svn commit: r358802 - in stable/12/contrib/llvm-project/clang: include/clang/Basic lib/CodeGen lib/Sema

Dimitry Andric dim at FreeBSD.org
Mon Mar 9 07:12:05 UTC 2020


Author: dim
Date: Mon Mar  9 07:12:02 2020
New Revision: 358802
URL: https://svnweb.freebsd.org/changeset/base/358802

Log:
  MFC r358711:
  
  Merge commit f75939599 from llvm git (by Erich Keane):
  
    Reland r374450 with Richard Smith's comments and test fixed.
  
    The behavior from the original patch has changed, since we're no
    longer allowing LLVM to just ignore the alignment.  Instead, we're
    just assuming the maximum possible alignment.
  
    Differential Revision: https://reviews.llvm.org/D68824
  
    llvm-svn: 374562
  
  This fixes 'Assertion failed: (Alignment != 0 && "Invalid Alignment"),
  function CreateAlignmentAssumption', when building recent versions of
  v8, which invoke __builtin_assume_aligned() with its alignment argument
  set to 4GiB or more.
  
  Clang will now report a warning, and show the maximum possible alignment
  instead, e.g.:
  
  huge-align.cpp:1:27: warning: requested alignment must be 536870912 bytes or smaller; maximum alignment assumed [-Wbuiltin-assume-aligned-alignment]
  void *f(void *g) { return __builtin_assume_aligned(g, 4294967296); }
                            ^                           ~~~~~~~~~~
  
  Upstream PR:	https://bugs.llvm.org/show_bug.cgi?id=43839
  Reported by:	cem

Modified:
  stable/12/contrib/llvm-project/clang/include/clang/Basic/DiagnosticSemaKinds.td
  stable/12/contrib/llvm-project/clang/lib/CodeGen/CGBuiltin.cpp
  stable/12/contrib/llvm-project/clang/lib/CodeGen/CGCall.cpp
  stable/12/contrib/llvm-project/clang/lib/CodeGen/CGExprScalar.cpp
  stable/12/contrib/llvm-project/clang/lib/CodeGen/CGStmtOpenMP.cpp
  stable/12/contrib/llvm-project/clang/lib/CodeGen/CodeGenFunction.cpp
  stable/12/contrib/llvm-project/clang/lib/CodeGen/CodeGenFunction.h
  stable/12/contrib/llvm-project/clang/lib/Sema/SemaChecking.cpp
Directory Properties:
  stable/12/   (props changed)
  stable/12/contrib/llvm-project/clang/   (props changed)

Modified: stable/12/contrib/llvm-project/clang/include/clang/Basic/DiagnosticSemaKinds.td
==============================================================================
--- stable/12/contrib/llvm-project/clang/include/clang/Basic/DiagnosticSemaKinds.td	Mon Mar  9 04:09:36 2020	(r358801)
+++ stable/12/contrib/llvm-project/clang/include/clang/Basic/DiagnosticSemaKinds.td	Mon Mar  9 07:12:02 2020	(r358802)
@@ -2797,6 +2797,10 @@ def err_alignment_dependent_typedef_name : Error<
 
 def err_attribute_aligned_too_great : Error<
   "requested alignment must be %0 bytes or smaller">;
+def warn_assume_aligned_too_great
+    : Warning<"requested alignment must be %0 bytes or smaller; maximum "
+              "alignment assumed">,
+      InGroup<DiagGroup<"builtin-assume-aligned-alignment">>;
 def warn_redeclaration_without_attribute_prev_attribute_ignored : Warning<
   "%q0 redeclared without %1 attribute: previous %1 ignored">,
   InGroup<MicrosoftInconsistentDllImport>;

Modified: stable/12/contrib/llvm-project/clang/lib/CodeGen/CGBuiltin.cpp
==============================================================================
--- stable/12/contrib/llvm-project/clang/lib/CodeGen/CGBuiltin.cpp	Mon Mar  9 04:09:36 2020	(r358801)
+++ stable/12/contrib/llvm-project/clang/lib/CodeGen/CGBuiltin.cpp	Mon Mar  9 07:12:02 2020	(r358802)
@@ -2026,11 +2026,13 @@ RValue CodeGenFunction::EmitBuiltinExpr(const GlobalDe
 
     Value *AlignmentValue = EmitScalarExpr(E->getArg(1));
     ConstantInt *AlignmentCI = cast<ConstantInt>(AlignmentValue);
-    unsigned Alignment = (unsigned)AlignmentCI->getZExtValue();
+    if (AlignmentCI->getValue().ugt(llvm::Value::MaximumAlignment))
+      AlignmentCI = ConstantInt::get(AlignmentCI->getType(),
+                                     llvm::Value::MaximumAlignment);
 
