[clang] 3933c43 - [clang] Add cc1 option -fctor-dtor-return-this

[Shu-Chun Weng via cfe-commits]

Author: Shu-Chun Weng
Date: 2022-10-03T14:28:06-07:00
New Revision: 3933c43d9008bb1b151156da92827a109e7963b6

URL: 
https://github.com/llvm/llvm-project/commit/3933c43d9008bb1b151156da92827a109e7963b6
DIFF: 
https://github.com/llvm/llvm-project/commit/3933c43d9008bb1b151156da92827a109e7963b6.diff

LOG: [clang] Add cc1 option -fctor-dtor-return-this

This option forces constructors and non-deleting destructors to return
`this` pointer in C++ ABI (except for Microsoft ABI, on which this flag
has no effect).

This is similar to ARM32, Apple ARM64, or Fuchsia C++ ABI, but can be
applied to any target triple.

Differential Revision: https://reviews.llvm.org/D119209

Added: 


Modified: 
clang/include/clang/Basic/CodeGenOptions.def
clang/include/clang/Driver/Options.td
clang/lib/CodeGen/CGCXXABI.h
clang/lib/CodeGen/ItaniumCXXABI.cpp
clang/test/CodeGenCXX/constructor-destructor-return-this.cpp

Removed: 




diff  --git a/clang/include/clang/Basic/CodeGenOptions.def 
b/clang/include/clang/Basic/CodeGenOptions.def
index ddeabfc9d5451..62d0c936c60a5 100644
--- a/clang/include/clang/Basic/CodeGenOptions.def
+++ b/clang/include/clang/Basic/CodeGenOptions.def
@@ -492,6 +492,10 @@ ENUM_CODEGENOPT(ZeroCallUsedRegs, 
llvm::ZeroCallUsedRegs::ZeroCallUsedRegsKind,
 /// Whether to use opaque pointers.
 CODEGENOPT(OpaquePointers, 1, 0)
 
+/// Modify C++ ABI to returning `this` pointer from constructors and
+/// non-deleting destructors. (No effect on Microsoft ABI.)
+CODEGENOPT(CtorDtorReturnThis, 1, 0)
+
 #undef CODEGENOPT
 #undef ENUM_CODEGENOPT
 #undef VALUE_CODEGENOPT

diff  --git a/clang/include/clang/Driver/Options.td 
b/clang/include/clang/Driver/Options.td
index 655bf0d58d8e1..b6130f3410830 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -5604,6 +5604,11 @@ def ehcontguard : Flag<["-"], "ehcontguard">,
 def fdenormal_fp_math_f32_EQ : Joined<["-"], "fdenormal-fp-math-f32=">,
Group;
 
+def fctor_dtor_return_this : Flag<["-"], "fctor-dtor-return-this">,
+  HelpText<"Change the C++ ABI to returning `this` pointer from constructors "
+   "and non-deleting destructors. (No effect on Microsoft ABI)">,
+  MarshallingInfoFlag>;
+
 } // let Flags = [CC1Option, NoDriverOption]
 
 
//===--===//

diff  --git a/clang/lib/CodeGen/CGCXXABI.h b/clang/lib/CodeGen/CGCXXABI.h
index 0768e6581acb8..a600768b20746 100644
--- a/clang/lib/CodeGen/CGCXXABI.h
+++ b/clang/lib/CodeGen/CGCXXABI.h
@@ -105,6 +105,10 @@ class CGCXXABI {
   /// final class will have been taken care of by the caller.
   virtual bool isThisCompleteObject(GlobalDecl GD) const = 0;
 
+  virtual bool constructorsAndDestructorsReturnThis() const {
+return CGM.getCodeGenOpts().CtorDtorReturnThis;
+  }
+
 public:
 
   virtual ~CGCXXABI();
@@ -120,7 +124,13 @@ class CGCXXABI {
   ///
   /// There currently is no way to indicate if a destructor returns 'this'
   /// when called virtually, and code generation does not support the case.
-  virtual bool HasThisReturn(GlobalDecl GD) const { return false; }
+  virtual bool HasThisReturn(GlobalDecl GD) const {
+if (isa(GD.getDecl()) ||
+(isa(GD.getDecl()) &&
+ GD.getDtorType() != Dtor_Deleting))
+  return constructorsAndDestructorsReturnThis();
+return false;
+  }
 
   virtual bool hasMostDerivedReturn(GlobalDecl GD) const { return false; }
 

diff  --git a/clang/lib/CodeGen/ItaniumCXXABI.cpp 
b/clang/lib/CodeGen/ItaniumCXXABI.cpp
index cb97af7ab11ab..c84faf468ea22 100644
--- a/clang/lib/CodeGen/ItaniumCXXABI.cpp
+++ b/clang/lib/CodeGen/ItaniumCXXABI.cpp
@@ -433,11 +433,7 @@ class ARMCXXABI : public ItaniumCXXABI {
 ItaniumCXXABI(CGM, /*UseARMMethodPtrABI=*/true,
   /*UseARMGuardVarABI=*/true) {}
 
