[clang] dd16b3f - [BPF] Restrict preserve_access_index attribute to C only
Yonghong Song via cfe-commits
cfe-commits at lists.llvm.org
Thu Nov 14 14:15:16 PST 2019
Author: Yonghong Song
Date: 2019-11-14T14:14:59-08:00
New Revision: dd16b3fe2559789adcdd7d4d0bfe2796897877a3
URL: https://github.com/llvm/llvm-project/commit/dd16b3fe2559789adcdd7d4d0bfe2796897877a3
DIFF: https://github.com/llvm/llvm-project/commit/dd16b3fe2559789adcdd7d4d0bfe2796897877a3.diff
LOG: [BPF] Restrict preserve_access_index attribute to C only
This patch is a follow-up for commit 4e2ce228ae79
[BPF] Add preserve_access_index attribute for record definition
to restrict attribute for C only. A new test case is added
to check for this restriction.
Additional code polishing is done based on
Aaron Ballman's suggestion in https://reviews.llvm.org/D69759/new/.
Differential Revision: https://reviews.llvm.org/D70257
Added:
clang/test/Sema/bpf-attr-preserve-access-index.cpp
Modified:
clang/include/clang/Basic/Attr.td
clang/lib/CodeGen/CGExpr.cpp
Removed:
################################################################################
diff --git a/clang/include/clang/Basic/Attr.td b/clang/include/clang/Basic/Attr.td
index 91140c0ddf17..ce7ad2ceaac2 100644
--- a/clang/include/clang/Basic/Attr.td
+++ b/clang/include/clang/Basic/Attr.td
@@ -1584,6 +1584,7 @@ def BPFPreserveAccessIndex : InheritableAttr,
let Spellings = [Clang<"preserve_access_index">];
let Subjects = SubjectList<[Record], ErrorDiag>;
let Documentation = [BPFPreserveAccessIndexDocs];
+ let LangOpts = [COnly];
}
def WebAssemblyImportModule : InheritableAttr,
diff --git a/clang/lib/CodeGen/CGExpr.cpp b/clang/lib/CodeGen/CGExpr.cpp
index e32db8c56df9..384e8f72a619 100644
--- a/clang/lib/CodeGen/CGExpr.cpp
+++ b/clang/lib/CodeGen/CGExpr.cpp
@@ -3408,10 +3408,6 @@ static bool IsPreserveAIArrayBase(CodeGenFunction &CGF, const Expr *ArrayBase) {
if (!ArrayBase || !CGF.getDebugInfo())
return false;
- const auto *ImplicitCast = dyn_cast<ImplicitCastExpr>(ArrayBase);
- if (!ImplicitCast)
- return false;
-
// Only support base as either a MemberExpr or DeclRefExpr.
// DeclRefExpr to cover cases like:
// struct s { int a; int b[10]; };
@@ -3419,39 +3415,24 @@ static bool IsPreserveAIArrayBase(CodeGenFunction &CGF, const Expr *ArrayBase) {
// p[1].a
// p[1] will generate a DeclRefExpr and p[1].a is a MemberExpr.
// p->b[5] is a MemberExpr example.
- const Expr *E = ImplicitCast->getSubExpr();
- const auto *MemberCast = dyn_cast<MemberExpr>(E);
- if (MemberCast)
- return MemberCast->getMemberDecl()->hasAttr<BPFPreserveAccessIndexAttr>();
-
- const auto *DeclRefCast = dyn_cast<DeclRefExpr>(E);
- if (DeclRefCast) {
- const VarDecl *VarDef = dyn_cast<VarDecl>(DeclRefCast->getDecl());
+ const Expr *E = ArrayBase->IgnoreImpCasts();
+ if (const auto *ME = dyn_cast<MemberExpr>(E))
+ return ME->getMemberDecl()->hasAttr<BPFPreserveAccessIndexAttr>();
+
+ if (const auto *DRE = dyn_cast<DeclRefExpr>(E)) {
+ const auto *VarDef = dyn_cast<VarDecl>(DRE->getDecl());
if (!VarDef)
return false;
- const auto *PtrT = dyn_cast<PointerType>(VarDef->getType().getTypePtr());
+ const auto *PtrT = VarDef->getType()->getAs<PointerType>();
if (!PtrT)
return false;
- const auto *PointeeT = PtrT->getPointeeType().getTypePtr();
-
- // Peel off typedef's
- const auto *TypedefT = dyn_cast<TypedefType>(PointeeT);
- while (TypedefT) {
- PointeeT = TypedefT->desugar().getTypePtr();
- TypedefT = dyn_cast<TypedefType>(PointeeT);
- }
-
- // Not a typedef any more, it should be an elaborated type.
- const auto ElaborateT = dyn_cast<ElaboratedType>(PointeeT);
- if (!ElaborateT)
- return false;
- const auto *RecT = dyn_cast<RecordType>(ElaborateT->desugar().getTypePtr());
- if (!RecT)
- return false;
-
- return RecT->getDecl()->hasAttr<BPFPreserveAccessIndexAttr>();
+ const auto *PointeeT = PtrT->getPointeeType()
+ ->getUnqualifiedDesugaredType();
+ if (const auto *RecT = dyn_cast<RecordType>(PointeeT))
+ return RecT->getDecl()->hasAttr<BPFPreserveAccessIndexAttr>();
+ return false;
}
return false;
diff --git a/clang/test/Sema/bpf-attr-preserve-access-index.cpp b/clang/test/Sema/bpf-attr-preserve-access-index.cpp
new file mode 100644
index 000000000000..4a88ec2eda3c
--- /dev/null
+++ b/clang/test/Sema/bpf-attr-preserve-access-index.cpp
@@ -0,0 +1,9 @@
+// RUN: %clang_cc1 -x c++ -triple bpf-pc-linux-gnu -dwarf-version=4 -fsyntax-only -verify %s
+
+#define __reloc__ __attribute__((preserve_access_index))
+
+struct t1 {
+ int a;
+ int b[4];
+ int c:1;
+} __reloc__; // expected-warning {{'preserve_access_index' attribute ignored}}
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