Allow for querying of build_id from objects

base/loading.jl

@@ -3047,6 +3047,14 @@ function module_build_id(m::Module)
     return (UInt128(hi) << 64) | lo
 end
 
+function object_build_id(obj)
+    mod = ccall(:jl_object_top_module, Any, (Any,), obj)
+    if mod === nothing
+        return nothing
+    end
+    return module_build_id(mod::Module)
+end
+
 function isvalid_cache_header(f::IOStream)
     pkgimage = Ref{UInt8}()
     checksum = ccall(:jl_read_verify_header, UInt64, (Ptr{Cvoid}, Ptr{UInt8}, Ptr{Int64}, Ptr{Int64}), f.ios, pkgimage, Ref{Int64}(), Ref{Int64}()) # returns checksum id or zero

src/init.c

@@ -826,6 +826,7 @@ JL_DLLEXPORT void julia_init(JL_IMAGE_SEARCH rel)
 
     arraylist_new(&jl_linkage_blobs, 0);
     arraylist_new(&jl_image_relocs, 0);
+    arraylist_new(&jl_top_mods, 0);
     arraylist_new(&eytzinger_image_tree, 0);
     arraylist_new(&eytzinger_idxs, 0);
     arraylist_push(&eytzinger_idxs, (void*)0);

src/julia.h

@@ -2078,6 +2078,7 @@ JL_DLLEXPORT void jl_create_system_image(void **, jl_array_t *worklist, bool_t e
 JL_DLLEXPORT void jl_restore_system_image(const char *fname);
 JL_DLLEXPORT void jl_restore_system_image_data(const char *buf, size_t len);
 JL_DLLEXPORT jl_value_t *jl_restore_incremental(const char *fname, jl_array_t *depmods, int complete, const char *pkgimage);
+JL_DLLEXPORT jl_value_t *jl_object_top_module(jl_value_t* v) JL_NOTSAFEPOINT;
 
 JL_DLLEXPORT void jl_set_newly_inferred(jl_value_t *newly_inferred);
 JL_DLLEXPORT void jl_push_newly_inferred(jl_value_t *ci);

src/julia_internal.h

@@ -333,6 +333,7 @@ void print_func_loc(JL_STREAM *s, jl_method_t *m);
 extern jl_array_t *_jl_debug_method_invalidation JL_GLOBALLY_ROOTED;
 JL_DLLEXPORT extern arraylist_t jl_linkage_blobs; // external linkage: sysimg/pkgimages
 JL_DLLEXPORT extern arraylist_t jl_image_relocs;  // external linkage: sysimg/pkgimages
+JL_DLLEXPORT extern arraylist_t jl_top_mods;  // external linkage: sysimg/pkgimages
 extern arraylist_t eytzinger_image_tree;
 extern arraylist_t eytzinger_idxs;
 
@@ -1012,7 +1013,8 @@ STATIC_INLINE size_t n_linkage_blobs(void) JL_NOTSAFEPOINT
 
 size_t external_blob_index(jl_value_t *v) JL_NOTSAFEPOINT;
 
-uint8_t jl_object_in_image(jl_value_t* v) JL_NOTSAFEPOINT;
+// Query if this object is perm-allocated in an image.
+JL_DLLEXPORT uint8_t jl_object_in_image(jl_value_t* v) JL_NOTSAFEPOINT;
 
 // the first argument to jl_idtable_rehash is used to return a value
 // make sure it is rooted if it is used after the function returns

src/staticdata.c

@@ -337,6 +337,8 @@ static arraylist_t object_worklist;  // used to mimic recursion by jl_serialize_
 // jl_linkage_blobs.items[2i:2i+1] correspond to build_ids[i]   (0-offset indexing)
 arraylist_t jl_linkage_blobs;
 arraylist_t jl_image_relocs;
+// Keep track of which image corresponds to which top module.
+arraylist_t jl_top_mods;
 
 // Eytzinger tree of images. Used for very fast jl_object_in_image queries
 // See https://algorithmica.org/en/eytzinger
@@ -451,11 +453,23 @@ size_t external_blob_index(jl_value_t *v) JL_NOTSAFEPOINT
     return idx;
 }
 
-uint8_t jl_object_in_image(jl_value_t *obj) JL_NOTSAFEPOINT
+JL_DLLEXPORT uint8_t jl_object_in_image(jl_value_t *obj) JL_NOTSAFEPOINT
 {
     return eyt_obj_in_img(obj);
 }
 
