[Lldb-commits] [lldb] 82ce912 - [lldb] [gdb-server] Fix fill_clamp to handle signed src types

[Michał Górny via lldb-commits]

Author: Michał Górny
Date: 2021-11-10T09:38:55+01:00
New Revision: 82ce9127436b316eca6763b926b2cde2e3d4bb8a

URL: https://github.com/llvm/llvm-project/commit/82ce9127436b316eca6763b926b2cde2e3d4bb8a
DIFF: https://github.com/llvm/llvm-project/commit/82ce9127436b316eca6763b926b2cde2e3d4bb8a.diff

LOG: [lldb] [gdb-server] Fix fill_clamp to handle signed src types

Fix the fill_clamp() function to handle signed source types.  Make sure
that the source value is always non-negative, and cast it to unsigned
when verifying the upper bound.  This fixes compiler warnings about
comparing unsigned and signed types.

Differential Revision: https://reviews.llvm.org/D113519

Added: 
    

Modified: 
    lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerCommon.cpp

Removed: 
    


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diff  --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerCommon.cpp b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerCommon.cpp
index c61ce2a74b99..f371649842e8 100644
--- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerCommon.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerCommon.cpp
@@ -771,8 +771,11 @@ GDBRemoteCommunicationServerCommon::Handle_qPlatform_shell(
 
 template <typename T, typename U>
 static void fill_clamp(T &dest, U src, typename T::value_type fallback) {
-  dest = src <= std::numeric_limits<typename T::value_type>::max() ? src
-                                                                   : fallback;
+  static_assert(std::is_unsigned<typename T::value_type>::value,
+                "Destination type must be unsigned.");
+  using UU = typename std::make_unsigned<U>::type;
+  constexpr auto T_max = std::numeric_limits<typename T::value_type>::max();
+  dest = src >= 0 && static_cast<UU>(src) <= T_max ? src : fallback;
 }
 
 GDBRemoteCommunication::PacketResult