Add a test verifying that reconstructed executables are usable

... ensuring we do not regress on the recently fixed race that allowed
file descriptors to reconstructed executables to be kept alive.

2 files changed, 167 insertions, 1 deletions

diff --git a/test/end-to-end/gc/TARGETS b/test/end-to-end/gc/TARGETS
index 34fc869a..104ef360 100644
--- a/test/end-to-end/gc/TARGETS
+++ b/test/end-to-end/gc/TARGETS
@@ -22,9 +22,25 @@
   , "test": ["tc-deps.sh"]
   , "deps": [["", "tool-under-test"], ["", "mr-tool-under-test"]]
   }
+, "reconstruct-executable":
+  { "type": ["@", "rules", "shell/test", "script"]
+  , "name": ["reconstruct-executable"]
+  , "test": ["reconstruct-executable.sh"]
+  , "deps": [["", "tool-under-test"], ["", "mr-tool-under-test"]]
+  }
 , "TESTS":
   { "type": "install"
   , "tainted": ["test"]
-  , "deps": ["basic", "compactification", "export", "tc-deps"]
+  , "deps":
+    { "type": "++"
+    , "$1":
+      [ ["basic", "compactification", "export", "tc-deps"]
+      , { "type": "if"
+        , "cond": {"type": "var", "name": "TEST_BOOTSTRAP_JUST_MR"}
+        , "then": []
+        , "else": ["reconstruct-executable"]
+        }
+      ]
+    }
   }
 }
diff --git a/test/end-to-end/gc/reconstruct-executable.sh b/test/end-to-end/gc/reconstruct-executable.sh
new file mode 100644
index 00000000..3ece44a9
--- /dev/null
+++ b/test/end-to-end/gc/reconstruct-executable.sh
@@ -0,0 +1,150 @@
+#!/bin/sh
+# Copyright 2024 Huawei Cloud Computing Technology Co., Ltd.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+set -eu
+
+readonly JUST="${PWD}/bin/tool-under-test"
+readonly LBR="${TEST_TMPDIR}/local-build-root"
+readonly JUST_MR="${PWD}/bin/mr-tool-under-test"
+readonly JUST_MR_ARGS="--norc --local-build-root ${LBR} --just ${JUST}"
+
+mkdir repo
+cd repo
+touch ROOT
+cat > repos.json <<'EOF'
+{"repositories": {"": {"repository": {"type": "file", "path": "."}}}}
+EOF
+
+cat > generate-data.py <<'EOF'
+#!/usr/bin/env python3
+
+# Generates a C source file where we know the binary
+# will be larger than the compactification threshold, as
+# it contains enough data embedded.
+
+import random
+import sys
+
+count = 4 * 1024 * 1024
+
+random.seed(sys.argv[1])
+
+print("#include <stdio.h>")
+print("int main(int argc, char **argv) {")
+print("   char data[%d] = {" % (count+1,))
+bytes_to_embed = random.randbytes(count);
+for c in bytes_to_embed:
+    print("        '\\x%02x'," %(c,))
+print("        '\\x00'};");
+print("    int i;")
+print("    for (i=0; i < %d; i++) {" % (count,));
+print("      printf(\"%c\", data[i]);")
+print("    }")
+print("    return 0;")
+print("}")
+EOF
+chmod 755 generate-data.py
+
+# The default target depends on many large binaries that need to be run
+cat > TARGETS <<'EOF'
+{ "source":
+  { "type": "generic"
+  , "arguments_config": ["SEED"]
+  , "outs": ["src.c"]
+  , "deps": ["generate-data.py"]
+  , "cmds":
+    [ { "type": "join"
+      , "$1":
+        [ { "type": "join_cmd"
+          , "$1": ["./generate-data.py", {"type": "var", "name": "SEED"}]
+          }
+        , "> src.c"
+        ]
+      }
+    ]
+  }
+, "binary":
+  { "type": "generic"
+  , "outs": ["generate"]
+  , "deps": ["source"]
+  , "cmds": ["cc -o generate src.c"]
+  }
+, "data":
+  { "type": "generic"
+  , "outs": ["data"]
+  , "deps": ["binary"]
+  , "cmds": ["./generate > data"]
+  }
+, "aaa":
+  { "type": "configure"
+  , "target": "data"
+  , "config": {"type": "singleton_map", "key": "SEED", "value": "aaa"}
+  }
+, "bbb":
+  { "type": "configure"
+  , "target": "data"
+  , "config": {"type": "singleton_map", "key": "SEED", "value": "bbb"}
+  }
+, "ccc":
+  { "type": "configure"
+  , "target": "data"
+  , "config": {"type": "singleton_map", "key": "SEED", "value": "ccc"}
+  }
+, "ddd":
+  { "type": "configure"
+  , "target": "data"
+  , "config": {"type": "singleton_map", "key": "SEED", "value": "ddd"}
+  }
+, "eee":
+  { "type": "configure"
+  , "target": "data"
+  , "config": {"type": "singleton_map", "key": "SEED", "value": "eee"}
+  }
+, "fff":
+  { "type": "configure"
+  , "target": "data"
+  , "config": {"type": "singleton_map", "key": "SEED", "value": "fff"}
+  }
+, "":
+  { "type": "install"
+  , "files":
+    { "aaa": "aaa"
+    , "bbb": "bbb"
+    , "ccc": "ccc"
+    , "ddd": "ddd"
+    , "eee": "eee"
+    , "fff": "fff"
+    }
+  }
+}
+EOF
+
+# First we build all the relevant binaries to have them in test
+"${JUST_MR}" ${JUST_MR_ARGS} build -L '["env", "PATH='"${PATH}"'"]' -D '{"SEED": "aaa"}' binary 2>&1
+"${JUST_MR}" ${JUST_MR_ARGS} build -L '["env", "PATH='"${PATH}"'"]' -D '{"SEED": "bbb"}' binary 2>&1
+"${JUST_MR}" ${JUST_MR_ARGS} build -L '["env", "PATH='"${PATH}"'"]' -D '{"SEED": "ccc"}' binary 2>&1
+"${JUST_MR}" ${JUST_MR_ARGS} build -L '["env", "PATH='"${PATH}"'"]' -D '{"SEED": "ddd"}' binary 2>&1
+"${JUST_MR}" ${JUST_MR_ARGS} build -L '["env", "PATH='"${PATH}"'"]' -D '{"SEED": "eee"}' binary 2>&1
+"${JUST_MR}" ${JUST_MR_ARGS} build -L '["env", "PATH='"${PATH}"'"]' -D '{"SEED": "fff"}' binary 2>&1
+
+# Now, compactify
+"${JUST_MR}" ${JUST_MR_ARGS} gc --no-rotate
+
+# Finally, run the default target; this will, in parallel, reconstruct the
+# compactified binaries and use them
+"${JUST_MR}" ${JUST_MR_ARGS} build -L '["env", "PATH='"${PATH}"'"]' -J20 2>&1
+
+echo
+echo OK