jemalloc: Import 5.3.0 54eaed1d8b56b1aa528be3bdd1877e59c56fa90cvendor/jemalloc/5.3.0vendor/jemalloc

Import jemalloc 5.3.0.

This import changes how manage the jemalloc vendor branch (which was
just started anyway). Starting with 5.3.0, we import a clean tree from
the upstream github, removing all the old files that are no longer
upstream, or that we've kept around for some reason. We do this because
we merge from this raw version of jemalloc into the FreeBSD
contrib/jemalloc, then we run autogen stuff, generate all the generated
.h files with gmake, then finally remove much of the generated files in
contrib/jemalloc using an update script.

Sponsored by:		Netflix

10 files changed, 469 insertions, 117 deletions

diff --git a/scripts/check-formatting.sh b/scripts/check-formatting.sh
new file mode 100755
index 000000000000..68cafd8e546e
--- /dev/null
+++ b/scripts/check-formatting.sh
@@ -0,0 +1,28 @@
+#!/bin/bash
+
+# The files that need to be properly formatted.  We'll grow this incrementally
+# until it includes all the jemalloc source files (as we convert things over),
+# and then just replace it with
+#    find -name '*.c' -o -name '*.h' -o -name '*.cpp
+FILES=(
+)
+
+if command -v clang-format &> /dev/null; then
+  CLANG_FORMAT="clang-format"
+elif command -v clang-format-8 &> /dev/null; then
+  CLANG_FORMAT="clang-format-8"
+else
+  echo "Couldn't find clang-format."
+fi
+
+if ! $CLANG_FORMAT -version | grep "version 8\." &> /dev/null; then
+  echo "clang-format is the wrong version."
+  exit 1
+fi
+
+for file in ${FILES[@]}; do
+  if ! cmp --silent $file <($CLANG_FORMAT $file) &> /dev/null; then
+    echo "Error: $file is not clang-formatted"
+    exit 1
+  fi
+done
diff --git a/scripts/freebsd/before_install.sh b/scripts/freebsd/before_install.sh
new file mode 100644
index 000000000000..f2bee321f73f
--- /dev/null
+++ b/scripts/freebsd/before_install.sh
@@ -0,0 +1,3 @@
+#!/bin/tcsh
+
+su -m root -c 'pkg install -y git'
diff --git a/scripts/freebsd/before_script.sh b/scripts/freebsd/before_script.sh
new file mode 100644
index 000000000000..29406f6fbbdf
--- /dev/null
+++ b/scripts/freebsd/before_script.sh
@@ -0,0 +1,10 @@
+#!/bin/tcsh
+
+autoconf
+# We don't perfectly track freebsd stdlib.h definitions.  This is fine when
+# we count as a system header, but breaks otherwise, like during these
+# tests.
+./configure --with-jemalloc-prefix=ci_ ${COMPILER_FLAGS:+ CC="$CC $COMPILER_FLAGS" CXX="$CXX $COMPILER_FLAGS"} $CONFIGURE_FLAGS
+JE_NCPUS=`sysctl -n kern.smp.cpus`
+gmake -j${JE_NCPUS}
+gmake -j${JE_NCPUS} tests
diff --git a/scripts/freebsd/script.sh b/scripts/freebsd/script.sh
new file mode 100644
index 000000000000..d9c53a201f5e
--- /dev/null
+++ b/scripts/freebsd/script.sh
@@ -0,0 +1,3 @@
+#!/bin/tcsh
+
+gmake check
diff --git a/scripts/gen_run_tests.py b/scripts/gen_run_tests.py
index a414f812a3a0..7c3075f9f6a6 100755
--- a/scripts/gen_run_tests.py
+++ b/scripts/gen_run_tests.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import sys
 from itertools import combinations
@@ -14,14 +14,14 @@ nparallel = cpu_count() * 2
 
 uname = uname()[0]
 
-if "BSD" in uname:
+if call("command -v gmake", shell=True) == 0:
     make_cmd = 'gmake'
 else:
     make_cmd = 'make'
 
 def powerset(items):
     result = []
-    for i in xrange(len(items) + 1):
+    for i in range(len(items) + 1):
         result += combinations(items, i)
     return result
 
@@ -41,6 +41,7 @@ possible_config_opts = [
     '--enable-prof',
     '--disable-stats',
     '--enable-opt-safety-checks',
+    '--with-lg-page=16',
 ]
 if bits_64:
     possible_config_opts.append('--with-lg-vaddr=56')
@@ -52,19 +53,20 @@ possible_malloc_conf_opts = [
     'background_thread:true',
 ]
 
