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

3 files changed, 50 insertions, 28 deletions

diff --git a/contrib/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp b/contrib/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
index 97ef68780f71..50f5cc912aba 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())
diff --git a/contrib/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.h b/contrib/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.h
index 69a96df193c8..b9e941ebb472 100644
--- a/contrib/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.h
+++ b/contrib/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.h
@@ -342,6 +342,9 @@ public:
   void emitHeader(const MCSection *ASection, const MCSymbol *ASectionSym);
 
 private:
+  /// constructSubprogramArguments - Construct function argument DIEs.
+  void constructSubprogramArguments(DIE &Buffer, DIArray Args);
+
   /// constructTypeDIE - Construct basic type die from DIBasicType.
   void constructTypeDIE(DIE &Buffer, DIBasicType BTy);
 
diff --git a/contrib/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/contrib/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index d1e1ad1d5003..d922433e447c 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)