-  bool HasThisReturn(GlobalDecl GD) const override {
-return (isa(GD.getDecl()) || (
-  isa(GD.getDecl()) &&
-  GD.getDtorType() != Dtor_Deleting));
-  }
+  bool constructorsAndDestructorsReturnThis() const override { return true; }
 
   void EmitReturnFromThunk(CodeGenFunction &CGF, RValue RV,
QualType ResTy) override;
@@ -468,11 +464,7 @@ class FuchsiaCXXABI final : public ItaniumCXXABI {
   : ItaniumCXXABI(CGM) {}
 
 private:
-  bool HasThisReturn(GlobalDecl GD) const override {
-return isa(GD.getDecl()) ||
-   (isa(GD.getDecl()) &&
-GD.getDtorType() != Dtor_Deleting);
-  }
+  bool constructorsAndDestructorsReturnThis() const override { return true; }
 };
 
 class WebAssemblyCXXABI final : public ItaniumCXXABI {
@@ -486,11 +478,7 @@ class WebAssemblyCXXABI final : public ItaniumCXXABI {
   llvm::Value *Exn) override;
 
 private:
-  bool HasThisReturn(GlobalDecl GD) const override {
-return isa(GD.getDecl()) ||
-   (isa(G

[clang] 1c57172 - [libTooling] Add smart pointer support to the `access` Stencil

[Shu-Chun Weng via cfe-commits]

Author: Shu-Chun Weng
Date: 2021-04-14T10:45:59-07:00
New Revision: 1c5717225e89d4b266784f1a1fe482530bc4b6f2

URL: 
https://github.com/llvm/llvm-project/commit/1c5717225e89d4b266784f1a1fe482530bc4b6f2
DIFF: 
https://github.com/llvm/llvm-project/commit/1c5717225e89d4b266784f1a1fe482530bc4b6f2.diff

LOG: [libTooling] Add smart pointer support to the `access` Stencil

This extends smart pointer support beyond the existing `maybeDeref` and
`maybeAddressOf`.

Differential Revision: https://reviews.llvm.org/D100450

Added: 


Modified: 
clang/lib/Tooling/Transformer/Stencil.cpp
clang/unittests/Tooling/StencilTest.cpp

Removed: 




diff  --git a/clang/lib/Tooling/Transformer/Stencil.cpp 
b/clang/lib/Tooling/Transformer/Stencil.cpp
index d46087e4b04bc..235473b691878 100644
--- a/clang/lib/Tooling/Transformer/Stencil.cpp
+++ b/clang/lib/Tooling/Transformer/Stencil.cpp
@@ -323,10 +323,23 @@ Error evalData(const AccessData &Data, const 
MatchFinder::MatchResult &Match,
 return llvm::make_error(errc::invalid_argument,
  "Id not bound: " + Data.BaseId);
   if (!E->isImplicitCXXThis()) {
-if (llvm::Optional S =
-E->getType()->isAnyPointerType()
-? tooling::buildArrow(*E, *Match.Context)
-: tooling::buildDot(*E, *Match.Context))
+llvm::Optional S;
+if (E->getType()->isAnyPointerType() ||
+isSmartPointerType(E->getType(), *Match.Context)) {
+  // Strip off any operator->. This can only occur inside an actual arrow
+  // member access, so we treat it as equivalent to an actual object
+  // expression.
+  if (const auto *OpCall = dyn_cast(E)) {
+if (OpCall->getOperator() == clang::OO_Arrow &&
+OpCall->getNumArgs() == 1) {
+  E = OpCall->getArg(0);
+}
+  }
+  S = tooling::buildArrow(*E, *Match.Context);
+} else {
+  S = tooling::buildDot(*E, *Match.Context);
+}
+if (S.hasValue())
   *Result += *S;
 else
   return llvm::make_error(

diff  --git a/clang/unittests/Tooling/StencilTest.cpp 
b/clang/unittests/Tooling/StencilTest.cpp
index 219339014..df05e6deeb577 100644
--- a/clang/unittests/Tooling/StencilTest.cpp
+++ b/clang/unittests/Tooling/StencilTest.cpp
@@ -392,6 +392,37 @@ TEST_F(StencilTest, AccessOpPointerDereference) {
   testExpr(Id, Snippet, access(Id, "field"), "x->field");
 }
 
+TEST_F(StencilTest, AccessOpSmartPointer) {
+  StringRef Snippet = R"cc(
+Smart x;
+x;
+  )cc";
+  StringRef Id = "id";
+  testExpr(Id, Snippet, access(Id, "field"), "x->field");
+}
+
+TEST_F(StencilTest, AccessOpSmartPointerDereference) {
+  StringRef Snippet = R"cc(
+Smart x;
+*x;
+  )cc";
+  StringRef Id = "id";
+  testExpr(Id, Snippet, access(Id, "field"), "(*x).field");
+}
+
+TEST_F(StencilTest, AccessOpSmartPointerMemberCall) {
+  StringRef Snippet = R"cc(
+Smart x;
+x->Field;
+  )cc";
+  StringRef Id = "id";
+  auto StmtMatch =
+  matchStmt(Snippet, memberExpr(hasObjectExpression(expr().bind(Id;
+  ASSERT_TRUE(StmtMatch);
+  EXPECT_THAT_EXPECTED(access(Id, "field")->eval(StmtMatch->Result),
+   HasValue("x->field"));
+}
+
 TEST_F(StencilTest, AccessOpExplicitThis) {
   using clang::ast_matchers::hasObjectExpression;
   using clang::ast_matchers::memberExpr;



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