Remove support for versioned debug info.

Versioned debug info support has been a burden to maintain & also compromised
current debug info verification by causing test cases testing old debug info to
remain rather than being updated to the latest. It also makes it hard to add or
change the metadata schema by requiring various backwards-compatibility in the
DI* hierarchy.

So it's being removed in preparation for new changes to the schema to tidy up
old/unnecessary fields and add new fields needed for new debug info (well, new
to LLVM at least).

The more surprising part of this is the changes to DI*::Verify - this became
necessary due to the changes to AsmWriter. AsmWriter was relying on the version
test to decide which bits of metadata were actually debug info when printing
the comment annotations. Without the version information the tag numbers were
too common & it would print debug info on random metadata that happened to
start with an integer that matched a tag number. Instead this change makes the
Verify functions more precise (just adding "number of operands" checks - not
type checking those operands yet) & relies on that to decide which metadata is
debug info metadata.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176838 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 87 insertions, 95 deletions

diff --git a/lib/IR/AsmWriter.cpp b/lib/IR/AsmWriter.cpp
index 9954a29..fb591a8 100644
--- a/lib/IR/AsmWriter.cpp
+++ b/lib/IR/AsmWriter.cpp
@@ -2094,7 +2094,7 @@ static void WriteMDNodeComment(const MDNode *Node,
     return;
 
   DIDescriptor Desc(Node);
-  if (Desc.getVersion() < LLVMDebugVersion11)
+  if (!Desc.Verify())
     return;
 
   unsigned Tag = Desc.getTag();
diff --git a/lib/IR/DebugInfo.cpp b/lib/IR/DebugInfo.cpp
index 9a5e473..e85d4ad 100644
--- a/lib/IR/DebugInfo.cpp
+++ b/lib/IR/DebugInfo.cpp
@@ -51,6 +51,21 @@ DIDescriptor::DIDescriptor(const DIVariable F) : DbgNode(F.DbgNode) {
 DIDescriptor::DIDescriptor(const DIType F) : DbgNode(F.DbgNode) {
 }
 
+bool DIDescriptor::Verify() const {
+  return DbgNode &&
+         (DIDerivedType(DbgNode).Verify() ||
+          DICompositeType(DbgNode).Verify() || DIBasicType(DbgNode).Verify() ||
+          DIVariable(DbgNode).Verify() || DISubprogram(DbgNode).Verify() ||
+          DIGlobalVariable(DbgNode).Verify() || DIFile(DbgNode).Verify() ||
+          DICompileUnit(DbgNode).Verify() || DINameSpace(DbgNode).Verify() ||
+          DILexicalBlock(DbgNode).Verify() ||
+          DILexicalBlockFile(DbgNode).Verify() ||
+          DISubrange(DbgNode).Verify() || DIEnumerator(DbgNode).Verify() ||
+          DIObjCProperty(DbgNode).Verify() ||
+          DITemplateTypeParameter(DbgNode).Verify() ||
+          DITemplateValueParameter(DbgNode).Verify());
+}
+
 StringRef
 DIDescriptor::getStringField(unsigned Elt) const {
   if (DbgNode == 0)
@@ -135,17 +150,11 @@ void DIDescriptor::replaceFunctionField(unsigned Elt, Function *F) {
 }
 
 unsigned DIVariable::getNumAddrElements() const {
-  if (getVersion() <= LLVMDebugVersion8)
-    return DbgNode->getNumOperands()-6;
-  if (getVersion() == LLVMDebugVersion9)
-    return DbgNode->getNumOperands()-7;
   return DbgNode->getNumOperands()-8;
 }
 
 /// getInlinedAt - If this variable is inlined then return inline location.
 MDNode *DIVariable::getInlinedAt() const {
-  if (getVersion() <= LLVMDebugVersion9)
-    return NULL;
   return dyn_cast_or_null<MDNode>(DbgNode->getOperand(7));
 }
 