     EmitAlignmentAssumption(PtrValue, Ptr,
                             /*The expr loc is sufficient.*/ SourceLocation(),
-                            Alignment, OffsetValue);
+                            AlignmentCI, OffsetValue);
     return RValue::get(PtrValue);
   }
   case Builtin::BI__assume:

Modified: stable/12/contrib/llvm-project/clang/lib/CodeGen/CGCall.cpp
==============================================================================
--- stable/12/contrib/llvm-project/clang/lib/CodeGen/CGCall.cpp	Mon Mar  9 04:09:36 2020	(r358801)
+++ stable/12/contrib/llvm-project/clang/lib/CodeGen/CGCall.cpp	Mon Mar  9 07:12:02 2020	(r358802)
@@ -4548,7 +4548,7 @@ RValue CodeGenFunction::EmitCall(const CGFunctionInfo 
       llvm::Value *Alignment = EmitScalarExpr(AA->getAlignment());
       llvm::ConstantInt *AlignmentCI = cast<llvm::ConstantInt>(Alignment);
       EmitAlignmentAssumption(Ret.getScalarVal(), RetTy, Loc, AA->getLocation(),
-                              AlignmentCI->getZExtValue(), OffsetValue);
+                              AlignmentCI, OffsetValue);
     } else if (const auto *AA = TargetDecl->getAttr<AllocAlignAttr>()) {
       llvm::Value *AlignmentVal = CallArgs[AA->getParamIndex().getLLVMIndex()]
                                       .getRValue(*this)

Modified: stable/12/contrib/llvm-project/clang/lib/CodeGen/CGExprScalar.cpp
==============================================================================
--- stable/12/contrib/llvm-project/clang/lib/CodeGen/CGExprScalar.cpp	Mon Mar  9 04:09:36 2020	(r358801)
+++ stable/12/contrib/llvm-project/clang/lib/CodeGen/CGExprScalar.cpp	Mon Mar  9 07:12:02 2020	(r358802)
@@ -294,8 +294,7 @@ class ScalarExprEmitter (public)
 
     Value *AlignmentValue = CGF.EmitScalarExpr(AVAttr->getAlignment());
     llvm::ConstantInt *AlignmentCI = cast<llvm::ConstantInt>(AlignmentValue);
-    CGF.EmitAlignmentAssumption(V, E, AVAttr->getLocation(),
-                                AlignmentCI->getZExtValue());
+    CGF.EmitAlignmentAssumption(V, E, AVAttr->getLocation(), AlignmentCI);
   }
 
   /// EmitLoadOfLValue - Given an expression with complex type that represents a

Modified: stable/12/contrib/llvm-project/clang/lib/CodeGen/CGStmtOpenMP.cpp
==============================================================================
--- stable/12/contrib/llvm-project/clang/lib/CodeGen/CGStmtOpenMP.cpp	Mon Mar  9 04:09:36 2020	(r358801)
+++ stable/12/contrib/llvm-project/clang/lib/CodeGen/CGStmtOpenMP.cpp	Mon Mar  9 07:12:02 2020	(r358802)
@@ -1460,14 +1460,14 @@ static void emitAlignedClause(CodeGenFunction &CGF,
   if (!CGF.HaveInsertPoint())
     return;
   for (const auto *Clause : D.getClausesOfKind<OMPAlignedClause>()) {
-    unsigned ClauseAlignment = 0;
+    llvm::APInt ClauseAlignment(64, 0);
     if (const Expr *AlignmentExpr = Clause->getAlignment()) {
       auto *AlignmentCI =
           cast<llvm::ConstantInt>(CGF.EmitScalarExpr(AlignmentExpr));
-      ClauseAlignment = static_cast<unsigned>(AlignmentCI->getZExtValue());
+      ClauseAlignment = AlignmentCI->getValue();
     }
     for (const Expr *E : Clause->varlists()) {
-      unsigned Alignment = ClauseAlignment;
+      llvm::APInt Alignment(ClauseAlignment);
       if (Alignment == 0) {
         // OpenMP [2.8.1, Description]
         // If no optional parameter is specified, implementation-defined default
@@ -1478,12 +1478,13 @@ static void emitAlignedClause(CodeGenFunction &CGF,
                     E->getType()->getPointeeType()))
                 .getQuantity();
       }
-      assert((Alignment == 0 || llvm::isPowerOf2_32(Alignment)) &&
+      assert((Alignment == 0 || Alignment.isPowerOf2()) &&
              "alignment is not power of 2");
       if (Alignment != 0) {
         llvm::Value *PtrValue = CGF.EmitScalarExpr(E);
         CGF.EmitAlignmentAssumption(
-            PtrValue, E, /*No second loc needed*/ SourceLocation(), Alignment);
+            PtrValue, E, /*No second loc needed*/ SourceLocation(),
+            llvm::ConstantInt::get(CGF.getLLVMContext(), Alignment));
       }
     }
   }

