From c44885db3b56c83a12e88a176c03f2a2268428b8 Mon Sep 17 00:00:00 2001 From: Andrew Burgess Date: Thu, 19 May 2022 13:55:41 +0100 Subject: [PATCH] gdb: ensure the cast in gdbarch_tdep is valid This commit makes use of gdb::checked_static_cast when casting the generic gdbarch_tdep pointer to a specific sub-class type. This means that, when compiled in developer mode, GDB will validate that the cast is correct. In order to use gdb::checked_static_cast the types involved must have RTTI, which is why the gdbarch_tdep base class now has a virtual destructor. Assuming there are no bugs in GDB where we cast a gdbarch_tdep pointer to the wrong type, then there should be no changes after this commit. If any bugs do exist, then GDB will now assert (in a developer build). --- gdb/gdbarch.h | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/gdb/gdbarch.h b/gdb/gdbarch.h index b2c91db0c4f..16c73915c64 100644 --- a/gdb/gdbarch.h +++ b/gdb/gdbarch.h @@ -28,6 +28,7 @@ #include "infrun.h" #include "osabi.h" #include "displaced-stepping.h" +#include "gdbsupport/gdb-checked-static-cast.h" struct floatformat; struct ui_file; @@ -58,7 +59,14 @@ struct inferior; #include "regcache.h" -struct gdbarch_tdep {}; +/* The base class for every architecture's tdep sub-class. The virtual + destructor ensures the class has RTTI information, which allows + gdb::checked_static_cast to be used, the gdbarch_tdep the function. */ + +struct gdbarch_tdep +{ + virtual ~gdbarch_tdep() = default; +}; /* The architecture associated with the inferior through the connection to the target. @@ -157,7 +165,7 @@ static inline TDepType * gdbarch_tdep (struct gdbarch *gdbarch) { struct gdbarch_tdep *tdep = gdbarch_tdep_1 (gdbarch); - return static_cast (tdep); + return gdb::checked_static_cast (tdep); } /* Mechanism for co-ordinating the selection of a specific -- 2.30.2