[Clang][Interp] Fix the location of uninitialized base warning (llvm#100761)

Fix the location of `diag::note_constexpr_uninitialized_base`, make it
same as current interpreter.
This PR does not print type name with namespacethat was used to improve
the current interpreter's type dump of base class type.

---------

Signed-off-by: yronglin <yronglin777@gmail.com>

Author: yronglin

clang/lib/AST/Interp/EvaluationResult.cpp

@@ -10,7 +10,9 @@
 #include "InterpState.h"
 #include "Record.h"
 #include "clang/AST/ExprCXX.h"
+#include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SetVector.h"
+#include <iterator>
 
 namespace clang {
 namespace interp {
@@ -122,19 +124,18 @@ static bool CheckFieldsInitialized(InterpState &S, SourceLocation Loc,
   }
 
   // Check Fields in all bases
-  for (const Record::Base &B : R->bases()) {
+  for (auto [I, B] : llvm::enumerate(R->bases())) {
     Pointer P = BasePtr.atField(B.Offset);
     if (!P.isInitialized()) {
       const Descriptor *Desc = BasePtr.getDeclDesc();
-      if (Desc->asDecl())
-        S.FFDiag(BasePtr.getDeclDesc()->asDecl()->getLocation(),
-                 diag::note_constexpr_uninitialized_base)
+      if (const auto *CD = dyn_cast_if_present<CXXRecordDecl>(R->getDecl())) {
+        const auto &BS = *std::next(CD->bases_begin(), I);
+        S.FFDiag(BS.getBaseTypeLoc(), diag::note_constexpr_uninitialized_base)
+            << B.Desc->getType() << BS.getSourceRange();
+      } else {
+        S.FFDiag(Desc->getLocation(), diag::note_constexpr_uninitialized_base)
             << B.Desc->getType();
-      else
-        S.FFDiag(BasePtr.getDeclDesc()->asExpr()->getExprLoc(),
-                 diag::note_constexpr_uninitialized_base)
-            << B.Desc->getType();
-
+      }
       return false;
     }
     Result &= CheckFieldsInitialized(S, Loc, P, B.R);

clang/test/AST/Interp/constexpr-subobj-initialization.cpp

@@ -5,42 +5,36 @@
 /// Differences:
 ///   1) The type of the uninitialized base class is printed WITH the namespace,
 ///      i.e. 'baseclass_uninit::DelBase' instead of just 'DelBase'.
-///   2) The location is not the base specifier declaration, but the call site
-///      of the constructor.
 
 
 namespace baseclass_uninit {
 struct DelBase {
   constexpr DelBase() = delete; // expected-note {{'DelBase' has been explicitly marked deleted here}}
 };
 
-struct Foo : DelBase {
+struct Foo : DelBase { // expected-note 2{{constructor of base class 'baseclass_uninit::DelBase' is not called}}
   constexpr Foo() {}; // expected-error {{call to deleted constructor of 'DelBase'}}
 };
-constexpr Foo f; // expected-error {{must be initialized by a constant expression}} \
-                 // expected-note {{constructor of base class 'baseclass_uninit::DelBase' is not called}}
+constexpr Foo f; // expected-error {{must be initialized by a constant expression}}
 
 struct Bar : Foo {
   constexpr Bar() {};
 };
-constexpr Bar bar; // expected-error {{must be initialized by a constant expression}} \
-                   // expected-note {{constructor of base class 'baseclass_uninit::DelBase' is not called}}
+constexpr Bar bar; // expected-error {{must be initialized by a constant expression}}
 
 struct Base {};
-struct A : Base {
+struct A : Base { // expected-note {{constructor of base class 'baseclass_uninit::Base' is not called}}
   constexpr A() : value() {} // expected-error {{member initializer 'value' does not name a non-static data member or base class}}
 };
 
-constexpr A a; // expected-error {{must be initialized by a constant expression}} \
-               // expected-note {{constructor of base class 'baseclass_uninit::Base' is not called}}
+constexpr A a; // expected-error {{must be initialized by a constant expression}}
 
