merge main into amd-staging

Change-Id: I3f22ab5402113df190587c26aa5dcc8b370cbb35

.github/workflows/docs.yml

@@ -106,9 +106,9 @@ jobs:
         with:
           python-version: '3.11'
           cache: 'pip'
-          cache-dependency-path: 'llvm/docs/requirements.txt'
+          cache-dependency-path: 'llvm/docs/requirements-hashed.txt'
       - name: Install python dependencies
-        run: pip install -r llvm/docs/requirements.txt
+        run: pip install -r llvm/docs/requirements-hashed.txt
       - name: Install system dependencies
         run: |
           sudo apt-get update

clang-tools-extra/test/clang-doc/builtin_types.cpp

@@ -0,0 +1,136 @@
+// RUN: rm -rf %t
+// RUN: mkdir -p %t/yaml %t/md
+
+// RUN: clang-doc --doxygen --executor=standalone %s -output=%t/yaml
+// RUN: FileCheck %s < %t/yaml/index.yaml --check-prefix=YAML
+
+// RUN: clang-doc --doxygen --executor=standalone %s -output=%t/md --format=md
+// RUN: FileCheck %s < %t/md/GlobalNamespace/index.md  --check-prefix=MD
+
+//      YAML: ---
+// YAML-NEXT: USR:             '0000000000000000000000000000000000000000'
+// YAML-NEXT: ChildFunctions:
+
+// MD: # Global Namespace
+// MD: ## Functions
+
+extern bool b();
+
+// YAML-NEXT:   - USR:             '88A104C263241E354ECF5B55B04AE8CEAD625B71'
+// YAML-NEXT:     Name:            'b'
+// YAML-NEXT:     Location:
+// YAML-NEXT:       - LineNumber:      [[# @LINE-5]]
+// YAML-NEXT:         Filename:        '{{.*}}'
+// YAML-NEXT:     ReturnType:
+// YAML-NEXT:       Type:
+// YAML-NEXT:         Name:            '_Bool'
+// YAML-NEXT:         QualName:        '_Bool'
+
+// MD: ### b
+// MD: *_Bool b()*
+
+char c();
+
+// YAML-NEXT:   - USR:             'EA3287837B3F175C8DB154406B4DAD2924F479B5'
+// YAML-NEXT:     Name:            'c'
+// YAML-NEXT:     Location:
+// YAML-NEXT:       - LineNumber:      [[# @LINE-5]]
+// YAML-NEXT:         Filename:        '{{.*}}'
+// YAML-NEXT:     ReturnType:
+// YAML-NEXT:       Type:
+// YAML-NEXT:         Name:            'char'
+// YAML-NEXT:         QualName:        'char'
+
+// MD: ### c
+// MD: *char c()*
+
+double d();
+
+// YAML-NEXT:   - USR:             '60A47E4696CEFC411AB2E1EEFA2DD914E2A7E450'
+// YAML-NEXT:     Name:            'd'
+// YAML-NEXT:     Location:
+// YAML-NEXT:       - LineNumber:      [[# @LINE-5]]
+// YAML-NEXT:         Filename:        '{{.*}}'
+// YAML-NEXT:     ReturnType:
+// YAML-NEXT:       Type:
+// YAML-NEXT:         Name:            'double'
+// YAML-NEXT:         QualName:        'double'
+
+// MD: ### d
+// MD: *double d()*
+
+float f();
+
+// YAML-NEXT:   - USR:             'B3A9EC6BECD5869CF3ACDFB25153CFE6BBDD5EAB'
+// YAML-NEXT:     Name:            'f'
+// YAML-NEXT:     Location:
+// YAML-NEXT:       - LineNumber:      [[# @LINE-5]]
+// YAML-NEXT:         Filename:        '{{.*}}'
+// YAML-NEXT:     ReturnType:
+// YAML-NEXT:       Type:
+// YAML-NEXT:         Name:            'float'
+// YAML-NEXT:         QualName:        'float'
+
+// MD: ### f
+// MD: *float f()*
+
+int i();
+
+// YAML-NEXT:   - USR:             '307041280A81EB46F949A94AD52587C659FD801C'
+// YAML-NEXT:     Name:            'i'
+// YAML-NEXT:     Location:
+// YAML-NEXT:       - LineNumber:      [[# @LINE-5]]
+// YAML-NEXT:         Filename:        '{{.*}}'
+// YAML-NEXT:     ReturnType:
+// YAML-NEXT:       Type:
+// YAML-NEXT:         Name:            'int'
+// YAML-NEXT:         QualName:        'int'
+
+// MD: ### i
+// MD: *int i()*
+
+long l();
+
+// YAML-NEXT:   - USR:             'A1CE9AB0064C412F857592E01332C641C1A06F37'
+// YAML-NEXT:     Name:            'l'
+// YAML-NEXT:     Location:
+// YAML-NEXT:       - LineNumber:      [[# @LINE-5]]
+// YAML-NEXT:         Filename:        '{{.*}}'
+// YAML-NEXT:     ReturnType:
+// YAML-NEXT:       Type:
+// YAML-NEXT:         Name:            'long'
+// YAML-NEXT:         QualName:        'long'
+
+// MD: ### l
+// MD: *long l()*
+
+long long ll();
+
+// YAML-NEXT:   - USR:             '5C2C44ED4825C066EF6ED796863586F343C8BCA9'
+// YAML-NEXT:     Name:            'll'
+// YAML-NEXT:     Location:
+// YAML-NEXT:       - LineNumber:      [[# @LINE-5]]
+// YAML-NEXT:         Filename:        '{{.*}}'
+// YAML-NEXT:     ReturnType:
+// YAML-NEXT:       Type:
+// YAML-NEXT:         Name:            'long long'
+// YAML-NEXT:         QualName:        'long long'
+
+// MD: ### ll
+// MD: *long long ll()*
+
+short s();
+
+// YAML-NEXT:   - USR:             '412341570FD3AD2C3A1E9A1DE7B3C01C07BEACFE'
+// YAML-NEXT:     Name:            's'
+// YAML-NEXT:     Location:
+// YAML-NEXT:       - LineNumber:      [[# @LINE-5]]
+// YAML-NEXT:         Filename:        '{{.*}}'
+// YAML-NEXT:     ReturnType:
+// YAML-NEXT:       Type:
+// YAML-NEXT:         Name:            'short'
+// YAML-NEXT:         QualName:        'short'
+// YAML-NEXT: ...
+
+// MD: ### s
+// MD: *short s()*