Modified: stable/12/contrib/llvm-project/clang/lib/CodeGen/CodeGenFunction.cpp
==============================================================================
--- stable/12/contrib/llvm-project/clang/lib/CodeGen/CodeGenFunction.cpp	Mon Mar  9 04:09:36 2020	(r358801)
+++ stable/12/contrib/llvm-project/clang/lib/CodeGen/CodeGenFunction.cpp	Mon Mar  9 07:12:02 2020	(r358802)
@@ -2048,24 +2048,9 @@ void CodeGenFunction::EmitAlignmentAssumption(llvm::Va
 }
 
 void CodeGenFunction::EmitAlignmentAssumption(llvm::Value *PtrValue,
-                                              QualType Ty, SourceLocation Loc,
-                                              SourceLocation AssumptionLoc,
-                                              unsigned Alignment,
-                                              llvm::Value *OffsetValue) {
-  llvm::Value *TheCheck;
-  llvm::Instruction *Assumption = Builder.CreateAlignmentAssumption(
-      CGM.getDataLayout(), PtrValue, Alignment, OffsetValue, &TheCheck);
-  if (SanOpts.has(SanitizerKind::Alignment)) {
-    llvm::Value *AlignmentVal = llvm::ConstantInt::get(IntPtrTy, Alignment);
-    EmitAlignmentAssumptionCheck(PtrValue, Ty, Loc, AssumptionLoc, AlignmentVal,
-                                 OffsetValue, TheCheck, Assumption);
-  }
-}
-
-void CodeGenFunction::EmitAlignmentAssumption(llvm::Value *PtrValue,
                                               const Expr *E,
                                               SourceLocation AssumptionLoc,
-                                              unsigned Alignment,
+                                              llvm::Value *Alignment,
                                               llvm::Value *OffsetValue) {
   if (auto *CE = dyn_cast<CastExpr>(E))
     E = CE->getSubExprAsWritten();

Modified: stable/12/contrib/llvm-project/clang/lib/CodeGen/CodeGenFunction.h
==============================================================================
--- stable/12/contrib/llvm-project/clang/lib/CodeGen/CodeGenFunction.h	Mon Mar  9 04:09:36 2020	(r358801)
+++ stable/12/contrib/llvm-project/clang/lib/CodeGen/CodeGenFunction.h	Mon Mar  9 07:12:02 2020	(r358802)
@@ -2829,13 +2829,8 @@ class CodeGenFunction : public CodeGenTypeCache { (pub
                                llvm::Value *Alignment,
                                llvm::Value *OffsetValue = nullptr);
 
-  void EmitAlignmentAssumption(llvm::Value *PtrValue, QualType Ty,
-                               SourceLocation Loc, SourceLocation AssumptionLoc,
-                               unsigned Alignment,
-                               llvm::Value *OffsetValue = nullptr);
-
   void EmitAlignmentAssumption(llvm::Value *PtrValue, const Expr *E,
-                               SourceLocation AssumptionLoc, unsigned Alignment,
+                               SourceLocation AssumptionLoc, llvm::Value *Alignment,
                                llvm::Value *OffsetValue = nullptr);
 
   //===--------------------------------------------------------------------===//

Modified: stable/12/contrib/llvm-project/clang/lib/Sema/SemaChecking.cpp
==============================================================================
--- stable/12/contrib/llvm-project/clang/lib/Sema/SemaChecking.cpp	Mon Mar  9 04:09:36 2020	(r358801)
+++ stable/12/contrib/llvm-project/clang/lib/Sema/SemaChecking.cpp	Mon Mar  9 07:12:02 2020	(r358802)
@@ -5961,6 +5961,12 @@ bool Sema::SemaBuiltinAssumeAligned(CallExpr *TheCall)
     if (!Result.isPowerOf2())
       return Diag(TheCall->getBeginLoc(), diag::err_alignment_not_power_of_two)
              << Arg->getSourceRange();
+
+    // Alignment calculations can wrap around if it's greater than 2**29.
+    unsigned MaximumAlignment = 536870912;
+    if (Result > MaximumAlignment)
+      Diag(TheCall->getBeginLoc(), diag::warn_assume_aligned_too_great)
+          << Arg->getSourceRange() << MaximumAlignment;
   }
 
   if (NumArgs > 2) {


More information about the svn-src-all mailing list