-print 'set -e'
-print 'if [ -f Makefile ] ; then %(make_cmd)s relclean ; fi' % {'make_cmd': make_cmd}
-print 'autoconf'
-print 'rm -rf run_tests.out'
-print 'mkdir run_tests.out'
-print 'cd run_tests.out'
+print('set -e')
+print('if [ -f Makefile ] ; then %(make_cmd)s relclean ; fi' % {'make_cmd':
+    make_cmd})
+print('autoconf')
+print('rm -rf run_tests.out')
+print('mkdir run_tests.out')
+print('cd run_tests.out')
 
 ind = 0
 for cc, cxx in possible_compilers:
     for compiler_opts in powerset(possible_compiler_opts):
         for config_opts in powerset(possible_config_opts):
             for malloc_conf_opts in powerset(possible_malloc_conf_opts):
-                if cc is 'clang' \
+                if cc == 'clang' \
                   and '-m32' in possible_compiler_opts \
                   and '--enable-prof' in config_opts:
                     continue
@@ -79,9 +81,9 @@ for cc, cxx in possible_compilers:
                 )
 
                 # We don't want to test large vaddr spaces in 32-bit mode.
-		if ('-m32' in compiler_opts and '--with-lg-vaddr=56' in
-                  config_opts):
-		    continue
+                if ('-m32' in compiler_opts and '--with-lg-vaddr=56' in
+                    config_opts):
+                    continue
 
                 # Per CPU arenas are only supported on Linux.
                 linux_supported = ('percpu_arena:percpu' in malloc_conf_opts \
@@ -92,7 +94,7 @@ for cc, cxx in possible_compilers:
                 if (uname == 'Linux' and linux_supported) \
                   or (not linux_supported and (uname != 'Darwin' or \
                   not darwin_unsupported)):
-                    print """cat <<EOF > run_test_%(ind)d.sh
+                    print("""cat <<EOF > run_test_%(ind)d.sh
 #!/bin/sh
 
 set -e
@@ -120,7 +122,9 @@ run_cmd %(make_cmd)s all tests
 run_cmd %(make_cmd)s check
 run_cmd %(make_cmd)s distclean
 EOF
-chmod 755 run_test_%(ind)d.sh""" % {'ind': ind, 'config_line': config_line, 'make_cmd': make_cmd}
+chmod 755 run_test_%(ind)d.sh""" % {'ind': ind, 'config_line': config_line,
+      'make_cmd': make_cmd})
                     ind += 1
 
-print 'for i in `seq 0 %(last_ind)d` ; do echo run_test_${i}.sh ; done | xargs -P %(nparallel)d -n 1 sh' % {'last_ind': ind-1, 'nparallel': nparallel}
+print('for i in `seq 0 %(last_ind)d` ; do echo run_test_${i}.sh ; done | xargs'
+    ' -P %(nparallel)d -n 1 sh' % {'last_ind': ind-1, 'nparallel': nparallel})
diff --git a/scripts/gen_travis.py b/scripts/gen_travis.py
index f1478c62c2e4..4366a066eeab 100755
--- a/scripts/gen_travis.py
+++ b/scripts/gen_travis.py
@@ -1,149 +1,327 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
-from itertools import combinations
+from itertools import combinations, chain
+from enum import Enum, auto
 
-travis_template = """\
-language: generic
-dist: precise
 
-matrix:
+LINUX = 'linux'
+OSX = 'osx'
+WINDOWS = 'windows'
+FREEBSD = 'freebsd'
+
+
+AMD64 = 'amd64'
+ARM64 = 'arm64'
+PPC64LE = 'ppc64le'
+
+
+TRAVIS_TEMPLATE = """\
+# This config file is generated by ./scripts/gen_travis.py.
+# Do not edit by hand.
+
+# We use 'minimal', because 'generic' makes Windows VMs hang at startup. Also
+# the software provided by 'generic' is simply not needed for our tests.
+# Differences are explained here:
+# https://docs.travis-ci.com/user/languages/minimal-and-generic/
+language: minimal
+dist: focal
+
+jobs:
   include:
-%s
+{jobs}
+
+before_install:
+  - |-
+    if test -f "./scripts/$TRAVIS_OS_NAME/before_install.sh"; then
+      source ./scripts/$TRAVIS_OS_NAME/before_install.sh
+    fi
 
