Problem: CI doesn't run Valgrind

Solution: run Valgrind only on the default Linux build to avoid
increasing the runtime.

.travis.yml

@@ -13,11 +13,14 @@ env:
 - BUILD_TYPE=default CURVE=libsodium
 - BUILD_TYPE=default
 - BUILD_TYPE=coverage CURVE=tweetnacl
+- BUILD_TYPE=valgrind CURVE=tweetnacl
 
 matrix:
   exclude:
     -  env: BUILD_TYPE=coverage CURVE=tweetnacl
        os: osx
+    -  env: BUILD_TYPE=valgrind CURVE=tweetnacl
+       os: osx
 
 sudo: false
 
@@ -28,6 +31,7 @@ addons:
     packages:
     - cmake
     - lcov
+    - valgrind
 
 before_install:
 - if [ $TRAVIS_OS_NAME == "osx" ] ; then brew update; brew install binutils ; fi

builds/valgrind/ci_build.sh

@@ -0,0 +1,27 @@
+#!/usr/bin/env bash
+
+set -x
+
+mkdir tmp
+BUILD_PREFIX=$PWD/tmp
+
+CONFIG_OPTS=()
+CONFIG_OPTS+=("CFLAGS=-I${BUILD_PREFIX}/include")
+CONFIG_OPTS+=("CPPFLAGS=-I${BUILD_PREFIX}/include")
+CONFIG_OPTS+=("CXXFLAGS=-I${BUILD_PREFIX}/include")
+CONFIG_OPTS+=("LDFLAGS=-L${BUILD_PREFIX}/lib")
+CONFIG_OPTS+=("PKG_CONFIG_PATH=${BUILD_PREFIX}/lib/pkgconfig")
+CONFIG_OPTS+=("--prefix=${BUILD_PREFIX}")
+CONFIG_OPTS+=("--enable-valgrind")
+
+if [ -z $CURVE ]; then
+    CONFIG_OPTS+=("--disable-curve")
+elif [ $CURVE == "libsodium" ]; then
+    CONFIG_OPTS+=("--with-libsodium=yes")
+
+    git clone --depth 1 -b stable git://github.com/jedisct1/libsodium.git
+    ( cd libsodium; ./autogen.sh; ./configure --prefix=$BUILD_PREFIX; make install)
+fi
+
+# Build, check, and install from local source
+( cd ../..; ./autogen.sh && ./configure "${CONFIG_OPTS[@]}" && make -j5 && make VERBOSE=1 check-valgrind-memcheck) || exit 1