From: Mike Hommey <mh@glandium.org>
Date: Wed, 27 Apr 2011 08:58:01 +0200
Subject: Bug 626035 - Modify the way arm compiler flags are set in configure

---
 configure.in        |  292 ++++++++++++++++++++++++++++++++-------------------
 js/src/configure.in |  284 ++++++++++++++++++++++++++++++++-----------------
 2 files changed, 372 insertions(+), 204 deletions(-)

--- a/js/src/configure.in
+++ b/js/src/configure.in
@@ -3535,34 +3535,6 @@ case $target in
     AC_CHECK_LIB(socket, socket)
 esac
 
-AC_MSG_CHECKING(for ARM SIMD support in compiler)
-AC_TRY_COMPILE([],
-               [asm("uqadd8 r1, r1, r2");],
-               result="yes", result="no")
-AC_MSG_RESULT("$result")
-if test "$result" = "yes"; then
-    AC_DEFINE(HAVE_ARM_SIMD)
-    HAVE_ARM_SIMD=1
-fi
-AC_SUBST(HAVE_ARM_SIMD)
-
-AC_MSG_CHECKING(for ARM NEON support in compiler)
-_SAVE_CFLAGS="$CFLAGS"
-if test "$GNU_CC"; then
-  # gcc needs -mfpu=neon to recognize NEON instructions
-  CFLAGS="$CFLAGS -mfpu=neon -mfloat-abi=softfp"
-fi
-AC_TRY_COMPILE([],
-               [asm("vadd.i8 d0, d0, d0");],
-               result="yes", result="no")
-AC_MSG_RESULT("$result")
-if test "$result" = "yes"; then
-    AC_DEFINE(HAVE_ARM_NEON)
-    HAVE_ARM_NEON=1
-fi
-CFLAGS="$_SAVE_CFLAGS"
-AC_SUBST(HAVE_ARM_NEON)
-
 dnl ========================================================
 dnl = pthread support
 dnl = Start by checking whether the system support pthreads
@@ -4614,13 +4586,11 @@ MOZ_ARG_HEADER(Application)
 BUILD_STATIC_LIBS=
 ENABLE_TESTS=1
 
-MOZ_THUMB2=
 USE_ARM_KUSER=
 
 case "${target}" in
     arm-android-eabi)
         USE_ARM_KUSER=1
-        MOZ_THUMB2=1
         ;;
 esac
 
@@ -4666,80 +4636,204 @@ dnl =
 dnl ========================================================
 MOZ_ARG_HEADER(Individual module options)
 
