chore: lean --stats gives number of imported bytes (#8725)

Thanks to `mmap`, startup time is not necessarily related to this
figure, but it can be used as a rough measure for that and how much data
the module depends on, i.e. the rebuild chance.

Also adds new cumulative benchmarks for this metric as well as the
number of imported constants and env ext entries.

src/Lean/Environment.lean

@@ -103,6 +103,10 @@ def CompactedRegion := USize
 @[extern "lean_compacted_region_is_memory_mapped"]
 opaque CompactedRegion.isMemoryMapped : CompactedRegion → Bool
 
+/-- Size in bytes. -/
+@[extern "lean_compacted_region_size"]
+opaque CompactedRegion.size : CompactedRegion → USize
+
 /-- Free a compacted region and its contents. No live references to the contents may exist at the time of invocation. -/
 @[extern "lean_compacted_region_free"]
 unsafe opaque CompactedRegion.free : CompactedRegion → IO Unit
@@ -2178,6 +2182,7 @@ def displayStats (env : Environment) : IO Unit := do
   IO.println ("direct imports:                        " ++ toString env.header.imports);
   IO.println ("number of imported modules:            " ++ toString env.header.regions.size);
   IO.println ("number of memory-mapped modules:       " ++ toString (env.header.regions.filter (·.isMemoryMapped) |>.size));
+  IO.println ("number of imported bytes:              " ++ toString (env.header.regions.map (·.size) |>.sum));
   IO.println ("number of imported consts:             " ++ toString env.constants.map₁.size);
   IO.println ("number of buckets for imported consts: " ++ toString env.constants.numBuckets);
   IO.println ("trust level:                           " ++ toString env.header.trustLevel);

src/runtime/compact.cpp

@@ -379,6 +379,7 @@ void object_compactor::operator()(object * o) {
 }
 
 compacted_region::compacted_region(size_t sz, void * data, void * base_addr, bool is_mmap, std::function<void()> free_data):
+    m_size(sz),
     m_base_addr(base_addr),
     m_is_mmap(is_mmap),
     m_free_data(free_data),
@@ -502,6 +503,10 @@ extern "C" LEAN_EXPORT uint8 lean_compacted_region_is_memory_mapped(usize region
     return reinterpret_cast<compacted_region *>(region)->is_memory_mapped();
 }
 
+extern "C" LEAN_EXPORT usize lean_compacted_region_size(usize region) {
+    return reinterpret_cast<compacted_region *>(region)->size();
+}
+
 extern "C" LEAN_EXPORT obj_res lean_compacted_region_free(usize region, object *) {
     delete reinterpret_cast<compacted_region *>(region);
     return lean_io_result_mk_ok(lean_box(0));

src/runtime/compact.h

@@ -57,6 +57,7 @@ public:
 };
 
 class LEAN_EXPORT compacted_region {
+    size_t m_size;
     // see `object_compactor::m_base_addr`
     void * m_base_addr;
     bool m_is_mmap;
@@ -88,5 +89,6 @@ public:
     compacted_region operator=(compacted_region &&) = delete;
     object * read();
     bool is_memory_mapped() const { return m_is_mmap; }
+    size_t size() const { return m_size; }
 };
 }

tests/bench/accumulate_profile.py

@@ -6,7 +6,8 @@ import sys
 
 cats = collections.defaultdict(lambda: 0)
 for line in sys.stdin:
-    if m := re.match("(.+?) ([\d.]+)(m?)s", line):
+    if m := re.match(r"(.+?) ([\d.]+)(m?)s", line) or \
+            re.match(r"\s*(number of imported bytes|number of imported consts|number of imported entries):\s+(\d+)()", line):
         cats[m[1].strip()] += float(m[2]) * (1e-3 if m[3] else 1)
     sys.stderr.write(line)
 

tests/bench/speedcenter.exec.velcom.yaml

@@ -18,7 +18,7 @@
   run_config:
     <<: *time
     cmd: |
-      bash -c 'set -eo pipefail; touch ../../src/Init/Prelude.lean; make LEAN_OPTS="-Dprofiler=true -Dprofiler.threshold=9999" -C ${BUILD:-../../build/release}/stage2 --output-sync -j$(nproc) 2>&1 | ./accumulate_profile.py'
+      bash -c 'set -eo pipefail; touch ../../src/Init/Prelude.lean; make LEAN_OPTS="-Dprofiler=true -Dprofiler.threshold=99999 --stats" -C ${BUILD:-../../build/release}/stage2 --output-sync -j$(nproc) 2>&1 | ./accumulate_profile.py'
     max_runs: 2
     parse_output: true
   # initialize stage2 cmake + warmup