[Diagnostics] Add -[no-]warning-as-error flags for precise control over warning behavior

This commit adds new compiler options -no-warning-as-error/-warning-as-error which allows users to specify behavior for exact warnings and warning groups.

Author: DmT021

include/swift/AST/ASTBridging.h

@@ -309,7 +309,7 @@ struct BridgedPatternBindingEntry {
 // NOTE: This must be the same underlying value as C++ 'swift::DiagID' defined
 // in 'DiagnosticList.cpp'.
 enum ENUM_EXTENSIBILITY_ATTR(open) BridgedDiagID : uint32_t {
-#define DIAG(KIND, ID, Options, Text, Signature) BridgedDiagID_##ID,
+#define DIAG(KIND, ID, Group, Options, Text, Signature) BridgedDiagID_##ID,
 #include "swift/AST/DiagnosticsAll.def"
 };
 

include/swift/AST/DefineDiagnosticGroupsMacros.h

@@ -0,0 +1,80 @@
+//===--- DefineDiagnosticGroupsMacros.def -----------------------*- C++ -*-===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2024 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file defines macros defining diagnostic groups.
+//
+//===----------------------------------------------------------------------===//
+
+// Define macros
+#if defined(DEFINE_DIAGNOSTIC_GROUPS_MACROS) &&                                \
+    !defined(UNDEFINE_DIAGNOSTIC_GROUPS_MACROS)
+
+#undef DEFINE_DIAGNOSTIC_GROUPS_MACROS
+
+#ifndef GROUP_DECL
+#error GROUP_DECL(Name, Version) macro is not defined
+#endif
+
+#ifndef GROUP_LINK
+#error GROUP_LINK(Parent, Child) macro is not defined
+#endif
+
+// FOR_EACH macro implementation from
+// https://www.scs.stanford.edu/~dm/blog/va-opt.html
+// Extended with "context" parameter to pass an additional common argument
+#define PARENS ()
+#define EXPAND(...) EXPAND4(EXPAND4(EXPAND4(EXPAND4(__VA_ARGS__))))
+#define EXPAND4(...) EXPAND3(EXPAND3(EXPAND3(EXPAND3(__VA_ARGS__))))
+#define EXPAND3(...) EXPAND2(EXPAND2(EXPAND2(EXPAND2(__VA_ARGS__))))
+#define EXPAND2(...) EXPAND1(EXPAND1(EXPAND1(EXPAND1(__VA_ARGS__))))
+#define EXPAND1(...) __VA_ARGS__
+#define FOR_EACH_WITH_CTX(macro, context, ...)                                 \
+  __VA_OPT__(EXPAND(FOR_EACH_WITH_CTX_HELPER(macro, context, __VA_ARGS__)))
+#define FOR_EACH_WITH_CTX_HELPER(macro, context, a1, ...)                      \
+  macro(context, a1)                                                           \
+  __VA_OPT__(FOR_EACH_WITH_CTX_AGAIN PARENS (macro, context, __VA_ARGS__))
+#define FOR_EACH_WITH_CTX_AGAIN() FOR_EACH_WITH_CTX_HELPER
+
+// GROUP macro:
+//   Name - group name as it appears in DiagGroupID enum and DiagGroupInfo.name
+//   Version - compiler version when this group was added
+//   __VA_ARGS__ - subgroups of this group
+#define GROUP(Name, Version, ...)                                              \
+  GROUP_DECL(Name, Version)                                                    \
+  FOR_EACH_WITH_CTX(GROUP_LINK, Name, __VA_ARGS__)
+
+// Undefine macros
+#elif defined(UNDEFINE_DIAGNOSTIC_GROUPS_MACROS) &&                            \
+    !defined(DEFINE_DIAGNOSTIC_GROUPS_MACROS)
+
+#undef UNDEFINE_DIAGNOSTIC_GROUPS_MACROS
+
+#ifndef GROUP
+#error Trying to undefine the diagnostic groups macros, but GROUP macro wasn't defined
+#endif
+
+#undef PARENS
+#undef EXPAND
+#undef EXPAND4
+#undef EXPAND3
+#undef EXPAND2
+#undef EXPAND1
+#undef FOR_EACH
+#undef FOR_EACH_HELPER
+#undef FOR_EACH_AGAIN
+#undef GROUP
+#undef GROUP_DECL
+#undef GROUP_LINK
+
+#else
+#error Invalid DefineDiagnosticGroupsMacros.h inclusion
+#endif

