yonghong-song updated this revision to Diff 200639.
yonghong-song retitled this revision from "[BPF] Preserve debuginfo
array/union/struct type name/access index" to "[BPF] Preserve debuginfo
array/union/struct type/access index".
yonghong-song edited the summary of this revision.
yonghong-song added a comment.
add clang builtin __builtin_preserve_access_index
Repository:
rC Clang
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D61809/new/
https://reviews.llvm.org/D61809
Files:
include/clang/Basic/Builtins.def
lib/Basic/Targets/BPF.h
lib/CodeGen/CGBuilder.h
lib/CodeGen/CGBuiltin.cpp
lib/CodeGen/CGExpr.cpp
lib/CodeGen/CodeGenFunction.h
lib/Sema/SemaChecking.cpp
test/CodeGen/bpf-offsetreloc.c
Index: test/CodeGen/bpf-offsetreloc.c
===================================================================
--- /dev/null
+++ test/CodeGen/bpf-offsetreloc.c
@@ -0,0 +1,19 @@
+// RUN: %clang -target bpf -emit-llvm -S -g -O2 -o - %s > %t1
+// RUN: grep "llvm.preserve.struct.access.index" %t1
+// RUN: grep "llvm.preserve.array.access.index" %t1
+// RUN: grep "llvm.preserve.union.access.index" %t1
+
+struct t {
+ int i:1;
+ int j:2;
+ union {
+ int a;
+ int b;
+ } c[4];
+};
+
+#define _(x) (__builtin_preserve_access_index(x))
+
+void *test(struct t *arg) {
+ return _(&arg->c[3].b);
+}
Index: lib/Sema/SemaChecking.cpp
===================================================================
--- lib/Sema/SemaChecking.cpp
+++ lib/Sema/SemaChecking.cpp
@@ -190,6 +190,16 @@
return false;
}
+/// Check the number of arguments, and set the result type to
+/// the argument type.
+static bool SemaBuiltinPreserveAI(Sema &S, CallExpr *TheCall) {
+ if (checkArgCount(S, TheCall, 1))
+ return true;
+
+ TheCall->setType(TheCall->getArg(0)->getType());
+ return false;
+}
+
static bool SemaBuiltinOverflow(Sema &S, CallExpr *TheCall) {
if (checkArgCount(S, TheCall, 3))
return true;
@@ -1407,6 +1417,10 @@
TheCall->setType(Context.IntTy);
break;
}
+ case Builtin::BI__builtin_preserve_access_index:
+ if (SemaBuiltinPreserveAI(*this, TheCall))
+ return ExprError();
+ break;
case Builtin::BI__builtin_call_with_static_chain:
if (SemaBuiltinCallWithStaticChain(*this, TheCall))
return ExprError();
Index: lib/CodeGen/CodeGenFunction.h
===================================================================
--- lib/CodeGen/CodeGenFunction.h
+++ lib/CodeGen/CodeGenFunction.h
@@ -1027,6 +1027,10 @@
store->setAlignment(addr.getAlignment().getQuantity());
}
+ /// isPreserveDIAccessIndexNeeded - Return true if it is needed to
+ /// preserve the Debuginfo access index.
+ bool isPreserveDIAccessIndexNeeded(const Expr *E);
+
/// An RAII object to record that we're evaluating a statement
/// expression.
class StmtExprEvaluation {
@@ -3545,7 +3549,8 @@
llvm::Value *EmitIvarOffset(const ObjCInterfaceDecl *Interface,
const ObjCIvarDecl *Ivar);
- LValue EmitLValueForField(LValue Base, const FieldDecl* Field);
+ LValue EmitLValueForField(LValue Base, const FieldDecl* Field,
+ const Expr *E = nullptr);
LValue EmitLValueForLambdaField(const FieldDecl *Field);
/// EmitLValueForFieldInitialization - Like EmitLValueForField, except that
Index: lib/CodeGen/CGExpr.cpp
===================================================================
--- lib/CodeGen/CGExpr.cpp
+++ lib/CodeGen/CGExpr.cpp
@@ -25,6 +25,7 @@
#include "clang/AST/Attr.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/NSAPI.h"
+#include "clang/Basic/Builtins.h"
#include "clang/Basic/CodeGenOptions.h"
#include "llvm/ADT/Hashing.h"
#include "llvm/ADT/StringExtras.h"
@@ -649,6 +650,52 @@
SanOpts.has(SanitizerKind::Vptr);
}
+/// The expression E is a candidate for preserving debuginfo access index
+/// if it is inside an __builtin_preserve_access_index intrinsic call.
