Squashed 'src/secp256k1/' changes from 6c527ec..7a49cac

7a49cac Merge #410: Add string.h include to ecmult_impl
0bbd5d4 Add string.h include to ecmult_impl
c5b32e1 Merge #405: Make secp256k1_fe_sqrt constant time
926836a Make secp256k1_fe_sqrt constant time
e2a8e92 Merge #404: Replace 3M + 4S doubling formula with 2M + 5S one
8ec49d8 Add note about 2M + 5S doubling formula
5a91bd7 Merge #400: A couple minor cleanups
ac01378 build: add -DSECP256K1_BUILD to benchmark_internal build flags
a6c6f99 Remove a bunch of unused stdlib #includes
65285a6 Merge #403: configure: add flag to disable OpenSSL tests
a9b2a5d configure: add flag to disable OpenSSL tests
b340123 Merge #402: Add support for testing quadratic residues
e6e9805 Add function for testing quadratic residue field/group elements.
efd953a Add Jacobi symbol test via GMP
fa36a0d Merge #401: ecmult_const: unify endomorphism and non-endomorphism skew cases
c6191fd ecmult_const: unify endomorphism and non-endomorphism skew cases
0b3e618 Merge #378: .gitignore build-aux cleanup
6042217 Merge #384: JNI: align shared files copyright/comments to bitcoinj's
24ad20f Merge #399: build: verify that the native compiler works for static precomp
b3be852 Merge #398: Test whether ECDH and Schnorr are enabled for JNI
aa0b1fd build: verify that the native compiler works for static precomp
eee808d Test whether ECDH and Schnorr are enabled for JNI
7b0fb18 Merge #366: ARM assembly implementation of field_10x26 inner (rebase of #173)
001f176 ARM assembly implementation of field_10x26 inner
0172be9 Merge #397: Small fixes for sha256
3f8b78e Fix undefs in hash_impl.h
2ab4695 Fix state size in sha256 struct
6875b01 Merge #386: Add some missing `VERIFY_CHECK(ctx != NULL)`
2c52b5d Merge #389: Cast pointers through uintptr_t under JNI
43097a4 Merge #390: Update bitcoin-core GitHub links
31c9c12 Merge #391: JNI: Only call ecdsa_verify if its inputs parsed correctly
1cb2302 Merge #392: Add testcase which hits additional branch in secp256k1_scalar_sqr
d2ee340 Merge #388: bench_ecdh: fix call to secp256k1_context_create
093a497 Add testcase which hits additional branch in secp256k1_scalar_sqr
a40c701 JNI: Only call ecdsa_verify if its inputs parsed correctly
faa2a11 Update bitcoin-core GitHub links
47b9e78 Cast pointers through uintptr_t under JNI
f36f9c6 bench_ecdh: fix call to secp256k1_context_create
bcc4881 Add some missing `VERIFY_CHECK(ctx != NULL)` for functions that use `ARG_CHECK`
6ceea2c align shared files copyright/comments to bitcoinj's
70141a8 Update .gitignore
7b549b1 Merge #373: build: fix x86_64 asm detection for some compilers
bc7c93c Merge #374: Add note about y=0 being possible on one of the sextic twists
e457018 Merge #364: JNI rebased
86e2d07 JNI library: cleanup, removed unimplemented code
3093576a JNI library
bd2895f Merge pull request #371
e72e93a Add note about y=0 being possible on one of the sextic twists
3f8fdfb build: fix x86_64 asm detection for some compilers
e5a9047 [Trivial] Remove double semicolons
c18b869 Merge pull request #360
3026daa Merge pull request #302
03d4611 Add sage verification script for the group laws
a965937 Merge pull request #361
83221ec Add experimental features to configure
5d4c5a3 Prevent damage_array in the signature test from going out of bounds.
419bf7f Merge pull request #356
03d84a4 Benchmark against OpenSSL verification

git-subtree-dir: src/secp256k1
git-subtree-split: 7a49cacd3937311fcb1cb36b6ba3336fca811991

