[clang] Extend diagnose_if to accept more detailed warning information

Author: philnik777

clang-tools-extra/clang-tidy/ClangTidyDiagnosticConsumer.h

@@ -79,6 +79,10 @@ class ClangTidyContext {
     this->DiagEngine = DiagEngine;
   }
 
+  const DiagnosticsEngine* getDiagnosticsEngine() const {
+    return DiagEngine;
+  }
+
   ~ClangTidyContext();
 
   /// Report any errors detected using this method.

clang-tools-extra/clangd/Diagnostics.cpp

@@ -579,7 +579,9 @@ std::vector<Diag> StoreDiags::take(const clang::tidy::ClangTidyContext *Tidy) {
   for (auto &Diag : Output) {
     if (const char *ClangDiag = getDiagnosticCode(Diag.ID)) {
       // Warnings controlled by -Wfoo are better recognized by that name.
-      StringRef Warning = DiagnosticIDs::getWarningOptionForDiag(Diag.ID);
+      StringRef Warning = Tidy->getDiagnosticsEngine()
+                              ->getDiagnosticIDs()
+                              ->getWarningOptionForDiag(Diag.ID);
       if (!Warning.empty()) {
         Diag.Name = ("-W" + Warning).str();
       } else {
@@ -909,7 +911,7 @@ bool isBuiltinDiagnosticSuppressed(unsigned ID,
     if (Suppress.contains(normalizeSuppressedCode(CodePtr)))
       return true;
   }
-  StringRef Warning = DiagnosticIDs::getWarningOptionForDiag(ID);
+  StringRef Warning = DiagnosticIDs{}.getWarningOptionForDiag(ID);
   if (!Warning.empty() && Suppress.contains(Warning))
     return true;
   return false;

clang-tools-extra/clangd/ParsedAST.cpp

@@ -340,7 +340,7 @@ void applyWarningOptions(llvm::ArrayRef<std::string> ExtraArgs,
       if (Enable) {
         if (Diags.getDiagnosticLevel(ID, SourceLocation()) <
             DiagnosticsEngine::Warning) {
-          auto Group = DiagnosticIDs::getGroupForDiag(ID);
+          auto Group = Diags.getDiagnosticIDs()->getGroupForDiag(ID);
           if (!Group || !EnabledGroups(*Group))
             continue;
           Diags.setSeverity(ID, diag::Severity::Warning, SourceLocation());

clang/include/clang/Basic/Attr.td

@@ -2959,18 +2959,15 @@ def DiagnoseIf : InheritableAttr {
   let Spellings = [GNU<"diagnose_if">];
   let Subjects = SubjectList<[Function, ObjCMethod, ObjCProperty]>;
   let Args = [ExprArgument<"Cond">, StringArgument<"Message">,
-              EnumArgument<"DiagnosticType",
-                           "DiagnosticType",
-                           ["error", "warning"],
-                           ["DT_Error", "DT_Warning"]>,
+              EnumArgument<"DefaultSeverity",
+                           "DefaultSeverity",
+                           ["error",    "warning"],
+                           ["DS_error", "DS_warning"]>,
+              StringArgument<"WarningGroup", /*optional*/ 1>,
               BoolArgument<"ArgDependent", 0, /*fake*/ 1>,
               DeclArgument<Named, "Parent", 0, /*fake*/ 1>];
   let InheritEvenIfAlreadyPresent = 1;
   let LateParsed = 1;
-  let AdditionalMembers = [{
-    bool isError() const { return diagnosticType == DT_Error; }
-    bool isWarning() const { return diagnosticType == DT_Warning; }
-  }];
   let TemplateDependent = 1;
   let Documentation = [DiagnoseIfDocs];
 }

clang/include/clang/Basic/Diagnostic.h

@@ -331,10 +331,12 @@ class DiagnosticsEngine : public RefCountedBase<DiagnosticsEngine> {
     // Map extensions to warnings or errors?
     diag::Severity ExtBehavior = diag::Severity::Ignored;
 
