build: Generate asm_support_gen.h from the build, validate up-to-date

When building libart/libartd, also generate asm_support_gen.h
automatically. In addition, verify that our checked-in version
(runtime/generated/asm_support_gen.h) is up-to-date with what the build
generates.

Furthermore, add a presubmit hook that runs with 'repo upload'
that validates that the up-to-date version of asm_support_gen.h
is being uploaded to gerrit.

This makes it significantly more difficult to accidentally
merge a CL that doesn't have the auto-generated headers updated
and break the build as a result.

Bug: 34387670
Test: make libart libartd
Test: cd art && tools/repohooks/pre-upload.py
Change-Id: I1f0f94914d328c396906583d0732e281c076e69f

6 files changed, 186 insertions, 1 deletions

diff --git a/PREUPLOAD.cfg b/PREUPLOAD.cfg
new file mode 100644
index 0000000000..cf1832beb4
--- /dev/null
+++ b/PREUPLOAD.cfg
@@ -0,0 +1,2 @@
+[Hook Scripts]
+check_generated_files_up_to_date = tools/cpp-define-generator/presubmit-check-files-up-to-date
diff --git a/runtime/Android.bp b/runtime/Android.bp
index 5581810b4e..2bf8a76cdb 100644
--- a/runtime/Android.bp
+++ b/runtime/Android.bp
@@ -378,6 +378,10 @@ cc_defaults {
     },
     cflags: ["-DBUILDING_LIBART=1"],
     generated_sources: ["art_operator_srcs"],
+    // asm_support_gen.h (used by asm_support.h) is generated with cpp-define-generator
+    generated_headers: ["cpp-define-generator-asm-support"],
+    // export our headers so the libart-gtest targets can use it as well.
+    export_generated_headers: ["cpp-define-generator-asm-support"],
     clang: true,
     include_dirs: [
         "art/cmdline",
diff --git a/runtime/asm_support.h b/runtime/asm_support.h
index 46f2c08663..c7a94a90dc 100644
--- a/runtime/asm_support.h
+++ b/runtime/asm_support.h
@@ -72,7 +72,7 @@ ADD_TEST_EQ(static_cast<size_t>(1U << POINTER_SIZE_SHIFT),
 // Import platform-independent constant defines from our autogenerated list.
 // Export new defines (for assembly use) by editing cpp-define-generator def files.
 #define DEFINE_CHECK_EQ ADD_TEST_EQ
-#include "generated/asm_support_gen.h"
+#include "asm_support_gen.h"
 
