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, 23 insertions, 20 deletions

diff --git a/contrib/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp b/contrib/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
index 97ef687..50f5cc9 100644
--- a/contrib/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
+++ b/contrib/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
@@ -1116,6 +1116,22 @@ void CompileUnit::constructTypeDIE(DIE &Buffer, DIDerivedType DTy) {
     addSourceLine(&Buffer, DTy);
 }
 
+/// constructSubprogramArguments - Construct function argument DIEs.
+void CompileUnit::constructSubprogramArguments(DIE &Buffer, DIArray Args) {
+    for (unsigned i = 1, N = Args.getNumElements(); i < N; ++i) {
+      DIDescriptor Ty = Args.getElement(i);
+      if (Ty.isUnspecifiedParameter()) {
+        assert(i == N-1 && "ellipsis must be the last argument");
+        createAndAddDIE(dwarf::DW_TAG_unspecified_parameters, Buffer);
+      } else {
+        DIE *Arg = createAndAddDIE(dwarf::DW_TAG_formal_parameter, Buffer);
+        addType(Arg, DIType(Ty));
+        if (DIType(Ty).isArtificial())
+          addFlag(Arg, dwarf::DW_AT_artificial);
+      }
+    }
+}
+
 /// Return true if the type is appropriately scoped to be contained inside
 /// its own type unit.
 static bool isTypeUnitScoped(DIType Ty, const DwarfDebug *DD) {
@@ -1170,19 +1186,12 @@ void CompileUnit::constructTypeDIE(DIE &Buffer, DICompositeType CTy) {
       addType(&Buffer, RTy);
 
     bool isPrototyped = true;
-    // Add arguments.
-    for (unsigned i = 1, N = Elements.getNumElements(); i < N; ++i) {
-      DIDescriptor Ty = Elements.getElement(i);
-      if (Ty.isUnspecifiedParameter()) {
-        createAndAddDIE(dwarf::DW_TAG_unspecified_parameters, Buffer);
-        isPrototyped = false;
-      } else {
-        DIE *Arg = createAndAddDIE(dwarf::DW_TAG_formal_parameter, Buffer);
-        addType(Arg, DIType(Ty));
-        if (DIType(Ty).isArtificial())
-          addFlag(Arg, dwarf::DW_AT_artificial);
-      }
-    }
+    if (Elements.getNumElements() == 2 &&
+        Elements.getElement(1).isUnspecifiedParameter())
+      isPrototyped = false;
+
+    constructSubprogramArguments(Buffer, Elements);
+
     // Add prototype flag if we're dealing with a C language and the
     // function has been prototyped.
     uint16_t Language = getLanguage();
@@ -1475,13 +1484,7 @@ DIE *CompileUnit::getOrCreateSubprogramDIE(DISubprogram SP) {
 
     // Add arguments. Do not add arguments for subprogram definition. They will
     // be handled while processing variables.
-    for (unsigned i = 1, N = Args.getNumElements(); i < N; ++i) {
-      DIE *Arg = createAndAddDIE(dwarf::DW_TAG_formal_parameter, *SPDie);
-      DIType ATy(Args.getElement(i));
-      addType(Arg, ATy);
-      if (ATy.isArtificial())
-        addFlag(Arg, dwarf::DW_AT_artificial);
-    }
+    constructSubprogramArguments(*SPDie, Args);
   }
 
   if (SP.isArtificial())