Add option to optionally wipe state at the end of a build.

This will serve as an alternative to --batch, leaving behind a server without state from the previous build.

RELNOTES: Introduces --[no]keep_state_after_build
PiperOrigin-RevId: 182778500

4 files changed, 134 insertions, 8 deletions

diff --git a/src/test/shell/integration/BUILD b/src/test/shell/integration/BUILD
index 37a19332ce..95f6498193 100644
--- a/src/test/shell/integration/BUILD
+++ b/src/test/shell/integration/BUILD
@@ -230,6 +230,16 @@ sh_test(
 )
 
 sh_test(
+    name = "nonincremental_builds_test",
+    size = "medium",
+    srcs = ["nonincremental_builds_test.sh"],
+    data = [
+        ":discard_graph_edges_lib.sh",
+        ":test-deps",
+    ],
+)
+
+sh_test(
     name = "build_event_stream_test",
     size = "medium",
     srcs = ["build_event_stream_test.sh"],
diff --git a/src/test/shell/integration/discard_graph_edges_lib.sh b/src/test/shell/integration/discard_graph_edges_lib.sh
index af51665fb3..88a6c4783f 100644
--- a/src/test/shell/integration/discard_graph_edges_lib.sh
+++ b/src/test/shell/integration/discard_graph_edges_lib.sh
@@ -36,17 +36,23 @@ function run_test_actions_deleted_after_execution() {
   readonly local extra_build_arg="$4"
   rm -rf histodump
   mkdir -p histodump || fail "Couldn't create directory"
-  readonly local wait_fifo="$TEST_TMPDIR/wait_fifo"
-  readonly local exec_fifo="$TEST_TMPDIR/exec_fifo"
   readonly local server_pid_file="$TEST_TMPDIR/server_pid.txt"
+  # Use fifo objects to block the execution phase of the dummy build.
+  readonly local exec_has_started_fifo="$TEST_TMPDIR/exec_fifo"
+  readonly local unblock_exec_fifo="$TEST_TMPDIR/wait_fifo"
+
+  # Create the chain of four genrules, using fifos to block execution
   cat > histodump/BUILD <<EOF || fail "Couldn't create BUILD file"
 genrule(name = 'action0',
         outs = ['wait.out'],
         local = 1,
-        cmd = 'echo "" > $exec_fifo; cat $wait_fifo > /dev/null; touch \$@'
+        cmd = 'echo "" > $exec_has_started_fifo; ' +
+              'cat $unblock_exec_fifo > /dev/null; ' +
+              'touch \$@'
         )
 EOF
   for i in $(seq 1 3); do
+    # Outputs a histogram of the server's memory, logging failures.
     iminus=$((i-1))
     cat >> histodump/BUILD <<EOF || fail "Couldn't append"
 genrule(name = 'action${i}',
@@ -63,7 +69,8 @@ genrule(name = 'action${i}',
        )
 EOF
   done
-  mkfifo "$wait_fifo" "$exec_fifo"
+
+  mkfifo "$unblock_exec_fifo" "$exec_has_started_fifo"
   local readonly histo_root="$("$product" info \
       "${PRODUCT_NAME:-$product}-genfiles" 2> /dev/null)/histodump/histo."
   "$product" clean >& "$TEST_log" || fail "Couldn't clean"
@@ -72,7 +79,10 @@ EOF
   "$product" $STARTUP_FLAGS build --show_timestamps $BUILD_FLAGS \
       $extra_build_arg //histodump:action3 >> "$TEST_log" 2>&1 &
   subshell_pid="$!"
-  cat "$exec_fifo" > /dev/null
+  # We will only get past the following line once execution has started,
+  # at which point we can look for the pid.
+  cat "$exec_has_started_fifo" > /dev/null
+
   # We plan to remove batch mode from the relevant flags for discarding
   # incrementality state. In the interim, tests that are not in batch mode
   # explicitly pass --nobatch, so we can use it as a signal.
@@ -89,9 +99,12 @@ EOF
   echo "$server_pid" > "$server_pid_file"
   echo "Finished writing pid to fifo at " >> "$TEST_log"
   date >> "$TEST_log"
-  echo "" > "$wait_fifo"
-  # Wait for previous command to finish.
+
+  # Now that all of the above is finished, unblock the execution of action0
+  echo "" > "$unblock_exec_fifo"
+  # Wait for the build to finish.
   wait "$subshell_pid" || fail "Bazel command failed"
+
   local genrule_action_count=100
   for i in $(seq 1 3); do
     local histo_file="$histo_root$i"
diff --git a/src/test/shell/integration/discard_graph_edges_test.sh b/src/test/shell/integration/discard_graph_edges_test.sh
index 0ec8559979..b64a62b8b2 100755
--- a/src/test/shell/integration/discard_graph_edges_test.sh
+++ b/src/test/shell/integration/discard_graph_edges_test.sh
@@ -434,7 +434,7 @@ function test_warns_on_unexpected_combos() {
   expect_log "--batch and --discard_analysis_cache specified, but --notrack_incremental_state not specified"
   bazel build --nobuild --discard_analysis_cache --notrack_incremental_state \
       >& "$TEST_log" || fail "Expected success"
-  expect_log "--batch not specified with --notrack_incremental_state"
+  expect_log "--notrack_incremental_state was specified, but without --nokeep_state_after_build."
 }
 
