build_windows_jni.sh: move file to subdirectory

The script more logically belongs in
src/main/native/windows than in src/main/native.

Also move the //src/main/native:windows_jni rule
into //src/main/native/windows:windows_jni, so the
logic of building the JNI library is fully
contained in that package.

Change-Id: I96e19003932cc0ddc5af3471b0b31a1aec09b8fa
PiperOrigin-RevId: 160876594

2 files changed, 117 insertions, 11 deletions

diff --git a/src/main/native/windows/BUILD b/src/main/native/windows/BUILD
index c7dead2469..926643c878 100644
--- a/src/main/native/windows/BUILD
+++ b/src/main/native/windows/BUILD
@@ -6,8 +6,8 @@ filegroup(
     visibility = ["//src/main/native:__pkg__"],
 )
 
-# TODO(xingao): verify that this filegroup contains exactly what it has to wrt.
-# where it is used (//src/main/native:embedded_tools).
+# TODO(xingao): verify that this filegroup contains exactly what it has to, with
+# regard to where it is used (//src/main/native:embedded_tools).
 # Context: https://github.com/bazelbuild/bazel/commit/33d05f6b551cf2fdb257cb536a5e864d095144a1
 filegroup(
     name = "embedded_tools",
@@ -15,15 +15,6 @@ filegroup(
     visibility = ["//src/main/native:__pkg__"],
 )
 
-filegroup(
-    name = "raw-sources",
-    srcs = glob([
-        "*.cc",
-        "*.h",
-    ]),
-    visibility = ["//src/main/native:__pkg__"],
-)
-
 cc_library(
     name = "lib-file",
     srcs = ["file.cc"],
@@ -41,3 +32,18 @@ cc_library(
     srcs = ["util.cc"],
     hdrs = ["util.h"],
 )
+
+genrule(
+    name = "windows_jni",
+    srcs = glob([
+        "*.cc",
+        "*.h",
+    ]),
+    outs = ["windows_jni.dll"],
+    cmd = "$(location build_windows_jni.sh) $@ $(SRCS)",
+    tools = ["build_windows_jni.sh"],
+    visibility = [
+        "//src:__pkg__",
+        "//src/test/java/com/google/devtools/build/lib:__subpackages__",
+    ],
+)
diff --git a/src/main/native/windows/build_windows_jni.sh b/src/main/native/windows/build_windows_jni.sh
new file mode 100755
index 0000000000..a66267814a
--- /dev/null
+++ b/src/main/native/windows/build_windows_jni.sh
@@ -0,0 +1,100 @@
+#!/bin/bash -eu
+
+# Copyright 2016 The Bazel Authors. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# It's not a good idea to link an MSYS dynamic library into a native Windows
+# JVM, so we need to build it with Visual Studio. However, Bazel doesn't
+# support multiple compilers in the same build yet, so we need to hack around
+# this limitation using a genrule.
+
+DLL="$1"
+shift 1
+
+function fail() {
+  echo >&2 "ERROR: $@"
+  exit 1
+}
+
+# Ensure the PATH is set up correctly.
+if ! which which >&/dev/null ; then
+  PATH="/bin:/usr/bin:$PATH"
+  which which >&/dev/null \
+      || fail "System PATH is not set up correctly, cannot run GNU bintools"
+fi
+
+# Create a temp directory. It will used for the batch file we generate soon and
+# as the temp directory for CL.EXE .
+VSTEMP=$(mktemp -d)
+trap "rm -fr \"$VSTEMP\"" EXIT
+
+# Find Visual Studio. We don't have any regular environment variables available
+# so this is the best we can do.
+if [ -z "${BAZEL_VS+set}" ]; then
+  VSVERSION="$(ls "C:/Program Files (x86)" \
+      | grep -E "Microsoft Visual Studio [0-9]+" \
+      | sort --version-sort \
+      | tail -n 1)"
+  [[ -n "$VSVERSION" ]] || fail "Visual Studio not found"
+  BAZEL_VS="C:/Program Files (x86)/$VSVERSION"
+fi
+VSVARS="${BAZEL_VS}/VC/VCVARSALL.BAT"
+
+# Check if Visual Studio 2017 is installed. Look for it at the default
+# locations.
+if [ ! -f "${VSVARS}" ]; then
+  VSVARS="C:/Program Files (x86)/Microsoft Visual Studio/2017/"
+  VSEDITION="BuildTools"
+  if [ -d "${VSVARS}Enterprise" ]; then
+    VSEDITION="Enterprise"
+  elif [ -d "${VSVARS}Professional" ]; then
+    VSEDITION="Professional"
+  elif [ -d "${VSVARS}Community" ]; then
+    VSEDITION="Community"
+  fi
+  VSVARS+="$VSEDITION/VC/Auxiliary/Build/VCVARSALL.BAT"
+fi
+
+if [ ! -f "${VSVARS}" ]; then
+  fail "VCVARSALL.bat not found, check your Visual Studio installation"
+fi
+
+# Find Java. $(JAVA) in the BUILD file points to external/local_jdk/..., which
+# is not very useful for anything not MSYS-based.
+JAVA=$(ls "C:/Program Files/java" | grep -E "^jdk" | sort | tail -n 1)
+[[ -n "$JAVA" ]] || fail "JDK not found"
+JAVAINCLUDES="C:/Program Files/java/$JAVA/include"
+
+# Convert all compilation units to Windows paths.
+WINDOWS_SOURCES=()
+for i in $*; do
+  if [[ "$i" =~ ^.*\.cc$ ]]; then
+    WINDOWS_SOURCES+=("\"$(cygpath -a -w $i)\"")
+  fi
+done
+
+# CL.EXE needs a bunch of environment variables whose official location is a
+# batch file. We can't make that have an effect on a bash instance, so
+# generate a batch file that invokes it.
+cat > "${VSTEMP}/windows_jni.bat" <<EOF
+@echo OFF
+@call "${VSVARS}" amd64
+@cd $(cygpath -a -w "${PWD}")
+@set TMP=$(cygpath -a -w "${VSTEMP}")
+@CL /O2 /EHsc /LD /Fe:"$(cygpath -a -w ${DLL})" /I "${JAVAINCLUDES}" /I "${JAVAINCLUDES}/win32" /I . ${WINDOWS_SOURCES[*]}
+EOF
+
+# Invoke the file and hopefully generate the .DLL .
+chmod +x "${VSTEMP}/windows_jni.bat"
+exec "${VSTEMP}/windows_jni.bat"