[Clang] [NFC] Introduce a helper for emitting compatibility diagnostics

clang/include/clang/Basic/CMakeLists.txt

@@ -8,6 +8,11 @@ macro(clang_diag_gen component)
     -gen-clang-diags-enums -clang-component=${component}
     SOURCE Diagnostic.td
     TARGET ClangDiagnostic${component}Enums)
+
+  clang_tablegen(Diagnostic${component}CompatIDs.inc
+    -gen-clang-diags-compat-ids -clang-component=${component}
+    SOURCE Diagnostic.td
+    TARGET ClangDiagnostic${component}CompatIDs)
 endmacro(clang_diag_gen)
 
 clang_diag_gen(Analysis)
@@ -31,6 +36,11 @@ clang_tablegen(DiagnosticIndexName.inc -gen-clang-diags-index-name
   SOURCE Diagnostic.td
   TARGET ClangDiagnosticIndexName)
 
+clang_tablegen(DiagnosticAllCompatIDs.inc
+  -gen-clang-diags-compat-ids
+  SOURCE Diagnostic.td
+  TARGET ClangDiagnosticAllCompatIDs)
+
 clang_tablegen(AttrList.inc -gen-clang-attr-list
   -I ${CMAKE_CURRENT_SOURCE_DIR}/../../
   SOURCE Attr.td

clang/include/clang/Basic/Diagnostic.td

@@ -155,6 +155,19 @@ class DefaultWarnNoWerror {
 }
 class DefaultRemark { Severity DefaultSeverity = SEV_Remark; }
 
+class CompatWarningId<string name, int std, string diag, string diag_pre> {
+  string Component = ?;
+  string Name = name;
+  string Diag = diag;
+  string DiagPre = diag_pre;
+  int Std = std;
+
+  // This is unused, but Tablegen will complain if it's missing because we define
+  // the compatibility ids in the same place as the other diagnostics (which means
+  // that we'll be inside a 'let CategoryName = "" in { ... }' block).
+  string CategoryName = ?;
+}
+
 // C++ compatibility warnings.
 multiclass CXXCompat<
     string message,
@@ -178,6 +191,11 @@ multiclass CXXCompat<
                                      "CXX98Compat",
                                      "CXXPre"#std_ver#"Compat"))>,
         DefaultIgnore;
+
+    def : CompatWarningId<
+        NAME, std_ver,
+        "compat_cxx"#std_ver#"_"#NAME,
+        "compat_pre_cxx"#std_ver#"_"#NAME>;
 }
 
 // These generate pairs of C++ compatibility warnings of the form:

clang/include/clang/Basic/DiagnosticAST.h

@@ -36,6 +36,18 @@ enum {
 #undef DIAG_ENUM_ITEM
 #undef DIAG_ENUM
 } // end namespace diag
+
+namespace diag_compat {
+#define DIAG_COMPAT_IDS_BEGIN() enum {
+#define DIAG_COMPAT_IDS_END()                                                  \
+  }                                                                            \
+  ;
+#define DIAG_COMPAT_ID(IDX, NAME, ...) NAME = IDX,
+#include "clang/Basic/DiagnosticASTCompatIDs.inc"
+#undef DIAG_COMPAT_ID
+#undef DIAG_COMPAT_IDS_BEGIN
+#undef DIAG_COMPAT_IDS_END
+} // end namespace diag_compat
 } // end namespace clang
 
 #endif // LLVM_CLANG_BASIC_DIAGNOSTICAST_H

clang/include/clang/Basic/DiagnosticAnalysis.h

@@ -35,6 +35,18 @@ enum {
 #undef DIAG_ENUM_ITEM
 #undef DIAG_ENUM
 } // end namespace diag
+
+namespace diag_compat {
+#define DIAG_COMPAT_IDS_BEGIN() enum {
+#define DIAG_COMPAT_IDS_END()                                                  \
+  }                                                                            \
+  ;
+#define DIAG_COMPAT_ID(IDX, NAME, ...) NAME = IDX,
+#include "clang/Basic/DiagnosticAnalysisCompatIDs.inc"
+#undef DIAG_COMPAT_ID
+#undef DIAG_COMPAT_IDS_BEGIN
+#undef DIAG_COMPAT_IDS_END
+} // end namespace diag_compat
 } // end namespace clang
 
