Merge from 'main' to 'sycl-web' (161 commits)

Author: fineg74

.github/workflows/docs.yml

@@ -119,7 +119,7 @@ jobs:
         if: steps.docs-changed-subprojects.outputs.libc_any_changed == 'true'
         run: |
           cmake -B libc-build -GNinja -DCMAKE_BUILD_TYPE=Release -DLLVM_ENABLE_RUNTIMES="libc" -DLLVM_ENABLE_SPHINX=ON ./runtimes
-          TZ=UTC ninja -C docs-libc-html
+          TZ=UTC ninja -C libc-build docs-libc-html
       - name: Build LLD docs
         if: steps.docs-changed-subprojects.outputs.lld_any_changed == 'true'
         run: |

clang-tools-extra/clang-tidy/bugprone/UnusedReturnValueCheck.cpp

@@ -130,26 +130,35 @@ UnusedReturnValueCheck::UnusedReturnValueCheck(llvm::StringRef Name,
                                             "::std::error_condition;"
                                             "::std::errc;"
                                             "::std::expected;"
-                                            "::boost::system::error_code"))) {}
+                                            "::boost::system::error_code"))),
+      AllowCastToVoid(Options.get("AllowCastToVoid", false)) {}
 
 void UnusedReturnValueCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
   Options.store(Opts, "CheckedFunctions", CheckedFunctions);
   Options.store(Opts, "CheckedReturnTypes",
                 utils::options::serializeStringList(CheckedReturnTypes));
+  Options.store(Opts, "AllowCastToVoid", AllowCastToVoid);
 }
 
 void UnusedReturnValueCheck::registerMatchers(MatchFinder *Finder) {
   auto FunVec = utils::options::parseStringList(CheckedFunctions);
 
-  auto MatchedCallExpr = expr(ignoringImplicit(ignoringParenImpCasts(
-      callExpr(callee(functionDecl(
-                   // Don't match void overloads of checked functions.
-                   unless(returns(voidType())),
-                   anyOf(isInstantiatedFrom(hasAnyName(FunVec)),
-                         returns(hasCanonicalType(hasDeclaration(
-                             namedDecl(matchers::matchesAnyListedName(
-                                 CheckedReturnTypes)))))))))
-          .bind("match"))));
+  auto MatchedDirectCallExpr =
+      expr(callExpr(callee(functionDecl(
+                        // Don't match void overloads of checked functions.
+                        unless(returns(voidType())),
+                        anyOf(isInstantiatedFrom(hasAnyName(FunVec)),
+                              returns(hasCanonicalType(hasDeclaration(
+                                  namedDecl(matchers::matchesAnyListedName(
+                                      CheckedReturnTypes)))))))))
+               .bind("match"));
+
+  auto CheckCastToVoid =
+      AllowCastToVoid ? castExpr(unless(hasCastKind(CK_ToVoid))) : castExpr();
+  auto MatchedCallExpr = expr(
+      anyOf(MatchedDirectCallExpr,
+            explicitCastExpr(unless(cxxFunctionalCastExpr()), CheckCastToVoid,
+                             hasSourceExpression(MatchedDirectCallExpr))));
 
   auto UnusedInCompoundStmt =
       compoundStmt(forEach(MatchedCallExpr),
@@ -178,8 +187,13 @@ void UnusedReturnValueCheck::registerMatchers(MatchFinder *Finder) {
 void UnusedReturnValueCheck::check(const MatchFinder::MatchResult &Result) {
   if (const auto *Matched = Result.Nodes.getNodeAs<CallExpr>("match")) {
     diag(Matched->getBeginLoc(),
-         "the value returned by this function should be used")
+         "the value returned by this function should not be disregarded; "
+         "neglecting it may lead to errors")
         << Matched->getSourceRange();
+
+    if (!AllowCastToVoid)
+      return;
+
     diag(Matched->getBeginLoc(),
          "cast the expression to void to silence this warning",
          DiagnosticIDs::Note);

clang-tools-extra/clang-tidy/bugprone/UnusedReturnValueCheck.h

@@ -24,10 +24,14 @@ class UnusedReturnValueCheck : public ClangTidyCheck {
   void storeOptions(ClangTidyOptions::OptionMap &Opts) override;
   void registerMatchers(ast_matchers::MatchFinder *Finder) override;
   void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+  std::optional<TraversalKind> getCheckTraversalKind() const override {
+    return TK_IgnoreUnlessSpelledInSource;
+  }
 
 private:
   std::string CheckedFunctions;
   const std::vector<StringRef> CheckedReturnTypes;
+  const bool AllowCastToVoid;
 };
 
