[cfe-commits] r89668 - in /cfe/trunk: include/clang/AST/ASTContext.h lib/AST/ASTContext.cpp lib/AST/ExprConstant.cpp lib/Sema/SemaExpr.cpp test/CodeGenCXX/references.cpp test/SemaCXX/alignof-sizeof-reference.cpp
Sebastian Redl
sebastian.redl at getdesigned.at
Mon Nov 23 09:18:46 PST 2009
Author: cornedbee
Date: Mon Nov 23 11:18:46 2009
New Revision: 89668
URL: http://llvm.org/viewvc/llvm-project?rev=89668&view=rev
Log:
Intercept sizeof and alignof references before they get into ASTContext methods. This fixes a crash when writing sizeof(Incomplete&), and lets ASTContext's methods do the right thing for CodeGen, which fixes PR5590.
Added:
cfe/trunk/test/SemaCXX/alignof-sizeof-reference.cpp
Modified:
cfe/trunk/include/clang/AST/ASTContext.h
cfe/trunk/lib/AST/ASTContext.cpp
cfe/trunk/lib/AST/ExprConstant.cpp
cfe/trunk/lib/Sema/SemaExpr.cpp
cfe/trunk/test/CodeGenCXX/references.cpp
Modified: cfe/trunk/include/clang/AST/ASTContext.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/AST/ASTContext.h?rev=89668&r1=89667&r2=89668&view=diff
==============================================================================
--- cfe/trunk/include/clang/AST/ASTContext.h (original)
+++ cfe/trunk/include/clang/AST/ASTContext.h Mon Nov 23 11:18:46 2009
@@ -810,10 +810,7 @@
/// a data type.
unsigned getPreferredTypeAlign(const Type *T);
- /// getDeclAlignInBytes - Return the alignment of the specified decl
- /// that should be returned by __alignof(). Note that bitfields do
- /// not have a valid alignment, so this method will assert on them.
- unsigned getDeclAlignInBytes(const Decl *D);
+ unsigned getDeclAlignInBytes(const Decl *D, bool RefAsPointee = false);
/// getASTRecordLayout - Get or compute information about the layout of the
/// specified record (struct/union/class), which indicates its size and field
Modified: cfe/trunk/lib/AST/ASTContext.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/ASTContext.cpp?rev=89668&r1=89667&r2=89668&view=diff
==============================================================================
--- cfe/trunk/lib/AST/ASTContext.cpp (original)
+++ cfe/trunk/lib/AST/ASTContext.cpp Mon Nov 23 11:18:46 2009
@@ -520,7 +520,9 @@
/// getDeclAlignInBytes - Return a conservative estimate of the alignment of the
/// specified decl. Note that bitfields do not have a valid alignment, so
/// this method will assert on them.
-unsigned ASTContext::getDeclAlignInBytes(const Decl *D) {
+/// If @p RefAsPointee, references are treated like their underlying type
+/// (for alignof), else they're treated like pointers (for CodeGen).
+unsigned ASTContext::getDeclAlignInBytes(const Decl *D, bool RefAsPointee) {
unsigned Align = Target.getCharWidth();
if (const AlignedAttr* AA = D->getAttr<AlignedAttr>())
@@ -529,9 +531,12 @@
if (const ValueDecl *VD = dyn_cast<ValueDecl>(D)) {
QualType T = VD->getType();
if (const ReferenceType* RT = T->getAs<ReferenceType>()) {
- unsigned AS = RT->getPointeeType().getAddressSpace();
- Align = Target.getPointerAlign(AS);
- } else if (!T->isIncompleteType() && !T->isFunctionType()) {
+ if (RefAsPointee)
+ T = RT->getPointeeType();
+ else
+ T = getPointerType(RT->getPointeeType());
+ }
+ if (!T->isIncompleteType() && !T->isFunctionType()) {
// Incomplete or function types default to 1.
while (isa<VariableArrayType>(T) || isa<IncompleteArrayType>(T))
T = cast<ArrayType>(T)->getElementType();
@@ -690,19 +695,21 @@
Align = Target.getPointerAlign(AS);
break;
}
+ case Type::LValueReference:
+ case Type::RValueReference: {
+ // alignof and sizeof should never enter this code path here, so we go
+ // the pointer route.
+ unsigned AS = cast<ReferenceType>(T)->getPointeeType().getAddressSpace();
+ Width = Target.getPointerWidth(AS);
+ Align = Target.getPointerAlign(AS);
+ break;
+ }
case Type::Pointer: {
unsigned AS = cast<PointerType>(T)->getPointeeType().getAddressSpace();
Width = Target.getPointerWidth(AS);
Align = Target.getPointerAlign(AS);
break;
}
- case Type::LValueReference:
- case Type::RValueReference:
- // "When applied to a reference or a reference type, the result is the size
- // of the referenced type." C++98 5.3.3p2: expr.sizeof.
