Make loading fail if it detects a buildid collision

Author: gbaraldi

src/julia_internal.h

@@ -756,7 +756,7 @@ void push_edge(jl_array_t *list, jl_value_t *invokesig, jl_code_instance_t *call
 void jl_mi_done_backedges(jl_method_instance_t *mi JL_PROPAGATES_ROOT, uint8_t old_flags);
 
 JL_DLLEXPORT void jl_add_method_root(jl_method_t *m, jl_module_t *mod, jl_value_t* root);
-void jl_append_method_roots(jl_method_t *m, uint64_t modid, jl_array_t* roots);
+int jl_append_method_roots(jl_method_t *m, uint64_t modid, jl_array_t* roots);
 int get_root_reference(rle_reference *rr, jl_method_t *m, size_t i) JL_NOTSAFEPOINT;
 jl_value_t *lookup_root(jl_method_t *m, uint64_t key, int index) JL_NOTSAFEPOINT;
 int nroots_with_key(jl_method_t *m, uint64_t key) JL_NOTSAFEPOINT;

src/method.c

@@ -1521,14 +1521,22 @@ static uint64_t current_root_id(jl_array_t *root_blocks)
 }
 
 // Add a new block of `len` roots with key `modid` (module id)
-static void add_root_block(jl_array_t *root_blocks, uint64_t modid, size_t len)
+static int add_root_block(jl_array_t *root_blocks, uint64_t modid, size_t len)
 {
     assert(jl_is_array(root_blocks));
     jl_array_grow_end(root_blocks, 2);
     uint64_t *blocks = jl_array_data(root_blocks, uint64_t);
     int nx2 = jl_array_nrows(root_blocks);
+    int failed = 0;
+    for (size_t i = 0; i < nx2; i+=2) {
+        if (blocks[i] == modid) {
+            // found duplicate block
+            failed = -1;
+        }
+    }
     blocks[nx2-2] = modid;
     blocks[nx2-1] = len;
+    return failed;
 }
 
 // Allocate storage for roots
@@ -1555,22 +1563,26 @@ JL_DLLEXPORT void jl_add_method_root(jl_method_t *m, jl_module_t *mod, jl_value_
     }
     assert(jl_is_method(m));
     prepare_method_for_roots(m, modid);
-    if (current_root_id(m->root_blocks) != modid)
-        add_root_block(m->root_blocks, modid, jl_array_nrows(m->roots));
+    if (current_root_id(m->root_blocks) != modid) {
+        int failed = add_root_block(m->root_blocks, modid, jl_array_nrows(m->roots));
+        assert(failed == 0);
+        (void)failed;
+    }
     jl_array_ptr_1d_push(m->roots, root);
     JL_GC_POP();
 }
 
 // Add a list of roots with key `modid` to a method
-void jl_append_method_roots(jl_method_t *m, uint64_t modid, jl_array_t* roots)
+int jl_append_method_roots(jl_method_t *m, uint64_t modid, jl_array_t* roots)
 {
     JL_GC_PUSH2(&m, &roots);
     assert(jl_is_method(m));
     assert(jl_is_array(roots));
     prepare_method_for_roots(m, modid);
-    add_root_block(m->root_blocks, modid, jl_array_nrows(m->roots));
+    int failed = add_root_block(m->root_blocks, modid, jl_array_nrows(m->roots));
     jl_array_ptr_1d_append(m->roots, roots);
     JL_GC_POP();
+    return failed;
 }
 
 // given the absolute index i of a root, retrieve its relocatable reference

src/staticdata.c

@@ -4410,7 +4410,11 @@ static jl_value_t *jl_restore_package_image_from_stream(ios_t *f, jl_image_t *im
             JL_SIGATOMIC_END();
 
             // Add roots to methods
-            jl_copy_roots(method_roots_list, jl_worklist_key((jl_array_t*)restored));
+            int failed = jl_copy_roots(method_roots_list, jl_worklist_key((jl_array_t*)restored));
+            if (failed != 0) {
+                jl_printf(JL_STDERR, "Error copying roots to methods from Module: %s\n", pkgname);
+                abort();
+            }
             // Insert method extensions and handle edges
             int new_methods = jl_array_nrows(extext_methods) > 0;
             if (!new_methods) {

src/staticdata_utils.c

@@ -736,17 +736,19 @@ static void jl_activate_methods(jl_array_t *external, jl_array_t *internal, size
     }
 }
 
-static void jl_copy_roots(jl_array_t *method_roots_list, uint64_t key)
+static int jl_copy_roots(jl_array_t *method_roots_list, uint64_t key)
 {
     size_t i, l = jl_array_nrows(method_roots_list);
+    int failed = 0;
     for (i = 0; i < l; i+=2) {
         jl_method_t *m = (jl_method_t*)jl_array_ptr_ref(method_roots_list, i);
         jl_array_t *roots = (jl_array_t*)jl_array_ptr_ref(method_roots_list, i+1);
         if (roots) {
             assert(jl_is_array(roots));
-            jl_append_method_roots(m, key, roots);
+            failed -= jl_append_method_roots(m, key, roots);
         }
     }
+    return failed;
 }
 
 static jl_value_t *read_verify_mod_list(ios_t *s, jl_array_t *depmods)