-dnl Setup default CPU arch for arm target
-case "$target_cpu" in
-  arm*)
-    MOZ_ARM_ARCH=armv7
-  ;;
-esac
 dnl ========================================================
-dnl = Enable building the Thumb2 instruction set
+dnl = ARM toolchain tweaks
 dnl ========================================================
-MOZ_ARG_ENABLE_BOOL(thumb2,
- [  --enable-thumb2         Enable Thumb2 instruction set (implies ARMv7)],
-    MOZ_THUMB2=1,
-    MOZ_THUMB2=)
-if test -n "$MOZ_THUMB2"; then
-  MOZ_ARM_ARCH=armv7
+
+dnl Defaults
+case "${target}" in
+arm-android-eabi)
+    MOZ_THUMB=yes
+    MOZ_ARCH=armv7-a
+    MOZ_FPU=vfp
+    MOZ_FLOAT_ABI=softfp
+    ;;
+arm*-*)
+    if test -n "$MOZ_PLATFORM_MAEMO"; then
+        MOZ_THUMB=no
+        MOZ_ARCH=armv7-a
+        MOZ_FLOAT_ABI=softfp
+    fi
+    if test "$MOZ_PLATFORM_MAEMO" = 6; then
+        MOZ_THUMB=yes
+    fi
+    ;;
+esac
+
+dnl Kept for compatibility with some buildbot mozconfig
+MOZ_ARG_DISABLE_BOOL(thumb2, [], MOZ_THUMB=no, MOZ_THUMB=yes)
+
+MOZ_ARG_WITH_STRING(thumb,
+[  --with-thumb[[=yes|no|toolchain]]]
+[                          Use Thumb instruction set (-mthumb)],
+    if test -z "$GNU_CC"; then
+        AC_MSG_ERROR([--with-thumb is not supported on non-GNU toolchains])
+    fi
+    MOZ_THUMB=$withval)
+
+MOZ_ARG_WITH_STRING(thumb-interwork,
+[  --with-thumb-interwork[[=yes|no|toolchain]]
+                           Use Thumb/ARM instuctions interwork (-mthumb-interwork)],
+    if test -z "$GNU_CC"; then
+        AC_MSG_ERROR([--with-thumb-interwork is not supported on non-GNU toolchains])
+    fi
+    MOZ_THUMB_INTERWORK=$withval)
+
+MOZ_ARG_WITH_STRING(arch,
+[  --with-arch=[[type|toolchain]]
+                           Use specific CPU features (-march=type)],
+    if test -z "$GNU_CC"; then
+        AC_MSG_ERROR([--with-arch is not supported on non-GNU toolchains])
+    fi
+    MOZ_ARCH=$withval)
+
+MOZ_ARG_WITH_STRING(fpu,
+[  --with-fpu=[[type|toolchain]]
+                           Use specific FPU type (-mfpu=type)],
+    if test -z "$GNU_CC"; then
+        AC_MSG_ERROR([--with-fpu is not supported on non-GNU toolchains])
+    fi
+    MOZ_FPU=$withval)
+
+MOZ_ARG_WITH_STRING(float-abi,
+[  --with-float-abi=[[type|toolchain]]
+                           Use specific arm float ABI (-mfloat-abi=type)],
+    if test -z "$GNU_CC"; then
+        AC_MSG_ERROR([--with-float-abi is not supported on non-GNU toolchains])
+    fi
+    MOZ_FLOAT_ABI=$withval)
+
+MOZ_ARG_WITH_STRING(soft-float,
+[  --with-soft-float[[=yes|no|toolchain]]
+                           Use soft float library (-msoft-float)],
+    if test -z "$GNU_CC"; then
+        AC_MSG_ERROR([--with-soft-float is not supported on non-GNU toolchains])
+    fi
+    MOZ_SOFT_FLOAT=$withval)
+
+case "$MOZ_ARCH" in
+toolchain|"")
+    arch_flag=""
+    ;;
+*)
+    arch_flag="-march=$MOZ_ARCH"
+    ;;
+esac
+
+case "$MOZ_THUMB" in
+yes)
+    MOZ_THUMB2=1
+    thumb_flag="-mthumb"
+    ;;
+no)
+    MOZ_THUMB2=
+    thumb_flag="-marm"
+    ;;
+*)
+    _SAVE_CFLAGS="$CFLAGS"
+    CFLAGS="$arch_flag"
+    AC_TRY_COMPILE([],[return sizeof(__thumb2__);],
+        MOZ_THUMB2=1,
+        MOZ_THUMB2=)
+    CFLAGS="$_SAVE_CFLAGS"
+    thumb_flag=""
+    ;;
+esac
+
+if test "$MOZ_THUMB2" = 1; then
+    AC_DEFINE(MOZ_THUMB2)
 fi
 
-dnl ========================================================
-dnl = Enable building for ARM specific CPU features
-dnl ========================================================
-MOZ_ARG_WITH_STRING(cpu-arch,
-[  --with-cpu-arch=arch      Use specific arm architecture CPU features, default armv7],
-    MOZ_ARM_ARCH=$withval)
+case "$MOZ_THUMB_INTERWORK" in
+yes)
+    thumb_interwork_flag="-mthumb-interwork"
+    ;;
+no)
+    thumb_interwork_flag="-mno-thumb-interwork"
+    ;;
+*) # toolchain
+    thumb_interwork_flag=""
+    ;;
+esac
 
