rt: Allow iteration over the dynastack

1 files changed, 49 insertions, 1 deletions

diff --git a/src/rt/rust_obstack.h b/src/rt/rust_obstack.h
index 6483a5f8d11..99d9ba801b4 100644
--- a/src/rt/rust_obstack.h
+++ b/src/rt/rust_obstack.h
@@ -3,10 +3,28 @@
 #ifndef RUST_OBSTACK_H
 #define RUST_OBSTACK_H
 
-struct rust_obstack_chunk;
+#include <utility>
+
+struct rust_obstack_alloc;
 struct rust_task;
 struct type_desc;
 
+// A contiguous set of allocations.
+struct rust_obstack_chunk {
+    rust_obstack_chunk *prev;
+    size_t size;
+    size_t alen;
+    size_t pad;
+    uint8_t data[];
+
+    rust_obstack_chunk(rust_obstack_chunk *in_prev, size_t in_size)
+    : prev(in_prev), size(in_size), alen(0) {}
+
+    void *alloc(size_t len, type_desc *tydesc);
+    bool free(void *ptr);
+    void *mark();
+};
+
 class rust_obstack {
     rust_obstack_chunk *chunk;
     rust_task *task;
@@ -15,12 +33,42 @@ class rust_obstack {
     void *alloc_new(size_t len, type_desc *tydesc);
 
 public:
+    class iterator {
+        rust_obstack_chunk *chunk;
+        rust_obstack_alloc *alloc;
+
+    public:
+        iterator(rust_obstack_chunk *in_chunk)
+        : chunk(in_chunk),
+          alloc(in_chunk
+                ? reinterpret_cast<rust_obstack_alloc *>(in_chunk->data)
+                : NULL) {}
+
+        std::pair<const type_desc *,void *> operator*() const;
+        iterator &operator++();
+        bool operator==(const iterator &other) const;
+        bool operator!=(const iterator &other) const;
+    };
+
     rust_obstack(rust_task *in_task) : chunk(NULL), task(in_task) {}
     ~rust_obstack();
 
+    inline iterator begin() const {
+        iterator it(chunk);
+        return it;
+    }
+
+    inline iterator end() const {
+        iterator it(NULL);
+        return it;
+    }
+
     void *alloc(size_t len, type_desc *tydesc);
     void free(void *ptr);
     void *mark();
+
+    /** Debugging tool: dumps the contents of this obstack to stderr. */
+    void dump() const;
 };
 
 #endif