-    DiagState()
+    DiagnosticIDs& DiagIDs;
+
+    DiagState(DiagnosticIDs &DiagIDs)
         : IgnoreAllWarnings(false), EnableAllWarnings(false),
           WarningsAsErrors(false), ErrorsAsFatal(false),
-          SuppressSystemWarnings(false) {}
+          SuppressSystemWarnings(false), DiagIDs(DiagIDs) {}
 
     using iterator = llvm::DenseMap<unsigned, DiagnosticMapping>::iterator;
     using const_iterator =
@@ -865,7 +867,8 @@ class DiagnosticsEngine : public RefCountedBase<DiagnosticsEngine> {
   /// \param FormatString A fixed diagnostic format string that will be hashed
   /// and mapped to a unique DiagID.
   template <unsigned N>
-  unsigned getCustomDiagID(Level L, const char (&FormatString)[N]) {
+  [[deprecated("Use a CustomDiagDesc instead of a Level")]] unsigned
+  getCustomDiagID(Level L, const char (&FormatString)[N]) {
     return Diags->getCustomDiagID((DiagnosticIDs::Level)L,
                                   StringRef(FormatString, N - 1));
   }

clang/include/clang/Basic/DiagnosticCategories.h

@@ -26,6 +26,7 @@ namespace clang {
 #include "clang/Basic/DiagnosticGroups.inc"
 #undef CATEGORY
 #undef DIAG_ENTRY
+      NUM_GROUPS
     };
   }  // end namespace diag
 }  // end namespace clang

clang/include/clang/Basic/DiagnosticIDs.h

@@ -14,6 +14,7 @@
 #ifndef LLVM_CLANG_BASIC_DIAGNOSTICIDS_H
 #define LLVM_CLANG_BASIC_DIAGNOSTICIDS_H
 
+#include "clang/Basic/DiagnosticCategories.h"
 #include "clang/Basic/LLVM.h"
 #include "llvm/ADT/IntrusiveRefCntPtr.h"
 #include "llvm/ADT/StringRef.h"
@@ -80,7 +81,7 @@ namespace clang {
     /// to either Ignore (nothing), Remark (emit a remark), Warning
     /// (emit a warning) or Error (emit as an error).  It allows clients to
     /// map ERRORs to Error or Fatal (stop emitting diagnostics after this one).
-    enum class Severity {
+    enum class Severity : uint8_t {
       // NOTE: 0 means "uncomputed".
       Ignored = 1, ///< Do not present this diagnostic, ignore it.
       Remark = 2,  ///< Present this diagnostic as a remark.
@@ -171,13 +172,61 @@ class DiagnosticMapping {
 class DiagnosticIDs : public RefCountedBase<DiagnosticIDs> {
 public:
   /// The level of the diagnostic, after it has been through mapping.
-  enum Level {
+  enum Level : uint8_t {
     Ignored, Note, Remark, Warning, Error, Fatal
   };
 
+  // Diagnostic classes.
+  enum Class {
+    CLASS_NOTE       = 0x01,
+    CLASS_REMARK     = 0x02,
+    CLASS_WARNING    = 0x03,
+    CLASS_EXTENSION  = 0x04,
+    CLASS_ERROR      = 0x05
+  };
+
+  class CustomDiagDesc {
+    diag::Severity DefaultSeverity : 3;
+    unsigned Class : 3;
+    unsigned ShowInSystemHeader : 1;
+    unsigned ShowInSystemMacro : 1;
+    unsigned HasGroup : 1;
+    diag::Group Group;
+    std::string Description;
+
+    auto get_as_tuple() const {
+      return std::tuple(Class, ShowInSystemHeader, ShowInSystemMacro, HasGroup,
+                      Group, std::string_view{Description});
+    }
+
+  public:
+    CustomDiagDesc(diag::Severity DefaultSeverity, std::string Description,
+                   unsigned Class = CLASS_WARNING,
+                   bool ShowInSystemHeader = false,
+                   bool ShowInSystemMacro = false,
+                   std::optional<diag::Group> Group = std::nullopt)
+        : DefaultSeverity(DefaultSeverity), Class(Class),
+          ShowInSystemHeader(ShowInSystemHeader),
+          ShowInSystemMacro(ShowInSystemMacro), HasGroup(Group != std::nullopt),
+          Group(Group.value_or(diag::Group{})) {}
+
+    friend bool operator==(const CustomDiagDesc &lhs,
+                           const CustomDiagDesc &rhs) {
+      return lhs.get_as_tuple() == rhs.get_as_tuple();
+    }
+
+    friend bool operator<(const CustomDiagDesc &lhs,
+                          const CustomDiagDesc &rhs) {
+      return lhs.get_as_tuple() < rhs.get_as_tuple();
+    }
+  };
+
 private:
   /// Information for uniquing and looking up custom diags.
   std::unique_ptr<diag::CustomDiagInfo> CustomDiagInfo;
+  std::unique_ptr<diag::Severity[]> GroupSeverity =
+      std::make_unique<diag::Severity[]>(
+          static_cast<size_t>(diag::Group::NUM_GROUPS));
 
