NFC: Replace asserts with if() in SourceLocation accessors

Summary:
Nowhere else in the AST classes assert on these kinds of accessors.

This way, we can call the accessors and check the validity of the result
instead of externally duplicating the conditions.  This generality will
make it possible to introspect instances for source locations:

 http://ec2-18-191-7-3.us-east-2.compute.amazonaws.com:10240/z/iiaWhw

Reviewers: aaron.ballman

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D56354

llvm-svn: 350573

Author: steveire

clang/include/clang/AST/DeclarationName.h

@@ -729,9 +729,10 @@ struct DeclarationNameInfo {
   /// getNamedTypeInfo - Returns the source type info associated to
   /// the name. Assumes it is a constructor, destructor or conversion.
   TypeSourceInfo *getNamedTypeInfo() const {
-    assert(Name.getNameKind() == DeclarationName::CXXConstructorName ||
-           Name.getNameKind() == DeclarationName::CXXDestructorName ||
-           Name.getNameKind() == DeclarationName::CXXConversionFunctionName);
+    if (Name.getNameKind() != DeclarationName::CXXConstructorName &&
+        Name.getNameKind() != DeclarationName::CXXDestructorName &&
+        Name.getNameKind() != DeclarationName::CXXConversionFunctionName)
+      return nullptr;
     return LocInfo.NamedType.TInfo;
   }
 
@@ -747,7 +748,8 @@ struct DeclarationNameInfo {
   /// getCXXOperatorNameRange - Gets the range of the operator name
   /// (without the operator keyword). Assumes it is a (non-literal) operator.
   SourceRange getCXXOperatorNameRange() const {
-    assert(Name.getNameKind() == DeclarationName::CXXOperatorName);
+    if (Name.getNameKind() != DeclarationName::CXXOperatorName)
+      return SourceRange();
     return SourceRange(
      SourceLocation::getFromRawEncoding(LocInfo.CXXOperatorName.BeginOpNameLoc),
      SourceLocation::getFromRawEncoding(LocInfo.CXXOperatorName.EndOpNameLoc)
@@ -766,7 +768,8 @@ struct DeclarationNameInfo {
   /// operator name (not the operator keyword).
   /// Assumes it is a literal operator.
   SourceLocation getCXXLiteralOperatorNameLoc() const {
-    assert(Name.getNameKind() == DeclarationName::CXXLiteralOperatorName);
+    if (Name.getNameKind() != DeclarationName::CXXLiteralOperatorName)
+      return SourceLocation();
     return SourceLocation::
       getFromRawEncoding(LocInfo.CXXLiteralOperatorName.OpNameLoc);
   }

clang/include/clang/AST/TemplateBase.h

@@ -530,19 +530,22 @@ class TemplateArgumentLoc {
   }
 
   NestedNameSpecifierLoc getTemplateQualifierLoc() const {
-    assert(Argument.getKind() == TemplateArgument::Template ||
-           Argument.getKind() == TemplateArgument::TemplateExpansion);
+    if (Argument.getKind() != TemplateArgument::Template &&
+        Argument.getKind() != TemplateArgument::TemplateExpansion)
+      return NestedNameSpecifierLoc();
     return LocInfo.getTemplateQualifierLoc();
   }
 
   SourceLocation getTemplateNameLoc() const {
-    assert(Argument.getKind() == TemplateArgument::Template ||
-           Argument.getKind() == TemplateArgument::TemplateExpansion);
+    if (Argument.getKind() != TemplateArgument::Template &&
+        Argument.getKind() != TemplateArgument::TemplateExpansion)
+      return SourceLocation();
     return LocInfo.getTemplateNameLoc();
   }
 
   SourceLocation getTemplateEllipsisLoc() const {
-    assert(Argument.getKind() == TemplateArgument::TemplateExpansion);
+    if (Argument.getKind() != TemplateArgument::TemplateExpansion)
+      return SourceLocation();
     return LocInfo.getTemplateEllipsisLoc();
   }
 };

clang/lib/AST/NestedNameSpecifier.cpp

@@ -462,9 +462,9 @@ SourceRange NestedNameSpecifierLoc::getLocalSourceRange() const {
 }
 
 TypeLoc NestedNameSpecifierLoc::getTypeLoc() const {
-  assert((Qualifier->getKind() == NestedNameSpecifier::TypeSpec ||
-          Qualifier->getKind() == NestedNameSpecifier::TypeSpecWithTemplate) &&
-         "Nested-name-specifier location is not a type");
+  if (Qualifier->getKind() != NestedNameSpecifier::TypeSpec &&
+      Qualifier->getKind() != NestedNameSpecifier::TypeSpecWithTemplate)
+    return TypeLoc();
 
   // The "void*" that points at the TypeLoc data.
   unsigned Offset = getDataLength(Qualifier->getPrefix());