Merged main:f50d3582b4844b86ad86372028e44b52c560ec7d into amd-gfx:75f020611ed6

Local branch amd-gfx 75f0206 Merged main:8a8ef1cacfcd7745d2b6ad00431e6fa9ab9a2fb4 into amd-gfx:c6ac0bd36762
Remote branch main f50d358 [clang][modules] giving the __stddef_ headers their own modules can cause redeclaration errors with -fbuiltin-headers-in-system-modules (llvm#84127)

Author: SC llvm team

.github/workflows/llvm-project-tests.yml

@@ -118,6 +118,11 @@ jobs:
           else
             builddir="$(pwd)"/build
           fi
+          if [ "${{ runner.os }}" == "macOS" ]; then
+            # Workaround test failure on some lld tests on MacOS
+            # https://github.com/llvm/llvm-project/issues/81967
+            extra_cmake_args="-DLLVM_DISABLE_ASSEMBLY_FILES=ON"
+          fi
           echo "llvm-builddir=$builddir" >> "$GITHUB_OUTPUT"
           cmake -G Ninja \
                 -B "$builddir" \

clang/docs/ReleaseNotes.rst

@@ -237,6 +237,10 @@ Improvements to Clang's diagnostics
 - Clang now diagnoses lambda function expressions being implicitly cast to boolean values, under ``-Wpointer-bool-conversion``.
   Fixes #GH82512.
 
+- Clang now provides improved warnings for the ``cleanup`` attribute to detect misuse scenarios,
+  such as attempting to call ``free`` on an unallocated object. Fixes
+  `#79443 <https://github.com/llvm/llvm-project/issues/79443>`_.
+
 Improvements to Clang's time-trace
 ----------------------------------
 
@@ -274,6 +278,13 @@ Bug Fixes in This Version
 - Clang now correctly generates overloads for bit-precise integer types for
   builtin operators in C++. Fixes #GH82998.
 
+- When performing mixed arithmetic between ``_Complex`` floating-point types and integers,
+  Clang now correctly promotes the integer to its corresponding real floating-point
+  type only rather than to the complex type (e.g. ``_Complex float / int`` is now evaluated
+  as ``_Complex float / float`` rather than ``_Complex float / _Complex float``), as mandated
+  by the C standard. This significantly improves codegen of `*` and `/` especially.
+  Fixes (`#31205 <https://github.com/llvm/llvm-project/issues/31205>`_).
+
 Bug Fixes to Compiler Builtins
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
@@ -362,6 +373,9 @@ Bug Fixes to C++ Support
   and (`#74494 <https://github.com/llvm/llvm-project/issues/74494>`_)
 - Allow access to a public template alias declaration that refers to friend's
   private nested type. (#GH25708).
+- Fixed a crash in constant evaluation when trying to access a
+  captured ``this`` pointer in a lambda with an explicit object parameter.
+  Fixes (#GH80997)
 
 Bug Fixes to AST Handling
 ^^^^^^^^^^^^^^^^^^^^^^^^^

clang/include/clang/Sema/Sema.h

@@ -2152,14 +2152,15 @@ class Sema final {
 
   bool IsLayoutCompatible(QualType T1, QualType T2) const;
 
+  bool CheckFunctionCall(FunctionDecl *FDecl, CallExpr *TheCall,
+                         const FunctionProtoType *Proto);
+
 private:
   void CheckArrayAccess(const Expr *BaseExpr, const Expr *IndexExpr,
                         const ArraySubscriptExpr *ASE = nullptr,
                         bool AllowOnePastEnd = true, bool IndexNegated = false);
   void CheckArrayAccess(const Expr *E);
 
-  bool CheckFunctionCall(FunctionDecl *FDecl, CallExpr *TheCall,
-                         const FunctionProtoType *Proto);
   bool CheckObjCMethodCall(ObjCMethodDecl *Method, SourceLocation loc,
                            ArrayRef<const Expr *> Args);
   bool CheckPointerCall(NamedDecl *NDecl, CallExpr *TheCall,

clang/include/clang/StaticAnalyzer/Core/PathSensitive/CallDescription.h

@@ -41,8 +41,12 @@ class CallDescription {
     ///  - We also accept calls where the number of arguments or parameters is
     ///    greater than the specified value.
     /// For the exact heuristics, see CheckerContext::isCLibraryFunction().
-    /// (This mode only matches functions that are declared either directly
-    /// within a TU or in the namespace `std`.)
+    /// Note that functions whose declaration context is not a TU (e.g.
+    /// methods, functions in namespaces) are not accepted as C library
+    /// functions.
+    /// FIXME: If I understand it correctly, this discards calls where C++ code
+    /// refers a C library function through the namespace `std::` via headers
+    /// like <cstdlib>.
     CLibrary,
 
