From 23a0e9ffba00bb559554d64e2cfc17aed71a5fea Mon Sep 17 00:00:00 2001 From: Andrew Savonichev Date: Thu, 6 Sep 2018 11:54:09 +0000 Subject: [OpenCL] Disallow negative attribute arguments Summary: Negative arguments in kernel attributes are silently bitcast'ed to unsigned, for example: __attribute__((reqd_work_group_size(1, -1, 1))) __kernel void k() {} is a complete equivalent of: __attribute__((reqd_work_group_size(1, 4294967294, 1))) __kernel void k() {} This is likely an error, so the patch forbids negative arguments in several OpenCL attributes. Users who really want 4294967294 can still use it as an unsigned representation. Reviewers: Anastasia, yaxunl, bader Reviewed By: Anastasia, yaxunl, bader Subscribers: bader, cfe-commits Differential Revision: https://reviews.llvm.org/D50259 git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@341539 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Sema/SemaDeclAttr.cpp | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) (limited to 'lib/Sema/SemaDeclAttr.cpp') diff --git a/lib/Sema/SemaDeclAttr.cpp b/lib/Sema/SemaDeclAttr.cpp index d72b8fbb1a..488299a970 100644 --- a/lib/Sema/SemaDeclAttr.cpp +++ b/lib/Sema/SemaDeclAttr.cpp @@ -227,9 +227,13 @@ static SourceLocation getAttrLoc(const ParsedAttr &AL) { return AL.getLoc(); } /// If Expr is a valid integer constant, get the value of the integer /// expression and return success or failure. May output an error. +/// +/// Negative argument is implicitly converted to unsigned, unless +/// \p StrictlyUnsigned is true. template static bool checkUInt32Argument(Sema &S, const AttrInfo &AI, const Expr *Expr, - uint32_t &Val, unsigned Idx = UINT_MAX) { + uint32_t &Val, unsigned Idx = UINT_MAX, + bool StrictlyUnsigned = false) { llvm::APSInt I(32); if (Expr->isTypeDependent() || Expr->isValueDependent() || !Expr->isIntegerConstantExpr(I, S.Context)) { @@ -249,6 +253,11 @@ static bool checkUInt32Argument(Sema &S, const AttrInfo &AI, const Expr *Expr, return false; } + if (StrictlyUnsigned && I.isSigned() && I.isNegative()) { + S.Diag(getAttrLoc(AI), diag::err_attribute_argument_negative) << AI; + return false; + } + Val = (uint32_t)I.getZExtValue(); return true; } @@ -2766,7 +2775,8 @@ static void handleWorkGroupSize(Sema &S, Decl *D, const ParsedAttr &AL) { uint32_t WGSize[3]; for (unsigned i = 0; i < 3; ++i) { const Expr *E = AL.getArgAsExpr(i); - if (!checkUInt32Argument(S, AL, E, WGSize[i], i)) + if (!checkUInt32Argument(S, AL, E, WGSize[i], i, + /*StrictlyUnsigned=*/true)) return; if (WGSize[i] == 0) { S.Diag(AL.getLoc(), diag::err_attribute_argument_is_zero) -- cgit v1.2.1