Pull in r354937 from upstream clang trunk (by Jörg Sonnenberger):

Fix inline assembler constraint validation

  The current constraint logic is both too lax and too strict. It fails
  for input outside the [INT_MIN..INT_MAX] range, but it also
  implicitly accepts 0 as value when it should not. Adjust logic to
  handle both correctly.

  Differential Revision: https://reviews.llvm.org/D58649

Pull in r355491 from upstream clang trunk (by Hans Wennborg):

  Inline asm constraints: allow ICE-like pointers for the "n"
  constraint (PR40890)

  Apparently GCC allows this, and there's code relying on it (see bug).

  The idea is to allow expression that would have been allowed if they
  were cast to int. So I based the code on how such a cast would be
  done (the CK_PointerToIntegral case in
  IntExprEvaluator::VisitCastExpr()).

  Differential Revision: https://reviews.llvm.org/D58821

These should fix assertions and errors when using the inline assembly
"n" constraint in certain ways.

In case of devel/valgrind, a pointer was used as the input for the
constraint, which lead to "Assertion failed: (isInt() && "Invalid
accessor"), function getInt".

In case of math/secp256k1, a very large integer value was used as input
for the constraint, which lead to "error: value '4624529908474429119'
out of range for constraint 'n'".

PR:             236216, 236194
MFC after:      1 month
X-MFC-With:     r344779

contrib/llvm/tools/clang/include/clang/AST/APValue.h

@@ -257,6 +257,12 @@ class APValue {
     return const_cast<APValue*>(this)->getInt();
   }
 
+  /// Try to convert this value to an integral constant. This works if it's an
+  /// integer, null pointer, or offset from a null pointer. Returns true on
+  /// success.
+  bool toIntegralConstant(APSInt &Result, QualType SrcTy,
+                          const ASTContext &Ctx) const;
+
   APFloat &getFloat() {
     assert(isFloat() && "Invalid accessor");
     return *(APFloat*)(char*)Data.buffer;

contrib/llvm/tools/clang/include/clang/Basic/TargetInfo.h

@@ -807,6 +807,7 @@ class TargetInfo : public RefCountedBase<TargetInfo> {
     struct {
       int Min;
       int Max;
+      bool isConstrained;
     } ImmRange;
     llvm::SmallSet<int, 4> ImmSet;
 
@@ -817,6 +818,7 @@ class TargetInfo : public RefCountedBase<TargetInfo> {
         : Flags(0), TiedOperand(-1), ConstraintStr(ConstraintStr.str()),
           Name(Name.str()) {
       ImmRange.Min = ImmRange.Max = 0;
+      ImmRange.isConstrained = false;
     }
 
     const std::string &getConstraintStr() const { return ConstraintStr; }
@@ -845,8 +847,9 @@ class TargetInfo : public RefCountedBase<TargetInfo> {
       return (Flags & CI_ImmediateConstant) != 0;
     }
     bool isValidAsmImmediate(const llvm::APInt &Value) const {
-      return (Value.sge(ImmRange.Min) && Value.sle(ImmRange.Max)) ||
-             ImmSet.count(Value.getZExtValue()) != 0;
+      if (!ImmSet.empty())
+        return ImmSet.count(Value.getZExtValue()) != 0;
+      return !ImmRange.isConstrained || (Value.sge(ImmRange.Min) && Value.sle(ImmRange.Max));
     }
 
     void setIsReadWrite() { Flags |= CI_ReadWrite; }
@@ -858,6 +861,7 @@ class TargetInfo : public RefCountedBase<TargetInfo> {
       Flags |= CI_ImmediateConstant;
       ImmRange.Min = Min;
       ImmRange.Max = Max;
+      ImmRange.isConstrained = true;
     }
     void setRequiresImmediate(llvm::ArrayRef<int> Exacts) {
       Flags |= CI_ImmediateConstant;
@@ -870,8 +874,6 @@ class TargetInfo : public RefCountedBase<TargetInfo> {
     }
     void setRequiresImmediate() {
       Flags |= CI_ImmediateConstant;
-      ImmRange.Min = INT_MIN;
-      ImmRange.Max = INT_MAX;
     }
 