include/swift/AST/DefineDiagnosticMacros.h

@@ -17,29 +17,39 @@
 // Define macros
 #ifdef DEFINE_DIAGNOSTIC_MACROS
 
-#if !(defined(DIAG) || (defined(ERROR) && defined(WARNING) && defined(NOTE) && \
-                        defined(REMARK)))
-#error Must define either DIAG or the set {ERROR,WARNING,NOTE,REMARK}
+#if !(defined(DIAG) || (defined(GROUPED_ERROR) && defined(GROUPED_WARNING) &&  \
+                        defined(NOTE) && defined(REMARK)))
+#error Must define either DIAG or the set {GROUPED_ERROR,GROUPED_WARNING,NOTE,REMARK}
+#endif
+
+#ifndef GROUPED_ERROR
+#define GROUPED_ERROR(ID, Group, Options, Text, Signature)                     \
+  DIAG(ERROR, ID, Group, Options, Text, Signature)
 #endif
 
 #ifndef ERROR
 #define ERROR(ID, Options, Text, Signature)                                    \
-  DIAG(ERROR, ID, Options, Text, Signature)
+  GROUPED_ERROR(ID, no_group, Options, Text, Signature)
+#endif
+
+#ifndef GROUPED_WARNING
+#define GROUPED_WARNING(ID, Group, Options, Text, Signature)                   \
+  DIAG(WARNING, ID, Group, Options, Text, Signature)
 #endif
 
 #ifndef WARNING
 #define WARNING(ID, Options, Text, Signature)                                  \
-  DIAG(WARNING, ID, Options, Text, Signature)
+  GROUPED_WARNING(ID, no_group, Options, Text, Signature)
 #endif
 
 #ifndef NOTE
 #define NOTE(ID, Options, Text, Signature)                                     \
-  DIAG(NOTE, ID, Options, Text, Signature)
+  DIAG(NOTE, ID, no_group, Options, Text, Signature)
 #endif
 
 #ifndef REMARK
 #define REMARK(ID, Options, Text, Signature)                                   \
-  DIAG(REMARK, ID, Options, Text, Signature)
+  DIAG(REMARK, ID, no_group, Options, Text, Signature)
 #endif
 
 #ifndef FIXIT
@@ -61,7 +71,9 @@
 #undef REMARK
 #undef NOTE
 #undef WARNING
+#undef GROUPED_WARNING
 #undef ERROR
+#undef GROUPED_ERROR
 #undef FIXIT
 
 #endif

include/swift/AST/DiagnosticEngine.h

@@ -24,6 +24,7 @@
 #include "swift/AST/TypeLoc.h"
 #include "swift/Basic/Statistic.h"
 #include "swift/Basic/Version.h"
+#include "swift/Basic/WarningAsErrorRule.h"
 #include "swift/Localization/LocalizationFormat.h"
 #include "llvm/ADT/BitVector.h"
 #include "llvm/ADT/StringRef.h"
@@ -839,8 +840,8 @@ namespace swift {
     /// Don't emit any remarks
     bool suppressRemarks = false;
 
-    /// Emit all warnings as errors
-    bool warningsAsErrors = false;
+    /// Treat these warnings as errors. Indicies here corespond to DiagID enum
+    llvm::BitVector warningsAsErrors;
 
     /// Whether a fatal error has occurred
     bool fatalErrorOccurred = false;
@@ -881,9 +882,22 @@ namespace swift {
     void setSuppressRemarks(bool val) { suppressRemarks = val; }
     bool getSuppressRemarks() const { return suppressRemarks; }
 
