Address review comments for r202188.

This is refactoring / simplifying code, updating comments and enabling the
testcase on non-x86 platforms.

No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202199 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/AsmPrinter/DwarfDebug.cpp

@@ -403,22 +403,7 @@ DIE *DwarfDebug::updateSubprogramScopeDIE(DwarfCompileUnit *SPCU,
         DIArray Args = SPTy.getTypeArray();
         uint16_t SPTag = SPTy.getTag();
         if (SPTag == dwarf::DW_TAG_subroutine_type)
-          // FIXME: Use DwarfUnit::constructSubprogramArguments() here.
+          SPCU->constructSubprogramArguments(*SPDie, Args);
-          for (unsigned i = 1, N = Args.getNumElements(); i < N; ++i) {
-            DIType ATy(Args.getElement(i));
-            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 = SPCU->createAndAddDIE(dwarf::DW_TAG_subprogram,
                                       *SPCU->getUnitDie());
@@ -598,9 +583,8 @@ DIE *DwarfDebug::createScopeChildrenDIE(DwarfCompileUnit *TheCU,
             ObjectPointer = Arg;
         }
 
-    // Create the unspecified parameter that marks a function as variadic.
+    // If this is a variadic function, add an unspecified parameter.
     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);

lib/CodeGen/AsmPrinter/DwarfUnit.cpp

@@ -1141,18 +1141,18 @@ void DwarfUnit::constructTypeDIE(DIE &Buffer, DIDerivedType DTy) {
 
 /// constructSubprogramArguments - Construct function argument DIEs.
 void DwarfUnit::constructSubprogramArguments(DIE &Buffer, DIArray Args) {
-    for (unsigned i = 1, N = Args.getNumElements(); i < N; ++i) {
+  for (unsigned i = 1, N = Args.getNumElements(); i < N; ++i) {
-      DIDescriptor Ty = Args.getElement(i);
+    DIDescriptor Ty = Args.getElement(i);
-      if (Ty.isUnspecifiedParameter()) {
+    if (Ty.isUnspecifiedParameter()) {
-        assert(i == N-1 && "ellipsis must be the last argument");
+      assert(i == N-1 && "Unspecified parameter must be the last argument");
-        createAndAddDIE(dwarf::DW_TAG_unspecified_parameters, Buffer);
+      createAndAddDIE(dwarf::DW_TAG_unspecified_parameters, Buffer);
-      } else {
+    } else {
-        DIE *Arg = createAndAddDIE(dwarf::DW_TAG_formal_parameter, Buffer);
+      DIE *Arg = createAndAddDIE(dwarf::DW_TAG_formal_parameter, Buffer);
-        addType(Arg, DIType(Ty));
+      addType(Arg, DIType(Ty));
-        if (DIType(Ty).isArtificial())
+      if (DIType(Ty).isArtificial())
-          addFlag(Arg, dwarf::DW_AT_artificial);
+        addFlag(Arg, dwarf::DW_AT_artificial);
-      }
     }
+  }
 }
 
 /// constructTypeDIE - Construct type DIE from DICompositeType.

lib/CodeGen/AsmPrinter/DwarfUnit.h

@@ -452,6 +452,9 @@ public:
   /// constructVariableDIE - Construct a DIE for the given DbgVariable.
   DIE *constructVariableDIE(DbgVariable &DV, bool isScopeAbstract);
 
+  /// constructSubprogramArguments - Construct function argument DIEs.
+  void constructSubprogramArguments(DIE &Buffer, DIArray Args);
+
   /// Create a DIE with the given Tag, add the DIE to its parent, and
   /// call insertDIE if MD is not null.
   DIE *createAndAddDIE(unsigned Tag, DIE &Parent,
@@ -476,9 +479,6 @@ protected:
   DIE *getOrCreateStaticMemberDIE(DIDerivedType DT);
 
 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);
 

test/DebugInfo/varargs.ll

@@ -1,18 +1,31 @@
 ; RUN: llc -O0 -filetype=obj -o %t.o %s
 ; RUN: llvm-dwarfdump -debug-dump=info %t.o | FileCheck %s
+; REQUIRES: object-emission
+;
+; Test debug info for variadic function arguments.
+; Created from tools/clang/tests/CodeGenCXX/debug-info-varargs.cpp
+;
+; The ... parameter of variadic should be emitted as
+; DW_TAG_unspecified_parameters.
 ;
 ; Normal variadic function.
+; void b(int c, ...);
 ;
 ; CHECK: DW_TAG_subprogram
 ; CHECK-NOT: DW_TAG
+; CHECK: DW_AT_name {{.*}} "b"
+; CHECK-NOT: DW_TAG
 ; CHECK: DW_TAG_formal_parameter
 ; CHECK-NOT: DW_TAG
 ; CHECK: DW_TAG_unspecified_parameters
 ;
 ; Variadic C++ member function.
+; struct A { void a(int c, ...); }
 ;
 ; CHECK: DW_TAG_subprogram
 ; CHECK-NOT: DW_TAG
+; CHECK: DW_AT_name {{.*}} "a"
+; CHECK-NOT: DW_TAG
 ; CHECK: DW_TAG_formal_parameter
 ; CHECK-NOT: DW_TAG
 ; CHECK: DW_TAG_formal_parameter
@@ -20,6 +33,7 @@
 ; CHECK: DW_TAG_unspecified_parameters
 ;
 ; Variadic function pointer.
+; void (*fptr)(int, ...);
 ;
 ; CHECK: DW_TAG_subroutine_type
 ; CHECK-NOT: DW_TAG
@@ -27,12 +41,7 @@
 ; CHECK-NOT: DW_TAG
 ; CHECK: DW_TAG_unspecified_parameters
 ;
-; Test debug info for variadic function arguments.
-; Created from tools/clang/tests/CodeGenCXX/debug-info-varargs.cpp
-;
 ; ModuleID = 'llvm/tools/clang/test/CodeGenCXX/debug-info-varargs.cpp'
-target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
-target triple = "x86_64-apple-macosx10.9.0"
 
 %struct.A = type { i8 }