[Index] Use locations to uniquify function-scope BindingDecl USR

[MaskRay]

Summary

This makes BindingDecl's of the same name have different USRs, so that references can be correctly attributed.

int a[1] = {};
{ auto [x] = a; x; }
{ auto [x] = a; x; }

[MaskRay]

Ping

[hokein]

Can you add a test?

[MaskRay]

Add test to Core/index-source.cpp

[hokein]

The change looks reasonable to me, so lg. I'd wait a bit to see whether other reviewers have comments.

lib/Index/USRGeneration.cpp

339

use isLocal(D) instead.

[MaskRay]

Use isLocal

lib/Index/USRGeneration.cpp

void VisitObjCContainerDecl(const ObjCContainerDecl *CD,
                               const ObjCCategoryDecl *CatD = nullptr);
   void VisitObjCMethodDecl(const ObjCMethodDecl *MD);
   void VisitObjCPropertyDecl(const ObjCPropertyDecl *D);
   void VisitObjCPropertyImplDecl(const ObjCPropertyImplDecl *D);
   void VisitTagDecl(const TagDecl *D);
   void VisitTypedefDecl(const TypedefDecl *D);
   void VisitTemplateTypeParmDecl(const TemplateTypeParmDecl *D);
   void VisitVarDecl(const VarDecl *D);
+  void VisitBindingDecl(const BindingDecl *D);
   void VisitNonTypeTemplateParmDecl(const NonTypeTemplateParmDecl *D);
   void VisitTemplateTemplateParmDecl(const TemplateTemplateParmDecl *D);
   void VisitUnresolvedUsingValueDecl(const UnresolvedUsingValueDecl *D);
   void VisitUnresolvedUsingTypenameDecl(const UnresolvedUsingTypenameDecl *D);
 
   void VisitLinkageSpecDecl(const LinkageSpecDecl *D) {
     IgnoreResults = true; // No USRs for linkage specs themselves.
   }
if (const VarTemplateSpecializationDecl *Spec
     Out << '>';
     for (unsigned I = 0, N = Args.size(); I != N; ++I) {
       Out << '#';
       VisitTemplateArgument(Args.get(I));
     }
   }
 }
 
+void USRGenerator::VisitBindingDecl(const BindingDecl *D) {
+  if (isLocal(D) && GenLoc(D, /*IncludeOffset=*/true))
+    return;
+  VisitNamedDecl(D);
+}
+
 void USRGenerator::VisitNonTypeTemplateParmDecl(
                                         const NonTypeTemplateParmDecl *D) {
   GenLoc(D, /*IncludeOffset=*/true);
 }
 
 void USRGenerator::VisitTemplateTemplateParmDecl(
                                         const TemplateTemplateParmDecl *D) {
   GenLoc(D, /*IncludeOffset=*/true);

test/Index/Core/index-source.cpp

 // RUN: c-index-test core -print-source-symbols -- %s -std=c++1z -target x86_64-apple-macosx10.7 | FileCheck %s
+// RUN: c-index-test core -print-source-symbols -include-locals -- %s -std=c++1z -target x86_64-apple-macosx10.7 | FileCheck -check-prefix=LOCAL %s
 
 // CHECK: [[@LINE+1]]:7 | class/C++ | Cls | [[Cls_USR:.*]] | <no-cgname> | Def | rel: 0
 class Cls { public:
   // CHECK: [[@LINE+3]]:3 | constructor/C++ | Cls | c:@S@Cls@F@Cls#I# | __ZN3ClsC1Ei | Decl,RelChild | rel: 1
   // CHECK-NEXT: RelChild | Cls | c:@S@Cls
   // CHECK: [[@LINE+1]]:3 | class/C++ | Cls | c:@S@Cls | <no-cgname> | Ref,RelCont | rel: 1
   Cls(int x);
   // CHECK: [[@LINE+2]]:3 | constructor/cxx-copy-ctor/C++ | Cls | c:@S@Cls@F@Cls#&1$@S@Cls# | __ZN3ClsC1ERKS_ | Decl,RelChild | rel: 1

 void localStructuredBindingAndRef() {
   int ref = structuredBinding1;
 // CHECK: [[@LINE-1]]:13 | variable/C++ | structuredBinding1 | c:@N@cpp17structuredBinding@structuredBinding1 | <no-cgname> | Ref,Read,RelCont | rel: 1
 // CHECK-NEXT: RelCont | localStructuredBindingAndRef | c:@N@cpp17structuredBinding@F@localStructuredBindingAndRef#
   auto [localBinding1, localBinding2] = Cpp17StructuredBinding(ref, structuredBinding2);
 // CHECK: [[@LINE-1]]:69 | variable/C++ | structuredBinding2 | c:@N@cpp17structuredBinding@structuredBinding2 | <no-cgname> | Ref,Read,RelCont | rel: 1
 // CHECK-NEXT: RelCont | localStructuredBindingAndRef | c:@N@cpp17structuredBinding@F@localStructuredBindingAndRef#
 // CHECK-NOT: localBinding
+// LOCAL: [[@LINE-4]]:9 | variable(local)/C++ | localBinding1 | c:index-source.cpp@25382@N@cpp17structuredBinding@F@localStructuredBindingAndRef#@localBinding1
 }
 
 }
 
 template<typename T>
 struct Guided { T t; };
 // CHECK: [[@LINE-1]]:8 | struct(Gen)/C++ | Guided | c:@ST>1#T@Guided | <no-cgname> | Def | rel: 0
 // CHECK-NEXT: [[@LINE-2]]:19 | field/C++ | t | c:@ST>1#T@Guided@FI@t | <no-cgname> | Def,RelChild | rel: 1