fixup! Implement support for debug information in the runtime system

erlang · Jan 29, 2025 · 463d057 · 463d057
1 parent f181f0d
commit 463d057
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Showing 2 changed files with 25 additions and 14 deletions.
diff --git a/erts/emulator/beam/beam_bif_load.c b/erts/emulator/beam/beam_bif_load.c
@@ -1288,27 +1288,31 @@ BIF_RETTYPE code_get_debug_info_1(BIF_ALIST_1)
     alloc_size = 0;
 
     for (i = 0; i < debug->item_count; i++) {
-        /* [ {Index, {FrameSize,[{Name,Value}]} ] */
-        alloc_size += 2 + 3 + 3 + debug->items[i].num_vars * (2 + 3 + 3);
+        /* [ {Line, {FrameSize, Pairs}} ] */
+        alloc_size += 2 + 3 + 3;
+        /* Pairs = [{Name, Value}], where Value is an atom or 2-tuple.
+         *
+         * Assume they are all 2-tuples and HRelease() the excess
+         * later. */
+        alloc_size += debug->items[i].num_vars * (2 + 3 + 3);
     }
 
     hp = HAlloc(BIF_P, alloc_size);
     hend = hp + alloc_size;
 
     for (i = debug->item_count-1; i >= 0; i--) {
         BeamDebugItem* items = &debug->items[i];
-        Uint32 location_index;
         Sint frame_size = items->frame_size;
-        Uint32 location;
         Uint num_vars = items->num_vars;
-        Eterm *tp = items->first + 2 * num_vars - 2;
+        Eterm *tp = &items->first[2 * (num_vars - 1)];
+        Uint32 location_index, location;
         Eterm frame_size_term;
         Eterm var_list = NIL;
         Eterm tmp;
 
         location_index = items->location_index;
 
-        if (location_index == (Uint32)-1) {
+        if (location_index == ERTS_UINT32_MAX) {
             continue;
         }
         if (lt->loc_size == 2) {
@@ -1326,6 +1330,7 @@ BIF_RETTYPE code_get_debug_info_1(BIF_ALIST_1)
             frame_size_term = am_none;
             break;
         default:
+            ASSERT(frame_size >= 0);
             frame_size_term = make_small(frame_size);
             break;
         }
@@ -1334,17 +1339,19 @@ BIF_RETTYPE code_get_debug_info_1(BIF_ALIST_1)
             Eterm val;
             Eterm tag;
 
-            if (_is_loader_x_reg(tp[1])) {
-                Uint xreg = loader_x_reg_index(tp[1]);
+            switch(loader_tag(tp[1])) {
+            case LOADER_X_REG:
                 tag = am_x;
-                val = make_small(xreg);
-            } else if (_is_loader_y_reg(tp[1])) {
-                Uint yreg = loader_y_reg_index(tp[1]);
+                val = make_small(loader_x_reg_index(tp[1]));
+                break;
+            case LOADER_Y_REG:
                 tag = am_y;
-                val = make_small(yreg);
-            } else {
+                val = make_small(loader_y_reg_index(tp[1]));
+                break;
+            default:
                 tag = am_value;
                 val = tp[1];
+                break;
             }
             tmp = TUPLE2(hp, tag, val);
             hp += 3;

diff --git a/erts/emulator/beam/beam_file.c b/erts/emulator/beam/beam_file.c
@@ -753,10 +753,14 @@ static int parse_debug_chunk_data(BeamFile *beam, BeamReader *p_reader) {
 
         arg++;
 
+        if (extra_args % 2 != 0) {
+            goto error;
+        }
+
         /* Process the list of variable mappings. */
 
         num_vars = extra_args / 2;
-        if (2 * num_vars != extra_args || num_vars > total_num_vars) {
+        if (num_vars > total_num_vars) {
             goto error;
         }
         total_num_vars -= num_vars;