[PATCH] D52918: Emit CK_NoOp casts in C mode, not just C++.
James Y Knight via Phabricator via cfe-commits
cfe-commits at lists.llvm.org
Fri Oct 5 14:55:46 PDT 2018
This revision was automatically updated to reflect the committed changes.
Closed by commit rL343892: Emit CK_NoOp casts in C mode, not just C++. (authored by jyknight, committed by ).
Herald added a subscriber: llvm-commits.
Changed prior to commit:
https://reviews.llvm.org/D52918?vs=168477&id=168542#toc
Repository:
rL LLVM
https://reviews.llvm.org/D52918
Files:
cfe/trunk/lib/AST/ExprConstant.cpp
cfe/trunk/lib/Sema/SemaExpr.cpp
cfe/trunk/test/Sema/c-casts.c
Index: cfe/trunk/lib/AST/ExprConstant.cpp
===================================================================
--- cfe/trunk/lib/AST/ExprConstant.cpp
+++ cfe/trunk/lib/AST/ExprConstant.cpp
@@ -5864,11 +5864,7 @@
// permitted in constant expressions in C++11. Bitcasts from cv void* are
// also static_casts, but we disallow them as a resolution to DR1312.
if (!E->getType()->isVoidPointerType()) {
- // If we changed anything other than cvr-qualifiers, we can't use this
- // value for constant folding. FIXME: Qualification conversions should
- // always be CK_NoOp, but we get this wrong in C.
- if (!Info.Ctx.hasCvrSimilarType(E->getType(), E->getSubExpr()->getType()))
- Result.Designator.setInvalid();
+ Result.Designator.setInvalid();
if (SubExpr->getType()->isVoidPointerType())
CCEDiag(E, diag::note_constexpr_invalid_cast)
<< 3 << SubExpr->getType();
Index: cfe/trunk/lib/Sema/SemaExpr.cpp
===================================================================
--- cfe/trunk/lib/Sema/SemaExpr.cpp
+++ cfe/trunk/lib/Sema/SemaExpr.cpp
@@ -5862,6 +5862,8 @@
LangAS DestAS = DestTy->getPointeeType().getAddressSpace();
if (SrcAS != DestAS)
return CK_AddressSpaceConversion;
+ if (Context.hasCvrSimilarType(SrcTy, DestTy))
+ return CK_NoOp;
return CK_BitCast;
}
case Type::STK_BlockPointer:
@@ -7762,7 +7764,12 @@
if (isa<PointerType>(RHSType)) {
LangAS AddrSpaceL = LHSPointer->getPointeeType().getAddressSpace();
LangAS AddrSpaceR = RHSType->getPointeeType().getAddressSpace();
- Kind = AddrSpaceL != AddrSpaceR ? CK_AddressSpaceConversion : CK_BitCast;
+ if (AddrSpaceL != AddrSpaceR)
+ Kind = CK_AddressSpaceConversion;
+ else if (Context.hasCvrSimilarType(RHSType, LHSType))
+ Kind = CK_NoOp;
+ else
+ Kind = CK_BitCast;
return checkPointerTypesForAssignment(*this, LHSType, RHSType);
}
Index: cfe/trunk/test/Sema/c-casts.c
===================================================================
--- cfe/trunk/test/Sema/c-casts.c
+++ cfe/trunk/test/Sema/c-casts.c
@@ -0,0 +1,25 @@
+// RUN: %clang_cc1 -w -ast-dump %s | FileCheck %s
+
+// The cast construction code both for implicit and c-style casts is very
+// different in C vs C++. This file is intended to test the C behavior.
+
+// TODO: add tests covering the rest of the code in
+// Sema::CheckAssignmentConstraints and Sema::PrepareScalarCast
+
+// CHECK-LABEL: FunctionDecl {{.*}} cast_cvr_pointer
+void cast_cvr_pointer(char volatile * __restrict * const * p) {
+ char*** x;
+ // CHECK: ImplicitCastExpr {{.*}} 'char ***' <NoOp>
+ x = p;
+ // CHECK: CStyleCastExpr {{.*}} 'char ***' <NoOp>
+ x = (char***)p;
+}
+
+// CHECK-LABEL: FunctionDecl {{.*}} cast_pointer_type
+void cast_pointer_type(char *p) {
+ void *x;
+ // CHECK: ImplicitCastExpr {{.*}} 'void *' <BitCast>
+ x = p;
+ // CHECK: CStyleCastExpr {{.*}} 'void *' <BitCast>
+ x = (void*)p;
+}
-------------- next part --------------
A non-text attachment was scrubbed...
Name: D52918.168542.patch
Type: text/x-patch
Size: 3022 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20181005/f7203fd8/attachment-0001.bin>
More information about the cfe-commits
mailing list