 public:
   DiagnosticIDs();
@@ -192,7 +241,27 @@ class DiagnosticIDs : public RefCountedBase<DiagnosticIDs> {
   // FIXME: Replace this function with a create-only facilty like
   // createCustomDiagIDFromFormatString() to enforce safe usage. At the time of
   // writing, nearly all callers of this function were invalid.
-  unsigned getCustomDiagID(Level L, StringRef FormatString);
+  unsigned getCustomDiagID(CustomDiagDesc Diag);
+
+  [[deprecated("Use a CustomDiagDesc instead of a Level")]] unsigned
+  getCustomDiagID(Level Level, StringRef Message) {
+    return getCustomDiagID([&] -> CustomDiagDesc {
+      switch (Level) {
+      case DiagnosticIDs::Level::Ignored:
+        return {diag::Severity::Ignored, std::string(Message), CLASS_WARNING};
+      case DiagnosticIDs::Level::Note:
+        return {diag::Severity::Fatal, std::string(Message), CLASS_NOTE};
+      case DiagnosticIDs::Level::Remark:
+        return {diag::Severity::Remark, std::string(Message), CLASS_REMARK};
+      case DiagnosticIDs::Level::Warning:
+        return {diag::Severity::Warning, std::string(Message), CLASS_WARNING};
+      case DiagnosticIDs::Level::Error:
+        return {diag::Severity::Error, std::string(Message), CLASS_ERROR};
+      case DiagnosticIDs::Level::Fatal:
+        return {diag::Severity::Fatal, std::string(Message), CLASS_ERROR};
+      }
+    }());
+  }
 
   //===--------------------------------------------------------------------===//
   // Diagnostic classification and reporting interfaces.
@@ -204,35 +273,34 @@ class DiagnosticIDs : public RefCountedBase<DiagnosticIDs> {
   /// Return true if the unmapped diagnostic levelof the specified
   /// diagnostic ID is a Warning or Extension.
   ///
-  /// This only works on builtin diagnostics, not custom ones, and is not
-  /// legal to call on NOTEs.
-  static bool isBuiltinWarningOrExtension(unsigned DiagID);
+  /// This is not legal to call on NOTEs.
+  bool isWarningOrExtension(unsigned DiagID) const;
 
   /// Return true if the specified diagnostic is mapped to errors by
   /// default.
-  static bool isDefaultMappingAsError(unsigned DiagID);
+  bool isDefaultMappingAsError(unsigned DiagID) const;
 
   /// Get the default mapping for this diagnostic.
-  static DiagnosticMapping getDefaultMapping(unsigned DiagID);
+  DiagnosticMapping getDefaultMapping(unsigned DiagID) const;
 
-  /// Determine whether the given built-in diagnostic ID is a Note.
-  static bool isBuiltinNote(unsigned DiagID);
+  /// Determine whether the given diagnostic ID is a Note.
+  bool isNote(unsigned DiagID) const;
 
-  /// Determine whether the given built-in diagnostic ID is for an
+  /// Determine whether the given diagnostic ID is for an
   /// extension of some sort.
-  static bool isBuiltinExtensionDiag(unsigned DiagID) {
+  bool isExtensionDiag(unsigned DiagID) const {
     bool ignored;
-    return isBuiltinExtensionDiag(DiagID, ignored);
+    return isExtensionDiag(DiagID, ignored);
   }
 
-  /// Determine whether the given built-in diagnostic ID is for an
+  /// Determine whether the given diagnostic ID is for an
   /// extension of some sort, and whether it is enabled by default.
   ///
   /// This also returns EnabledByDefault, which is set to indicate whether the
   /// diagnostic is ignored by default (in which case -pedantic enables it) or
   /// treated as a warning/error by default.
   ///
-  static bool isBuiltinExtensionDiag(unsigned DiagID, bool &EnabledByDefault);
+  bool isExtensionDiag(unsigned DiagID, bool &EnabledByDefault) const;
 
   /// Given a group ID, returns the flag that toggles the group.
   /// For example, for Group::DeprecatedDeclarations, returns
@@ -242,19 +310,21 @@ class DiagnosticIDs : public RefCountedBase<DiagnosticIDs> {
   /// Given a diagnostic group ID, return its documentation.
   static StringRef getWarningOptionDocumentation(diag::Group GroupID);
 
+  void setGroupSeverity(StringRef Group, diag::Severity);
+
   /// Given a group ID, returns the flag that toggles the group.
   /// For example, for "deprecated-declarations", returns
   /// Group::DeprecatedDeclarations.
   static std::optional<diag::Group> getGroupForWarningOption(StringRef);
 
   /// Return the lowest-level group that contains the specified diagnostic.
-  static std::optional<diag::Group> getGroupForDiag(unsigned DiagID);
+  std::optional<diag::Group> getGroupForDiag(unsigned DiagID) const;
 