+bool CodeGenFunction::isPreserveDIAccessIndexNeeded(const Expr *E) {
+ if (!E)
+ return false;
+
+ if (!getDebugInfo())
+ return false;
+
+ while (true) {
+ const auto &Parents = getContext().getParents(*E);
+ if (Parents.size() != 1)
+ return false;
+
+ E = Parents[0].get<Expr>();
+ if (!E)
+ return false;
+
+ // Check whether E is a BI__builtin_preserve_access_index
+ // intrinsic call.
+ const auto *CE = dyn_cast<CallExpr>(E);
+ if (CE) {
+ // Callee must a builtin function.
+ const Expr *Callee = CE->getCallee()->IgnoreParens();
+ auto ICE = dyn_cast<ImplicitCastExpr>(Callee);
+ if (!ICE)
+ return false;
+ if (ICE->getCastKind() != CK_BuiltinFnToFnPtr)
+ return false;
+
+ auto DRE = dyn_cast<DeclRefExpr>(ICE->getSubExpr());
+ if (!DRE)
+ return false;
+
+ if (auto FD = dyn_cast<FunctionDecl>(DRE->getDecl())) {
+ if (FD->getBuiltinID() == Builtin::BI__builtin_preserve_access_index)
+ return true;
+ }
+
+ break;
+ }
+ }
+
+ return false;
+}
+
void CodeGenFunction::EmitTypeCheck(TypeCheckKind TCK, SourceLocation Loc,
llvm::Value *Ptr, QualType Ty,
CharUnits Alignment,
@@ -3330,7 +3377,7 @@
static Address emitArraySubscriptGEP(CodeGenFunction &CGF, Address addr,
ArrayRef<llvm::Value *> indices,
QualType eltType, bool inbounds,
- bool signedIndices, SourceLocation loc,
+ bool signedIndices, const Expr *E,
const llvm::Twine &name = "arrayidx") {
// All the indices except that last must be zero.
#ifndef NDEBUG
@@ -3350,8 +3397,20 @@
CharUnits eltAlign =
getArrayElementAlign(addr.getAlignment(), indices.back(), eltSize);
- llvm::Value *eltPtr = emitArraySubscriptGEP(
- CGF, addr.getPointer(), indices, inbounds, signedIndices, loc, name);
+ llvm::Value *eltPtr;
+ auto LastIndex = dyn_cast<llvm::ConstantInt>(indices.back());
+ if (!CGF.isPreserveDIAccessIndexNeeded(E) || !LastIndex) {
+ eltPtr = emitArraySubscriptGEP(
+ CGF, addr.getPointer(), indices, inbounds, signedIndices,
+ E->getExprLoc(), name);
+ } else {
+ // Remember the original array subscript for bpf target
+ unsigned idx = LastIndex->getZExtValue();
+ eltPtr = CGF.Builder.CreatePreserveArrayAccessIndex(addr.getPointer(),
+ indices.size() - 1,
+ idx);
+ }
+
return Address(eltPtr, eltAlign);
}
@@ -3406,7 +3465,7 @@
QualType EltType = LV.getType()->castAs<VectorType>()->getElementType();
Addr = emitArraySubscriptGEP(*this, Addr, Idx, EltType, /*inbounds*/ true,
- SignedIndices, E->getExprLoc());
+ SignedIndices, E);
return MakeAddrLValue(Addr, EltType, LV.getBaseInfo(),
CGM.getTBAAInfoForSubobject(LV, EltType));
}
@@ -3437,7 +3496,7 @@
Addr = emitArraySubscriptGEP(*this, Addr, Idx, vla->getElementType(),
!getLangOpts().isSignedOverflowDefined(),
- SignedIndices, E->getExprLoc());
+ SignedIndices, E);
} else if (const ObjCObjectType *OIT = E->getType()->getAs<ObjCObjectType>()){
// Indexing over an interface, as in "NSString *P; P[4];"
@@ -3489,7 +3548,7 @@
Addr = emitArraySubscriptGEP(
*this, ArrayLV.getAddress(), {CGM.getSize(CharUnits::Zero()), Idx},