 before_script:
-  - autoconf
-  - scripts/gen_travis.py > travis_script && diff .travis.yml travis_script
-  - ./configure ${COMPILER_FLAGS:+ \
-      CC="$CC $COMPILER_FLAGS" \
-      CXX="$CXX $COMPILER_FLAGS" } \
-      $CONFIGURE_FLAGS
-  - make -j3
-  - make -j3 tests
+  - |-
+    if test -f "./scripts/$TRAVIS_OS_NAME/before_script.sh"; then
+      source ./scripts/$TRAVIS_OS_NAME/before_script.sh
+    else
+      scripts/gen_travis.py > travis_script && diff .travis.yml travis_script
+      autoconf
+      # If COMPILER_FLAGS are not empty, add them to CC and CXX
+      ./configure ${{COMPILER_FLAGS:+ CC="$CC $COMPILER_FLAGS" \
+CXX="$CXX $COMPILER_FLAGS"}} $CONFIGURE_FLAGS
+      make -j3
+      make -j3 tests
+    fi
 
 script:
-  - make check
+  - |-
+    if test -f "./scripts/$TRAVIS_OS_NAME/script.sh"; then
+      source ./scripts/$TRAVIS_OS_NAME/script.sh
+    else
+      make check
+    fi
 """
 
+
+class Option(object):
+    class Type:
+        COMPILER = auto()
+        COMPILER_FLAG = auto()
+        CONFIGURE_FLAG = auto()
+        MALLOC_CONF = auto()
+        FEATURE = auto()
+
+    def __init__(self, type, value):
+        self.type = type
+        self.value = value
+
+    @staticmethod
+    def as_compiler(value):
+        return Option(Option.Type.COMPILER, value)
+
+    @staticmethod
+    def as_compiler_flag(value):
+        return Option(Option.Type.COMPILER_FLAG, value)
+
+    @staticmethod
+    def as_configure_flag(value):
+        return Option(Option.Type.CONFIGURE_FLAG, value)
+
+    @staticmethod
+    def as_malloc_conf(value):
+        return Option(Option.Type.MALLOC_CONF, value)
+
+    @staticmethod
+    def as_feature(value):
+        return Option(Option.Type.FEATURE, value)
+
+    def __eq__(self, obj):
+        return (isinstance(obj, Option) and obj.type == self.type
+                and obj.value == self.value)
+
+
 # The 'default' configuration is gcc, on linux, with no compiler or configure
 # flags.  We also test with clang, -m32, --enable-debug, --enable-prof,
 # --disable-stats, and --with-malloc-conf=tcache:false.  To avoid abusing
 # travis though, we don't test all 2**7 = 128 possible combinations of these;
 # instead, we only test combinations of up to 2 'unusual' settings, under the
 # hope that bugs involving interactions of such settings are rare.
-# Things at once, for C(7, 0) + C(7, 1) + C(7, 2) = 29
 MAX_UNUSUAL_OPTIONS = 2
 
-os_default = 'linux'
-os_unusual = 'osx'
 
-compilers_default = 'CC=gcc CXX=g++'
-compilers_unusual = 'CC=clang CXX=clang++'
+GCC = Option.as_compiler('CC=gcc CXX=g++')
+CLANG = Option.as_compiler('CC=clang CXX=clang++')
+CL = Option.as_compiler('CC=cl.exe CXX=cl.exe')
+
 
-compiler_flag_unusuals = ['-m32']
+compilers_unusual = [CLANG,]
 
-configure_flag_unusuals = [
+
+CROSS_COMPILE_32BIT = Option.as_feature('CROSS_COMPILE_32BIT')
+feature_unusuals = [CROSS_COMPILE_32BIT]
+
+
+configure_flag_unusuals = [Option.as_configure_flag(opt) for opt in (
     '--enable-debug',
     '--enable-prof',
     '--disable-stats',
     '--disable-libdl',
     '--enable-opt-safety-checks',
-]
+    '--with-lg-page=16',
+)]
 
-malloc_conf_unusuals = [
+
+malloc_conf_unusuals = [Option.as_malloc_conf(opt) for opt in (
     'tcache:false',
     'dss:primary',
     'percpu_arena:percpu',
     'background_thread:true',
-]
+)]
 
