Add a way for a frontend to generate more complex dwarf location

information.  This allows arbitrary code involving DW_OP_plus_uconst
and DW_OP_deref.  The scheme allows for easy extention to include,
any, or all of the DW_OP_ opcodes.  I thought about just exposing all
of them, but, wasn't sure if people wanted the dwarf opcodes exposed
in the api.  Is that a layering violation?

With this scheme, the entire existing block scheme used by llvm-gcc
can be switched over to the new scheme.  I think that would be
cleaner, as then the compiler specific bits are not present in llvm
proper.  Before the old code can be yanked however, similar code in
clang would have to be removed.

Next up, more testing.

llvm-svn: 83120

1 files changed, 22 insertions, 0 deletions

diff --git a/llvm/lib/Analysis/DebugInfo.cpp b/llvm/lib/Analysis/DebugInfo.cpp
index 58bee90372d..db5a0cbb214 100644
--- a/llvm/lib/Analysis/DebugInfo.cpp
+++ b/llvm/lib/Analysis/DebugInfo.cpp
@@ -531,6 +531,8 @@ void DIVariable::dump() const {
   errs() << " [" << getLineNumber() << "] ";
   getType().dump();
   errs() << "\n";
+
+  // FIXME: Dump complex addresses
 }
 
 //===----------------------------------------------------------------------===//
@@ -781,6 +783,26 @@ DIVariable DIFactory::CreateVariable(unsigned Tag, DIDescriptor Context,
 }
 
 
+/// CreateComplexVariable - Create a new descriptor for the specified variable
+/// which has a complex address expression for its address.
+DIVariable DIFactory::CreateComplexVariable(unsigned Tag, DIDescriptor Context,
+                                            const std::string &Name,
+                                            DICompileUnit CompileUnit,
+                                            unsigned LineNo,
+                                   DIType Type, SmallVector<Value *, 9> &addr) {
+  SmallVector<Value *, 9> Elts;
+  Elts.push_back(GetTagConstant(Tag));
+  Elts.push_back(Context.getNode());
+  Elts.push_back(MDString::get(VMContext, Name));
+  Elts.push_back(CompileUnit.getNode());
+  Elts.push_back(ConstantInt::get(Type::getInt32Ty(VMContext), LineNo));
+  Elts.push_back(Type.getNode());
+  Elts.insert(Elts.end(), addr.begin(), addr.end());
+
+  return DIVariable(MDNode::get(VMContext, &Elts[0], 6+addr.size()));
+}
+
+
 /// CreateBlock - This creates a descriptor for a lexical block with the
 /// specified parent VMContext.
 DILexicalBlock DIFactory::CreateLexicalBlock(DIDescriptor Context) {