     /// Matches "simple" functions that are not methods. (Static methods are

clang/lib/AST/ExprConstant.cpp

@@ -8517,6 +8517,53 @@ class LValueExprEvaluator
 };
 } // end anonymous namespace
 
+/// Get an lvalue to a field of a lambda's closure type.
+static bool HandleLambdaCapture(EvalInfo &Info, const Expr *E, LValue &Result,
+                                const CXXMethodDecl *MD, const FieldDecl *FD,
+                                bool LValueToRValueConversion) {
+  // Static lambda function call operators can't have captures. We already
+  // diagnosed this, so bail out here.
+  if (MD->isStatic()) {
+    assert(Info.CurrentCall->This == nullptr &&
+           "This should not be set for a static call operator");
+    return false;
+  }
+
+  // Start with 'Result' referring to the complete closure object...
+  if (MD->isExplicitObjectMemberFunction()) {
+    // Self may be passed by reference or by value.
+    const ParmVarDecl *Self = MD->getParamDecl(0);
+    if (Self->getType()->isReferenceType()) {
+      APValue *RefValue = Info.getParamSlot(Info.CurrentCall->Arguments, Self);
+      Result.setFrom(Info.Ctx, *RefValue);
+    } else {
+      const ParmVarDecl *VD = Info.CurrentCall->Arguments.getOrigParam(Self);
+      CallStackFrame *Frame =
+          Info.getCallFrameAndDepth(Info.CurrentCall->Arguments.CallIndex)
+              .first;
+      unsigned Version = Info.CurrentCall->Arguments.Version;
+      Result.set({VD, Frame->Index, Version});
+    }
+  } else
+    Result = *Info.CurrentCall->This;
+
+  // ... then update it to refer to the field of the closure object
+  // that represents the capture.
+  if (!HandleLValueMember(Info, E, Result, FD))
+    return false;
+
+  // And if the field is of reference type (or if we captured '*this' by
+  // reference), update 'Result' to refer to what
+  // the field refers to.
+  if (LValueToRValueConversion) {
+    APValue RVal;
+    if (!handleLValueToRValueConversion(Info, E, FD->getType(), Result, RVal))
+      return false;
+    Result.setFrom(Info.Ctx, RVal);
+  }
+  return true;
+}
+
 /// Evaluate an expression as an lvalue. This can be legitimately called on
 /// expressions which are not glvalues, in three cases:
 ///  * function designators in C, and
@@ -8561,37 +8608,8 @@ bool LValueExprEvaluator::VisitVarDecl(const Expr *E, const VarDecl *VD) {
 
     if (auto *FD = Info.CurrentCall->LambdaCaptureFields.lookup(VD)) {
       const auto *MD = cast<CXXMethodDecl>(Info.CurrentCall->Callee);
-
-      // Static lambda function call operators can't have captures. We already
-      // diagnosed this, so bail out here.
-      if (MD->isStatic()) {
-        assert(Info.CurrentCall->This == nullptr &&
-               "This should not be set for a static call operator");
-        return false;
-      }
-
-      // Start with 'Result' referring to the complete closure object...
-      if (MD->isExplicitObjectMemberFunction()) {
-        APValue *RefValue =
-            Info.getParamSlot(Info.CurrentCall->Arguments, MD->getParamDecl(0));
-        Result.setFrom(Info.Ctx, *RefValue);
-      } else
-        Result = *Info.CurrentCall->This;
-
-      // ... then update it to refer to the field of the closure object
-      // that represents the capture.
-      if (!HandleLValueMember(Info, E, Result, FD))
-        return false;
-      // And if the field is of reference type, update 'Result' to refer to what
-      // the field refers to.
-      if (FD->getType()->isReferenceType()) {
-        APValue RVal;
-        if (!handleLValueToRValueConversion(Info, E, FD->getType(), Result,
-                                            RVal))
-          return false;
-        Result.setFrom(Info.Ctx, RVal);
-      }
-      return true;
+      return HandleLambdaCapture(Info, E, Result, MD, FD,
+                                 FD->getType()->isReferenceType());
     }
   }
 