clang/docs/ReleaseNotes.rst

@@ -713,6 +713,16 @@ Improvements to Clang's diagnostics
       views.push_back(std::string("123")); // warning
     }
 
+- Clang now emits a ``-Wtautological-compare`` diagnostic when a check for
+  pointer addition overflow is always true or false, because overflow would
+  be undefined behavior.
+
+  .. code-block:: c++
+
+    bool incorrect_overflow_check(const char *ptr, size_t index) {
+      return ptr + index < ptr; // warning
+    }
+
 Improvements to Clang's time-trace
 ----------------------------------
 

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -10249,7 +10249,7 @@ def warn_dangling_reference_captured_by_unknown : Warning<
 // should result in a warning, since these always evaluate to a constant.
 // Array comparisons have similar warnings
 def warn_comparison_always : Warning<
-  "%select{self-|array }0comparison always evaluates to "
+  "%select{self-|array |pointer }0comparison always evaluates to "
   "%select{a constant|true|false|'std::strong_ordering::equal'}1">,
   InGroup<TautologicalCompare>;
 def warn_comparison_bitwise_always : Warning<

clang/lib/Driver/SanitizerArgs.cpp

@@ -248,48 +248,76 @@ static SanitizerMask setGroupBits(SanitizerMask Kinds) {
   return Kinds;
 }
 
