From 552b7d743dd6afa531cc28bd6ff0d4407e3b8561 Mon Sep 17 00:00:00 2001
From: John Viega <john@viega.org>
Date: Mon, 15 Jul 2024 02:59:52 -0400
Subject: [PATCH] Turned memcheck back on

---
 include/con4m.h                  |  4 ----
 include/con4m/datatypes/memory.h |  8 +++++---
 src/con4m/collect.c              | 16 +++++++++++++++-
 src/con4m/gcbase.c               |  8 ++++----
 src/con4m/types.c                | 11 +++++++++++
 5 files changed, 35 insertions(+), 12 deletions(-)

diff --git a/include/con4m.h b/include/con4m.h
index f691639e..5c3e023a 100644
--- a/include/con4m.h
+++ b/include/con4m.h
@@ -2,10 +2,6 @@
 
 #define C4M_DEBUG // Get backtrace on exceptions.
 
-#ifdef C4M_FULL_MEMCHECK
-#undef C4M_FULL_MEMCHECK
-#endif
-
 // #define C4M_FULL_MEMCHECK
 // #define C4M_STRICT_MEMCHECK
 // #define C4M_TRACE_GC
diff --git a/include/con4m/datatypes/memory.h b/include/con4m/datatypes/memory.h
index 7197c1a3..32576c53 100644
--- a/include/con4m/datatypes/memory.h
+++ b/include/con4m/datatypes/memory.h
@@ -56,13 +56,15 @@ typedef struct c4m_alloc_hdr {
     // bits that correspond to words with pointers should be set.
     c4m_mem_scan_fn       scan_fn;
 
-#ifdef C4M_FULL_MEMCHECK
-    uint64_t *end_guard_loc;
-#endif
 #if defined(C4M_GC_STATS) || defined(C4M_DEBUG)
     char *alloc_file;
     int   alloc_line;
 #endif
+
+#ifdef C4M_FULL_MEMCHECK
+    uint64_t *end_guard_loc;
+#endif
+
     // Set to 'true' if this object requires finalization. This is
     // necessary, even though the arena tracks allocations needing
     // finalization, because resizes could move the pointer.
diff --git a/src/con4m/collect.c b/src/con4m/collect.c
index 14b1db15..93cb25b0 100644
--- a/src/con4m/collect.c
+++ b/src/con4m/collect.c
@@ -692,7 +692,6 @@ _c4m_memcheck_raw_alloc(void *a, char *file, int line)
                 file,
                 line,
                 a);
-        return;
         abort();
     }
 
@@ -819,6 +818,20 @@ c4m_alloc_display_rear_guard_error(c4m_alloc_hdr *hdr,
 #endif
 }
 
+static void
+show_next_n_allocs(c4m_shadow_alloc_t *a, int n)
+{
+    printf("Next allocs:\n");
+
+    while (a && n) {
+        printf("%s:%d (@%p; %d bytes)\n", a->file, a->line, a->start, a->len);
+        a = a->next;
+        n -= 1;
+    }
+
+    abort();
+}
+
 static void
 memcheck_validate_old_records(c4m_arena_t *from_space)
 {
@@ -845,6 +858,7 @@ memcheck_validate_old_records(c4m_arena_t *from_space)
                                                a->file,
                                                a->line,
                                                false);
+            show_next_n_allocs(next, 1000);
         }
 
         if (a->start->fw_addr != NULL) {
diff --git a/src/con4m/gcbase.c b/src/con4m/gcbase.c
index 390c9485..02fbc792 100644
--- a/src/con4m/gcbase.c
+++ b/src/con4m/gcbase.c
@@ -15,7 +15,7 @@ thread_local uint32_t c4m_total_allocs    = 0;
 #ifdef C4M_FULL_MEMCHECK
 #ifndef C4M_MEMCHECK_RING_SZ
 // Must be a power of 2.
-#define C4M_MEMCHECK_RING_SZ 64
+#define C4M_MEMCHECK_RING_SZ 128
 #endif
 #if C4M_MEMCHECK_RING_SZ != 0
 #define C4M_USE_RING
@@ -641,7 +641,7 @@ c4m_alloc_from_arena(c4m_arena_t   **arena_ptr,
 #endif
 
 #ifdef C4M_FULL_MEMCHECK
-    len = len + 8; // Ensure room for sentinel.
+    len += 8; // Ensure room for sentinel.
 #endif
     c4m_arena_t *arena = *arena_ptr;
 
@@ -688,7 +688,7 @@ c4m_alloc_from_arena(c4m_arena_t   **arena_ptr,
     raw->scan_fn      = scan_fn;
 
 #ifdef C4M_FULL_MEMCHECK
-    uint64_t *end_guard_addr = &raw->data[wordlen - 1];
+    uint64_t *end_guard_addr = &raw->data[wordlen - 2];
 
     c4m_shadow_alloc_t *record = c4m_rc_alloc(sizeof(c4m_shadow_alloc_t));
     record->start              = raw;
@@ -713,7 +713,7 @@ c4m_alloc_from_arena(c4m_arena_t   **arena_ptr,
     // Duplicated in the header for spot-checking; this can get corrupted;
     // the out-of-heap list is better, but we don't want to bother searching
     // through the whole heap.
-    raw->end_guard_loc = record->end;
+    raw->end_guard_loc = end_guard_addr;
 
     assert(*raw->end_guard_loc == c4m_end_guard);
 
diff --git a/src/con4m/types.c b/src/con4m/types.c
index 2a3acb5d..f44c37b6 100644
--- a/src/con4m/types.c
+++ b/src/con4m/types.c
@@ -277,6 +277,7 @@ c4m_early_alloc_type(c4m_base_obj_t **bptr)
     base->concrete_type  = c4m_bi_types[C4M_T_TYPESPEC];
 
     result->details = info;
+    info->items     = NULL;
     info->base_type = tspec;
 
     return result;
@@ -400,9 +401,18 @@ internal_type_hash(c4m_type_t *node, type_hash_ctx *ctx)
         c4m_sha_int_update(ctx->sha, num_tvars);
         c4m_sha_int_update(ctx->sha, node->typeid);
         break;
+    case C4M_DT_KIND_primitive:
+    case C4M_DT_KIND_box:
+    case C4M_DT_KIND_nil:
+    case C4M_DT_KIND_internal:
+        return;
     default:; // Do nothing.
     }
 
+    if (!deets->items) {
+        return;
+    }
+
     size_t n = c4m_list_len(deets->items);
 
     c4m_sha_int_update(ctx->sha, n);
@@ -1690,6 +1700,7 @@ setup_primitive_types()
             c4m_type_t *t         = c4m_early_alloc_type(&base);
             t->typeid             = i;
             t->details->base_type = one_spec;
+            t->details->items     = NULL;
             c4m_bi_types[i]       = t;
 
             if (i) {