 } // namespace clang::tidy::bugprone

clang-tools-extra/clang-tidy/cert/CERTTidyModule.cpp

@@ -328,6 +328,7 @@ class CERTModule : public ClangTidyModule {
     ClangTidyOptions::OptionMap &Opts = Options.CheckOptions;
     Opts["cert-dcl16-c.NewSuffixes"] = "L;LL;LU;LLU";
     Opts["cert-err33-c.CheckedFunctions"] = CertErr33CCheckedFunctions;
+    Opts["cert-err33-c.AllowCastToVoid"] = "true";
     Opts["cert-oop54-cpp.WarnOnlyIfThisHasSuspiciousField"] = "false";
     Opts["cert-str34-c.DiagnoseSignedUnsignedCharComparisons"] = "false";
     return Options;

clang-tools-extra/clang-tidy/cppcoreguidelines/PreferMemberInitializerCheck.cpp

@@ -8,8 +8,10 @@
 
 #include "PreferMemberInitializerCheck.h"
 #include "clang/AST/ASTContext.h"
+#include "clang/AST/Decl.h"
 #include "clang/ASTMatchers/ASTMatchFinder.h"
 #include "clang/Lex/Lexer.h"
+#include "llvm/ADT/DenseMap.h"
 
 using namespace clang::ast_matchers;
 
@@ -54,31 +56,66 @@ static bool shouldBeDefaultMemberInitializer(const Expr *Value) {
 }
 
 namespace {
+
 AST_MATCHER_P(FieldDecl, indexNotLessThan, unsigned, Index) {
   return Node.getFieldIndex() >= Index;
 }
+
+enum class AssignedLevel {
+  // Field is not assigned.
+  None,
+  // Field is assigned.
+  Default,
+  // Assignment of field has side effect:
+  // - assign to reference.
+  // FIXME: support other side effect.
+  HasSideEffect,
+  // Assignment of field has data dependence.
+  HasDependence,
+};
+
 } // namespace
 
+static bool canAdvanceAssignment(AssignedLevel Level) {
+  return Level == AssignedLevel::None || Level == AssignedLevel::Default;
+}
+
 // Checks if Field is initialised using a field that will be initialised after
 // it.
 // TODO: Probably should guard against function calls that could have side
-// effects or if they do reference another field that's initialized before this
-// field, but is modified before the assignment.
-static bool isSafeAssignment(const FieldDecl *Field, const Expr *Init,
-                             const CXXConstructorDecl *Context) {
+// effects or if they do reference another field that's initialized before
+// this field, but is modified before the assignment.
+static void updateAssignmentLevel(
+    const FieldDecl *Field, const Expr *Init, const CXXConstructorDecl *Ctor,
+    llvm::DenseMap<const FieldDecl *, AssignedLevel> &AssignedFields) {
+  auto It = AssignedFields.find(Field);
+  if (It == AssignedFields.end())
+    It = AssignedFields.insert({Field, AssignedLevel::None}).first;
+
+  if (!canAdvanceAssignment(It->second))
+    // fast path for already decided field.
+    return;
+
+  if (Field->getType().getCanonicalType()->isReferenceType()) {
+    // assign to reference type twice cannot be simplified to once.
+    It->second = AssignedLevel::HasSideEffect;
+    return;
+  }
 