-// Computes the sanitizer mask based on the default plus opt-in (if supported)
-// minus opt-out.
+// Computes the sanitizer mask as:
+//     Default + Arguments (in or out)
+// with arguments parsed from left to right.
+//
+// Error messages are printed if the AlwaysIn or AlwaysOut invariants are
+// violated, but the caller must enforce these invariants themselves.
 static SanitizerMask
 parseSanitizeArgs(const Driver &D, const llvm::opt::ArgList &Args,
-                  bool DiagnoseErrors, SanitizerMask Supported,
-                  SanitizerMask Default, int OptInID, int OptOutID) {
-  SanitizerMask Remove; // During the loop below, the accumulated set of
-                        // sanitizers disabled by the current sanitizer
-                        // argument or any argument after it.
-  SanitizerMask Kinds;
-  SanitizerMask SupportedWithGroups = setGroupBits(Supported);
-
-  for (const llvm::opt::Arg *Arg : llvm::reverse(Args)) {
+                  bool DiagnoseErrors, SanitizerMask Default,
+                  SanitizerMask AlwaysIn, SanitizerMask AlwaysOut, int OptInID,
+                  int OptOutID) {
+  assert(!(AlwaysIn & AlwaysOut) &&
+         "parseSanitizeArgs called with contradictory in/out requirements");
+
+  SanitizerMask Output = Default;
+  // Keep track of which violations we have already reported, to avoid
+  // duplicate error messages.
+  SanitizerMask DiagnosedAlwaysInViolations;
+  SanitizerMask DiagnosedAlwaysOutViolations;
+  for (const auto *Arg : Args) {
     if (Arg->getOption().matches(OptInID)) {
-      Arg->claim();
-      SanitizerMask Add = parseArgValues(D, Arg, true);
-      Add &= ~Remove;
-      SanitizerMask InvalidValues = Add & ~SupportedWithGroups;
-      if (InvalidValues && DiagnoseErrors) {
-        SanitizerSet S;
-        S.Mask = InvalidValues;
-        D.Diag(diag::err_drv_unsupported_option_argument)
-            << Arg->getSpelling() << toString(S);
+      SanitizerMask Add = parseArgValues(D, Arg, DiagnoseErrors);
+      // Report error if user explicitly tries to opt-in to an always-out
+      // sanitizer.
+      if (SanitizerMask KindsToDiagnose =
+              Add & AlwaysOut & ~DiagnosedAlwaysOutViolations) {
+        if (DiagnoseErrors) {
+          SanitizerSet SetToDiagnose;
+          SetToDiagnose.Mask |= KindsToDiagnose;
+          D.Diag(diag::err_drv_unsupported_option_argument)
+              << Arg->getSpelling() << toString(SetToDiagnose);
+          DiagnosedAlwaysOutViolations |= KindsToDiagnose;
+        }
       }
-      Kinds |= expandSanitizerGroups(Add) & ~Remove;
+      Output |= expandSanitizerGroups(Add);
+      Arg->claim();
     } else if (Arg->getOption().matches(OptOutID)) {
+      SanitizerMask Remove = parseArgValues(D, Arg, DiagnoseErrors);
+      // Report error if user explicitly tries to opt-out of an always-in
+      // sanitizer.
+      if (SanitizerMask KindsToDiagnose =
+              Remove & AlwaysIn & ~DiagnosedAlwaysInViolations) {
+        if (DiagnoseErrors) {
+          SanitizerSet SetToDiagnose;
+          SetToDiagnose.Mask |= KindsToDiagnose;
+          D.Diag(diag::err_drv_unsupported_option_argument)
+              << Arg->getSpelling() << toString(SetToDiagnose);
+          DiagnosedAlwaysInViolations |= KindsToDiagnose;
+        }
+      }
+      Output &= ~expandSanitizerGroups(Remove);
       Arg->claim();
-      Remove |= expandSanitizerGroups(parseArgValues(D, Arg, DiagnoseErrors));
     }
   }
 
-  // Apply default behavior.
-  Kinds |= Default & ~Remove;
-
-  return Kinds;
+  return Output;
 }
 
 static SanitizerMask parseSanitizeTrapArgs(const Driver &D,
                                            const llvm::opt::ArgList &Args,
                                            bool DiagnoseErrors) {
-  return parseSanitizeArgs(D, Args, DiagnoseErrors, TrappingSupported,
-                           TrappingDefault, options::OPT_fsanitize_trap_EQ,
+  SanitizerMask AlwaysTrap; // Empty
+  SanitizerMask NeverTrap = ~(setGroupBits(TrappingSupported));
+
+  // N.B. We do *not* enforce NeverTrap. This maintains the behavior of
+  // '-fsanitize=undefined -fsanitize-trap=undefined'
+  // (clang/test/Driver/fsanitize.c ), which is that vptr is not enabled at all
+  // (not even in recover mode) in order to avoid the need for a ubsan runtime.
+  return parseSanitizeArgs(D, Args, DiagnoseErrors, TrappingDefault, AlwaysTrap,
+                           NeverTrap, options::OPT_fsanitize_trap_EQ,
                            options::OPT_fno_sanitize_trap_EQ);
 }
 
@@ -657,44 +685,13 @@ SanitizerArgs::SanitizerArgs(const ToolChain &TC,
   // default in ASan?
 
