Merge branch 'main' into Uncontrolled-data-used-in-path-expression

Author: MUSTAPHA BARKI

.clang-format

@@ -1 +1,2 @@
 BasedOnStyle: LLVM
+LineEnding: LF

.github/workflows/libcxx-build-and-test.yaml

@@ -215,7 +215,7 @@ jobs:
       - uses: maxim-lobanov/setup-xcode@60606e260d2fc5762a71e64e74b2174e8ea3c8bd # v1.6.0
         with:
           # https://github.com/actions/runner-images/blob/main/images/macos/macos-15-Readme.md
-          xcode-version: '16.3'
+          xcode-version: '26.0'
       - uses: seanmiddleditch/gha-setup-ninja@3b1f8f94a2f8254bd26914c4ab9474d4f0015f67 # v6
       - name: Build and test
         run: |

bolt/include/bolt/Rewrite/RewriteInstance.h

@@ -249,12 +249,11 @@ class RewriteInstance {
   /// Analyze relocation \p Rel.
   /// Return true if the relocation was successfully processed, false otherwise.
   /// The \p SymbolName, \p SymbolAddress, \p Addend and \p ExtractedValue
-  /// parameters will be set on success. The \p Skip argument indicates
-  /// that the relocation was analyzed, but it must not be processed.
+  /// parameters will be set on success.
   bool analyzeRelocation(const object::RelocationRef &Rel, uint32_t &RType,
                          std::string &SymbolName, bool &IsSectionRelocation,
                          uint64_t &SymbolAddress, int64_t &Addend,
-                         uint64_t &ExtractedValue, bool &Skip) const;
+                         uint64_t &ExtractedValue) const;
 
   /// Rewrite non-allocatable sections with modifications.
   void rewriteNoteSections();

bolt/lib/Core/Relocation.cpp

@@ -81,7 +81,6 @@ static bool isSupportedAArch64(uint32_t Type) {
   case ELF::R_AARCH64_LD64_GOT_LO12_NC:
   case ELF::R_AARCH64_TLSDESC_LD64_LO12:
   case ELF::R_AARCH64_TLSDESC_ADD_LO12:
-  case ELF::R_AARCH64_TLSDESC_CALL:
   case ELF::R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21:
   case ELF::R_AARCH64_PREL16:
   case ELF::R_AARCH64_PREL32:
@@ -193,7 +192,6 @@ static size_t getSizeForTypeAArch64(uint32_t Type) {
   case ELF::R_AARCH64_LD64_GOT_LO12_NC:
   case ELF::R_AARCH64_TLSDESC_LD64_LO12:
   case ELF::R_AARCH64_TLSDESC_ADD_LO12:
-  case ELF::R_AARCH64_TLSDESC_CALL:
   case ELF::R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21:
   case ELF::R_AARCH64_PREL32:
   case ELF::R_AARCH64_MOVW_UABS_G0:
@@ -248,7 +246,14 @@ static bool skipRelocationTypeX86(uint32_t Type) {
 }
 
 static bool skipRelocationTypeAArch64(uint32_t Type) {
-  return Type == ELF::R_AARCH64_NONE || Type == ELF::R_AARCH64_LD_PREL_LO19;
+  switch (Type) {
+  default:
+    return false;
+  case ELF::R_AARCH64_NONE:
+  case ELF::R_AARCH64_LD_PREL_LO19:
+  case ELF::R_AARCH64_TLSDESC_CALL:
+    return true;
+  }
 }
 