 #endif // LLVM_CLANG_BASIC_DIAGNOSTICANALYSIS_H

clang/include/clang/Basic/DiagnosticComment.h

@@ -36,6 +36,18 @@ enum {
 #undef DIAG_ENUM_ITEM
 #undef DIAG_ENUM
 } // end namespace diag
+
+namespace diag_compat {
+#define DIAG_COMPAT_IDS_BEGIN() enum {
+#define DIAG_COMPAT_IDS_END()                                                  \
+  }                                                                            \
+  ;
+#define DIAG_COMPAT_ID(IDX, NAME, ...) NAME = IDX,
+#include "clang/Basic/DiagnosticCommentCompatIDs.inc"
+#undef DIAG_COMPAT_ID
+#undef DIAG_COMPAT_IDS_BEGIN
+#undef DIAG_COMPAT_IDS_END
+} // end namespace diag_compat
 } // end namespace clang
 
 #endif // LLVM_CLANG_BASIC_DIAGNOSTICCOMMENT_H

clang/include/clang/Basic/DiagnosticCrossTU.h

@@ -36,6 +36,18 @@ enum {
 #undef DIAG_ENUM_ITEM
 #undef DIAG_ENUM
 } // end namespace diag
+
+namespace diag_compat {
+#define DIAG_COMPAT_IDS_BEGIN() enum {
+#define DIAG_COMPAT_IDS_END()                                                  \
+  }                                                                            \
+  ;
+#define DIAG_COMPAT_ID(IDX, NAME, ...) NAME = IDX,
+#include "clang/Basic/DiagnosticCrossTUCompatIDs.inc"
+#undef DIAG_COMPAT_ID
+#undef DIAG_COMPAT_IDS_BEGIN
+#undef DIAG_COMPAT_IDS_END
+} // end namespace diag_compat
 } // end namespace clang
 
 #endif // LLVM_CLANG_BASIC_DIAGNOSTICCROSSTU_H

clang/include/clang/Basic/DiagnosticDriver.h

@@ -36,6 +36,18 @@ enum {
 #undef DIAG_ENUM_ITEM
 #undef DIAG_ENUM
 } // end namespace diag
+
+namespace diag_compat {
+#define DIAG_COMPAT_IDS_BEGIN() enum {
+#define DIAG_COMPAT_IDS_END()                                                  \
+  }                                                                            \
+  ;
+#define DIAG_COMPAT_ID(IDX, NAME, ...) NAME = IDX,
+#include "clang/Basic/DiagnosticDriverCompatIDs.inc"
+#undef DIAG_COMPAT_ID
+#undef DIAG_COMPAT_IDS_BEGIN
+#undef DIAG_COMPAT_IDS_END
+} // end namespace diag_compat
 } // end namespace clang
 
 #endif // LLVM_CLANG_BASIC_DIAGNOSTICDRIVER_H

clang/include/clang/Basic/DiagnosticFrontend.h

@@ -36,6 +36,18 @@ enum {
 #undef DIAG_ENUM_ITEM
 #undef DIAG_ENUM
 } // end namespace diag
+
+namespace diag_compat {
+#define DIAG_COMPAT_IDS_BEGIN() enum {
+#define DIAG_COMPAT_IDS_END()                                                  \
+  }                                                                            \
+  ;
+#define DIAG_COMPAT_ID(IDX, NAME, ...) NAME = IDX,
+#include "clang/Basic/DiagnosticFrontendCompatIDs.inc"
+#undef DIAG_COMPAT_ID
+#undef DIAG_COMPAT_IDS_BEGIN
+#undef DIAG_COMPAT_IDS_END
+} // end namespace diag_compat
 } // end namespace clang
 
 #endif // LLVM_CLANG_BASIC_DIAGNOSTICFRONTEND_H

clang/include/clang/Basic/DiagnosticIDs.h

@@ -25,6 +25,7 @@
 namespace clang {
   class DiagnosticsEngine;
   class DiagnosticBuilder;
+  class LangOptions;
   class SourceLocation;
 
   // Import the diagnostic enums themselves.
@@ -104,6 +105,18 @@ namespace clang {
     };
   }
 
+  namespace diag_compat {
+#define DIAG_COMPAT_IDS_BEGIN() enum {
+#define DIAG_COMPAT_IDS_END()                                                \
+    }                                                                          \
+    ;
+#define DIAG_COMPAT_ID(IDX, NAME, ...) NAME = IDX,
+#include "clang/Basic/DiagnosticCommonCompatIDs.inc"
+#undef DIAG_COMPAT_ID
+#undef DIAG_COMPAT_IDS_BEGIN
+#undef DIAG_COMPAT_IDS_END
+  } // end namespace diag_compat
+
 class DiagnosticMapping {
   LLVM_PREFERRED_TYPE(diag::Severity)
   unsigned Severity : 3;
@@ -464,6 +477,11 @@ class DiagnosticIDs : public RefCountedBase<DiagnosticIDs> {
   /// given group name.
   static StringRef getNearestOption(diag::Flavor Flavor, StringRef Group);
 