@@ -392,31 +401,30 @@ bool DIType::isUnsignedDIType() {
 
 /// Verify - Verify that a compile unit is well formed.
 bool DICompileUnit::Verify() const {
-  if (!DbgNode)
+  if (!isCompileUnit())
     return false;
   StringRef N = getFilename();
   if (N.empty())
     return false;
   // It is possible that directory and produce string is empty.
-  return true;
+  return DbgNode->getNumOperands() == 15;
 }
 
 /// Verify - Verify that an ObjC property is well formed.
 bool DIObjCProperty::Verify() const {
-  if (!DbgNode)
+  if (!isObjCProperty())
     return false;
-  unsigned Tag = getTag();
-  if (Tag != dwarf::DW_TAG_APPLE_property) return false;
+
   DIType Ty = getType();
   if (!Ty.Verify()) return false;
 
   // Don't worry about the rest of the strings for now.
-  return true;
+  return DbgNode->getNumOperands() == 8;
 }
 
 /// Verify - Verify that a type descriptor is well formed.
 bool DIType::Verify() const {
-  if (!DbgNode)
+  if (!isType())
     return false;
   if (getContext() && !getContext().Verify())
     return false;
@@ -437,27 +445,28 @@ bool DIType::Verify() const {
 
 /// Verify - Verify that a basic type descriptor is well formed.
 bool DIBasicType::Verify() const {
-  return isBasicType();
+  return isBasicType() && DbgNode->getNumOperands() == 10;
 }
 
 /// Verify - Verify that a derived type descriptor is well formed.
 bool DIDerivedType::Verify() const {
-  return isDerivedType();
+  return isDerivedType() && DbgNode->getNumOperands() >= 10 &&
+         DbgNode->getNumOperands() <= 14;
 }
 
 /// Verify - Verify that a composite type descriptor is well formed.
 bool DICompositeType::Verify() const {
-  if (!DbgNode)
+  if (!isCompositeType())
     return false;
   if (getContext() && !getContext().Verify())
     return false;
 
-  return true;
+  return DbgNode->getNumOperands() >= 10 && DbgNode->getNumOperands() <= 14;
 }
 
 /// Verify - Verify that a subprogram descriptor is well formed.
 bool DISubprogram::Verify() const {
-  if (!DbgNode)
+  if (!isSubprogram())
     return false;
 
   if (getContext() && !getContext().Verify())
@@ -466,12 +475,12 @@ bool DISubprogram::Verify() const {
   DICompositeType Ty = getType();
   if (!Ty.Verify())
     return false;
-  return true;
+  return DbgNode->getNumOperands() == 21;
 }
 
 /// Verify - Verify that a global variable descriptor is well formed.
 bool DIGlobalVariable::Verify() const {
-  if (!DbgNode)
+  if (!isGlobalVariable())
     return false;
 
   if (getDisplayName().empty())
@@ -487,12 +496,12 @@ bool DIGlobalVariable::Verify() const {
   if (!getGlobal() && !getConstant())
     return false;
 
-  return true;
+  return DbgNode->getNumOperands() == 13;
 }
 
 /// Verify - Verify that a variable descriptor is well formed.
 bool DIVariable::Verify() const {
-  if (!DbgNode)
+  if (!isVariable())
     return false;
 
   if (getContext() && !getContext().Verify())
@@ -502,7 +511,7 @@ bool DIVariable::Verify() const {
   if (!Ty.Verify())
     return false;
 
-  return true;
+  return DbgNode->getNumOperands() >= 8;
 }
 
 /// Verify - Verify that a location descriptor is well formed.
@@ -515,9 +524,44 @@ bool DILocation::Verify() const {
 