 static bool skipRelocationTypeRISCV(uint32_t Type) {
@@ -362,7 +367,6 @@ static uint64_t extractValueAArch64(uint32_t Type, uint64_t Contents,
     return static_cast<int64_t>(PC) + SignExtend64<32>(Contents & 0xffffffff);
   case ELF::R_AARCH64_PREL64:
     return static_cast<int64_t>(PC) + Contents;
-  case ELF::R_AARCH64_TLSDESC_CALL:
   case ELF::R_AARCH64_JUMP26:
   case ELF::R_AARCH64_CALL26:
     // Immediate goes in bits 25:0 of B and BL.
@@ -552,7 +556,6 @@ static bool isGOTAArch64(uint32_t Type) {
   case ELF::R_AARCH64_TLSDESC_ADR_PAGE21:
   case ELF::R_AARCH64_TLSDESC_LD64_LO12:
   case ELF::R_AARCH64_TLSDESC_ADD_LO12:
-  case ELF::R_AARCH64_TLSDESC_CALL:
     return true;
   }
 }
@@ -591,7 +594,6 @@ static bool isTLSAArch64(uint32_t Type) {
   case ELF::R_AARCH64_TLSLE_MOVW_TPREL_G0_NC:
   case ELF::R_AARCH64_TLSDESC_LD64_LO12:
   case ELF::R_AARCH64_TLSDESC_ADD_LO12:
-  case ELF::R_AARCH64_TLSDESC_CALL:
   case ELF::R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21:
     return true;
   }
@@ -667,7 +669,6 @@ static bool isPCRelativeAArch64(uint32_t Type) {
   case ELF::R_AARCH64_MOVW_UABS_G2_NC:
   case ELF::R_AARCH64_MOVW_UABS_G3:
     return false;
-  case ELF::R_AARCH64_TLSDESC_CALL:
   case ELF::R_AARCH64_CALL26:
   case ELF::R_AARCH64_JUMP26:
   case ELF::R_AARCH64_TSTBR14:

bolt/lib/Rewrite/RewriteInstance.cpp

@@ -2274,8 +2274,7 @@ uint32_t getRelocationSymbol(const ELFObjectFileBase *Obj,
 bool RewriteInstance::analyzeRelocation(
     const RelocationRef &Rel, uint32_t &RType, std::string &SymbolName,
     bool &IsSectionRelocation, uint64_t &SymbolAddress, int64_t &Addend,
-    uint64_t &ExtractedValue, bool &Skip) const {
-  Skip = false;
+    uint64_t &ExtractedValue) const {
   if (!Relocation::isSupported(RType))
     return false;
 
@@ -2707,9 +2706,8 @@ void RewriteInstance::handleRelocation(const SectionRef &RelocatedSection,
   int64_t Addend;
   uint64_t ExtractedValue;
   bool IsSectionRelocation;
-  bool Skip;
   if (!analyzeRelocation(Rel, RType, SymbolName, IsSectionRelocation,
-                         SymbolAddress, Addend, ExtractedValue, Skip)) {
+                         SymbolAddress, Addend, ExtractedValue)) {
     LLVM_DEBUG({
       dbgs() << "BOLT-WARNING: failed to analyze relocation @ offset = "
              << formatv("{0:x}; type name = {1}\n", Rel.getOffset(), TypeName);
@@ -2718,14 +2716,6 @@ void RewriteInstance::handleRelocation(const SectionRef &RelocatedSection,
     return;
   }
 
-  if (Skip) {
-    LLVM_DEBUG({
-      dbgs() << "BOLT-DEBUG: skipping relocation @ offset = "
-             << formatv("{0:x}; type name = {1}\n", Rel.getOffset(), TypeName);
-    });
-    return;
-  }
-
   if (!IsFromCode && !IsWritable && (IsX86 || IsAArch64) &&
       Relocation::isPCRelative(RType)) {
     BinaryData *BD = BC->getBinaryDataContainingAddress(Rel.getOffset());

bolt/test/AArch64/tls-desc-call.s

@@ -0,0 +1,35 @@
+# RUN: %clang %cflags %s -o %t.so -fPIC -shared -Wl,-q
+# RUN: llvm-bolt %t.so -o %t.bolt --debug-only=bolt 2>&1 | FileCheck %s
+
+# REQUIRES: asserts
+
+## Verify that R_AARCH64_TLSDESC_CALL relocations are ignored
+
+# CHECK-NOT: Relocation {{.*}} R_AARCH64_TLSDESC_CALL
+
+  .text
+  .globl  get_tls_var
+  .p2align  2
+  .type get_tls_var,@function
+get_tls_var:
+  .cfi_startproc
+  str     x30, [sp, #-16]!
+  adrp  x0, :tlsdesc:tls_var
+  ldr x1, [x0, :tlsdesc_lo12:tls_var]
+  add x0, x0, :tlsdesc_lo12:tls_var
+  .tlsdesccall tls_var
+  blr x1
+  mrs x8, TPIDR_EL0
+  ldr w0, [x8, x0]
+  ldr x30, [sp], #16
+  ret
+  .size get_tls_var, .-get_tls_var
+  .cfi_endproc
+
+  .type tls_var,@object
+  .section  .tdata,"awT",@progbits
+  .globl  tls_var
+  .p2align  2, 0x0
+tls_var:
+  .word 42
+  .size tls_var, 4