+  /// Get the appropriate diagnostic Id to use for issuing a compatibility
+  /// diagnostic. For use by the various DiagCompat() helpers.
+  static unsigned getCXXCompatDiagId(const LangOptions &LangOpts,
+                                     unsigned CompatDiagId);
+
 private:
   /// Classify the specified diagnostic ID into a Level, consumable by
   /// the DiagnosticClient.

clang/include/clang/Basic/DiagnosticInstallAPI.h

@@ -35,5 +35,17 @@ enum {
 #undef DIAG_ENUM_ITEM
 #undef DIAG_ENUM
 } // namespace diag
+
+namespace diag_compat {
+#define DIAG_COMPAT_IDS_BEGIN() enum {
+#define DIAG_COMPAT_IDS_END()                                                  \
+  }                                                                            \
+  ;
+#define DIAG_COMPAT_ID(IDX, NAME, ...) NAME = IDX,
+#include "clang/Basic/DiagnosticInstallAPICompatIDs.inc"
+#undef DIAG_COMPAT_ID
+#undef DIAG_COMPAT_IDS_BEGIN
+#undef DIAG_COMPAT_IDS_END
+} // end namespace diag_compat
 } // namespace clang
 #endif // LLVM_CLANG_BASIC_DIAGNOSTICINSTALLAPI_H

clang/include/clang/Basic/DiagnosticLex.h

@@ -35,6 +35,18 @@ enum {
 #undef DIAG_ENUM_ITEM
 #undef DIAG_ENUM
 } // end namespace diag
+
+namespace diag_compat {
+#define DIAG_COMPAT_IDS_BEGIN() enum {
+#define DIAG_COMPAT_IDS_END()                                                  \
+  }                                                                            \
+  ;
+#define DIAG_COMPAT_ID(IDX, NAME, ...) NAME = IDX,
+#include "clang/Basic/DiagnosticLexCompatIDs.inc"
+#undef DIAG_COMPAT_ID
+#undef DIAG_COMPAT_IDS_BEGIN
+#undef DIAG_COMPAT_IDS_END
+} // end namespace diag_compat
 } // end namespace clang
 
 #endif // LLVM_CLANG_BASIC_DIAGNOSTICLEX_H

clang/include/clang/Basic/DiagnosticParse.h

@@ -36,6 +36,18 @@ enum {
 #undef DIAG_ENUM_ITEM
 #undef DIAG_ENUM
 } // end namespace diag
+
+namespace diag_compat {
+#define DIAG_COMPAT_IDS_BEGIN() enum {
+#define DIAG_COMPAT_IDS_END()                                                  \
+  }                                                                            \
+  ;
+#define DIAG_COMPAT_ID(IDX, NAME, ...) NAME = IDX,
+#include "clang/Basic/DiagnosticParseCompatIDs.inc"
+#undef DIAG_COMPAT_ID
+#undef DIAG_COMPAT_IDS_BEGIN
+#undef DIAG_COMPAT_IDS_END
+} // end namespace diag_compat
 } // end namespace clang
 
 #endif // LLVM_CLANG_BASIC_DIAGNOSTICPARSE_H

clang/include/clang/Basic/DiagnosticParseKinds.td

@@ -11,6 +11,12 @@
 //===----------------------------------------------------------------------===//
 
 let Component = "Parse" in {
+let CategoryName = "Parse Issue" in {
+// C++11 compatibility with C++98.
+defm enum_fixed_underlying_type : CXX11Compat<
+  "enumeration types with a fixed underlying type are",
+  /*ext_warn=*/false>;
+}
 
 def err_asm_qualifier_ignored : Error<
   "expected 'volatile', 'inline', 'goto', or '('">, CatInlineAsm;
@@ -107,9 +113,6 @@ def err_enumerator_list_missing_comma : Error<
   "missing ',' between enumerators">;
 def err_enumerator_unnamed_no_def : Error<
   "unnamed enumeration must be a definition">;
-def ext_cxx11_enum_fixed_underlying_type : Extension<
-  "enumeration types with a fixed underlying type are a C++11 extension">,
-  InGroup<CXX11>;
 def ext_ms_c_enum_fixed_underlying_type : Extension<
   "enumeration types with a fixed underlying type are a Microsoft extension">,
   InGroup<MicrosoftFixedEnum>;
@@ -119,9 +122,6 @@ def ext_c23_enum_fixed_underlying_type : Extension<
 def warn_c17_compat_enum_fixed_underlying_type : Warning<
   "enumeration types with a fixed underlying type are incompatible with C standards before C23">,
   DefaultIgnore, InGroup<CPre23Compat>;
-def warn_cxx98_compat_enum_fixed_underlying_type : Warning<
-  "enumeration types with a fixed underlying type are incompatible with C++98">,
-  InGroup<CXX98Compat>, DefaultIgnore;
 def ext_enum_base_in_type_specifier : ExtWarn<
   "non-defining declaration of enumeration with a fixed underlying type is "
   "only permitted as a standalone declaration"

