Merge LLVM r202188:

  Debug info: Support variadic functions.
  Variadic functions have an unspecified parameter tag after the last
  argument. In IR this is represented as an unspecified parameter in the
  subroutine type.

  Paired commit with CFE r202185.

  rdar://problem/13690847

  This re-applies r202184 + a bugfix in DwarfDebug's argument handling.

This merge includes a change to use the LLVM 3.4 API in
lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp:

DwarfUnit -> CompileUnit

Sponsored by:       DARPA, AFRL

1 files changed, 24 insertions, 8 deletions

diff --git a/contrib/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/contrib/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index d1e1ad1..d922433 100644
--- a/contrib/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/contrib/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -404,15 +404,21 @@ DIE *DwarfDebug::updateSubprogramScopeDIE(CompileUnit *SPCU, DISubprogram SP) {
         DIArray Args = SPTy.getTypeArray();
         uint16_t SPTag = SPTy.getTag();
         if (SPTag == dwarf::DW_TAG_subroutine_type)
+          // FIXME: Use DwarfUnit::constructSubprogramArguments() here.
           for (unsigned i = 1, N = Args.getNumElements(); i < N; ++i) {
-            DIE *Arg =
-                SPCU->createAndAddDIE(dwarf::DW_TAG_formal_parameter, *SPDie);
             DIType ATy(Args.getElement(i));
-            SPCU->addType(Arg, ATy);
-            if (ATy.isArtificial())
-              SPCU->addFlag(Arg, dwarf::DW_AT_artificial);
-            if (ATy.isObjectPointer())
-              SPCU->addDIEEntry(SPDie, dwarf::DW_AT_object_pointer, Arg);
+            if (ATy.isUnspecifiedParameter()) {
+              assert(i == N-1 && "ellipsis must be the last argument");
+              SPCU->createAndAddDIE(dwarf::DW_TAG_unspecified_parameters, *SPDie);
+            } else {
+              DIE *Arg =
+                SPCU->createAndAddDIE(dwarf::DW_TAG_formal_parameter, *SPDie);
+              SPCU->addType(Arg, ATy);
+              if (ATy.isArtificial())
+                SPCU->addFlag(Arg, dwarf::DW_AT_artificial);
+              if (ATy.isObjectPointer())
+                SPCU->addDIEEntry(SPDie, dwarf::DW_AT_object_pointer, Arg);
+            }
           }
         DIE *SPDeclDie = SPDie;
         SPDie =
@@ -579,7 +585,7 @@ DIE *DwarfDebug::createScopeChildrenDIE(CompileUnit *TheCU, LexicalScope *Scope,
     DIE *ObjectPointer = NULL;
 
   // Collect arguments for current function.
-  if (LScopes.isCurrentFunctionScope(Scope))
+  if (LScopes.isCurrentFunctionScope(Scope)) {
     for (unsigned i = 0, N = CurrentFnArguments.size(); i < N; ++i)
       if (DbgVariable *ArgDV = CurrentFnArguments[i])
         if (DIE *Arg =
@@ -588,6 +594,16 @@ DIE *DwarfDebug::createScopeChildrenDIE(CompileUnit *TheCU, LexicalScope *Scope,
           if (ArgDV->isObjectPointer()) ObjectPointer = Arg;
         }
 
+    // Create the unspecified parameter that marks a function as variadic.
+    DISubprogram SP(Scope->getScopeNode());
+    assert(SP.Verify());
+    DIArray FnArgs = SP.getType().getTypeArray();
+    if (FnArgs.getElement(FnArgs.getNumElements()-1).isUnspecifiedParameter()) {
+      DIE *Ellipsis = new DIE(dwarf::DW_TAG_unspecified_parameters);
+      Children.push_back(Ellipsis);
+    }
+  }
+
   // Collect lexical scope children first.
   const SmallVectorImpl<DbgVariable *> &Variables =ScopeVariables.lookup(Scope);
   for (unsigned i = 0, N = Variables.size(); i < N; ++i)