DI: Remove DW_TAG_arg_variable and DW_TAG_auto_variable

Remove the fake `DW_TAG_auto_variable` and `DW_TAG_arg_variable` tags,
using `DW_TAG_variable` in their place Stop exposing the `tag:` field at
all in the assembly format for `DILocalVariable`.

Most of the testcase updates were generated by the following sed script:

    find test/ -name "*.ll" -o -name "*.mir" |
    xargs grep -l 'DILocalVariable' |
    xargs sed -i '' \
      -e 's/tag: DW_TAG_arg_variable, //' \
      -e 's/tag: DW_TAG_auto_variable, //'

There were only a handful of tests in `test/Assembly` that I needed to
update by hand.

(Note: a follow-up could change `DILocalVariable::DILocalVariable()` to
set the tag to `DW_TAG_formal_parameter` instead of `DW_TAG_variable`
(as appropriate), instead of having that logic magically in the backend
in `DbgVariable`.  I've added a FIXME to that effect.)

llvm-svn: 243774

5 files changed, 25 insertions, 34 deletions

diff --git a/llvm/lib/IR/AsmWriter.cpp b/llvm/lib/IR/AsmWriter.cpp
index e3905de6597..4f4e9850061 100644
--- a/llvm/lib/IR/AsmWriter.cpp
+++ b/llvm/lib/IR/AsmWriter.cpp
@@ -1800,11 +1800,8 @@ static void writeDILocalVariable(raw_ostream &Out, const DILocalVariable *N,
                                  SlotTracker *Machine, const Module *Context) {
   Out << "!DILocalVariable(";
   MDFieldPrinter Printer(Out, TypePrinter, Machine, Context);
-  Printer.printTag(N);
   Printer.printString("name", N->getName());
-  Printer.printInt("arg", N->getArg(),
-                   /* ShouldSkipZero */
-                   N->getTag() == dwarf::DW_TAG_auto_variable);
+  Printer.printInt("arg", N->getArg());
   Printer.printMetadata("scope", N->getRawScope(), /* ShouldSkipNull */ false);
   Printer.printMetadata("file", N->getRawFile());
   Printer.printInt("line", N->getLine());
diff --git a/llvm/lib/IR/DIBuilder.cpp b/llvm/lib/IR/DIBuilder.cpp
index 7a4c5203965..3e5a50a8952 100644
--- a/llvm/lib/IR/DIBuilder.cpp
+++ b/llvm/lib/IR/DIBuilder.cpp
@@ -613,10 +613,9 @@ static DILocalVariable *createLocalVariable(
   // the only valid scopes)?
   DIScope *Context = getNonCompileUnitScope(Scope);
 
-  dwarf::Tag Tag = ArgNo ? dwarf::DW_TAG_arg_variable : dwarf::DW_TAG_auto_variable;
-  auto *Node = DILocalVariable::get(
-      VMContext, Tag, cast_or_null<DILocalScope>(Context), Name, File, LineNo,
-      DITypeRef::get(Ty), ArgNo, Flags);
+  auto *Node =
+      DILocalVariable::get(VMContext, cast_or_null<DILocalScope>(Context), Name,
+                           File, LineNo, DITypeRef::get(Ty), ArgNo, Flags);
   if (AlwaysPreserve) {
     // The optimizer may remove local variables. If there is an interest
     // to preserve variable info in such situation then stash it in a
diff --git a/llvm/lib/IR/DebugInfoMetadata.cpp b/llvm/lib/IR/DebugInfoMetadata.cpp
index db6da05cfd8..4adda6fb293 100644
--- a/llvm/lib/IR/DebugInfoMetadata.cpp
+++ b/llvm/lib/IR/DebugInfoMetadata.cpp
@@ -466,21 +466,21 @@ DIGlobalVariable::getImpl(LLVMContext &Context, Metadata *Scope, MDString *Name,
                        Ops);
 }
 
-DILocalVariable *DILocalVariable::getImpl(LLVMContext &Context, unsigned Tag,
-                                          Metadata *Scope, MDString *Name,
-                                          Metadata *File, unsigned Line,
-                                          Metadata *Type, unsigned Arg,
-                                          unsigned Flags, StorageType Storage,
+DILocalVariable *DILocalVariable::getImpl(LLVMContext &Context, Metadata *Scope,
+                                          MDString *Name, Metadata *File,
+                                          unsigned Line, Metadata *Type,
+                                          unsigned Arg, unsigned Flags,
+                                          StorageType Storage,
                                           bool ShouldCreate) {
   // 64K ought to be enough for any frontend.
   assert(Arg <= UINT16_MAX && "Expected argument number to fit in 16-bits");
 
   assert(Scope && "Expected scope");
   assert(isCanonical(Name) && "Expected canonical MDString");
-  DEFINE_GETIMPL_LOOKUP(DILocalVariable, (Tag, Scope, getString(Name), File,
-                                          Line, Type, Arg, Flags));
+  DEFINE_GETIMPL_LOOKUP(DILocalVariable,
+                        (Scope, getString(Name), File, Line, Type, Arg, Flags));
   Metadata *Ops[] = {Scope, Name, File, Type};
-  DEFINE_GETIMPL_STORE(DILocalVariable, (Tag, Line, Arg, Flags), Ops);
+  DEFINE_GETIMPL_STORE(DILocalVariable, (Line, Arg, Flags), Ops);
 }
 