-all_unusuals = (
-    [os_unusual] + [compilers_unusual] + compiler_flag_unusuals
-    + configure_flag_unusuals + malloc_conf_unusuals
-)
 
-unusual_combinations_to_test = []
-for i in xrange(MAX_UNUSUAL_OPTIONS + 1):
-    unusual_combinations_to_test += combinations(all_unusuals, i)
+all_unusuals = (compilers_unusual + feature_unusuals
+    + configure_flag_unusuals + malloc_conf_unusuals)
 
-gcc_multilib_set = False
-# Formats a job from a combination of flags
-def format_job(combination):
-    global gcc_multilib_set
 
-    os = os_unusual if os_unusual in combination else os_default
-    compilers = compilers_unusual if compilers_unusual in combination else compilers_default
+def get_extra_cflags(os, compiler):
+    if os == FREEBSD:
+        return []
+
+    if os == WINDOWS:
+        # For non-CL compilers under Windows (for now it's only MinGW-GCC),
+        # -fcommon needs to be specified to correctly handle multiple
+        # 'malloc_conf' symbols and such, which are declared weak under Linux.
+        # Weak symbols don't work with MinGW-GCC.
+        if compiler != CL.value:
+            return ['-fcommon']
+        else:
+            return []
+
+    # We get some spurious errors when -Warray-bounds is enabled.
+    extra_cflags = ['-Werror', '-Wno-array-bounds']
+    if compiler == CLANG.value or os == OSX:
+        extra_cflags += [
+            '-Wno-unknown-warning-option',
+            '-Wno-ignored-attributes'
+        ]
+    if os == OSX:
+        extra_cflags += [
+            '-Wno-deprecated-declarations',
+        ]
+    return extra_cflags
 
-    compiler_flags = [x for x in combination if x in compiler_flag_unusuals]
-    configure_flags = [x for x in combination if x in configure_flag_unusuals]
-    malloc_conf = [x for x in combination if x in malloc_conf_unusuals]
 
-    # Filter out unsupported configurations on OS X.
-    if os == 'osx' and ('dss:primary' in malloc_conf or \
-      'percpu_arena:percpu' in malloc_conf or 'background_thread:true' \
-      in malloc_conf):
-        return ""
+# Formats a job from a combination of flags
+def format_job(os, arch, combination):
+    compilers = [x.value for x in combination if x.type == Option.Type.COMPILER]
+    assert(len(compilers) <= 1)
+    compiler_flags = [x.value for x in combination if x.type == Option.Type.COMPILER_FLAG]
+    configure_flags = [x.value for x in combination if x.type == Option.Type.CONFIGURE_FLAG]
+    malloc_conf = [x.value for x in combination if x.type == Option.Type.MALLOC_CONF]
+    features = [x.value for x in combination if x.type == Option.Type.FEATURE]
+
     if len(malloc_conf) > 0:
-        configure_flags.append('--with-malloc-conf=' + ",".join(malloc_conf))
+        configure_flags.append('--with-malloc-conf=' + ','.join(malloc_conf))
 
-    # Filter out an unsupported configuration - heap profiling on OS X.
-    if os == 'osx' and '--enable-prof' in configure_flags:
-        return ""
+    if not compilers:
+        compiler = GCC.value
+    else:
+        compiler = compilers[0]
 
-    # We get some spurious errors when -Warray-bounds is enabled.
-    env_string = ('{} COMPILER_FLAGS="{}" CONFIGURE_FLAGS="{}" '
-	'EXTRA_CFLAGS="-Werror -Wno-array-bounds"').format(
-        compilers, " ".join(compiler_flags), " ".join(configure_flags))
-
-    job = ""
-    job += '    - os: %s\n' % os
-    job += '      env: %s\n' % env_string
-    if '-m32' in combination and os == 'linux':
-        job += '      addons:'
-        if gcc_multilib_set:
-            job += ' *gcc_multilib\n'
-        else:
-            job += ' &gcc_multilib\n'
-            job += '        apt:\n'
-            job += '          packages:\n'
-            job += '            - gcc-multilib\n'
-            gcc_multilib_set = True
+    extra_environment_vars = ''
+    cross_compile = CROSS_COMPILE_32BIT.value in features
+    if os == LINUX and cross_compile:
+        compiler_flags.append('-m32')
+
+    features_str = ' '.join([' {}=yes'.format(feature) for feature in features])
+
+    stringify = lambda arr, name: ' {}="{}"'.format(name, ' '.join(arr)) if arr else ''
+    env_string = '{}{}{}{}{}{}'.format(
+            compiler,
+            features_str,
+            stringify(compiler_flags, 'COMPILER_FLAGS'),
+            stringify(configure_flags, 'CONFIGURE_FLAGS'),
+            stringify(get_extra_cflags(os, compiler), 'EXTRA_CFLAGS'),
+            extra_environment_vars)
+
+    job = '    - os: {}\n'.format(os)
+    job += '      arch: {}\n'.format(arch)
+    job += '      env: {}'.format(env_string)
     return job
 