clang/.clang-format

@@ -1 +1,2 @@
 BasedOnStyle: LLVM
+LineEnding: LF

clang/docs/InternalsManual.rst

@@ -2859,6 +2859,67 @@ This library is called by the :ref:`Parser library <Parser>` during parsing to
 do semantic analysis of the input.  For valid programs, Sema builds an AST for
 parsed constructs.
 
+
+Concept Satisfaction Checking and Subsumption
+---------------------------------------------
+
+As per the C++ standard, constraints are `normalized <https://eel.is/c++draft/temp.constr.normal>`_
+and the normal form is used both for subsumption, and constraint checking.
+Both depend on a parameter mapping that substitutes lazily. In particular,
+we should not substitute in unused arguments.
+
+Clang follows the order of operations prescribed by the standard.
+
+Normalization happens prior to satisfaction and subsumption
+and is handled by ``NormalizedConstraint``.
+
+Clang preserves in the normalized form intermediate concept-ids
+(``ConceptIdConstraint``) This is used for diagnostics only and no substitution
+happens in a ConceptIdConstraint if its expression is satisfied.
+
+The normal form of the associated constraints of a declaration is cached in
+Sema::NormalizationCache such that it is only computed once.
+
+A ``NormalizedConstraint`` is a recursive data structure, where each node
+contains a parameter mapping, represented by the indexes of all parameter
+being used.
+
+Checking satisfaction is done by ``ConstraintSatisfactionChecker``, recursively
+walking ``NormalizedConstraint``. At each level, we substitute the outermost
+level of the template arguments referenced in the parameter mapping of a
+normalized expression (``MultiLevelTemplateArgumentList``).
+
+For the following example,
+
+.. code-block:: c++
+
+  template <typename T>
+  concept A = __is_same(T, int);
+
+  template <typename U>
+  concept B = A<U> && __is_same(U, int);
+
+The normal form of B is
+
+.. code-block:: c++
+
+    __is_same(T, int) /*T->U, innermost level*/
+ && __is_same(U, int) {U->U} /*T->U, outermost level*/
+
+After substitution in the mapping, we substitute in the constraint expression
+using that copy of the ``MultiLevelTemplateArgumentList``, and then evaluate it.
+
+Because this is expensive, it is cached in
+``UnsubstitutedConstraintSatisfactionCache``.
+
+Any error during satisfaction is recorded in ``ConstraintSatisfaction``.
+for nested requirements, ``ConstraintSatisfaction`` is stored (including
+diagnostics) in the AST, which is something we might want to improve.
+
+When an atomic constraint is not satified, we try to substitute into any
+enclosing concept-id using the same mechanism described above, for
+diagnostics purpose, and inject that in the ``ConstraintSatisfaction``.
+
 .. _CodeGen:
 
 The CodeGen Library

clang/docs/ReleaseNotes.rst

@@ -160,6 +160,10 @@ C++23 Feature Support
 C++20 Feature Support
 ^^^^^^^^^^^^^^^^^^^^^
 
+- Clang now normalizes constraints before checking whether they are satisfied, as mandated by the standard.
+  As a result, Clang no longer incorrectly diagnoses substitution failures in template arguments only
+  used in concept-ids, and produces better diagnostics for satisfaction failure. (#GH61811) (#GH135190)
+
 C++17 Feature Support
 ^^^^^^^^^^^^^^^^^^^^^
 
