From 106a620dfca6e8113e8e515e36e2c0e6e820c70e Mon Sep 17 00:00:00 2001
From: Gabriel Ionita <d9rect@pm.me>
Date: Sat, 25 Oct 2025 15:10:00 +0100
Subject: [PATCH] implement find_global_var to locate variable by name

---
 src/symbol.cpp | 67 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 67 insertions(+)

diff --git a/src/symbol.cpp b/src/symbol.cpp
index d5af909..93ed08a 100644
--- a/src/symbol.cpp
+++ b/src/symbol.cpp
@@ -224,6 +224,73 @@ size_t Symbol::get_var_size(Dwarf_Debug dbg, Dwarf_Die die) {
   return byte_size;
 }
 
+std::optional<VarInfo> Symbol::find_global_var(Dwarf_Debug dbg, const std::string &var_name) {
+  Dwarf_Error err;
+  Dwarf_Unsigned cu_hdr_len, abbr_offset, next_cu_hdr;
+  Dwarf_Half ver_stamp, addr_sz;
+  Dwarf_Half length_size, extension_size;
+  Dwarf_Sig8 type_signature;
+  Dwarf_Unsigned typeoffset;
+  Dwarf_Half header_cu_type;
+
+  // Iterate through all compilation units
+  while (dwarf_next_cu_header_d(dbg, true, &cu_hdr_len, &ver_stamp, &abbr_offset,
+                                &addr_sz, &length_size, &extension_size,
+                                &type_signature, &typeoffset, &next_cu_hdr,
+                                &header_cu_type, &err) == DW_DLV_OK) {
+
+    Dwarf_Die cu_die = nullptr;
+
+    // Get the compilation unit DIE
+    if (dwarf_siblingof_b(dbg, nullptr, true, &cu_die, &err) != DW_DLV_OK)
+      continue;
+
+    // Get the first child DIE
+    Dwarf_Die child_die = nullptr;
+    if (dwarf_child(cu_die, &child_die, &err) != DW_DLV_OK) {
+      dwarf_dealloc(dbg, cu_die, DW_DLA_DIE);
+      continue;
+    }
+
+    // Iterate through all child DIEs
+    while (child_die != nullptr) {
+      Dwarf_Half tag;
+
+      if (dwarf_tag(child_die, &tag, &err) == DW_DLV_OK && tag == DW_TAG_variable) {
+        char *name = nullptr;
+
+        if (dwarf_diename(child_die, &name, &err) == DW_DLV_OK && name) {
+          if (var_name == name) {
+            Dwarf_Addr addr = get_global_var_addr(dbg, child_die);
+            size_t size = get_var_size(dbg, child_die);
+
+            VarInfo info{std::string(name), addr, size};
+            dwarf_dealloc(dbg, name, DW_DLA_STRING);
+            dwarf_dealloc(dbg, child_die, DW_DLA_DIE);
+            dwarf_dealloc(dbg, cu_die, DW_DLA_DIE);
+            return info;
+          }
+          dwarf_dealloc(dbg, name, DW_DLA_STRING);
+        }
+      }
+
+      // Move to the next sibling
+      Dwarf_Die next_die = nullptr;
+      int rc = dwarf_siblingof_c(child_die, &next_die, &err);
+
+      dwarf_dealloc(dbg, child_die, DW_DLA_DIE);
+      child_die = next_die;
+
+      if (rc != DW_DLV_OK)
+        break;
+    }
+
+    dwarf_dealloc(dbg, cu_die, DW_DLA_DIE);
+  }
+
+  return std::nullopt;
+}
+
 void Symbol::list_global_integer_vars(Dwarf_Debug dbg) {
   Dwarf_Error err;
   Dwarf_Unsigned cu_hdr_len, abbr_offset, next_cu_hdr;