clang/include/clang/Basic/DiagnosticRefactoring.h

@@ -36,6 +36,18 @@ enum {
 #undef DIAG_ENUM_ITEM
 #undef DIAG_ENUM
 } // end namespace diag
+
+namespace diag_compat {
+#define DIAG_COMPAT_IDS_BEGIN() enum {
+#define DIAG_COMPAT_IDS_END()                                                  \
+  }                                                                            \
+  ;
+#define DIAG_COMPAT_ID(IDX, NAME, ...) NAME = IDX,
+#include "clang/Basic/DiagnosticRefactoringCompatIDs.inc"
+#undef DIAG_COMPAT_ID
+#undef DIAG_COMPAT_IDS_BEGIN
+#undef DIAG_COMPAT_IDS_END
+} // end namespace diag_compat
 } // end namespace clang
 
 #endif // LLVM_CLANG_BASIC_DIAGNOSTICREFACTORING_H

clang/include/clang/Basic/DiagnosticSema.h

@@ -35,7 +35,20 @@ enum {
 #undef DIAG_ENUM_END
 #undef DIAG_ENUM_ITEM
 #undef DIAG_ENUM
+
 } // end namespace diag
+
+namespace diag_compat {
+#define DIAG_COMPAT_IDS_BEGIN() enum {
+#define DIAG_COMPAT_IDS_END()                                                  \
+  }                                                                            \
+  ;
+#define DIAG_COMPAT_ID(IDX, NAME, ...) NAME = IDX,
+#include "clang/Basic/DiagnosticSemaCompatIDs.inc"
+#undef DIAG_COMPAT_ID
+#undef DIAG_COMPAT_IDS_BEGIN
+#undef DIAG_COMPAT_IDS_END
+} // end namespace diag_compat
 } // end namespace clang
 
 #endif // LLVM_CLANG_BASIC_DIAGNOSTICSEMA_H

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -61,7 +61,7 @@ defm decomp_decl_cond : CXX26Compat<"structured binding declaration in a conditi
 
 // Compatibility warnings duplicated across multiple language versions.
 foreach std = [14, 20, 23] in {
-  defm constexpr_body_invalid_stmt : CXXCompat<
+  defm cxx#std#_constexpr_body_invalid_stmt : CXXCompat<
     "use of this statement in a constexpr %select{function|constructor}0 is", std>;
 }
 

clang/include/clang/Basic/DiagnosticSerialization.h

@@ -36,6 +36,18 @@ enum {
 #undef DIAG_ENUM_ITEM
 #undef DIAG_ENUM
 } // end namespace diag
+
+namespace diag_compat {
+#define DIAG_COMPAT_IDS_BEGIN() enum {
+#define DIAG_COMPAT_IDS_END()                                                  \
+  }                                                                            \
+  ;
+#define DIAG_COMPAT_ID(IDX, NAME, ...) NAME = IDX,
+#include "clang/Basic/DiagnosticSerializationCompatIDs.inc"
+#undef DIAG_COMPAT_ID
+#undef DIAG_COMPAT_IDS_BEGIN
+#undef DIAG_COMPAT_IDS_END
+} // end namespace diag_compat
 } // end namespace clang
 
 #endif // LLVM_CLANG_BASIC_DIAGNOSTICSERIALIZATION_H

clang/include/clang/Parse/Parser.h

@@ -1263,6 +1263,12 @@ class Parser : public CodeCompletionHandler {
     return Diag(Tok, DiagID);
   }
 
+  DiagnosticBuilder DiagCompat(SourceLocation Loc, unsigned CompatDiagId);
+  DiagnosticBuilder DiagCompat(const Token &Tok, unsigned CompatDiagId);
+  DiagnosticBuilder DiagCompat(unsigned CompatDiagId) {
+    return DiagCompat(Tok, CompatDiagId);
+  }
+
 private:
   void SuggestParentheses(SourceLocation Loc, unsigned DK,
                           SourceRange ParenRange);

clang/include/clang/Sema/SemaBase.h

@@ -219,6 +219,10 @@ class SemaBase {
   SemaDiagnosticBuilder Diag(SourceLocation Loc, const PartialDiagnostic &PD,
                              bool DeferHint = false);
 
+  /// Emit a compatibility diagnostic.
+  SemaDiagnosticBuilder DiagCompat(SourceLocation Loc, unsigned CompatDiagId,
+                                   bool DeferHint = false);
+
   /// Build a partial diagnostic.
   PartialDiagnostic PDiag(unsigned DiagID = 0);
 };