+// Map an object to it's "owning" top module
+JL_DLLEXPORT jl_value_t *jl_object_top_module(jl_value_t* v) JL_NOTSAFEPOINT
+{
+    size_t idx = external_blob_index(v);
+    size_t lbids = n_linkage_blobs();
+    if (idx < lbids) {
+        return (jl_value_t*)jl_top_mods.items[idx];
+    }
+    // The object is runtime allocated
+    return (jl_value_t*)jl_nothing;
+}
+
 // hash of definitions for predefined function pointers
 static htable_t fptr_to_id;
 void *native_functions;   // opaque jl_native_code_desc_t blob used for fetching data from LLVM
@@ -3550,6 +3564,15 @@ static void jl_restore_system_image_from_stream_(ios_t *f, jl_image_t *image, jl
     arraylist_push(&jl_linkage_blobs, (void*)image_base);
     arraylist_push(&jl_linkage_blobs, (void*)(image_base + sizeof_sysimg));
     arraylist_push(&jl_image_relocs, (void*)relocs_base);
+    if (restored == NULL) {
+        arraylist_push(&jl_top_mods, (void*)jl_top_module);
+    } else {
+        size_t len = jl_array_nrows(*restored);
+        assert(len > 0);
+        jl_module_t *topmod = (jl_module_t*)jl_array_ptr_ref(*restored, len-1);
+        assert(jl_is_module(topmod));
+        arraylist_push(&jl_top_mods, (void*)topmod);
+    }
     jl_timing_counter_inc(JL_TIMING_COUNTER_ImageSize, sizeof_sysimg + sizeof(uintptr_t));
     rebuild_image_blob_tree();
 

test/precompile.jl

@@ -15,6 +15,11 @@ FooBase_module = :FooBase4b3a94a1a081a8cb
 end
 using .ConflictingBindings
 
+@testset "object_build_id" begin
+    @test Base.object_build_id([1]) === nothing
+    @test Base.object_build_id(Base) == Base.module_build_id(Base)
+end
+
 # method root provenance
 
 rootid(m::Module) = Base.module_build_id(Base.parentmodule(m)) % UInt64
@@ -350,6 +355,9 @@ precompile_test_harness(false) do dir
         @test objectid(Foo.a_vec_int) === Foo.oid_vec_int
         @test objectid(Foo.a_mat_int) === Foo.oid_mat_int
         @test Foo.oid_vec_int !== Foo.oid_mat_int
+        @test Base.object_build_id(Foo.a_vec_int) == Base.object_build_id(Foo.a_mat_int)
+        @test Base.object_build_id(Foo) == Base.module_build_id(Foo)
+        @test Base.object_build_id(Foo.a_vec_int) == Base.module_build_id(Foo)
     end
 
     @eval begin function ccallable_test()

test/precompile_absint1.jl

@@ -44,10 +44,14 @@ precompile_test_harness() do load_path
             @test isdefined(ci, :next)
             @test ci.owner === nothing
             @test ci.max_world == typemax(UInt)
+            @test Base.module_build_id(TestAbsIntPrecompile1) ==
+                Base.object_build_id(ci)
             ci = ci.next
             @test !isdefined(ci, :next)
             @test ci.owner === cache_owner
             @test ci.max_world == typemax(UInt)
+            @test Base.module_build_id(TestAbsIntPrecompile1) ==
+                Base.object_build_id(ci)
         end
         let m = only(methods(sum, (Vector{Float64},)))
             found = false
@@ -57,10 +61,14 @@ precompile_test_harness() do load_path
                     @test isdefined(ci, :next)
                     @test ci.owner === cache_owner
                     @test ci.max_world == typemax(UInt)
+                    @test Base.module_build_id(TestAbsIntPrecompile1) ==
+                        Base.object_build_id(ci)
                     ci = ci.next
                     @test !isdefined(ci, :next)
                     @test ci.owner === nothing
                     @test ci.max_world == typemax(UInt)
+                    @test Base.module_build_id(TestAbsIntPrecompile1) ==
+                        Base.object_build_id(ci)
                     found = true
                     break
                 end

test/precompile_absint2.jl

@@ -67,10 +67,14 @@ precompile_test_harness() do load_path
             @test isdefined(ci, :next)
             @test ci.owner === nothing
             @test ci.max_world == typemax(UInt)
+            @test Base.module_build_id(TestAbsIntPrecompile2) ==
+                Base.object_build_id(ci)
             ci = ci.next
             @test !isdefined(ci, :next)
             @test ci.owner === cache_owner
             @test ci.max_world == typemax(UInt)
+            @test Base.module_build_id(TestAbsIntPrecompile2) ==
+                Base.object_build_id(ci)
         end
         let m = only(methods(sum, (Vector{Float64},)))
             found = false
@@ -80,10 +84,14 @@ precompile_test_harness() do load_path
                     @test isdefined(ci, :next)
                     @test ci.owner === cache_owner
                     @test ci.max_world == typemax(UInt)
+                    @test Base.module_build_id(TestAbsIntPrecompile2) ==
+                        Base.object_build_id(ci)
                     ci = ci.next
                     @test !isdefined(ci, :next)
                     @test ci.owner === nothing
                     @test ci.max_world == typemax(UInt)
+                    @test Base.module_build_id(TestAbsIntPrecompile2) ==
+                        Base.object_build_id(ci)
                     found = true
                     break
                 end