refactor(memory): add tracked allocation runtime to the standard library

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

1 files changed, 73 insertions, 0 deletions

diff --git a/pseudocode-lib/memory.cc b/pseudocode-lib/memory.cc
new file mode 100644
index 0000000..5eed4c0
--- /dev/null
+++ b/pseudocode-lib/memory.cc
@@ -0,0 +1,73 @@
+#include <cstddef>
+#include <cstdio>
+#include <cstdlib>
+
+extern "C" int __cps_user_line;
+
+namespace {
+struct Allocation {
+    void *Address;
+    Allocation *Next;
+};
+Allocation *Head = nullptr;
+
+[[noreturn]] void fail(const char *Reason) {
+    std::fprintf(stderr, "[Fatal] line %d: %s\n", __cps_user_line, Reason);
+    throw 0;
+}
+
+// Return the link owning the node so head and interior removals are identical.
+Allocation **find(void *Address) {
+    for (Allocation **Link = &Head; *Link; Link = &(*Link)->Next)
+        if ((*Link)->Address == Address) return Link;
+    fail("Invalid memory address (not an active allocation)");
+}
+}
+
+extern "C" {
+void *_memory_impl_malloc(unsigned long long Bytes) {
+    std::size_t Size = static_cast<std::size_t>(Bytes);
+    if (!Size) return nullptr;
+    auto *Node = static_cast<Allocation *>(std::malloc(sizeof(Allocation)));
+    if (!Node) fail("Allocation tracking failed");
+    void *Address = std::malloc(Size);
+    if (!Address) {
+        std::free(Node);
+        fail("Memory allocation failed");
+    }
+    Node->Address = Address;
+    Node->Next = Head;
+    Head = Node;
+    return Address;
+}
+
+void _memory_impl_validate(void *Address) {
+    find(Address);
+}
+
+void *_memory_impl_free(void *Address) {
+    if (Address) {
+        Allocation **Link = find(Address);
+        Allocation *Node = *Link;
+        *Link = Node->Next;
+        std::free(Address);
+        std::free(Node);
+    }
+    return Address;
+}
+
+void *_memory_impl_realloc(void *Address, unsigned long long Bytes) {
+    std::size_t Size = static_cast<std::size_t>(Bytes);
+    if (!Address) return _memory_impl_malloc(Bytes);
+    Allocation *Node = *find(Address);
+    if (!Size) {
+        _memory_impl_free(Address);
+        return nullptr;
+    }
+    void *Resized = std::realloc(Address, Size);
+    // Failure preserves both the original allocation and its tracking record.
+    if (!Resized) fail("Memory allocation failed");
+    Node->Address = Resized;
+    return Resized;
+}
+}