   // Parse -f(no-)?sanitize-recover flags.
-  SanitizerMask RecoverableKinds = RecoverableByDefault | AlwaysRecoverable;
-  SanitizerMask DiagnosedUnrecoverableKinds;
-  SanitizerMask DiagnosedAlwaysRecoverableKinds;
-  for (const auto *Arg : Args) {
-    if (Arg->getOption().matches(options::OPT_fsanitize_recover_EQ)) {
-      SanitizerMask Add = parseArgValues(D, Arg, DiagnoseErrors);
-      // Report error if user explicitly tries to recover from unrecoverable
-      // sanitizer.
-      if (SanitizerMask KindsToDiagnose =
-              Add & Unrecoverable & ~DiagnosedUnrecoverableKinds) {
-        SanitizerSet SetToDiagnose;
-        SetToDiagnose.Mask |= KindsToDiagnose;
-        if (DiagnoseErrors)
-          D.Diag(diag::err_drv_unsupported_option_argument)
-              << Arg->getSpelling() << toString(SetToDiagnose);
-        DiagnosedUnrecoverableKinds |= KindsToDiagnose;
-      }
-      RecoverableKinds |= expandSanitizerGroups(Add);
-      Arg->claim();
-    } else if (Arg->getOption().matches(options::OPT_fno_sanitize_recover_EQ)) {
-      SanitizerMask Remove = parseArgValues(D, Arg, DiagnoseErrors);
-      // Report error if user explicitly tries to disable recovery from
-      // always recoverable sanitizer.
-      if (SanitizerMask KindsToDiagnose =
-              Remove & AlwaysRecoverable & ~DiagnosedAlwaysRecoverableKinds) {
-        SanitizerSet SetToDiagnose;
-        SetToDiagnose.Mask |= KindsToDiagnose;
-        if (DiagnoseErrors)
-          D.Diag(diag::err_drv_unsupported_option_argument)
-              << Arg->getSpelling() << toString(SetToDiagnose);
-        DiagnosedAlwaysRecoverableKinds |= KindsToDiagnose;
-      }
-      RecoverableKinds &= ~expandSanitizerGroups(Remove);
-      Arg->claim();
-    }
-  }
-  RecoverableKinds &= Kinds;
+  SanitizerMask RecoverableKinds = parseSanitizeArgs(
+      D, Args, DiagnoseErrors, RecoverableByDefault, AlwaysRecoverable,
+      Unrecoverable, options::OPT_fsanitize_recover_EQ,
+      options::OPT_fno_sanitize_recover_EQ);
+  RecoverableKinds |= AlwaysRecoverable;
   RecoverableKinds &= ~Unrecoverable;
+  RecoverableKinds &= Kinds;
 
   TrappingKinds &= Kinds;
   RecoverableKinds &= ~TrappingKinds;

clang/lib/Sema/SemaExpr.cpp

@@ -11786,6 +11786,50 @@ static bool checkForArray(const Expr *E) {
   return D->getType()->isArrayType() && !D->isWeak();
 }
 
+/// Detect patterns ptr + size >= ptr and ptr + size < ptr, where ptr is a
+/// pointer and size is an unsigned integer. Return whether the result is
+/// always true/false.
+static std::optional<bool> isTautologicalBoundsCheck(const Expr *LHS,
+                                                     const Expr *RHS,
+                                                     BinaryOperatorKind Opc) {
+  if (!LHS->getType()->isPointerType())
+    return std::nullopt;
+
+  // Canonicalize to >= or < predicate.
+  switch (Opc) {
+  case BO_GE:
+  case BO_LT:
+    break;
+  case BO_GT:
+    std::swap(LHS, RHS);
+    Opc = BO_LT;
+    break;
+  case BO_LE:
+    std::swap(LHS, RHS);
+    Opc = BO_GE;
+    break;
+  default:
+    return std::nullopt;
+  }
+
+  auto *BO = dyn_cast<BinaryOperator>(LHS);
+  if (!BO || BO->getOpcode() != BO_Add)
+    return std::nullopt;
+
+  Expr *Other;
+  if (Expr::isSameComparisonOperand(BO->getLHS(), RHS))
+    Other = BO->getRHS();
+  else if (Expr::isSameComparisonOperand(BO->getRHS(), RHS))
+    Other = BO->getLHS();
+  else
+    return std::nullopt;
+
+  if (!Other->getType()->isUnsignedIntegerType())
+    return std::nullopt;
+
+  return Opc == BO_GE;
+}
+
 /// Diagnose some forms of syntactically-obvious tautological comparison.
 static void diagnoseTautologicalComparison(Sema &S, SourceLocation Loc,
                                            Expr *LHS, Expr *RHS,
@@ -11895,6 +11939,12 @@ static void diagnoseTautologicalComparison(Sema &S, SourceLocation Loc,
                             S.PDiag(diag::warn_comparison_always)
                                 << 1 /*array comparison*/
                                 << Result);
+    } else if (std::optional<bool> Res =
+                   isTautologicalBoundsCheck(LHS, RHS, Opc)) {
+      S.DiagRuntimeBehavior(Loc, nullptr,
+                            S.PDiag(diag::warn_comparison_always)
+                                << 2 /*pointer comparison*/
+                                << (*Res ? AlwaysTrue : AlwaysFalse));
     }
   }