yonghong-song created this revision.
yonghong-song added reviewers: anakryiko, ast.
Herald added subscribers: llvm-commits, cfe-commits, hiraditya.
Herald added projects: clang, LLVM.
[The patch needs more work e.g. to create proper test, to be agreed on
interface, etc.]
This patch added support of expression with typedef type
for FIELD_EXISTENCE relocation. This tries to address the
following use case:
enum { FIELD_EXISTENCE = 2, };
typedef unsigned long u64;
typedef unsigned int u32;
struct bpf_perf_event_data_kern;
typedef u64 (*btf_bpf_read_branch_records)(struct bpf_perf_event_data_kern *,
void *, u32, u64);
int test() {
btf_bpf_read_branch_records a;
return __builtin_preserve_field_info(a, FIELD_EXISTENCE);
}
A relocation with a type of typedef 'btf_bpf_read_branch_records' will be
recorded.
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D83242
Files:
clang/lib/CodeGen/CGBuiltin.cpp
clang/lib/Sema/SemaChecking.cpp
llvm/lib/Target/BPF/BPFAbstractMemberAccess.cpp
Index: llvm/lib/Target/BPF/BPFAbstractMemberAccess.cpp
===================================================================
--- llvm/lib/Target/BPF/BPFAbstractMemberAccess.cpp
+++ llvm/lib/Target/BPF/BPFAbstractMemberAccess.cpp
@@ -277,7 +277,7 @@
}
if (GV->getName().startswith("llvm.bpf.preserve.field.info")) {
CInfo.Kind = BPFPreserveFieldInfoAI;
- CInfo.Metadata = nullptr;
+ CInfo.Metadata = Call->getMetadata(LLVMContext::MD_preserve_access_index);
// Check validity of info_kind as clang did not check this.
uint64_t InfoKind = getConstant(Call->getArgOperand(1));
if (InfoKind >= BPFCoreSharedInfo::MAX_FIELD_RELOC_KIND)
@@ -742,6 +742,13 @@
break;
}
+ if (CInfo.Kind == BPFPreserveFieldInfoAI) {
+ // typedef type.
+ TypeName = std::string(PossibleTypeDef->getName());
+ TypeMeta = PossibleTypeDef;
+ break;
+ }
+
assert(CInfo.Kind == BPFPreserveArrayAI);
// Array entries will always be consumed for accumulative initial index.
Index: clang/lib/Sema/SemaChecking.cpp
===================================================================
--- clang/lib/Sema/SemaChecking.cpp
+++ clang/lib/Sema/SemaChecking.cpp
@@ -2582,6 +2582,15 @@
return false;
}
+ // The second argument needs to be a constant int
+ Arg = TheCall->getArg(1);
+ llvm::APSInt Value;
+ if (!Arg->isIntegerConstantExpr(Value, Context)) {
+ Diag(Arg->getBeginLoc(), diag::err_preserve_field_info_not_const)
+ << 2 << Arg->getSourceRange();
+ return true;
+ }
+
// The first argument needs to be a record field access.
// If it is an array element access, we delay decision
// to BPF backend to check whether the access is a
@@ -2590,21 +2599,14 @@
if (Arg->getType()->getAsPlaceholderType() ||
(Arg->IgnoreParens()->getObjectKind() != OK_BitField &&
!dyn_cast<MemberExpr>(Arg->IgnoreParens()) &&
- !dyn_cast<ArraySubscriptExpr>(Arg->IgnoreParens()))) {
+ !dyn_cast<ArraySubscriptExpr>(Arg->IgnoreParens()) &&
+ // Value 2 here represents reloc kind FIELD_EXISTENCE.
+ (Value != 2 || !Arg->getType()->getAs<TypedefType>()))) {
Diag(Arg->getBeginLoc(), diag::err_preserve_field_info_not_field)
<< 1 << Arg->getSourceRange();
return true;
}
- // The second argument needs to be a constant int
- Arg = TheCall->getArg(1);
- llvm::APSInt Value;
- if (!Arg->isIntegerConstantExpr(Value, Context)) {
- Diag(Arg->getBeginLoc(), diag::err_preserve_field_info_not_const)
- << 2 << Arg->getSourceRange();
- return true;
- }
-
TheCall->setType(Context.UnsignedIntTy);
return false;
}
Index: clang/lib/CodeGen/CGBuiltin.cpp
===================================================================
--- clang/lib/CodeGen/CGBuiltin.cpp
+++ clang/lib/CodeGen/CGBuiltin.cpp
@@ -10966,11 +10966,17 @@
ConstantInt *C = cast<ConstantInt>(EmitScalarExpr(E->getArg(1)));
Value *InfoKind = ConstantInt::get(Int64Ty, C->getSExtValue());
+ llvm::DIType *DbgInfo =
+ getDebugInfo()->getOrCreateStandaloneType(E->getArg(0)->getType(),
+ E->getArg(0)->getExprLoc());
+
// Built the IR for the preserve_field_info intrinsic.