 
-struct B : Base {
+struct B : Base { // expected-note {{constructor of base class 'baseclass_uninit::Base' is not called}}
   constexpr B() : {} // expected-error {{expected class member or base class name}}
 };
 
-constexpr B b; // expected-error {{must be initialized by a constant expression}} \
-               // expected-note {{constructor of base class 'baseclass_uninit::Base' is not called}}
+constexpr B b; // expected-error {{must be initialized by a constant expression}}
 } // namespace baseclass_uninit
 
 

clang/test/C/C23/n3018.c

@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -std=c23 -verify -triple x86_64 -pedantic -Wno-conversion -Wno-constant-conversion %s
+// RUN: %clang_cc1 -std=c23 -verify -triple x86_64 -pedantic -Wno-conversion -Wno-constant-conversion -fexperimental-new-constant-interpreter %s
 
 /* WG14 N3018: Full
  * The constexpr specifier for object definitions

clang/test/CodeGen/pr3518.c

@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 %s -emit-llvm -o - | FileCheck %s
+// RUN: %clang_cc1 %s -fexperimental-new-constant-interpreter -emit-llvm -o - | FileCheck %s
 // PR 3518
 // Some of the objects were coming out as uninitialized (external) before 3518
 // was fixed.  Internal names are different between llvm-gcc and clang so they

clang/test/Preprocessor/embed_weird.cpp

@@ -4,6 +4,8 @@
 // RUN: printf "\0" > %t/null_byte.bin
 // RUN: %clang_cc1 %s -fsyntax-only --embed-dir=%t -verify=expected,cxx -Wno-c23-extensions
 // RUN: %clang_cc1 -x c -std=c23 %s -fsyntax-only --embed-dir=%t -verify=expected,c
+// RUN: %clang_cc1 %s -fsyntax-only -fexperimental-new-constant-interpreter --embed-dir=%t -verify=expected,cxx -Wno-c23-extensions
+// RUN: %clang_cc1 -x c -std=c23 %s -fsyntax-only -fexperimental-new-constant-interpreter --embed-dir=%t -verify=expected,c
 #embed <media/empty>
 ;
 

clang/test/SemaCXX/constexpr-subobj-initialization.cpp

@@ -1,11 +1,12 @@
 // RUN: %clang_cc1 -fsyntax-only -verify %s
+// RUN: %clang_cc1 -fsyntax-only -verify -fexperimental-new-constant-interpreter %s
 
 namespace baseclass_uninit {
 struct DelBase {
   constexpr DelBase() = delete; // expected-note {{'DelBase' has been explicitly marked deleted here}}
 };
 
-struct Foo : DelBase {  // expected-note 2{{constructor of base class 'DelBase' is not called}}
+struct Foo : DelBase {  // expected-note-re 2{{constructor of base class '{{.*}}DelBase' is not called}}
   constexpr Foo() {}; // expected-error {{call to deleted constructor of 'DelBase'}}
 };
 constexpr Foo f; // expected-error {{must be initialized by a constant expression}}
@@ -15,13 +16,13 @@ struct Bar : Foo {
 constexpr Bar bar; // expected-error {{must be initialized by a constant expression}}
 
 struct Base {};
-struct A : Base { // expected-note {{constructor of base class 'Base' is not called}}
+struct A : Base { // expected-note-re {{constructor of base class '{{.*}}Base' is not called}}
   constexpr A() : value() {} // expected-error {{member initializer 'value' does not name a non-static data member or base class}}
 };
 
 constexpr A a; // expected-error {{must be initialized by a constant expression}}
 
-struct B : Base { // expected-note {{constructor of base class 'Base' is not called}}
+struct B : Base { // expected-note-re {{constructor of base class '{{.*}}Base' is not called}}
   constexpr B() : {} // expected-error {{expected class member or base class name}}
 };