E->getType(), !getLangOpts().isSignedOverflowDefined(), SignedIndices,
- E->getExprLoc());
+ E);
EltBaseInfo = ArrayLV.getBaseInfo();
EltTBAAInfo = CGM.getTBAAInfoForSubobject(ArrayLV, E->getType());
} else {
@@ -3498,7 +3557,7 @@
auto *Idx = EmitIdxAfterBase(/*Promote*/true);
Addr = emitArraySubscriptGEP(*this, Addr, Idx, E->getType(),
!getLangOpts().isSignedOverflowDefined(),
- SignedIndices, E->getExprLoc());
+ SignedIndices, E);
}
LValue LV = MakeAddrLValue(Addr, E->getType(), EltBaseInfo, EltTBAAInfo);
@@ -3668,7 +3727,7 @@
Idx = Builder.CreateNSWMul(Idx, NumElements);
EltPtr = emitArraySubscriptGEP(*this, Base, Idx, VLA->getElementType(),
!getLangOpts().isSignedOverflowDefined(),
- /*SignedIndices=*/false, E->getExprLoc());
+ /*SignedIndices=*/false, E);
} else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
// If this is A[i] where A is an array, the frontend will have decayed the
// base to be a ArrayToPointerDecay implicit cast. While correct, it is
@@ -3688,7 +3747,7 @@
EltPtr = emitArraySubscriptGEP(
*this, ArrayLV.getAddress(), {CGM.getSize(CharUnits::Zero()), Idx},
ResultExprTy, !getLangOpts().isSignedOverflowDefined(),
- /*SignedIndices=*/false, E->getExprLoc());
+ /*SignedIndices=*/false, E);
BaseInfo = ArrayLV.getBaseInfo();
TBAAInfo = CGM.getTBAAInfoForSubobject(ArrayLV, ResultExprTy);
} else {
@@ -3697,7 +3756,7 @@
IsLowerBound);
EltPtr = emitArraySubscriptGEP(*this, Base, Idx, ResultExprTy,
!getLangOpts().isSignedOverflowDefined(),
- /*SignedIndices=*/false, E->getExprLoc());
+ /*SignedIndices=*/false, E);
}
return MakeAddrLValue(EltPtr, ResultExprTy, BaseInfo, TBAAInfo);
@@ -3789,7 +3848,7 @@
NamedDecl *ND = E->getMemberDecl();
if (auto *Field = dyn_cast<FieldDecl>(ND)) {
- LValue LV = EmitLValueForField(BaseLV, Field);
+ LValue LV = EmitLValueForField(BaseLV, Field, E);
setObjCGCLValueClass(getContext(), E, LV);
return LV;
}
@@ -3825,6 +3884,19 @@
return CGF.Builder.CreateStructGEP(base, idx, field->getName());
}
+static Address emitPreserveStructAccess(CodeGenFunction &CGF, Address base,
+ const FieldDecl *field) {
+ const RecordDecl *rec = field->getParent();
+ llvm::DIType *DbgInfo = CGF.getDebugInfo()->getOrCreateRecordType(
+ CGF.getContext().getRecordType(rec), rec->getLocation());
+
+ unsigned idx =
+ CGF.CGM.getTypes().getCGRecordLayout(rec).getLLVMFieldNo(field);
+
+ return CGF.Builder.CreatePreserveStructAccessIndex(
+ base, idx, field->getFieldIndex(), DbgInfo);
+}
+
static bool hasAnyVptr(const QualType Type, const ASTContext &Context) {
const auto *RD = Type.getTypePtr()->getAsCXXRecordDecl();
if (!RD)
@@ -3845,7 +3917,8 @@
}
LValue CodeGenFunction::EmitLValueForField(LValue base,
- const FieldDecl *field) {
+ const FieldDecl *field,
+ const Expr *E) {
LValueBaseInfo BaseInfo = base.getBaseInfo();
if (field->isBitField()) {
@@ -3932,9 +4005,24 @@
// a barrier every time CXXRecord field with vptr is referenced.