-include_rows = ""
-for combination in unusual_combinations_to_test:
-    include_rows += format_job(combination)
 
-# Development build
-include_rows += '''\
+def generate_unusual_combinations(unusuals, max_unusual_opts):
+    """
+    Generates different combinations of non-standard compilers, compiler flags,
+    configure flags and malloc_conf settings.
+
+    @param max_unusual_opts: Limit of unusual options per combination.
+    """
+    return chain.from_iterable(
+            [combinations(unusuals, i) for i in range(max_unusual_opts + 1)])
+
+
+def included(combination, exclude):
+    """
+    Checks if the combination of options should be included in the Travis
+    testing matrix.
+
+    @param exclude: A list of options to be avoided.
+    """
+    return not any(excluded in combination for excluded in exclude)
+
+
+def generate_jobs(os, arch, exclude, max_unusual_opts, unusuals=all_unusuals):
+    jobs = []
+    for combination in generate_unusual_combinations(unusuals, max_unusual_opts):
+        if included(combination, exclude):
+            jobs.append(format_job(os, arch, combination))
+    return '\n'.join(jobs)
+
+
+def generate_linux(arch):
+    os = LINUX
+
+    # Only generate 2 unusual options for AMD64 to reduce matrix size
+    max_unusual_opts = MAX_UNUSUAL_OPTIONS if arch == AMD64 else 1
+
+    exclude = []
+    if arch == PPC64LE:
+        # Avoid 32 bit builds and clang on PowerPC
+        exclude = (CROSS_COMPILE_32BIT, CLANG,)
+
+    return generate_jobs(os, arch, exclude, max_unusual_opts)
+
+
+def generate_macos(arch):
+    os = OSX
+
+    max_unusual_opts = 1
+
+    exclude = ([Option.as_malloc_conf(opt) for opt in (
+            'dss:primary',
+            'percpu_arena:percpu',
+            'background_thread:true')] +
+        [Option.as_configure_flag('--enable-prof')] +
+        [CLANG,])
+
+    return generate_jobs(os, arch, exclude, max_unusual_opts)
+
+
+def generate_windows(arch):
+    os = WINDOWS
+
+    max_unusual_opts = 3
+    unusuals = (
+        Option.as_configure_flag('--enable-debug'),
+        CL,
+        CROSS_COMPILE_32BIT,
+    )
+    return generate_jobs(os, arch, (), max_unusual_opts, unusuals)
+
+
+def generate_freebsd(arch):
+    os = FREEBSD
+
+    max_unusual_opts = 4
+    unusuals = (
+        Option.as_configure_flag('--enable-debug'),
+        Option.as_configure_flag('--enable-prof --enable-prof-libunwind'),
+        Option.as_configure_flag('--with-lg-page=16 --with-malloc-conf=tcache:false'),
+        CROSS_COMPILE_32BIT,
+    )
+    return generate_jobs(os, arch, (), max_unusual_opts, unusuals)
+
+
+
+def get_manual_jobs():
+    return """\
     # Development build
     - os: linux
-      env: CC=gcc CXX=g++ COMPILER_FLAGS="" CONFIGURE_FLAGS="--enable-debug --disable-cache-oblivious --enable-stats --enable-log --enable-prof" EXTRA_CFLAGS="-Werror -Wno-array-bounds"
-'''
-
-# Enable-expermental-smallocx
-include_rows += '''\
+      env: CC=gcc CXX=g++ CONFIGURE_FLAGS="--enable-debug \
+--disable-cache-oblivious --enable-stats --enable-log --enable-prof" \
+EXTRA_CFLAGS="-Werror -Wno-array-bounds"
     # --enable-expermental-smallocx:
     - os: linux
-      env: CC=gcc CXX=g++ COMPILER_FLAGS="" CONFIGURE_FLAGS="--enable-debug --enable-experimental-smallocx --enable-stats --enable-prof" EXTRA_CFLAGS="-Werror -Wno-array-bounds"
-'''
+      env: CC=gcc CXX=g++ CONFIGURE_FLAGS="--enable-debug \
+--enable-experimental-smallocx --enable-stats --enable-prof" \
+EXTRA_CFLAGS="-Werror -Wno-array-bounds"
+"""
 