     /// Indicate that this is an input operand that is tied to

contrib/llvm/tools/clang/lib/AST/APValue.cpp

@@ -600,6 +600,26 @@ std::string APValue::getAsString(ASTContext &Ctx, QualType Ty) const {
   return Result;
 }
 
+bool APValue::toIntegralConstant(APSInt &Result, QualType SrcTy,
+                                 const ASTContext &Ctx) const {
+  if (isInt()) {
+    Result = getInt();
+    return true;
+  }
+
+  if (isLValue() && isNullPointer()) {
+    Result = Ctx.MakeIntValue(Ctx.getTargetNullPointerValue(SrcTy), SrcTy);
+    return true;
+  }
+
+  if (isLValue() && !getLValueBase()) {
+    Result = Ctx.MakeIntValue(getLValueOffset().getQuantity(), SrcTy);
+    return true;
+  }
+
+  return false;
+}
+
 const APValue::LValueBase APValue::getLValueBase() const {
   assert(isLValue() && "Invalid accessor");
   return ((const LV*)(const void*)Data.buffer)->Base;

contrib/llvm/tools/clang/lib/AST/ExprConstant.cpp

@@ -9821,13 +9821,12 @@ bool IntExprEvaluator::VisitCastExpr(const CastExpr *E) {
       return true;
     }
 
-    uint64_t V;
-    if (LV.isNullPointer())
-      V = Info.Ctx.getTargetNullPointerValue(SrcType);
-    else
-      V = LV.getLValueOffset().getQuantity();
+    APSInt AsInt;
+    APValue V;
+    LV.moveInto(V);
+    if (!V.toIntegralConstant(AsInt, SrcType, Info.Ctx))
+      llvm_unreachable("Can't cast this!");
 
-    APSInt AsInt = Info.Ctx.MakeIntValue(V, SrcType);
     return Success(HandleIntToIntCast(Info, E, DestType, SrcType, AsInt), E);
   }
 

contrib/llvm/tools/clang/lib/CodeGen/CGStmt.cpp

@@ -1821,8 +1821,15 @@ llvm::Value* CodeGenFunction::EmitAsmInput(
   // (immediate or symbolic), try to emit it as such.
   if (!Info.allowsRegister() && !Info.allowsMemory()) {
     if (Info.requiresImmediateConstant()) {
-      llvm::APSInt AsmConst = InputExpr->EvaluateKnownConstInt(getContext());
-      return llvm::ConstantInt::get(getLLVMContext(), AsmConst);
+      Expr::EvalResult EVResult;
+      InputExpr->EvaluateAsRValue(EVResult, getContext(), true);
+
+      llvm::APSInt IntResult;
+      if (!EVResult.Val.toIntegralConstant(IntResult, InputExpr->getType(),
+                                           getContext()))
+        llvm_unreachable("Invalid immediate constant!");
+
+      return llvm::ConstantInt::get(getLLVMContext(), IntResult);
     }
 
     Expr::EvalResult Result;

contrib/llvm/tools/clang/lib/Sema/SemaStmtAsm.cpp

@@ -383,11 +383,20 @@ StmtResult Sema::ActOnGCCAsmStmt(SourceLocation AsmLoc, bool IsSimple,
           return StmtError(
               Diag(InputExpr->getBeginLoc(), diag::err_asm_immediate_expected)
               << Info.getConstraintStr() << InputExpr->getSourceRange());
-        llvm::APSInt Result = EVResult.Val.getInt();
-        if (!Info.isValidAsmImmediate(Result))
+
+        // For compatibility with GCC, we also allow pointers that would be
+        // integral constant expressions if they were cast to int.
+        llvm::APSInt IntResult;
+        if (!EVResult.Val.toIntegralConstant(IntResult, InputExpr->getType(),
+                                             Context))
+          return StmtError(
+              Diag(InputExpr->getBeginLoc(), diag::err_asm_immediate_expected)
+              << Info.getConstraintStr() << InputExpr->getSourceRange());
+
+        if (!Info.isValidAsmImmediate(IntResult))
           return StmtError(Diag(InputExpr->getBeginLoc(),
                                 diag::err_invalid_asm_value_for_constraint)
-                           << Result.toString(10) << Info.getConstraintStr()
+                           << IntResult.toString(10) << Info.getConstraintStr()
                            << InputExpr->getSourceRange());
       }