   auto MemberMatcher =
       memberExpr(hasObjectExpression(cxxThisExpr()),
                  member(fieldDecl(indexNotLessThan(Field->getFieldIndex()))));
-
   auto DeclMatcher = declRefExpr(
-      to(varDecl(unless(parmVarDecl()), hasDeclContext(equalsNode(Context)))));
-
-  return match(expr(anyOf(MemberMatcher, DeclMatcher,
-                          hasDescendant(MemberMatcher),
-                          hasDescendant(DeclMatcher))),
-               *Init, Field->getASTContext())
-      .empty();
+      to(varDecl(unless(parmVarDecl()), hasDeclContext(equalsNode(Ctor)))));
+  const bool HasDependence = !match(expr(anyOf(MemberMatcher, DeclMatcher,
+                                               hasDescendant(MemberMatcher),
+                                               hasDescendant(DeclMatcher))),
+                                    *Init, Field->getASTContext())
+                                  .empty();
+  if (HasDependence) {
+    It->second = AssignedLevel::HasDependence;
+    return;
+  }
 }
 
 static std::pair<const FieldDecl *, const Expr *>
@@ -99,9 +136,9 @@ isAssignmentToMemberOf(const CXXRecordDecl *Rec, const Stmt *S,
     if (!isa<CXXThisExpr>(ME->getBase()))
       return std::make_pair(nullptr, nullptr);
     const Expr *Init = BO->getRHS()->IgnoreParenImpCasts();
-    if (isSafeAssignment(Field, Init, Ctor))
-      return std::make_pair(Field, Init);
-  } else if (const auto *COCE = dyn_cast<CXXOperatorCallExpr>(S)) {
+    return std::make_pair(Field, Init);
+  }
+  if (const auto *COCE = dyn_cast<CXXOperatorCallExpr>(S)) {
     if (COCE->getOperator() != OO_Equal)
       return std::make_pair(nullptr, nullptr);
 
@@ -117,10 +154,8 @@ isAssignmentToMemberOf(const CXXRecordDecl *Rec, const Stmt *S,
     if (!isa<CXXThisExpr>(ME->getBase()))
       return std::make_pair(nullptr, nullptr);
     const Expr *Init = COCE->getArg(1)->IgnoreParenImpCasts();
-    if (isSafeAssignment(Field, Init, Ctor))
-      return std::make_pair(Field, Init);
+    return std::make_pair(Field, Init);
   }
-
   return std::make_pair(nullptr, nullptr);
 }
 
@@ -156,6 +191,12 @@ void PreferMemberInitializerCheck::check(
   const CXXRecordDecl *Class = Ctor->getParent();
   bool FirstToCtorInits = true;
 
+  llvm::DenseMap<const FieldDecl *, AssignedLevel> AssignedFields{};
+
+  for (const CXXCtorInitializer *Init : Ctor->inits())
+    if (FieldDecl *Field = Init->getMember())
+      updateAssignmentLevel(Field, Init->getInit(), Ctor, AssignedFields);
+
   for (const Stmt *S : Body->body()) {
     if (S->getBeginLoc().isMacroID()) {
       StringRef MacroName = Lexer::getImmediateMacroName(
@@ -180,6 +221,9 @@ void PreferMemberInitializerCheck::check(
     std::tie(Field, InitValue) = isAssignmentToMemberOf(Class, S, Ctor);
     if (!Field)
       continue;
+    updateAssignmentLevel(Field, InitValue, Ctor, AssignedFields);
+    if (!canAdvanceAssignment(AssignedFields[Field]))
+      continue;
     const bool IsInDefaultMemberInitializer =
         IsUseDefaultMemberInitEnabled && getLangOpts().CPlusPlus11 &&
         Ctor->isDefaultConstructor() &&

clang-tools-extra/clang-tidy/cppcoreguidelines/ProTypeStaticCastDowncastCheck.cpp