2 files changed, 142 insertions, 2 deletions

diff --git a/build-aux/m4/ax_jni_include_dir.m4 b/build-aux/m4/ax_jni_include_dir.m4
new file mode 100644
index 0000000000..1fc3627614
--- /dev/null
+++ b/build-aux/m4/ax_jni_include_dir.m4
@@ -0,0 +1,140 @@
+# ===========================================================================
+#    http://www.gnu.org/software/autoconf-archive/ax_jni_include_dir.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+#   AX_JNI_INCLUDE_DIR
+#
+# DESCRIPTION
+#
+#   AX_JNI_INCLUDE_DIR finds include directories needed for compiling
+#   programs using the JNI interface.
+#
+#   JNI include directories are usually in the Java distribution. This is
+#   deduced from the value of $JAVA_HOME, $JAVAC, or the path to "javac", in
+#   that order. When this macro completes, a list of directories is left in
+#   the variable JNI_INCLUDE_DIRS.
+#
+#   Example usage follows:
+#
+#     AX_JNI_INCLUDE_DIR
+#
+#     for JNI_INCLUDE_DIR in $JNI_INCLUDE_DIRS
+#     do
+#             CPPFLAGS="$CPPFLAGS -I$JNI_INCLUDE_DIR"
+#     done
+#
+#   If you want to force a specific compiler:
+#
+#   - at the configure.in level, set JAVAC=yourcompiler before calling
+#   AX_JNI_INCLUDE_DIR
+#
+#   - at the configure level, setenv JAVAC
+#
+#   Note: This macro can work with the autoconf M4 macros for Java programs.
+#   This particular macro is not part of the original set of macros.
+#
+# LICENSE
+#
+#   Copyright (c) 2008 Don Anderson <dda@sleepycat.com>
+#
+#   Copying and distribution of this file, with or without modification, are
+#   permitted in any medium without royalty provided the copyright notice
+#   and this notice are preserved. This file is offered as-is, without any
+#   warranty.
+
+#serial 10
+
+AU_ALIAS([AC_JNI_INCLUDE_DIR], [AX_JNI_INCLUDE_DIR])
+AC_DEFUN([AX_JNI_INCLUDE_DIR],[
+
+JNI_INCLUDE_DIRS=""
+
+if test "x$JAVA_HOME" != x; then
+	_JTOPDIR="$JAVA_HOME"
+else
+	if test "x$JAVAC" = x; then
+		JAVAC=javac
+	fi
+	AC_PATH_PROG([_ACJNI_JAVAC], [$JAVAC], [no])
+	if test "x$_ACJNI_JAVAC" = xno; then
+		AC_MSG_WARN([cannot find JDK; try setting \$JAVAC or \$JAVA_HOME])
+	fi
+	_ACJNI_FOLLOW_SYMLINKS("$_ACJNI_JAVAC")
+	_JTOPDIR=`echo "$_ACJNI_FOLLOWED" | sed -e 's://*:/:g' -e 's:/[[^/]]*$::'`
+fi
+
+case "$host_os" in
+        darwin*)        _JTOPDIR=`echo "$_JTOPDIR" | sed -e 's:/[[^/]]*$::'`
+                        _JINC="$_JTOPDIR/Headers";;
+        *)              _JINC="$_JTOPDIR/include";;
+esac
+_AS_ECHO_LOG([_JTOPDIR=$_JTOPDIR])
+_AS_ECHO_LOG([_JINC=$_JINC])
+
+# On Mac OS X 10.6.4, jni.h is a symlink:
+# /System/Library/Frameworks/JavaVM.framework/Versions/Current/Headers/jni.h
+# -> ../../CurrentJDK/Headers/jni.h.
+
+AC_CACHE_CHECK(jni headers, ac_cv_jni_header_path,
+[