@@ -9069,45 +9087,46 @@ class PointerExprEvaluator
     return Error(E);
   }
   bool VisitCXXThisExpr(const CXXThisExpr *E) {
-    // Can't look at 'this' when checking a potential constant expression.
-    if (Info.checkingPotentialConstantExpression())
-      return false;
-    if (!Info.CurrentCall->This) {
+    auto DiagnoseInvalidUseOfThis = [&] {
       if (Info.getLangOpts().CPlusPlus11)
         Info.FFDiag(E, diag::note_constexpr_this) << E->isImplicit();
       else
         Info.FFDiag(E);
+    };
+
+    // Can't look at 'this' when checking a potential constant expression.
+    if (Info.checkingPotentialConstantExpression())
       return false;
+
+    bool IsExplicitLambda =
+        isLambdaCallWithExplicitObjectParameter(Info.CurrentCall->Callee);
+    if (!IsExplicitLambda) {
+      if (!Info.CurrentCall->This) {
+        DiagnoseInvalidUseOfThis();
+        return false;
+      }
+
+      Result = *Info.CurrentCall->This;
     }
-    Result = *Info.CurrentCall->This;
 
     if (isLambdaCallOperator(Info.CurrentCall->Callee)) {
       // Ensure we actually have captured 'this'. If something was wrong with
       // 'this' capture, the error would have been previously reported.
       // Otherwise we can be inside of a default initialization of an object
       // declared by lambda's body, so no need to return false.
-      if (!Info.CurrentCall->LambdaThisCaptureField)
-        return true;
-
-      // If we have captured 'this',  the 'this' expression refers
-      // to the enclosing '*this' object (either by value or reference) which is
-      // either copied into the closure object's field that represents the
-      // '*this' or refers to '*this'.
-      // Update 'Result' to refer to the data member/field of the closure object
-      // that represents the '*this' capture.
-      if (!HandleLValueMember(Info, E, Result,
-                             Info.CurrentCall->LambdaThisCaptureField))
-        return false;
-      // If we captured '*this' by reference, replace the field with its referent.
-      if (Info.CurrentCall->LambdaThisCaptureField->getType()
-              ->isPointerType()) {
-        APValue RVal;
-        if (!handleLValueToRValueConversion(Info, E, E->getType(), Result,
-                                            RVal))
+      if (!Info.CurrentCall->LambdaThisCaptureField) {
+        if (IsExplicitLambda && !Info.CurrentCall->This) {
+          DiagnoseInvalidUseOfThis();
           return false;
+        }
 
-        Result.setFrom(Info.Ctx, RVal);
+        return true;
       }
+
+      const auto *MD = cast<CXXMethodDecl>(Info.CurrentCall->Callee);
+      return HandleLambdaCapture(
+          Info, E, Result, MD, Info.CurrentCall->LambdaThisCaptureField,
+          Info.CurrentCall->LambdaThisCaptureField->getType()->isPointerType());
     }
     return true;
   }

clang/lib/Basic/Module.cpp

@@ -301,10 +301,9 @@ bool Module::directlyUses(const Module *Requested) {
     if (Requested->isSubModuleOf(Use))
       return true;
 
-  // Anyone is allowed to use our builtin stdarg.h and stddef.h and their
-  // accompanying modules.
-  if (Requested->getTopLevelModuleName() == "_Builtin_stdarg" ||
-      Requested->getTopLevelModuleName() == "_Builtin_stddef")
+  // Anyone is allowed to use our builtin stddef.h and its accompanying modules.
+  if (Requested->fullModuleNameIs({"_Builtin_stddef", "max_align_t"}) ||
+      Requested->fullModuleNameIs({"_Builtin_stddef_wint_t"}))
     return true;
 
   if (NoUndeclaredIncludes)

clang/lib/Headers/__stddef_null.h

@@ -7,7 +7,7 @@
  *===-----------------------------------------------------------------------===
  */
 