-# Valgrind build bots
-include_rows += '''
-    # Valgrind
-    - os: linux
-      env: CC=gcc CXX=g++ COMPILER_FLAGS="" CONFIGURE_FLAGS="" EXTRA_CFLAGS="-Werror -Wno-array-bounds" JEMALLOC_TEST_PREFIX="valgrind"
-      addons:
-        apt:
-          packages:
-            - valgrind
-'''
-
-# To enable valgrind on macosx add:
-#
-#  - os: osx
-#    env: CC=gcc CXX=g++ COMPILER_FLAGS="" CONFIGURE_FLAGS="" EXTRA_CFLAGS="-Werror -Wno-array-bounds" JEMALLOC_TEST_PREFIX="valgrind"
-#    install: brew install valgrind
-#
-# It currently fails due to: https://github.com/jemalloc/jemalloc/issues/1274
-
-print travis_template % include_rows
+
+def main():
+    jobs = '\n'.join((
+        generate_windows(AMD64),
+
+        generate_freebsd(AMD64),
+
+        generate_linux(AMD64),
+        generate_linux(PPC64LE),
+
+        generate_macos(AMD64),
+
+        get_manual_jobs(),
+    ))
+
+    print(TRAVIS_TEMPLATE.format(jobs=jobs))
+
+
+if __name__ == '__main__':
+    main()
diff --git a/scripts/linux/before_install.sh b/scripts/linux/before_install.sh
new file mode 100644
index 000000000000..674174639ea9
--- /dev/null
+++ b/scripts/linux/before_install.sh
@@ -0,0 +1,13 @@
+#!/bin/bash
+
+set -ev
+
+if [[ "$TRAVIS_OS_NAME" != "linux" ]]; then
+    echo "Incorrect \$TRAVIS_OS_NAME: expected linux, got $TRAVIS_OS_NAME"
+    exit 1
+fi
+
+if [[ "$CROSS_COMPILE_32BIT" == "yes" ]]; then
+    sudo apt-get update
+    sudo apt-get -y install gcc-multilib g++-multilib
+fi
diff --git a/scripts/windows/before_install.sh b/scripts/windows/before_install.sh
new file mode 100644
index 000000000000..2740c4588d61
--- /dev/null
+++ b/scripts/windows/before_install.sh
@@ -0,0 +1,83 @@
+#!/bin/bash
+
+set -e
+
+# The purpose of this script is to install build dependencies and set
+# $build_env to a function that sets appropriate environment variables,
+# to enable (mingw32|mingw64) environment if we want to compile with gcc, or
+# (mingw32|mingw64) + vcvarsall.bat if we want to compile with cl.exe
+
+if [[ "$TRAVIS_OS_NAME" != "windows" ]]; then
+    echo "Incorrect \$TRAVIS_OS_NAME: expected windows, got $TRAVIS_OS_NAME"
+    exit 1
+fi
+
+[[ ! -f C:/tools/msys64/msys2_shell.cmd ]] && rm -rf C:/tools/msys64
+choco uninstall -y mingw
+choco upgrade --no-progress -y msys2
+
+msys_shell_cmd="cmd //C RefreshEnv.cmd && set MSYS=winsymlinks:nativestrict && C:\\tools\\msys64\\msys2_shell.cmd"
+
+msys2() { $msys_shell_cmd -defterm -no-start -msys2 -c "$*"; }
+mingw32() { $msys_shell_cmd -defterm -no-start -mingw32 -c "$*"; }
+mingw64() { $msys_shell_cmd -defterm -no-start -mingw64 -c "$*"; }
+
+if [[ "$CROSS_COMPILE_32BIT" == "yes" ]]; then
+    mingw=mingw32
+    mingw_gcc_package_arch=i686
+else
+    mingw=mingw64
+    mingw_gcc_package_arch=x86_64
+fi
+
+if [[ "$CC" == *"gcc"* ]]; then
+    $mingw pacman -S --noconfirm --needed \
+        autotools \
+        git \
+        mingw-w64-${mingw_gcc_package_arch}-make \
+	    mingw-w64-${mingw_gcc_package_arch}-gcc \
+	    mingw-w64-${mingw_gcc_package_arch}-binutils
+    build_env=$mingw
+elif [[ "$CC" == *"cl"* ]]; then
+    $mingw pacman -S --noconfirm --needed \
+        autotools \
+	    git \
