Add $base function (#2005)

pwndbg/gdblib/functions.py

@@ -53,3 +53,16 @@ def rebase(addr: gdb.Value | int) -> int:
     """Return rebased address."""
     base = pwndbg.gdblib.elf.exe().address
     return base + int(addr)
+
+
+@GdbFunction(only_when_running=True)
+def base(name_pattern: gdb.Value | str) -> int:
+    if isinstance(name_pattern, gdb.Value):
+        name = name_pattern.string()
+    else:
+        name = name_pattern
+
+    for p in pwndbg.gdblib.vmmap.get():
+        if name in p.objfile:
+            return p.vaddr
+    raise ValueError(f"No mapping named {name}")

tests/gdb-tests/tests/test_function_base.py

@@ -0,0 +1,15 @@
+from __future__ import annotations
+
+import gdb
+
+import tests
+
+REFERENCE_BINARY = tests.binaries.get("reference-binary.out")
+
+
+def test_function_base(start_binary):
+    start_binary(REFERENCE_BINARY)
+
+    result = gdb.execute('p/x $base("reference-binary")', to_string=True).strip()
+
+    assert result.startswith("$1 = 0x") and result.endswith("000")

tests/gdb-tests/tests/test_loads.py

@@ -9,7 +9,7 @@ from .utils import run_gdb_with_script
 
 HELLO = [
     "pwndbg: loaded ### pwndbg commands and ### shell commands. Type pwndbg [--shell | --all] [filter] for a list.",
-    "pwndbg: created $rebase, $ida GDB functions (can be used with print/break)",
+    "pwndbg: created $rebase, $base, $ida GDB functions (can be used with print/break)",
 ]
 
 BINARY = tests.binaries.get("div_zero.out")