Improve the posix core file triple detection

Summary:
Posix core files sometime don't contain enough information to correctly
detect the OS. If that is the case we should use the OS from the target
instead as it will contain usable information in more cases and if the
target and the core contain different OS-es then we are already in a
pretty bad state so moving from an unknown OS to a known (but possibly
incorrect) OS will do no harm.

We already had similar code in place for MIPS. This change tries to make
it more generic by using ArchSpec::MergeFrom and extends it to all
architectures but some MIPS specific issue prevent us from getting rid
of special casing MIPS.

Reviewers: clayborg, nitesh.jain

Subscribers: aemerson, sdardis, arichardson, kristof.beyls, lldb-commits

Differential Revision: https://reviews.llvm.org/D36046

llvm-svn: 317411

diff --git a/lldb/source/Core/ArchSpec.cpp b/lldb/source/Core/ArchSpec.cpp
index e35df33..5e256b8 100644 (file)
--- a/lldb/source/Core/ArchSpec.cpp
+++ b/lldb/source/Core/ArchSpec.cpp
@@ -921,6 +921,9 @@ void ArchSpec::MergeFrom(const ArchSpec &other) {
     m_core = other.GetCore();
     CoreUpdated(true);
   }
+  if (GetFlags() == 0) {
+    SetFlags(other.GetFlags());
+  }
 }
 
 bool ArchSpec::SetArchitecture(ArchitectureType arch_type, uint32_t cpu,

diff --git a/lldb/source/Plugins/Process/elf-core/ProcessElfCore.cpp b/lldb/source/Plugins/Process/elf-core/ProcessElfCore.cpp
index 71eb643..ed9058e 100644 (file)
--- a/lldb/source/Plugins/Process/elf-core/ProcessElfCore.cpp
+++ b/lldb/source/Plugins/Process/elf-core/ProcessElfCore.cpp
@@ -724,15 +724,18 @@ uint32_t ProcessElfCore::GetNumThreadContexts() {
 }
 
 ArchSpec ProcessElfCore::GetArchitecture() {
-  ObjectFileELF *core_file =
-      (ObjectFileELF *)(m_core_module_sp->GetObjectFile());
   ArchSpec arch;
-  core_file->GetArchitecture(arch);
+  m_core_module_sp->GetObjectFile()->GetArchitecture(arch);
 
   ArchSpec target_arch = GetTarget().GetArchitecture();
-  
-  if (target_arch.IsMIPS())
+  arch.MergeFrom(target_arch);
+
+  // On MIPS there is no way to differentiate betwenn 32bit and 64bit core files
+  // and this information can't be merged in from the target arch so we fail
+  // back to unconditionally returning the target arch in this config.
+  if (target_arch.IsMIPS()) {
     return target_arch;
+  }
 
   return arch;
 }