   /// Return the lowest-level warning option that enables the specified
   /// diagnostic.
   ///
   /// If there is no -Wfoo flag that controls the diagnostic, this returns null.
-  static StringRef getWarningOptionForDiag(unsigned DiagID);
+  StringRef getWarningOptionForDiag(unsigned DiagID);
 
   /// Return the category number that a specified \p DiagID belongs to,
   /// or 0 if no category.
@@ -352,6 +422,8 @@ class DiagnosticIDs : public RefCountedBase<DiagnosticIDs> {
   getDiagnosticSeverity(unsigned DiagID, SourceLocation Loc,
                         const DiagnosticsEngine &Diag) const LLVM_READONLY;
 
+  Class getDiagClass(unsigned DiagID) const;
+
   /// Used to report a diagnostic that is finally fully formed.
   ///
   /// \returns \c true if the diagnostic was emitted, \c false if it was

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -2865,9 +2865,15 @@ def ext_constexpr_function_never_constant_expr : ExtWarn<
   "constant expression">, InGroup<DiagGroup<"invalid-constexpr">>, DefaultError;
 def err_attr_cond_never_constant_expr : Error<
   "%0 attribute expression never produces a constant expression">;
+def err_diagnose_if_unknown_warning : Error<"unknown warning group">;
 def err_diagnose_if_invalid_diagnostic_type : Error<
   "invalid diagnostic type for 'diagnose_if'; use \"error\" or \"warning\" "
   "instead">;
+def err_diagnose_if_unknown_option : Error<"unknown diagnostic option">;
+def err_diagnose_if_expected_equals : Error<
+  "expected '=' after diagnostic option">;
+def err_diagnose_if_unexpected_value : Error<
+  "unexpected value; use 'true' or 'false'">;
 def err_constexpr_body_no_return : Error<
   "no return statement in %select{constexpr|consteval}0 function">;
 def err_constexpr_return_missing_expr : Error<

clang/lib/Basic/Diagnostic.cpp

@@ -138,7 +138,7 @@ void DiagnosticsEngine::Reset(bool soft /*=false*/) {
 
     // Create a DiagState and DiagStatePoint representing diagnostic changes
     // through command-line.
-    DiagStates.emplace_back();
+    DiagStates.emplace_back(*Diags);
     DiagStatesByLoc.appendFirst(&DiagStates.back());
   }
 }
@@ -167,7 +167,7 @@ DiagnosticsEngine::DiagState::getOrAddMapping(diag::kind Diag) {
 
   // Initialize the entry if we added it.
   if (Result.second)
-    Result.first->second = DiagnosticIDs::getDefaultMapping(Diag);
+    Result.first->second = DiagIDs.getDefaultMapping(Diag);
 
   return Result.first->second;
 }
@@ -309,7 +309,8 @@ void DiagnosticsEngine::DiagStateMap::dump(SourceManager &SrcMgr,
 
       for (auto &Mapping : *Transition.State) {
         StringRef Option =
-            DiagnosticIDs::getWarningOptionForDiag(Mapping.first);
+            SrcMgr.getDiagnostics().Diags->getWarningOptionForDiag(
+                Mapping.first);
         if (!DiagName.empty() && DiagName != Option)
           continue;
 
@@ -353,9 +354,7 @@ void DiagnosticsEngine::PushDiagStatePoint(DiagState *State,
 
 void DiagnosticsEngine::setSeverity(diag::kind Diag, diag::Severity Map,
                                     SourceLocation L) {
-  assert(Diag < diag::DIAG_UPPER_LIMIT &&
-         "Can only map builtin diagnostics");
-  assert((Diags->isBuiltinWarningOrExtension(Diag) ||
+  assert((Diags->isWarningOrExtension(Diag) ||
           (Map == diag::Severity::Fatal || Map == diag::Severity::Error)) &&
          "Cannot map errors into warnings!");
   assert((L.isInvalid() || SourceMgr) && "No SourceMgr for valid location");
@@ -406,6 +405,8 @@ bool DiagnosticsEngine::setSeverityForGroup(diag::Flavor Flavor,
   if (Diags->getDiagnosticsInGroup(Flavor, Group, GroupDiags))
     return true;
 
+  Diags->setGroupSeverity(Group, Map);
+
   // Set the mapping.
   for (diag::kind Diag : GroupDiags)
     setSeverity(Diag, Map, Loc);
@@ -491,7 +492,7 @@ void DiagnosticsEngine::setSeverityForAll(diag::Flavor Flavor,
 
   // Set the mapping.
   for (diag::kind Diag : AllDiags)
-    if (Diags->isBuiltinWarningOrExtension(Diag))
+    if (Diags->isWarningOrExtension(Diag))
       setSeverity(Diag, Map, Loc);
 }