 /// Verify - Verify that a namespace descriptor is well formed.
 bool DINameSpace::Verify() const {
-  if (!DbgNode)
+  if (!isNameSpace())
     return false;
-  return true;
+  return DbgNode->getNumOperands() == 5;
+}
+
+/// \brief Verify that the file descriptor is well formed.
+bool DIFile::Verify() const {
+  return isFile() && DbgNode->getNumOperands() == 4;
+}
+
+/// \brief Verify that the enumerator descriptor is well formed.
+bool DIEnumerator::Verify() const {
+  return isEnumerator() && DbgNode->getNumOperands() == 3;
+}
+
+/// \brief Verify that the subrange descriptor is well formed.
+bool DISubrange::Verify() const {
+  return isSubrange() && DbgNode->getNumOperands() == 3;
+}
+
+/// \brief Verify that the lexical block descriptor is well formed.
+bool DILexicalBlock::Verify() const {
+  return isLexicalBlock() && DbgNode->getNumOperands() == 6;
+}
+
+/// \brief Verify that the file-scoped lexical block descriptor is well formed.
+bool DILexicalBlockFile::Verify() const {
+  return isLexicalBlockFile() && DbgNode->getNumOperands() == 3;
+}
+
+/// \brief Verify that the template type parameter descriptor is well formed.
+bool DITemplateTypeParameter::Verify() const {
+  return isTemplateTypeParameter() && DbgNode->getNumOperands() == 7;
+}
+
+/// \brief Verify that the template value parameter descriptor is well formed.
+bool DITemplateValueParameter::Verify() const {
+  return isTemplateValueParameter() && DbgNode->getNumOperands() == 8;
 }
 
 /// getOriginalTypeSize - If this type is derived from a base type then
@@ -551,7 +595,7 @@ uint64_t DIDerivedType::getOriginalTypeSize() const {
 