+if test -f "$_JINC/jni.h"; then
+  ac_cv_jni_header_path="$_JINC"
+  JNI_INCLUDE_DIRS="$JNI_INCLUDE_DIRS $ac_cv_jni_header_path"
+else
+  _JTOPDIR=`echo "$_JTOPDIR" | sed -e 's:/[[^/]]*$::'`
+  if test -f "$_JTOPDIR/include/jni.h"; then
+    ac_cv_jni_header_path="$_JTOPDIR/include"
+    JNI_INCLUDE_DIRS="$JNI_INCLUDE_DIRS $ac_cv_jni_header_path"
+  else
+    ac_cv_jni_header_path=none
+  fi
+fi
+])
+
+
+
+# get the likely subdirectories for system specific java includes
+case "$host_os" in
+bsdi*)          _JNI_INC_SUBDIRS="bsdos";;
+darwin*)        _JNI_INC_SUBDIRS="darwin";;
+freebsd*)       _JNI_INC_SUBDIRS="freebsd";;
+linux*)         _JNI_INC_SUBDIRS="linux genunix";;
+osf*)           _JNI_INC_SUBDIRS="alpha";;
+solaris*)       _JNI_INC_SUBDIRS="solaris";;
+mingw*)		_JNI_INC_SUBDIRS="win32";;
+cygwin*)	_JNI_INC_SUBDIRS="win32";;
+*)              _JNI_INC_SUBDIRS="genunix";;
+esac
+
+if test "x$ac_cv_jni_header_path" != "xnone"; then
+  # add any subdirectories that are present
+  for JINCSUBDIR in $_JNI_INC_SUBDIRS
+  do
+      if test -d "$_JTOPDIR/include/$JINCSUBDIR"; then
+           JNI_INCLUDE_DIRS="$JNI_INCLUDE_DIRS $_JTOPDIR/include/$JINCSUBDIR"
+      fi
+  done
+fi
+])
+
+# _ACJNI_FOLLOW_SYMLINKS <path>
+# Follows symbolic links on <path>,
+# finally setting variable _ACJNI_FOLLOWED
+# ----------------------------------------
+AC_DEFUN([_ACJNI_FOLLOW_SYMLINKS],[
+# find the include directory relative to the javac executable
+_cur="$1"
+while ls -ld "$_cur" 2>/dev/null | grep " -> " >/dev/null; do
+        AC_MSG_CHECKING([symlink for $_cur])
+        _slink=`ls -ld "$_cur" | sed 's/.* -> //'`
+        case "$_slink" in
+        /*) _cur="$_slink";;
+        # 'X' avoids triggering unwanted echo options.
+        *) _cur=`echo "X$_cur" | sed -e 's/^X//' -e 's:[[^/]]*$::'`"$_slink";;
+        esac
+        AC_MSG_RESULT([$_cur])
+done
+_ACJNI_FOLLOWED="$_cur"
+])# _ACJNI
diff --git a/build-aux/m4/bitcoin_secp.m4 b/build-aux/m4/bitcoin_secp.m4
index d41bbb6487..b25d8adb92 100644
--- a/build-aux/m4/bitcoin_secp.m4
+++ b/build-aux/m4/bitcoin_secp.m4
@@ -3,13 +3,13 @@ AC_DEFUN([SECP_INT128_CHECK],[
 has_int128=$ac_cv_type___int128
 ])
 
-dnl 
+dnl escape "$0x" below using the m4 quadrigaph @S|@, and escape it again with a \ for the shell.
 AC_DEFUN([SECP_64BIT_ASM_CHECK],[
 AC_MSG_CHECKING(for x86_64 assembly availability)
 AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
   #include <stdint.h>]],[[
   uint64_t a = 11, tmp;
-  __asm__ __volatile__("movq $0x100000000,%1; mulq %%rsi" : "+a"(a) : "S"(tmp) : "cc", "%rdx");
+  __asm__ __volatile__("movq \@S|@0x100000000,%1; mulq %%rsi" : "+a"(a) : "S"(tmp) : "cc", "%rdx");
   ]])],[has_64bit_asm=yes],[has_64bit_asm=no])
 AC_MSG_RESULT([$has_64bit_asm])
 ])