 run_suite "test for --discard_graph_edges"
diff --git a/src/test/shell/integration/nonincremental_builds_test.sh b/src/test/shell/integration/nonincremental_builds_test.sh
new file mode 100755
index 0000000000..56caa676ac
--- /dev/null
+++ b/src/test/shell/integration/nonincremental_builds_test.sh
@@ -0,0 +1,103 @@
+#!/bin/bash
+#
+# Copyright 2018 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.
+#
+# nonincremental_builds_test.sh: tests for the --keep_state_after_build flag.
+CURRENT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+source "${CURRENT_DIR}/../integration_test_setup.sh" \
+  || { echo "integration_test_setup.sh not found!" >&2; exit 1; }
+source "${CURRENT_DIR}/discard_graph_edges_lib.sh" \
+  || { echo "${CURRENT_DIR}/discard_graph_edges_lib.sh not found!" >&2; exit 1; }
+
+#### SETUP #############################################################
+set -e
+
+function tear_down() {
+    bazel shutdown || fail "Failed to shut down bazel"
+}
+
+#### TESTS #############################################################
+function create_minimal_target() {
+    rm -rf simpletarget
+    mkdir simpletarget
+    cat > simpletarget/BUILD <<EOF || fail "Couldn't make BUILD file"
+genrule(
+    name = 'top',
+    outs = ['final.out'],
+    local = 1,
+    cmd = 'touch \$@'
+)
+EOF
+    INCREMENTAL_ANALYSIS_LOGLINE="Analysed target //simpletarget:top (0 packages loaded)"
+    NONINCREMENTAL_ANALYSIS_LOGLINE="Analysed target //simpletarget:top ([1-9][0-9]* packages loaded)"
+}
+
+# Test that the execution is not repeated, test to validate the test case
+# for the nonincremental test below.
+function test_build_is_incremental_with_keep_state() {
+    create_minimal_target
+    bazel build simpletarget:top &> "$TEST_log"  \
+        || fail "Couldn't build simpletarget"
+    expect_log_once $NONINCREMENTAL_ANALYSIS_LOGLINE \
+        "First build expected to execute the target."
+
+    bazel build simpletarget:top &> "$TEST_log"  \
+        || fail "Couldn't build simpletarget"
+    expect_log_once $INCREMENTAL_ANALYSIS_LOGLINE \
+        "Second build not expected to reexecute."
+}
+
+# Test that the execution is actually repeated, indirect test that the state
+# was not reused.
+function test_build_is_nonincremental_with_nokeep_state() {
+    create_minimal_target
+    bazel build --nokeep_state_after_build simpletarget:top &> "$TEST_log"  \
+        || fail "Couldn't build simpletarget"
+    expect_log_once $NONINCREMENTAL_ANALYSIS_LOGLINE \
+        "First build expected to execute the target."
+
+    bazel build simpletarget:top &> "$TEST_log"  \
+        || fail "Couldn't build simpletarget"
+    expect_log_once $NONINCREMENTAL_ANALYSIS_LOGLINE \
+        "Second build should not use the cached state."
+}
+
+# Test directly that the inmemory state does persist after the build by default.
+function test_inmemory_state_present_after_build() {
+    create_minimal_target
+    bazel build simpletarget:top &> "$TEST_log"  \
+        || fail "Couldn't build simpletarget"
+    local server_pid="$(bazel info server_pid 2>> "$TEST_log")"
+    "$bazel_javabase"/bin/jmap -histo:live "$server_pid" > histo.txt
+
+    cat histo.txt >> "$TEST_log"
+    assert_contains "GenRuleAction" histo.txt
+    assert_contains "InMemoryNodeEntry" histo.txt
+}
+
+# Test directly that the inmemory state does not persist after the build.
+function test_inmemory_state_absent_after_build_with_nokeep_state() {
+    create_minimal_target
+    bazel build --nokeep_state_after_build simpletarget:top &> "$TEST_log"  \
+        || fail "Couldn't build simpletarget"
+    local server_pid="$(bazel info server_pid 2>> "$TEST_log")"
+    "$bazel_javabase"/bin/jmap -histo:live "$server_pid" > histo.txt
+
+    cat histo.txt >> "$TEST_log"
+    assert_not_contains "GenRuleAction" histo.txt
+    assert_not_contains "InMemoryNodeEntry" histo.txt
+}
+
+run_suite "test for --keep_state_after_build"