-    /// Whether to treat warnings as errors
-    void setWarningsAsErrors(bool val) { warningsAsErrors = val; }
-    bool getWarningsAsErrors() const { return warningsAsErrors; }
+    /// Whether a warning should be upgraded to an error or not
+    void setWarningAsErrorForDiagID(DiagID id, bool value) {
+      warningsAsErrors[(unsigned)id] = value;
+    }
+    bool getWarningAsErrorForDiagID(DiagID id) {
+      return warningsAsErrors[(unsigned)id];
+    }
+
+    /// Whether all warnings should be upgraded to errors or not
+    void setAllWarningsAsErrors(bool value) {
+      if (value) {
+        warningsAsErrors.set();
+      } else {
+        warningsAsErrors.reset();
+      }
+    }
 
     void resetHadAnyError() {
       anyErrorOccurred = false;
@@ -1093,11 +1107,15 @@ namespace swift {
       return state.getSuppressRemarks();
     }
 
-    /// Whether to treat warnings as errors
-    void setWarningsAsErrors(bool val) { state.setWarningsAsErrors(val); }
-    bool getWarningsAsErrors() const {
-      return state.getWarningsAsErrors();
-    }
+    /// Apply rules specifing what warnings should or shouldn't be treated as
+    /// errors. For group rules the string is either a group name defined by
+    /// DiagnosticGroups.def or a string with format "_id:<diag_id>" where
+    /// <diag_id> is one of the diagnostic IDs listed in
+    /// include/swift/AST/Diagnostics*.def
+    /// Rules are applied in order they appear in the vector.
+    /// In case the vector contains rules affecting the same diagnostic ID
+    /// the last rule wins.
+    void setWarningsAsErrorsRules(const std::vector<WarningAsErrorRule> &rules);
 
     /// Whether to print diagnostic names after their messages
     void setPrintDiagnosticNames(bool val) {

include/swift/AST/DiagnosticGroups.def

@@ -0,0 +1,34 @@
+//===--- DiagnosticGroups.def - Diagnostic Groups ---------------*- C++ -*-===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2024 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file defines diagnostic groups.
+//
+//===----------------------------------------------------------------------===//
+
+#define DEFINE_DIAGNOSTIC_GROUPS_MACROS
+#include "swift/AST/DefineDiagnosticGroupsMacros.h"
+
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wgnu-zero-variadic-macro-arguments"
+
+GROUP(no_group, 6.0)
+
+GROUP(deprecated, 6.0, availability_deprecated)
+GROUP(availability_deprecated, 6.0)
+
+GROUP(unknown_warning_group, 6.0)
+GROUP(error_in_future_swift_version, 6.0)
+
+#pragma clang diagnostic pop
+
+#define UNDEFINE_DIAGNOSTIC_GROUPS_MACROS
+#include "swift/AST/DefineDiagnosticGroupsMacros.h"

include/swift/AST/DiagnosticGroups.h

@@ -0,0 +1,61 @@
+//===--- DiagnosticGroups.h - Diagnostic Groups -----------------*- C++ -*-===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2024 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file defines the diagnostic groups enumaration, group graph
+//  and auxilary functions.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SWIFT_DIAGNOSTICGROUPS_H
+#define SWIFT_DIAGNOSTICGROUPS_H
+
+#include "swift/AST/DiagnosticList.h"
+#include "llvm/ADT/ArrayRef.h"
+#include <array>
+#include <string_view>
+#include <unordered_map>
+
+namespace swift {
+
+enum class DiagGroupID : uint16_t {
+#define GROUP_DECL(Name, Version) Name,
+#define GROUP_LINK(Parent, Child)
+#include "swift/AST/DiagnosticGroups.def"
+};
+
+constexpr const auto DiagGroupsCount = [] {
+  size_t count = 0;
+#define GROUP_DECL(Name, Version) count++;
+#define GROUP_LINK(Parent, Child)
+#include "DiagnosticGroups.def"
+  return count;
+}();
+
+struct DiagGroupInfo {
+  DiagGroupID id;
+  std::string_view name;
+  std::string_view version;
+  llvm::ArrayRef<DiagGroupID> supergroups;
+  llvm::ArrayRef<DiagGroupID> subgroups;
+  llvm::ArrayRef<DiagID> diagnostics;
+
+  void
+  traverseDepthFirst(std::function<void(const DiagGroupInfo &)> func) const;
+};
+
+extern const std::array<DiagGroupInfo, DiagGroupsCount> diagnosticGroupsInfo;
+const DiagGroupInfo &getDiagGroupInfoByID(DiagGroupID id);
+std::optional<DiagGroupID> getDiagGroupIDByName(std::string_view name);
+
+} // end namespace swift
+
+#endif /* SWIFT_DIAGNOSTICGROUPS_H */