 DIExpression *DIExpression::getImpl(LLVMContext &Context,
diff --git a/llvm/lib/IR/LLVMContextImpl.h b/llvm/lib/IR/LLVMContextImpl.h
index cbbf11e334c..35897a93788 100644
--- a/llvm/lib/IR/LLVMContextImpl.h
+++ b/llvm/lib/IR/LLVMContextImpl.h
@@ -759,7 +759,6 @@ template <> struct MDNodeKeyImpl<DIGlobalVariable> {
 };
 
 template <> struct MDNodeKeyImpl<DILocalVariable> {
-  unsigned Tag;
   Metadata *Scope;
   StringRef Name;
   Metadata *File;
@@ -768,23 +767,23 @@ template <> struct MDNodeKeyImpl<DILocalVariable> {
   unsigned Arg;
   unsigned Flags;
 
-  MDNodeKeyImpl(unsigned Tag, Metadata *Scope, StringRef Name, Metadata *File,
-                unsigned Line, Metadata *Type, unsigned Arg, unsigned Flags)
-      : Tag(Tag), Scope(Scope), Name(Name), File(File), Line(Line), Type(Type),
-        Arg(Arg), Flags(Flags) {}
+  MDNodeKeyImpl(Metadata *Scope, StringRef Name, Metadata *File, unsigned Line,
+                Metadata *Type, unsigned Arg, unsigned Flags)
+      : Scope(Scope), Name(Name), File(File), Line(Line), Type(Type), Arg(Arg),
+        Flags(Flags) {}
   MDNodeKeyImpl(const DILocalVariable *N)
-      : Tag(N->getTag()), Scope(N->getRawScope()), Name(N->getName()),
-        File(N->getRawFile()), Line(N->getLine()), Type(N->getRawType()),
-        Arg(N->getArg()), Flags(N->getFlags()) {}
+      : Scope(N->getRawScope()), Name(N->getName()), File(N->getRawFile()),
+        Line(N->getLine()), Type(N->getRawType()), Arg(N->getArg()),
+        Flags(N->getFlags()) {}
 
   bool isKeyOf(const DILocalVariable *RHS) const {
-    return Tag == RHS->getTag() && Scope == RHS->getRawScope() &&
-           Name == RHS->getName() && File == RHS->getRawFile() &&
-           Line == RHS->getLine() && Type == RHS->getRawType() &&
-           Arg == RHS->getArg() && Flags == RHS->getFlags();
+    return Scope == RHS->getRawScope() && Name == RHS->getName() &&
+           File == RHS->getRawFile() && Line == RHS->getLine() &&
+           Type == RHS->getRawType() && Arg == RHS->getArg() &&
+           Flags == RHS->getFlags();
   }
   unsigned getHashValue() const {
-    return hash_combine(Tag, Scope, Name, File, Line, Type, Arg, Flags);
+    return hash_combine(Scope, Name, File, Line, Type, Arg, Flags);
   }
 };
 
diff --git a/llvm/lib/IR/Verifier.cpp b/llvm/lib/IR/Verifier.cpp
index 855456d0b2b..7d791acf838 100644
--- a/llvm/lib/IR/Verifier.cpp
+++ b/llvm/lib/IR/Verifier.cpp
@@ -1077,13 +1077,9 @@ void Verifier::visitDILocalVariable(const DILocalVariable &N) {
   // Checks common to all variables.
   visitDIVariable(N);
 
-  Assert(N.getTag() == dwarf::DW_TAG_auto_variable ||
-             N.getTag() == dwarf::DW_TAG_arg_variable,
-         "invalid tag", &N);
+  Assert(N.getTag() == dwarf::DW_TAG_variable, "invalid tag", &N);
   Assert(N.getRawScope() && isa<DILocalScope>(N.getRawScope()),
          "local variable requires a valid scope", &N, N.getRawScope());
-  Assert(bool(N.getArg()) == (N.getTag() == dwarf::DW_TAG_arg_variable),
-         "local variable should have arg iff it's a DW_TAG_arg_variable", &N);
 }
 
 void Verifier::visitDIExpression(const DIExpression &N) {