 // Offset of field Thread::tlsPtr_.exception.
 #define THREAD_EXCEPTION_OFFSET (THREAD_CARD_TABLE_OFFSET + __SIZEOF_POINTER__)
diff --git a/tools/cpp-define-generator/Android.bp b/tools/cpp-define-generator/Android.bp
index d792e906ef..acb53a1ff9 100644
--- a/tools/cpp-define-generator/Android.bp
+++ b/tools/cpp-define-generator/Android.bp
@@ -34,3 +34,14 @@ art_cc_binary {
         "libbase",
     ],
 }
+
+// Note: See $OUT_DIR/soong/build.ninja
+// For the exact filename that this generates to run make command on just
+// this rule later.
+genrule {
+  name: "cpp-define-generator-asm-support",
+  out: ["asm_support_gen.h"],
+  tools: ["cpp-define-generator-data"],
+  tool_files: ["verify-asm-support"],
+  cmd: "$(location verify-asm-support) --quiet \"$(location cpp-define-generator-data)\" \"$(out)\""
+}
diff --git a/tools/cpp-define-generator/presubmit-check-files-up-to-date b/tools/cpp-define-generator/presubmit-check-files-up-to-date
new file mode 100755
index 0000000000..67a702adc7
--- /dev/null
+++ b/tools/cpp-define-generator/presubmit-check-files-up-to-date
@@ -0,0 +1,67 @@
+#!/bin/bash
+#
+# Copyright (C) 2017 The Android Open Source Project
+#
+# 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.
+
+# ---------------------------------------------------------------------------
+
+# Generates asm_support_gen.h into a temporary location.
+# Then verifies it is the same as our local stored copy.
+
+GEN_TOOL=cpp-define-generator-data
+
+if ! which "$GEN_TOOL"; then
+  echo "ERROR: Please build cpp-define-generator-data or source build/envsetup.sh" >&2
+  exit 1
+fi
+
+#######################
+#######################
+
+PREUPLOAD_COMMIT_COPY="$(mktemp ${TMPDIR:-/tmp}/tmp.XXXXXX)"
+BUILD_COPY="$(mktemp ${TMPDIR:-/tmp}/tmp.XXXXXX)"
+
+function finish() {
+  # Delete temp files.
+  [[ -f "$PREUPLOAD_COMMIT_COPY" ]] && rm "$PREUPLOAD_COMMIT_COPY"
+  [[ -f "$BUILD_COPY" ]] && rm "$BUILD_COPY"
+}
+trap finish EXIT
+
+DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+ART_DIR="$( cd "$DIR/../.." && pwd )"
+ASM_SUPPORT_GEN_CHECKED_IN_COPY="runtime/generated/asm_support_gen.h"
+
+# Repo upload hook runs inside of the top-level git directory.
+# If we run this script manually, be in the right place for git.
+cd "$ART_DIR"
+
+if [[ -z $PREUPLOAD_COMMIT ]]; then
+  echo "WARNING: Not running as a pre-upload hook. Assuming commit to check = 'HEAD'"
+  PREUPLOAD_COMMIT=HEAD
+fi
+
+# Get version we are about to push into git.
+git show "$PREUPLOAD_COMMIT:$ASM_SUPPORT_GEN_CHECKED_IN_COPY" > "$PREUPLOAD_COMMIT_COPY" || exit 1
+# Get version that our build would have made.
+"$GEN_TOOL" > "$BUILD_COPY" || exit 1
+
+if ! diff "$PREUPLOAD_COMMIT_COPY" "$BUILD_COPY"; then
+  echo "asm-support: ERROR: Checked-in copy of '$ASM_SUPPORT_GEN_CHECKED_IN_COPY' " >&2
+  echo "             has diverged from the build copy." >&2
+  echo "             Please re-run the 'generate-asm-support' command to resync the header." >&2
+  exit 1
+fi
+
+# Success. Print nothing to avoid spamming users.
diff --git a/tools/cpp-define-generator/verify-asm-support b/tools/cpp-define-generator/verify-asm-support
new file mode 100755
index 0000000000..745b1153c9
--- /dev/null
+++ b/tools/cpp-define-generator/verify-asm-support
@@ -0,0 +1,101 @@
+#!/bin/bash
+#
+# Copyright (C) 2017 The Android Open Source Project
+#
+# 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.
+
+# ---------------------------------------------------------------------------
+
+# Generates asm_support_gen.h into the $OUT directory in the build.
+# Then verifies that it is the same as in runtime/generated/asm_support_gen.h
+
+# Validates that art/runtime/generated/asm_support_gen.h
+# - This must be run after a build since it uses cpp-define-generator-data
+
+# Path to asm_support_gen.h that we check into our git repository.
+ASM_SUPPORT_GEN_CHECKED_IN_COPY="runtime/generated/asm_support_gen.h"
+# Instead of producing an error if checked-in copy differs from the generated version,
+# overwrite the local checked-in copy instead.
+OVERWRITE_CHECKED_IN_COPY_IF_CHANGED="n"
+
+#######################
+#######################
+
+DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+ART_DIR="$( cd "$DIR/../.." && pwd )"
+ABS_ASM_SUPPORT_GEN_CHECKED_IN_COPY="$ART_DIR/runtime/generated/asm_support_gen.h"
+
+# Sanity check that we haven't moved the file around.
+# If we did, perhaps the above constant should be updated.
+if ! [[ -f "$ABS_ASM_SUPPORT_GEN_CHECKED_IN_COPY" ]]; then
+  echo "ERROR: Missing asm_support_gen.h, expected to be in '$ABS_ASM_SUPPORT_GEN_CHECKED_IN_COPY'" >&2
+  exit 1
+fi
+
+# The absolute path to cpp-define-generator is in $1
+# Generate the file as part of the build into the out location specified by $2.
+
+# Compare that the generated file matches our golden copy that's checked into git.
+# If not, it is a fatal error and the user needs to run 'generate-asm-support' to rebuild.
+
+if [[ $# -lt 2 ]]; then
+  echo "Usage: $0 [--quiet] [--presubmit] <path-to-cpp-define-generator-data-binary> <output-file>'" >&2
+  exit 1
+fi
+
+# Supress 'chatty' messages during the build.
+# If anything is printed in a success case then
+# the main Android build can't reuse the same line for
+# showing multiple commands being executed.
+QUIET=false
+if [[ "$1" == "--quiet" ]]; then
+  QUIET=true
+  shift
+fi
+
+CPP_DEFINE_GENERATOR_TOOL="$1"
+OUTPUT_FILE="$2"
+
+function pecho() {
+  if ! $QUIET; then
+    echo "$@"
+  fi
+}
+
+# Generate the header. Print the command we're running to console for readability.
+pecho "cpp-define-generator-data > \"$OUTPUT_FILE\""
+"$CPP_DEFINE_GENERATOR_TOOL" > "$OUTPUT_FILE"
+retval="$?"
+
+if [[ $retval -ne 0 ]]; then
+  echo "verify-asm-support: FATAL: Error while running cpp-define-generator-data" >&2
+  exit $retval
+fi
+
+if ! diff "$ABS_ASM_SUPPORT_GEN_CHECKED_IN_COPY" "$OUTPUT_FILE"; then
+
+  if [[ $OVERWRITE_CHECKED_IN_COPY_IF_CHANGED == "y" ]]; then
+    cp "$OUTPUT_FILE" "$ABS_ASM_SUPPORT_GEN_CHECKED_IN_COPY"
+    echo "verify-asm-support: OK: Overwrote '$ASM_SUPPORT_GEN_CHECKED_IN_COPY' with build copy."
+    echo "                        Please 'git add $ASM_SUPPORT_GEN_CHECKED_IN_COPY'."
+  else
+    echo "---------------------------------------------------------------------------------------------" >&2
+    echo "verify-asm-support: ERROR: Checked-in copy of '$ASM_SUPPORT_GEN_CHECKED_IN_COPY' " >&2
+    echo "                    has diverged from the build copy." >&2
+    echo "                    Please re-run the 'generate-asm-support' command to resync the header." >&2
+    [[ -f "$OUTPUT_FILE" ]] && rm "$OUTPUT_FILE"
+    exit 1
+  fi
+fi
+
+pecho "verify-asm-support: SUCCESS. Built '$OUTPUT_FILE' which matches our checked in copy."