@@ -14,17 +14,24 @@ using namespace clang::ast_matchers;
 
 namespace clang::tidy::cppcoreguidelines {
 
+ProTypeStaticCastDowncastCheck::ProTypeStaticCastDowncastCheck(
+    StringRef Name, ClangTidyContext *Context)
+    : ClangTidyCheck(Name, Context),
+      StrictMode(Options.getLocalOrGlobal("StrictMode", true)) {}
+
+void ProTypeStaticCastDowncastCheck::storeOptions(
+    ClangTidyOptions::OptionMap &Opts) {
+  Options.store(Opts, "StrictMode", StrictMode);
+}
+
 void ProTypeStaticCastDowncastCheck::registerMatchers(MatchFinder *Finder) {
   Finder->addMatcher(
-      cxxStaticCastExpr(unless(isInTemplateInstantiation())).bind("cast"),
-      this);
+      cxxStaticCastExpr(hasCastKind(CK_BaseToDerived)).bind("cast"), this);
 }
 
 void ProTypeStaticCastDowncastCheck::check(
     const MatchFinder::MatchResult &Result) {
   const auto *MatchedCast = Result.Nodes.getNodeAs<CXXStaticCastExpr>("cast");
-  if (MatchedCast->getCastKind() != CK_BaseToDerived)
-    return;
 
   QualType SourceType = MatchedCast->getSubExpr()->getType();
   const auto *SourceDecl = SourceType->getPointeeCXXRecordDecl();
@@ -33,15 +40,20 @@ void ProTypeStaticCastDowncastCheck::check(
   if (!SourceDecl)
     return;
 
-  if (SourceDecl->isPolymorphic())
+  if (SourceDecl->isPolymorphic()) {
     diag(MatchedCast->getOperatorLoc(),
          "do not use static_cast to downcast from a base to a derived class; "
          "use dynamic_cast instead")
         << FixItHint::CreateReplacement(MatchedCast->getOperatorLoc(),
                                         "dynamic_cast");
-  else
-    diag(MatchedCast->getOperatorLoc(),
-         "do not use static_cast to downcast from a base to a derived class");
+    return;
+  }
+
+  if (!StrictMode)
+    return;
+
+  diag(MatchedCast->getOperatorLoc(),
+       "do not use static_cast to downcast from a base to a derived class");
 }
 
 } // namespace clang::tidy::cppcoreguidelines

clang-tools-extra/clang-tidy/cppcoreguidelines/ProTypeStaticCastDowncastCheck.h

@@ -20,13 +20,19 @@ namespace clang::tidy::cppcoreguidelines {
 /// http://clang.llvm.org/extra/clang-tidy/checks/cppcoreguidelines/pro-type-static-cast-downcast.html
 class ProTypeStaticCastDowncastCheck : public ClangTidyCheck {
 public:
-  ProTypeStaticCastDowncastCheck(StringRef Name, ClangTidyContext *Context)
-      : ClangTidyCheck(Name, Context) {}
+  ProTypeStaticCastDowncastCheck(StringRef Name, ClangTidyContext *Context);
   bool isLanguageVersionSupported(const LangOptions &LangOpts) const override {
     return LangOpts.CPlusPlus;
   }
   void registerMatchers(ast_matchers::MatchFinder *Finder) override;
   void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+  void storeOptions(ClangTidyOptions::OptionMap &Opts) override;
+  std::optional<TraversalKind> getCheckTraversalKind() const override {
+    return TK_IgnoreUnlessSpelledInSource;
+  }
+
+private:
+  const bool StrictMode;
 };
 
 } // namespace clang::tidy::cppcoreguidelines

clang-tools-extra/docs/ReleaseNotes.rst

@@ -232,6 +232,12 @@ Changes in existing checks
   <clang-tidy/checks/bugprone/undefined-memory-manipulation>` check to support
   fixed-size arrays of non-trivial types.
 
+- Improved :doc:`bugprone-unused-return-value
+  <clang-tidy/checks/bugprone/unused-return-value>` check diagnostic message,
+  added support for detection of unused results when cast to non-``void`` type.
+  Casting to ``void`` no longer suppresses issues by default, control this
+  behavior with the new `AllowCastToVoid` option.
+
 - Improved :doc:`cppcoreguidelines-avoid-non-const-global-variables
   <clang-tidy/checks/cppcoreguidelines/avoid-non-const-global-variables>` check
   to ignore ``static`` variables declared within the scope of
@@ -250,7 +256,8 @@ Changes in existing checks
 
 - Improved :doc:`cppcoreguidelines-prefer-member-initializer
   <clang-tidy/checks/cppcoreguidelines/prefer-member-initializer>` check to
-  ignore delegate constructors.
+  ignore delegate constructors and ignore re-assignment for reference or when
+  initialization depend on field that is initialized before.
 
