Invert ArchSpec<->Platform dependency

Summary:
ArchSpec::SetTriple was taking a Platform as an argument, and used it to
fill in missing pieces of the specified triple. I invert the dependency
by moving this code to other classes. For this purpose, I've created
three new functions.
- HostInfo::GetAugmentedArchSpec: fills in the triple using the host
  platform (this used to be implemented by passing a null platform
  pointer). By putting this code in the Host module, we can provide a
  way to anyone who does not have a platform instance (lldb-server) an
  easy way to get Host data.
- Platform::GetAugmentedArchSpec: if you have a platform instance, you
  can call this to let it fill in the triple.
- static Platform::GetAugmentedArchSpec: implements the "if platform ==
  0 then use_host() else use_platform()" part.

Reviewers: zturner, jingham, clayborg

Subscribers: mgorny, javed.absar, lldb-commits

Differential Revision: https://reviews.llvm.org/D39387

llvm-svn: 316987

1 files changed, 18 insertions, 0 deletions

diff --git a/lldb/source/Host/common/HostInfoBase.cpp b/lldb/source/Host/common/HostInfoBase.cpp
index a6c9e91a98e..1362a0cdd46 100644
--- a/lldb/source/Host/common/HostInfoBase.cpp
+++ b/lldb/source/Host/common/HostInfoBase.cpp
@@ -251,6 +251,24 @@ bool HostInfoBase::GetLLDBPath(lldb::PathType type, FileSpec &file_spec) {
   return true;
 }
 
+ArchSpec HostInfoBase::GetAugmentedArchSpec(llvm::StringRef triple) {
+  if (triple.empty())
+    return ArchSpec();
+  llvm::Triple normalized_triple(llvm::Triple::normalize(triple));
+  if (!ArchSpec::ContainsOnlyArch(normalized_triple))
+    return ArchSpec(triple);
+
+  llvm::Triple host_triple(llvm::sys::getDefaultTargetTriple());
+
+  if (normalized_triple.getVendorName().empty())
+    normalized_triple.setVendor(host_triple.getVendor());
+  if (normalized_triple.getOSName().empty())
+    normalized_triple.setOS(host_triple.getOS());
+  if (normalized_triple.getEnvironmentName().empty())
+    normalized_triple.setEnvironment(host_triple.getEnvironment());
+  return ArchSpec(normalized_triple);
+}
+
 bool HostInfoBase::ComputeSharedLibraryDirectory(FileSpec &file_spec) {
   // To get paths related to LLDB we get the path to the executable that
   // contains this function. On MacOSX this will be "LLDB.framework/.../LLDB",