADD FIRST_GCC_VERSION VERSIONS
     PREFIX=$(eval echo \"\$DEFAULT_ARCH_TOOLCHAIN_NAME_$1\")
     if [ -z "$PREFIX" ]; then
         return 0
     fi
     RET=""
-    DEFAULT_GCC_VERSION=$(get_default_gcc_version_for_arch $1)
+    FIRST_GCC_VERSION=$(get_first_gcc_version_for_arch $1)
     ADD=""
     VERSIONS=$(commas_to_spaces $2)
     if [ -z "$VERSIONS" ]; then
@@ -225,7 +238,7 @@ get_toolchain_name_list_for_arch ()
         ADD="yes" # include everything we passed explicitly
     fi
     for VERSION in $VERSIONS; do
-        if [ -z "$ADD" -a "$VERSION" = "$DEFAULT_GCC_VERSION" ]; then
+        if [ -z "$ADD" -a "$VERSION" = "$FIRST_GCC_VERSION" ]; then
             ADD="yes"
         fi
         if [ -z "$ADD" ]; then
diff --git a/build/tools/gen-platforms.sh b/build/tools/gen-platforms.sh
index 2f7982c43..49d4fd8ba 100755
--- a/build/tools/gen-platforms.sh
+++ b/build/tools/gen-platforms.sh
@@ -388,7 +388,9 @@ get_default_compiler_for_arch()
         elif [ -n "$OPTION_GCC_VERSION" -a "$OPTION_GCC_VERSION" != "default" ]; then
             GCC_VERSION=$OPTION_GCC_VERSION
         else
-            GCC_VERSION=$(get_default_gcc_version_for_arch $ARCH)
+            # By default we want to use the first gcc (currently 4.6) instead of the default (gcc4.8)
+            # for best compatibility, at least before gcc4.6 (now deprecated) is removed from NDK package
+            GCC_VERSION=$(get_first_gcc_version_for_arch $ARCH) # $(get_default_gcc_version_for_arch $ARCH)
         fi
         for TAG in $HOST_TAG $HOST_TAG32; do
             TOOLCHAIN_PREFIX="$NDK_DIR/$(get_toolchain_binprefix_for_arch $ARCH $GCC_VERSION $TAG)"