@@ -437,6 +441,7 @@ Bug Fixes to C++ Support
 - Fix the result of `__builtin_is_implicit_lifetime` for types with a user-provided constructor. (#GH160610)
 - Correctly deduce return types in ``decltype`` expressions. (#GH160497) (#GH56652) (#GH116319) (#GH161196)
 - Fixed a crash in the pre-C++23 warning for attributes before a lambda declarator (#GH161070).
+- Fix a crash when attempting to deduce a deduction guide from a non deducible template template parameter. (#130604)
 
 Bug Fixes to AST Handling
 ^^^^^^^^^^^^^^^^^^^^^^^^^

clang/include/clang/AST/ASTConcept.h

@@ -28,10 +28,20 @@ namespace clang {
 
 class ConceptDecl;
 class TemplateDecl;
+class ConceptReference;
 class Expr;
 class NamedDecl;
 struct PrintingPolicy;
 
+/// Unsatisfied constraint expressions if the template arguments could be
+/// substituted into them, or a diagnostic if substitution resulted in
+/// an invalid expression.
+///
+using ConstraintSubstitutionDiagnostic = std::pair<SourceLocation, StringRef>;
+using UnsatisfiedConstraintRecord =
+    llvm::PointerUnion<const Expr *, const ConceptReference *,
+                       const ConstraintSubstitutionDiagnostic *>;
+
 /// The result of a constraint satisfaction check, containing the necessary
 /// information to diagnose an unsatisfied constraint.
 class ConstraintSatisfaction : public llvm::FoldingSetNode {
@@ -48,16 +58,13 @@ class ConstraintSatisfaction : public llvm::FoldingSetNode {
                          ArrayRef<TemplateArgument> TemplateArgs)
       : ConstraintOwner(ConstraintOwner), TemplateArgs(TemplateArgs) {}
 
-  using SubstitutionDiagnostic = std::pair<SourceLocation, StringRef>;
-  using Detail = llvm::PointerUnion<Expr *, SubstitutionDiagnostic *>;
-
   bool IsSatisfied = false;
   bool ContainsErrors = false;
 
   /// \brief The substituted constraint expr, if the template arguments could be
   /// substituted into them, or a diagnostic if substitution resulted in an
   /// invalid expression.
-  llvm::SmallVector<Detail, 4> Details;
+  llvm::SmallVector<UnsatisfiedConstraintRecord, 4> Details;
 
   void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &C) {
     Profile(ID, C, ConstraintOwner, TemplateArgs);
@@ -69,19 +76,12 @@ class ConstraintSatisfaction : public llvm::FoldingSetNode {
 
   bool HasSubstitutionFailure() {
     for (const auto &Detail : Details)
-      if (Detail.dyn_cast<SubstitutionDiagnostic *>())
+      if (Detail.dyn_cast<const ConstraintSubstitutionDiagnostic *>())
         return true;
     return false;
   }
 };
 
-/// Pairs of unsatisfied atomic constraint expressions along with the
-/// substituted constraint expr, if the template arguments could be
-/// substituted into them, or a diagnostic if substitution resulted in
-/// an invalid expression.
-using UnsatisfiedConstraintRecord =
-    llvm::PointerUnion<Expr *, std::pair<SourceLocation, StringRef> *>;
-
 /// \brief The result of a constraint satisfaction check, containing the
 /// necessary information to diagnose an unsatisfied constraint.
 ///
@@ -101,6 +101,10 @@ struct ASTConstraintSatisfaction final :
     return getTrailingObjects() + NumRecords;
   }
 
+  ArrayRef<UnsatisfiedConstraintRecord> records() const {
+    return {begin(), end()};
+  }
+
   ASTConstraintSatisfaction(const ASTContext &C,
                             const ConstraintSatisfaction &Satisfaction);
   ASTConstraintSatisfaction(const ASTContext &C,
@@ -282,6 +286,11 @@ class TypeConstraint {
   }
 };
 
+/// Insertion operator for diagnostics.  This allows sending ConceptReferences's
+/// into a diagnostic with <<.
+const StreamingDiagnostic &operator<<(const StreamingDiagnostic &DB,
+                                      const ConceptReference *C);
+
 } // clang
 
 #endif // LLVM_CLANG_AST_ASTCONCEPT_H