- // FIXME: This is wrong for struct layout: a reference in a struct has
- // pointer size.
- return getTypeInfo(cast<ReferenceType>(T)->getPointeeType());
case Type::MemberPointer: {
// FIXME: This is ABI dependent. We use the Itanium C++ ABI.
// http://www.codesourcery.com/public/cxx-abi/abi.html#member-pointers
Modified: cfe/trunk/lib/AST/ExprConstant.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/ExprConstant.cpp?rev=89668&r1=89667&r2=89668&view=diff
==============================================================================
--- cfe/trunk/lib/AST/ExprConstant.cpp (original)
+++ cfe/trunk/lib/AST/ExprConstant.cpp Mon Nov 23 11:18:46 2009
@@ -1244,6 +1244,13 @@
}
unsigned IntExprEvaluator::GetAlignOfType(QualType T) {
+ // C++ [expr.sizeof]p2: "When applied to a reference or a reference type,
+ // the result is the size of the referenced type."
+ // C++ [expr.alignof]p3: "When alignof is applied to a reference type, the
+ // result shall be the alignment of the referenced type."
+ if (const ReferenceType *Ref = T->getAs<ReferenceType>())
+ T = Ref->getPointeeType();
+
// Get information about the alignment.
unsigned CharSize = Info.Ctx.Target.getCharWidth();
@@ -1257,10 +1264,11 @@
// alignof decl is always accepted, even if it doesn't make sense: we default
// to 1 in those cases.
if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E))
- return Info.Ctx.getDeclAlignInBytes(DRE->getDecl());
+ return Info.Ctx.getDeclAlignInBytes(DRE->getDecl(), /*RefAsPointee*/true);
if (const MemberExpr *ME = dyn_cast<MemberExpr>(E))
- return Info.Ctx.getDeclAlignInBytes(ME->getMemberDecl());
+ return Info.Ctx.getDeclAlignInBytes(ME->getMemberDecl(),
+ /*RefAsPointee*/true);
return GetAlignOfType(E->getType());
}
@@ -1280,6 +1288,12 @@
}
QualType SrcTy = E->getTypeOfArgument();
+ // C++ [expr.sizeof]p2: "When applied to a reference or a reference type,
+ // the result is the size of the referenced type."
+ // C++ [expr.alignof]p3: "When alignof is applied to a reference type, the
+ // result shall be the alignment of the referenced type."
+ if (const ReferenceType *Ref = SrcTy->getAs<ReferenceType>())
+ SrcTy = Ref->getPointeeType();
// sizeof(void), __alignof__(void), sizeof(function) = 1 as a gcc
// extension.
Modified: cfe/trunk/lib/Sema/SemaExpr.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExpr.cpp?rev=89668&r1=89667&r2=89668&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaExpr.cpp (original)
+++ cfe/trunk/lib/Sema/SemaExpr.cpp Mon Nov 23 11:18:46 2009
@@ -1341,6 +1341,13 @@
if (exprType->isDependentType())
return false;
+ // C++ [expr.sizeof]p2: "When applied to a reference or a reference type,
+ // the result is the size of the referenced type."
+ // C++ [expr.alignof]p3: "When alignof is applied to a reference type, the
+ // result shall be the alignment of the referenced type."
+ if (const ReferenceType *Ref = exprType->getAs<ReferenceType>())
+ exprType = Ref->getPointeeType();
+
// C99 6.5.3.4p1:
if (exprType->isFunctionType()) {
// alignof(function) is allowed as an extension.
Modified: cfe/trunk/test/CodeGenCXX/references.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/references.cpp?rev=89668&r1=89667&r2=89668&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenCXX/references.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/references.cpp Mon Nov 23 11:18:46 2009
@@ -136,3 +136,8 @@
(a = 10) = 20;
}
}
+
+// PR5590
+struct s0;
+struct s1 { struct s0 &s0; };
+void f0(s1 a) { s1 b = a; }
Added: cfe/trunk/test/SemaCXX/alignof-sizeof-reference.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/alignof-sizeof-reference.cpp?rev=89668&view=auto
==============================================================================
--- cfe/trunk/test/SemaCXX/alignof-sizeof-reference.cpp (added)
+++ cfe/trunk/test/SemaCXX/alignof-sizeof-reference.cpp Mon Nov 23 11:18:46 2009
@@ -0,0 +1,9 @@
+// RUN: clang-cc -std=c++0x -fsyntax-only -verify %s
+
+struct s0; // expected-note {{forward declaration}}
+char ar[sizeof(s0&)]; // expected-error {{invalid application of 'sizeof' to an incomplete type}}
+void test() {
+ char &r = ar[0];
+ static_assert(alignof(r) == 1, "bad alignment");
+ static_assert(sizeof(r) == 1, "bad size");
+}
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