llvm::Function *FnGetFieldInfo = llvm::Intrinsic::getDeclaration(
&CGM.getModule(), llvm::Intrinsic::bpf_preserve_field_info,
{FieldAddr->getType()});
- return Builder.CreateCall(FnGetFieldInfo, {FieldAddr, InfoKind});
+ CallInst *Fn = Builder.CreateCall(FnGetFieldInfo, {FieldAddr, InfoKind});
+ Fn->setMetadata(LLVMContext::MD_preserve_access_index, DbgInfo);
+ return Fn;
}
case BPF::BI__builtin_btf_type_id: {
Value *FieldVal = nullptr;
Index: llvm/lib/Target/BPF/BPFAbstractMemberAccess.cpp
===================================================================
--- llvm/lib/Target/BPF/BPFAbstractMemberAccess.cpp
+++ llvm/lib/Target/BPF/BPFAbstractMemberAccess.cpp
@@ -277,7 +277,7 @@
}
if (GV->getName().startswith("llvm.bpf.preserve.field.info")) {
CInfo.Kind = BPFPreserveFieldInfoAI;
- CInfo.Metadata = nullptr;
+ CInfo.Metadata = Call->getMetadata(LLVMContext::MD_preserve_access_index);
// Check validity of info_kind as clang did not check this.
uint64_t InfoKind = getConstant(Call->getArgOperand(1));
if (InfoKind >= BPFCoreSharedInfo::MAX_FIELD_RELOC_KIND)
@@ -742,6 +742,13 @@
break;
}
+ if (CInfo.Kind == BPFPreserveFieldInfoAI) {
+ // typedef type.
+ TypeName = std::string(PossibleTypeDef->getName());
+ TypeMeta = PossibleTypeDef;
+ break;
+ }
+
assert(CInfo.Kind == BPFPreserveArrayAI);
// Array entries will always be consumed for accumulative initial index.
Index: clang/lib/Sema/SemaChecking.cpp
===================================================================
--- clang/lib/Sema/SemaChecking.cpp
+++ clang/lib/Sema/SemaChecking.cpp
@@ -2582,6 +2582,15 @@
return false;
}
+ // The second argument needs to be a constant int
+ Arg = TheCall->getArg(1);
+ llvm::APSInt Value;
+ if (!Arg->isIntegerConstantExpr(Value, Context)) {
+ Diag(Arg->getBeginLoc(), diag::err_preserve_field_info_not_const)
+ << 2 << Arg->getSourceRange();
+ return true;
+ }
+
// The first argument needs to be a record field access.
// If it is an array element access, we delay decision
// to BPF backend to check whether the access is a
@@ -2590,21 +2599,14 @@
if (Arg->getType()->getAsPlaceholderType() ||
(Arg->IgnoreParens()->getObjectKind() != OK_BitField &&
!dyn_cast<MemberExpr>(Arg->IgnoreParens()) &&
- !dyn_cast<ArraySubscriptExpr>(Arg->IgnoreParens()))) {
+ !dyn_cast<ArraySubscriptExpr>(Arg->IgnoreParens()) &&
+ // Value 2 here represents reloc kind FIELD_EXISTENCE.
+ (Value != 2 || !Arg->getType()->getAs<TypedefType>()))) {
Diag(Arg->getBeginLoc(), diag::err_preserve_field_info_not_field)
<< 1 << Arg->getSourceRange();
return true;
}
- // The second argument needs to be a constant int
- Arg = TheCall->getArg(1);
- llvm::APSInt Value;
- if (!Arg->isIntegerConstantExpr(Value, Context)) {
- Diag(Arg->getBeginLoc(), diag::err_preserve_field_info_not_const)
- << 2 << Arg->getSourceRange();
- return true;
- }
-
TheCall->setType(Context.UnsignedIntTy);
return false;
}
Index: clang/lib/CodeGen/CGBuiltin.cpp
===================================================================
--- clang/lib/CodeGen/CGBuiltin.cpp
+++ clang/lib/CodeGen/CGBuiltin.cpp
@@ -10966,11 +10966,17 @@
ConstantInt *C = cast<ConstantInt>(EmitScalarExpr(E->getArg(1)));
Value *InfoKind = ConstantInt::get(Int64Ty, C->getSExtValue());
+ llvm::DIType *DbgInfo =
+ getDebugInfo()->getOrCreateStandaloneType(E->getArg(0)->getType(),
+ E->getArg(0)->getExprLoc());
+
// Built the IR for the preserve_field_info intrinsic.
llvm::Function *FnGetFieldInfo = llvm::Intrinsic::getDeclaration(
&CGM.getModule(), llvm::Intrinsic::bpf_preserve_field_info,
{FieldAddr->getType()});
- return Builder.CreateCall(FnGetFieldInfo, {FieldAddr, InfoKind});
+ CallInst *Fn = Builder.CreateCall(FnGetFieldInfo, {FieldAddr, InfoKind});
+ Fn->setMetadata(LLVMContext::MD_preserve_access_index, DbgInfo);
+ return Fn;
}
case BPF::BI__builtin_btf_type_id: {
Value *FieldVal = nullptr;
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