+	    mingw-w64-${mingw_gcc_package_arch}-make \
+	    mingw-w64-${mingw_gcc_package_arch}-binutils
+
+    # In order to use MSVC compiler (cl.exe), we need to correctly set some environment
+    # variables, namely PATH, INCLUDE, LIB and LIBPATH. The correct values of these
+    # variables are set by a batch script "vcvarsall.bat". The code below generates
+    # a batch script that calls "vcvarsall.bat" and prints the environment variables.
+    #
+    # Then, those environment variables are transformed from cmd to bash format and put
+    # into a script $apply_vsenv. If cl.exe needs to be used from bash, one can
+    # 'source $apply_vsenv' and it will apply the environment variables needed for cl.exe
+    # to be located and function correctly.
+    #
+    # At last, a function "mingw_with_msvc_vars" is generated which forwards user input
+    # into a correct mingw (32 or 64) subshell that automatically performs 'source $apply_vsenv',
+    # making it possible for autotools to discover and use cl.exe.
+    vcvarsall="vcvarsall.tmp.bat"
+    echo "@echo off" > $vcvarsall
+    echo "call \"c:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\\\vcvarsall.bat\" $USE_MSVC" >> $vcvarsall
+    echo "set" >> $vcvarsall
+
+    apply_vsenv="./apply_vsenv.sh"
+    cmd //C $vcvarsall | grep -E "^PATH=" | sed -n -e 's/\(.*\)=\(.*\)/export \1=$PATH:"\2"/g' \
+        -e 's/\([a-zA-Z]\):[\\\/]/\/\1\//g' \
+        -e 's/\\/\//g' \
+        -e 's/;\//:\//gp' > $apply_vsenv
+    cmd //C $vcvarsall | grep -E "^(INCLUDE|LIB|LIBPATH)=" | sed -n -e 's/\(.*\)=\(.*\)/export \1="\2"/gp' >> $apply_vsenv
+
+    cat $apply_vsenv
+    mingw_with_msvc_vars() { $msys_shell_cmd -defterm -no-start -$mingw -c "source $apply_vsenv && ""$*"; }
+    build_env=mingw_with_msvc_vars
+
+    rm -f $vcvarsall
+else
+    echo "Unknown C compiler: $CC"
+    exit 1
+fi
+
+echo "Build environment function: $build_env"
diff --git a/scripts/windows/before_script.sh b/scripts/windows/before_script.sh
new file mode 100644
index 000000000000..9d30ababd933
--- /dev/null
+++ b/scripts/windows/before_script.sh
@@ -0,0 +1,20 @@
+#!/bin/bash
+
+set -e
+
+if [[ "$TRAVIS_OS_NAME" != "windows" ]]; then
+    echo "Incorrect \$TRAVIS_OS_NAME: expected windows, got $TRAVIS_OS_NAME"
+    exit 1
+fi
+
+$build_env autoconf
+$build_env ./configure $CONFIGURE_FLAGS
+# mingw32-make simply means "make", unrelated to mingw32 vs mingw64.
+# Simply disregard the prefix and treat is as "make".
+$build_env mingw32-make -j3
+# At the moment, it's impossible to make tests in parallel,
+# seemingly due to concurrent writes to '.pdb' file. I don't know why
+# that happens, because we explicitly supply '/Fs' to the compiler.
+# Until we figure out how to fix it, we should build tests sequentially
+# on Windows.
+$build_env mingw32-make tests
diff --git a/scripts/windows/script.sh b/scripts/windows/script.sh
new file mode 100644
index 000000000000..3a27f70aa517
--- /dev/null
+++ b/scripts/windows/script.sh
@@ -0,0 +1,10 @@
+#!/bin/bash
+
+set -e
+
+if [[ "$TRAVIS_OS_NAME" != "windows" ]]; then
+    echo "Incorrect \$TRAVIS_OS_NAME: expected windows, got $TRAVIS_OS_NAME"
+    exit 1
+fi
+
+$build_env mingw32-make -k check