Fix type detection for 'char' variables

A char can have signed and unsigned encoding but previously lldb always
assumed it is signed. This CL adds a logic to detect the encoding of
'char' types based on the default encoding on the target architecture.
It fixes variable printing and expression evaluation on architectures
where 'char' is signed by default.

Differential revision: http://reviews.llvm.org/D8636

llvm-svn: 233682

1 files changed, 26 insertions, 0 deletions

diff --git a/lldb/source/Core/ArchSpec.cpp b/lldb/source/Core/ArchSpec.cpp
index be3f84b06aa..4040671e54c 100644
--- a/lldb/source/Core/ArchSpec.cpp
+++ b/lldb/source/Core/ArchSpec.cpp
@@ -577,6 +577,32 @@ ArchSpec::GetDefaultEndian () const
     return eByteOrderInvalid;
 }
 
+bool
+ArchSpec::CharIsSignedByDefault () const
+{
+    switch (m_triple.getArch()) {
+    default:
+        return true;
+
+    case llvm::Triple::aarch64:
+    case llvm::Triple::aarch64_be:
+    case llvm::Triple::arm:
+    case llvm::Triple::armeb:
+    case llvm::Triple::thumb:
+    case llvm::Triple::thumbeb:
+        return m_triple.isOSDarwin() || m_triple.isOSWindows();
+
+    case llvm::Triple::ppc:
+    case llvm::Triple::ppc64:
+        return m_triple.isOSDarwin();
+
+    case llvm::Triple::ppc64le:
+    case llvm::Triple::systemz:
+    case llvm::Triple::xcore:
+        return false;
+    }
+}
+
 lldb::ByteOrder
 ArchSpec::GetByteOrder () const
 {