-if test -n "$MOZ_THUMB2"; then
-  case "$target_cpu" in
-    arm*)
-      if test "$MOZ_ARM_ARCH" != "armv7"; then
-        AC_MSG_ERROR([--enable-thumb2 is not compatible with cpu-arch=$MOZ_ARM_ARCH])
-      fi
-      if test "$GNU_CC"; then
-        AC_DEFINE(MOZ_THUMB2)
-        AC_DEFINE(MOZ_ARM_ARCH)
-        CFLAGS="$CFLAGS -march=armv7-a -mthumb -mfloat-abi=softfp $MOZ_ARM_VFP_FLAGS"
-        CXXFLAGS="$CXXFLAGS -march=armv7-a -mthumb -mfloat-abi=softfp $MOZ_ARM_VFP_FLAGS"
-        ASFLAGS="$ASFLAGS -march=armv7-a -mthumb -mfloat-abi=softfp $MOZ_ARM_VFP_FLAGS"
-      else
-        AC_MSG_ERROR([--enable-thumb2 is not supported for non-GNU toolchains])
-      fi
+case "$MOZ_FPU" in
+toolchain|"")
+    fpu_flag=""
     ;;
-    *)
-      AC_MSG_ERROR([--enable-thumb2 is not supported for non-ARM CPU architectures])
+*)
+    fpu_flag="-mfpu=$MOZ_FPU"
     ;;
-  esac
-elif test "$MOZ_ARM_ARCH" = "armv7"; then
-  case "$target_cpu" in
-    arm*)
-      if test "$GNU_CC"; then
-        AC_DEFINE(MOZ_ARM_ARCH)
-        CFLAGS="$CFLAGS -march=armv7-a -marm -mfloat-abi=softfp $MOZ_ARM_VFP_FLAGS"
-        CXXFLAGS="$CXXFLAGS -march=armv7-a -marm -mfloat-abi=softfp $MOZ_ARM_VFP_FLAGS"
-        ASFLAGS="$ASFLAGS -march=armv7-a -marm -mfloat-abi=softfp $MOZ_ARM_VFP_FLAGS"
-      else
-        AC_MSG_ERROR([--with-cpu-arch=armv7 is not supported for non-GNU toolchains])
-      fi
+esac
+
+case "$MOZ_FLOAT_ABI" in
+toolchain|"")
+    float_abi_flag=""
     ;;
-    *)
-      AC_MSG_ERROR([--with-cpu-arch=armv7 is not supported for non-ARM CPU architectures])
+*)
+    float_abi_flag="-mfloat-abi=$MOZ_FLOAT_ABI"
     ;;
-  esac
-else
-  case "$target_cpu" in
-    arm*)
-      if test "$GNU_CC"; then
-        CFLAGS="$CFLAGS -march=armv5te -mthumb-interwork -msoft-float"
-        CXXFLAGS="$CXXFLAGS -march=armv5te -mthumb-interwork -msoft-float"
-        ASFLAGS="$ASFLAGS -march=armv5te -mthumb-interwork -msoft-float"
-      fi
-      ;;
-  esac
+esac
+
+case "$MOZ_SOFT_FLOAT" in
+yes)
+    soft_float_flag="-msoft-float"
+    ;;
+no)
+    soft_float_flag="-mno-soft-float"
+    ;;
+*) # toolchain
+    soft_float_flag=""
+    ;;
+esac
+
+dnl Use echo to avoid accumulating space characters
+all_flags=`echo $arch_flag $thumb_flag $thumb_interwork_flag $fpu_flag $float_abi_flag $soft_float_flag`
+if test -n "$all_flags"; then
+    _SAVE_CFLAGS="$CFLAGS"
+    CFLAGS="$all_flags"
+    AC_MSG_CHECKING(whether the chosen combination of compiler flags ($all_flags) works)
+    AC_TRY_COMPILE([],[return 0;],
+        AC_MSG_RESULT([yes]),
+        AC_MSG_ERROR([no]))
+
+    CFLAGS="$_SAVE_CFLAGS $all_flags"
+    CXXFLAGS="$CXXFLAGS $all_flags"
+    ASFLAGS="$ASFLAGS $all_flags"
+    if test -n "$thumb_flag"; then
+        LDFLAGS="$LDFLAGS $thumb_flag"
+    fi
 fi
 
 AC_SUBST(MOZ_THUMB2)
-AC_SUBST(MOZ_ARM_ARCH)
+
+if test "$CPU_ARCH" = "arm"; then
+  AC_MSG_CHECKING(for ARM SIMD support in compiler)
+  # We try to link so that this also fails when
+  # building with LTO.
+  AC_TRY_LINK([],
+                 [asm("uqadd8 r1, r1, r2");],
+                 result="yes", result="no")
+  AC_MSG_RESULT("$result")
+  if test "$result" = "yes"; then
+      AC_DEFINE(HAVE_ARM_SIMD)
+      HAVE_ARM_SIMD=1
+  fi
+
+  AC_MSG_CHECKING(for ARM NEON support in compiler)
+  # We try to link so that this also fails when
+  # building with LTO.
+  AC_TRY_LINK([],
+                 [asm(".fpu neon\n vadd.i8 d0, d0, d0");],
+                 result="yes", result="no")
+  AC_MSG_RESULT("$result")
+  if test "$result" = "yes"; then
+      AC_DEFINE(HAVE_ARM_NEON)
+      HAVE_ARM_NEON=1
+  fi
+fi # CPU_ARCH = arm
+
+AC_SUBST(HAVE_ARM_SIMD)
+AC_SUBST(HAVE_ARM_NEON)
 
 dnl ========================================================
 dnl =
@@ -6147,12 +6241,6 @@ if test "$JS_HAS_CTYPES" -a -z "$MOZ_NAT
   if test "$OS_ARCH" = "OS2"; then
     ac_configure_args="$ac_configure_args CFLAGS=-Zomf AR=emxomfar"
   fi
-  if test -n "$MOZ_THUMB2"; then
-    ac_configure_args="$ac_configure_args --enable-thumb2"
-  fi
-  if test -n "$MOZ_ARM_ARCH"; then
-    ac_configure_args="$ac_configure_args --with-cpu-arch=$MOZ_ARM_ARCH"
-  fi
 
   # Use a separate cache file for libffi, since it does things differently
   # from our configure.