-#if !defined(NULL) || !__has_feature(modules)
+#if !defined(NULL) || !__building_module(_Builtin_stddef)
 
 /* linux/stddef.h will define NULL to 0. glibc (and other) headers then define
  * __need_NULL and rely on stddef.h to redefine NULL to the correct value again.

clang/lib/Headers/__stddef_nullptr_t.h

@@ -7,7 +7,12 @@
  *===-----------------------------------------------------------------------===
  */
 
-#ifndef _NULLPTR_T
+/*
+ * When -fbuiltin-headers-in-system-modules is set this is a non-modular header
+ * and needs to behave as if it was textual.
+ */
+#if !defined(_NULLPTR_T) ||                                                    \
+    (__has_feature(modules) && !__building_module(_Builtin_stddef))
 #define _NULLPTR_T
 
 #ifdef __cplusplus

clang/lib/Headers/__stddef_offsetof.h

@@ -7,6 +7,11 @@
  *===-----------------------------------------------------------------------===
  */
 
-#ifndef offsetof
+/*
+ * When -fbuiltin-headers-in-system-modules is set this is a non-modular header
+ * and needs to behave as if it was textual.
+ */
+#if !defined(offsetof) ||                                                      \
+    (__has_feature(modules) && !__building_module(_Builtin_stddef))
 #define offsetof(t, d) __builtin_offsetof(t, d)
 #endif

clang/lib/Headers/__stddef_ptrdiff_t.h

@@ -7,7 +7,12 @@
  *===-----------------------------------------------------------------------===
  */
 
-#ifndef _PTRDIFF_T
+/*
+ * When -fbuiltin-headers-in-system-modules is set this is a non-modular header
+ * and needs to behave as if it was textual.
+ */
+#if !defined(_PTRDIFF_T) ||                                                    \
+    (__has_feature(modules) && !__building_module(_Builtin_stddef))
 #define _PTRDIFF_T
 
 typedef __PTRDIFF_TYPE__ ptrdiff_t;

clang/lib/Headers/__stddef_rsize_t.h

@@ -7,7 +7,12 @@
  *===-----------------------------------------------------------------------===
  */
 
-#ifndef _RSIZE_T
+/*
+ * When -fbuiltin-headers-in-system-modules is set this is a non-modular header
+ * and needs to behave as if it was textual.
+ */
+#if !defined(_RSIZE_T) ||                                                      \
+    (__has_feature(modules) && !__building_module(_Builtin_stddef))
 #define _RSIZE_T
 
 typedef __SIZE_TYPE__ rsize_t;

clang/lib/Headers/__stddef_size_t.h

@@ -7,7 +7,12 @@
  *===-----------------------------------------------------------------------===
  */
 
-#ifndef _SIZE_T
+/*
+ * When -fbuiltin-headers-in-system-modules is set this is a non-modular header
+ * and needs to behave as if it was textual.
+ */
+#if !defined(_SIZE_T) ||                                                       \
+    (__has_feature(modules) && !__building_module(_Builtin_stddef))
 #define _SIZE_T
 
 typedef __SIZE_TYPE__ size_t;

clang/lib/Headers/__stddef_unreachable.h

@@ -7,6 +7,11 @@
  *===-----------------------------------------------------------------------===
  */
 
-#ifndef unreachable
+/*
+ * When -fbuiltin-headers-in-system-modules is set this is a non-modular header
+ * and needs to behave as if it was textual.
+ */
+#if !defined(unreachable) ||                                                   \
+    (__has_feature(modules) && !__building_module(_Builtin_stddef))
 #define unreachable() __builtin_unreachable()
 #endif

clang/lib/Headers/__stddef_wchar_t.h

@@ -9,7 +9,12 @@
 
 #if !defined(__cplusplus) || (defined(_MSC_VER) && !_NATIVE_WCHAR_T_DEFINED)
 
-#ifndef _WCHAR_T
+/*
+ * When -fbuiltin-headers-in-system-modules is set this is a non-modular header
+ * and needs to behave as if it was textual.
+ */
+#if !defined(_WCHAR_T) ||                                                      \
+    (__has_feature(modules) && !__building_module(_Builtin_stddef))
 #define _WCHAR_T
 
 #ifdef _MSC_EXTENSIONS