 - Improved :doc:`cppcoreguidelines-pro-bounds-array-to-pointer-decay
   <clang-tidy/checks/cppcoreguidelines/pro-bounds-array-to-pointer-decay>` check
@@ -269,6 +276,11 @@ Changes in existing checks
   <clang-tidy/checks/cppcoreguidelines/pro-type-member-init>` check to ignore
   dependent delegate constructors.
 
+- Improved :doc:`cppcoreguidelines-pro-type-static-cast-downcast
+  <clang-tidy/checks/cppcoreguidelines/pro-type-static-cast-downcast>` check to
+  disregard casts on non-polymorphic types when the `StrictMode` option is set
+  to `false`.
+
 - Improved :doc:`cppcoreguidelines-pro-type-vararg
   <clang-tidy/checks/cppcoreguidelines/pro-type-vararg>` check to ignore
   false-positives in unevaluated context (e.g., ``decltype``, ``sizeof``, ...).

clang-tools-extra/docs/clang-tidy/checks/bugprone/unused-return-value.rst

@@ -52,5 +52,9 @@ Options
    By default the following function return types are checked:
    `::std::error_code`, `::std::error_condition`, `::std::errc`, `::std::expected`, `::boost::system::error_code`
 
+.. option:: AllowCastToVoid
+
+   Controls whether casting return values to ``void`` is permitted. Default: `false`.
+
 :doc:`cert-err33-c <../cert/err33-c>` is an alias of this check that checks a
 fixed and large set of standard library functions.

clang-tools-extra/docs/clang-tidy/checks/cert/err33-c.rst

@@ -189,6 +189,9 @@ functions are checked:
 This check is an alias of check :doc:`bugprone-unused-return-value <../bugprone/unused-return-value>`
 with a fixed set of functions.
 
+Suppressing issues by casting to ``void`` is enabled by default and can be
+disabled by setting `AllowCastToVoid` option to ``false``.
+
 The check corresponds to a part of CERT C Coding Standard rule `ERR33-C.
 Detect and handle standard library errors
 <https://wiki.sei.cmu.edu/confluence/display/c/ERR33-C.+Detect+and+handle+standard+library+errors>`_.

clang-tools-extra/docs/clang-tidy/checks/cppcoreguidelines/pro-type-static-cast-downcast.rst

@@ -14,3 +14,11 @@ unrelated type ``Z``.
 This rule is part of the `Type safety (Type.2)
 <https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#Pro-type-downcast>`_
 profile from the C++ Core Guidelines.
+
+Options
+-------
+
+.. option:: StrictMode
+
+  When set to `false`, no warnings are emitted for casts on non-polymorphic
+  types. Default is `true`.

clang-tools-extra/test/clang-tidy/checkers/bugprone/string-constructor.cpp

@@ -49,6 +49,8 @@ void Test() {
   // CHECK-MESSAGES: [[@LINE-1]]:15: warning: negative value used as length parameter
   std::string q2("test", 200);
   // CHECK-MESSAGES: [[@LINE-1]]:15: warning: length is bigger than string literal size
+  std::string t1("test", 5);
+  // CHECK-MESSAGES: [[@LINE-1]]:15: warning: length is bigger than string literal size
   std::string q3(kText, 200);
   // CHECK-MESSAGES: [[@LINE-1]]:15: warning: length is bigger than string literal size
   std::string q4(kText2, 200);
@@ -97,6 +99,8 @@ void Valid() {
   std::string s1("test", 4);
   std::string s2("test", 3);
   std::string s3("test");
+  std::string s4("test\000", 5);
+  std::string s6("te" "st", 4);
 
   std::string_view emptyv();
   std::string_view sv1("test", 4);