MFC debug info for variadic functions

r264826: 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

r264827: Merge Clang r202185:

    Debug info: Generate debug info for variadic functions.
    Paired commit with LLVM.

    rdar://problem/13690847

  This merege includes changes to use the Clang 3.4 API (revisions
  199686 and 200082) in lib/CodeGen/CGDebugInfo.cpp:

  getParamType  -> getArgType
  getNumParams  -> getNumArgs
  getReturnType -> getResultType

r264828: Add patches corresponding to r264826 and r264827

Sponsored by:	DARPA, AFRL

2 files changed, 250 insertions, 0 deletions

diff --git a/contrib/llvm/patches/patch-r264826-llvm-r202188-variadic-fn-debug-info.diff b/contrib/llvm/patches/patch-r264826-llvm-r202188-variadic-fn-debug-info.diff
new file mode 100644
index 0000000..6bb1db9
--- /dev/null
+++ b/contrib/llvm/patches/patch-r264826-llvm-r202188-variadic-fn-debug-info.diff
@@ -0,0 +1,176 @@
+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
+
+http://svnweb.freebsd.org/changeset/base/264826
+
+Index: include/llvm/DIBuilder.h
+===================================================================
+--- include/llvm/DIBuilder.h	(revision 264825)
++++ include/llvm/DIBuilder.h	(revision 264826)
+@@ -439,7 +439,7 @@
+     /// through debug info anchors.
+     void retainType(DIType T);
+ 
+-    /// createUnspecifiedParameter - Create unspeicified type descriptor
++    /// createUnspecifiedParameter - Create unspecified type descriptor
+     /// for a subroutine type.
+     DIDescriptor createUnspecifiedParameter();
+ 
+Index: lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+===================================================================
+--- lib/CodeGen/AsmPrinter/DwarfDebug.cpp	(revision 264825)
++++ lib/CodeGen/AsmPrinter/DwarfDebug.cpp	(revision 264826)
+@@ -404,15 +404,21 @@
+         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 =
++            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);
+-            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);
++              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 *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 @@
+           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)
+Index: lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
+===================================================================
+--- lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp	(revision 264825)
++++ lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp	(revision 264826)
+@@ -1116,6 +1116,22 @@
+     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 @@
+       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 @@
+ 
+     // 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())
+Index: lib/CodeGen/AsmPrinter/DwarfCompileUnit.h
+===================================================================
+--- lib/CodeGen/AsmPrinter/DwarfCompileUnit.h	(revision 264825)
++++ lib/CodeGen/AsmPrinter/DwarfCompileUnit.h	(revision 264826)
+@@ -342,6 +342,9 @@
+   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/patches/patch-r264827-clang-r202185-variadic-fn-debug-info.diff b/contrib/llvm/patches/patch-r264827-clang-r202185-variadic-fn-debug-info.diff
new file mode 100644
index 0000000..7084f7b
--- /dev/null
+++ b/contrib/llvm/patches/patch-r264827-clang-r202185-variadic-fn-debug-info.diff
@@ -0,0 +1,74 @@
+Merge Clang r202185:
+
+  Debug info: Generate debug info for variadic functions.
+  Paired commit with LLVM.
+
+  rdar://problem/13690847
+
+This merege includes changes to use the Clang 3.4 API (revisions
+199686 and 200082) in lib/CodeGen/CGDebugInfo.cpp:
+
+getParamType  -> getArgType
+getNumParams  -> getNumArgs
+getReturnType -> getResultType
+
+Sponsored by:	DARPA, AFRL
+
+http://svnweb.freebsd.org/changeset/base/264827
+
+Index: tools/clang/lib/CodeGen/CGDebugInfo.cpp
+===================================================================
+--- tools/clang/lib/CodeGen/CGDebugInfo.cpp	(revision 264826)
++++ tools/clang/lib/CodeGen/CGDebugInfo.cpp	(revision 264827)
+@@ -37,7 +37,7 @@
+ #include "llvm/IR/Module.h"
+ #include "llvm/Support/Dwarf.h"
+ #include "llvm/Support/FileSystem.h"
+-#include "llvm/Support/Path.h"

++#include "llvm/Support/Path.h"
+ using namespace clang;
+ using namespace clang::CodeGen;
+ 
+@@ -342,9 +342,9 @@
+   if (const FileEntry *MainFile = SM.getFileEntryForID(SM.getMainFileID())) {
+     MainFileDir = MainFile->getDir()->getName();
+     if (MainFileDir != ".") {
+-      llvm::SmallString<1024> MainFileDirSS(MainFileDir);

+-      llvm::sys::path::append(MainFileDirSS, MainFileName);

+-      MainFileName = MainFileDirSS.str();

++      llvm::SmallString<1024> MainFileDirSS(MainFileDir);
++      llvm::sys::path::append(MainFileDirSS, MainFileName);
++      MainFileName = MainFileDirSS.str();
+     }
+   }
+ 
+@@ -760,6 +760,8 @@
+   else if (const FunctionProtoType *FPT = dyn_cast<FunctionProtoType>(Ty)) {
+     for (unsigned i = 0, e = FPT->getNumArgs(); i != e; ++i)
+       EltTys.push_back(getOrCreateType(FPT->getArgType(i), Unit));
++    if (FPT->isVariadic())
++      EltTys.push_back(DBuilder.createUnspecifiedParameter());
+   }
+ 
+   llvm::DIArray EltTypeArray = DBuilder.getOrCreateArray(EltTys);
+@@ -2420,6 +2422,20 @@
+     llvm::DIArray EltTypeArray = DBuilder.getOrCreateArray(Elts);
+     return DBuilder.createSubroutineType(F, EltTypeArray);
+   }
++
++  // Variadic function.
++  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
++    if (FD->isVariadic()) {
++      SmallVector<llvm::Value *, 16> EltTys;
++      EltTys.push_back(getOrCreateType(FD->getResultType(), F));
++      if (const FunctionProtoType *FPT = dyn_cast<FunctionProtoType>(FnType))
++        for (unsigned i = 0, e = FPT->getNumArgs(); i != e; ++i)
++          EltTys.push_back(getOrCreateType(FPT->getArgType(i), F));
++      EltTys.push_back(DBuilder.createUnspecifiedParameter());
++      llvm::DIArray EltTypeArray = DBuilder.getOrCreateArray(EltTys);
++      return DBuilder.createSubroutineType(F, EltTypeArray);
++    }
++
+   return llvm::DICompositeType(getOrCreateType(FnType, F));
+ }
+