include/swift/AST/DiagnosticList.h

@@ -0,0 +1,43 @@
+//===--- DiagnosticList.h - Diagnostic Definitions --------------*- C++ -*-===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2024 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file defines all of the diagnostics emitted by Swift.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SWIFT_DIAGNOSTICLIST_H
+#define SWIFT_DIAGNOSTICLIST_H
+
+#include <cstdint>
+
+namespace swift {
+
+/// Enumeration describing all of possible diagnostics.
+///
+/// Each of the diagnostics described in Diagnostics.def has an entry in
+/// this enumeration type that uniquely identifies it.
+enum class DiagID : uint32_t {
+#define DIAG(KIND, ID, Group, Options, Text, Signature) ID,
+#include "swift/AST/DiagnosticsAll.def"
+};
+static_assert(static_cast<uint32_t>(swift::DiagID::invalid_diagnostic) == 0,
+              "0 is not the invalid diagnostic ID");
+
+enum class FixItID : uint32_t {
+#define DIAG(KIND, ID, Group, Options, Text, Signature)
+#define FIXIT(ID, Text, Signature) ID,
+#include "swift/AST/DiagnosticsAll.def"
+};
+
+} // end namespace swift
+
+#endif /* SWIFT_DIAGNOSTICLIST_H */

include/swift/AST/DiagnosticsClangImporter.h

@@ -23,8 +23,8 @@
 namespace swift {
   namespace diag {
   // Declare common diagnostics objects with their appropriate types.
-#define DIAG(KIND,ID,Options,Text,Signature) \
-  extern detail::DiagWithArguments<void Signature>::type ID;
+#define DIAG(KIND, ID, Group, Options, Text, Signature)                      \
+    extern detail::DiagWithArguments<void Signature>::type ID;
 #include "DiagnosticsClangImporter.def"
   }
 }

include/swift/AST/DiagnosticsCommon.def

@@ -47,7 +47,7 @@ ERROR(error_no_group_info,none,
 NOTE(brace_stmt_suggest_do,none,
      "did you mean to use a 'do' statement?", ())
 
-WARNING(error_in_future_swift_version,none,
+GROUPED_WARNING(error_in_future_swift_version,error_in_future_swift_version,none,
         "%0; this is an error in the Swift %1 language mode",
         (DiagnosticInfo *, unsigned))
 

include/swift/AST/DiagnosticsCommon.h

@@ -56,10 +56,10 @@ namespace swift {
     using DeclAttribute = const DeclAttribute *;
 
   // Declare common diagnostics objects with their appropriate types.
-#define DIAG(KIND,ID,Options,Text,Signature) \
-    extern detail::DiagWithArguments<void Signature>::type ID;
-#define FIXIT(ID, Text, Signature) \
-    extern detail::StructuredFixItWithArguments<void Signature>::type ID;
+#define DIAG(KIND, ID, Group, Options, Text, Signature)                    \
+      extern detail::DiagWithArguments<void Signature>::type ID;
+#define FIXIT(ID, Text, Signature)                                         \
+      extern detail::StructuredFixItWithArguments<void Signature>::type ID;
 #include "DiagnosticsCommon.def"
   } // end namespace diag
 } // end namespace swift

include/swift/AST/DiagnosticsDriver.h

@@ -25,8 +25,8 @@
 namespace swift {
   namespace diag {
   // Declare common diagnostics objects with their appropriate types.
-#define DIAG(KIND,ID,Options,Text,Signature) \
-  extern detail::DiagWithArguments<void Signature>::type ID;
+#define DIAG(KIND, ID, Group, Options, Text, Signature)                      \
+    extern detail::DiagWithArguments<void Signature>::type ID;
 #include "DiagnosticsDriver.def"
   }
 }