 /// getObjCProperty - Return property node, if this ivar is associated with one.
 MDNode *DIDerivedType::getObjCProperty() const {
-  if (getVersion() <= LLVMDebugVersion11 || DbgNode->getNumOperands() <= 10)
+  if (DbgNode->getNumOperands() <= 10)
     return NULL;
   return dyn_cast_or_null<MDNode>(DbgNode->getOperand(10));
 }
@@ -803,71 +847,25 @@ void DebugInfoFinder::processModule(const Module &M) {
     for (unsigned i = 0, e = CU_Nodes->getNumOperands(); i != e; ++i) {
       DICompileUnit CU(CU_Nodes->getOperand(i));
       addCompileUnit(CU);
-      if (CU.getVersion() > LLVMDebugVersion10) {
-        DIArray GVs = CU.getGlobalVariables();
-        for (unsigned i = 0, e = GVs.getNumElements(); i != e; ++i) {
-          DIGlobalVariable DIG(GVs.getElement(i));
-          if (addGlobalVariable(DIG))
-            processType(DIG.getType());
-        }
-        DIArray SPs = CU.getSubprograms();
-        for (unsigned i = 0, e = SPs.getNumElements(); i != e; ++i)
-          processSubprogram(DISubprogram(SPs.getElement(i)));
-        DIArray EnumTypes = CU.getEnumTypes();
-        for (unsigned i = 0, e = EnumTypes.getNumElements(); i != e; ++i)
-          processType(DIType(EnumTypes.getElement(i)));
-        DIArray RetainedTypes = CU.getRetainedTypes();
-        for (unsigned i = 0, e = RetainedTypes.getNumElements(); i != e; ++i)
-          processType(DIType(RetainedTypes.getElement(i)));
-        return;
-      }
-    }
-  }
-
-  for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I)
-    for (Function::const_iterator FI = (*I).begin(), FE = (*I).end();
-         FI != FE; ++FI)
-      for (BasicBlock::const_iterator BI = (*FI).begin(), BE = (*FI).end();
-           BI != BE; ++BI) {
-        if (const DbgDeclareInst *DDI = dyn_cast<DbgDeclareInst>(BI))
-          processDeclare(DDI);
-
-        DebugLoc Loc = BI->getDebugLoc();
-        if (Loc.isUnknown())
-          continue;
-
-        LLVMContext &Ctx = BI->getContext();
-        DIDescriptor Scope(Loc.getScope(Ctx));
-
-        if (Scope.isCompileUnit())
-          addCompileUnit(DICompileUnit(Scope));
-        else if (Scope.isSubprogram())
-          processSubprogram(DISubprogram(Scope));
-        else if (Scope.isLexicalBlockFile()) {
-          DILexicalBlockFile DBF = DILexicalBlockFile(Scope);
-          processLexicalBlock(DILexicalBlock(DBF.getScope()));
-        }
-        else if (Scope.isLexicalBlock())
-          processLexicalBlock(DILexicalBlock(Scope));
-
-        if (MDNode *IA = Loc.getInlinedAt(Ctx))
-          processLocation(DILocation(IA));
-      }
-
-  if (NamedMDNode *NMD = M.getNamedMetadata("llvm.dbg.gv")) {
-    for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
-      DIGlobalVariable DIG(cast<MDNode>(NMD->getOperand(i)));
-      if (addGlobalVariable(DIG)) {
-        if (DIG.getVersion() <= LLVMDebugVersion10)
-          addCompileUnit(DIG.getCompileUnit());
-        processType(DIG.getType());
+      DIArray GVs = CU.getGlobalVariables();
+      for (unsigned i = 0, e = GVs.getNumElements(); i != e; ++i) {
+        DIGlobalVariable DIG(GVs.getElement(i));
+        if (addGlobalVariable(DIG))
+          processType(DIG.getType());
       }
+      DIArray SPs = CU.getSubprograms();
+      for (unsigned i = 0, e = SPs.getNumElements(); i != e; ++i)
+        processSubprogram(DISubprogram(SPs.getElement(i)));
+      DIArray EnumTypes = CU.getEnumTypes();
+      for (unsigned i = 0, e = EnumTypes.getNumElements(); i != e; ++i)
+        processType(DIType(EnumTypes.getElement(i)));
+      DIArray RetainedTypes = CU.getRetainedTypes();
+      for (unsigned i = 0, e = RetainedTypes.getNumElements(); i != e; ++i)
+        processType(DIType(RetainedTypes.getElement(i)));
+      // FIXME: We really shouldn't be bailing out after visiting just one CU
+      return;
     }
   }
-
-  if (NamedMDNode *NMD = M.getNamedMetadata("llvm.dbg.sp"))
-    for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i)
-      processSubprogram(DISubprogram(NMD->getOperand(i)));
 }
 
 /// processLocation - Process DILocation.
@@ -891,8 +889,6 @@ void DebugInfoFinder::processLocation(DILocation Loc) {
 void DebugInfoFinder::processType(DIType DT) {
   if (!addType(DT))
     return;
-  if (DT.getVersion() <= LLVMDebugVersion10)
-    addCompileUnit(DT.getCompileUnit());
   if (DT.isCompositeType()) {
     DICompositeType DCT(DT);
     processType(DCT.getTypeDerivedFrom());
@@ -927,8 +923,6 @@ void DebugInfoFinder::processLexicalBlock(DILexicalBlock LB) {
 void DebugInfoFinder::processSubprogram(DISubprogram SP) {
   if (!addSubprogram(SP))
     return;
-  if (SP.getVersion() <= LLVMDebugVersion10)
-    addCompileUnit(SP.getCompileUnit());
   processType(SP.getType());
 }
 
@@ -943,8 +937,6 @@ void DebugInfoFinder::processDeclare(const DbgDeclareInst *DDI) {
 
   if (!NodesSeen.insert(DV))
     return;
-  if (DIVariable(N).getVersion() <= LLVMDebugVersion10)
-    addCompileUnit(DIVariable(N).getCompileUnit());
   processType(DIVariable(N).getType());
 }