addr = Address(Builder.CreateLaunderInvariantGroup(addr.getPointer()),
addr.getAlignment());
+
+ if (isPreserveDIAccessIndexNeeded(E)) {
+ // Remember the original union field index
+ llvm::DIType *DbgInfo = getDebugInfo()->getOrCreateRecordType(
+ getContext().getRecordType(rec), rec->getLocation());
+ addr = Address(
+ Builder.CreatePreserveUnionAccessIndex(
+ addr.getPointer(), field->getFieldIndex(), DbgInfo),
+ addr.getAlignment());
+ }
} else {
- // For structs, we GEP to the field that the record layout suggests.
- addr = emitAddrOfFieldStorage(*this, addr, field);
+
+ if (!isPreserveDIAccessIndexNeeded(E))
+ // For structs, we GEP to the field that the record layout suggests.
+ addr = emitAddrOfFieldStorage(*this, addr, field);
+ else
+ // Remember the original struct field index
+ addr = emitPreserveStructAccess(*this, addr, field);
// If this is a reference field, load the reference right now.
if (FieldType->isReferenceType()) {
Index: lib/CodeGen/CGBuiltin.cpp
===================================================================
--- lib/CodeGen/CGBuiltin.cpp
+++ lib/CodeGen/CGBuiltin.cpp
@@ -1804,6 +1804,11 @@
return RValue::get(Res);
}
+ case Builtin::BI__builtin_preserve_access_index: {
+ Value *Res = EmitScalarExpr(E->getArg(0));
+ return RValue::get(Res);
+ }
+
case Builtin::BI__builtin_cimag:
case Builtin::BI__builtin_cimagf:
case Builtin::BI__builtin_cimagl:
Index: lib/CodeGen/CGBuilder.h
===================================================================
--- lib/CodeGen/CGBuilder.h
+++ lib/CodeGen/CGBuilder.h
@@ -298,6 +298,21 @@
return CreateMemSet(Dest.getPointer(), Value, Size,
Dest.getAlignment().getQuantity(), IsVolatile);
}
+
+ using CGBuilderBaseTy::CreatePreserveStructAccessIndex;
+ Address CreatePreserveStructAccessIndex(Address Addr,
+ unsigned Index,
+ unsigned FieldIndex,
+ llvm::MDNode *DbgInfo) {
+ llvm::StructType *ElTy = cast<llvm::StructType>(Addr.getElementType());
+ const llvm::DataLayout &DL = BB->getParent()->getParent()->getDataLayout();
+ const llvm::StructLayout *Layout = DL.getStructLayout(ElTy);
+ auto Offset = CharUnits::fromQuantity(Layout->getElementOffset(Index));
+
+ return Address(CreatePreserveStructAccessIndex(Addr.getPointer(),
+ Index, FieldIndex, DbgInfo),
+ Addr.getAlignment().alignmentAtOffset(Offset));
+ }
};
} // end namespace CodeGen
Index: lib/Basic/Targets/BPF.h
===================================================================
--- lib/Basic/Targets/BPF.h
+++ lib/Basic/Targets/BPF.h
@@ -46,7 +46,8 @@
MacroBuilder &Builder) const override;
bool hasFeature(StringRef Feature) const override {
- return Feature == "bpf" || Feature == "alu32" || Feature == "dwarfris";
+ return Feature == "bpf" || Feature == "alu32" || Feature == "dwarfris" ||
+ Feature == "checkoffsetreloc";
}
void setFeatureEnabled(llvm::StringMap<bool> &Features, StringRef Name,
Index: include/clang/Basic/Builtins.def
===================================================================
--- include/clang/Basic/Builtins.def
+++ include/clang/Basic/Builtins.def
@@ -1445,6 +1445,7 @@
BUILTIN(__builtin_operator_delete, "vv*", "tn")
BUILTIN(__builtin_char_memchr, "c*cC*iz", "n")
BUILTIN(__builtin_dump_struct, "ivC*v*", "tn")
+BUILTIN(__builtin_preserve_access_index, "v*v*", "nc")
// Safestack builtins
BUILTIN(__builtin___get_unsafe_stack_start, "v*", "Fn")
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