1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This provides an abstract class for C++ code generation. Concrete subclasses
10 // of this implement code generation for specific C++ ABIs.
11 //
12 //===----------------------------------------------------------------------===//
13
14 #include "CIRGenCXXABI.h"
15 #include "CIRGenFunction.h"
16
17 #include "clang/AST/Decl.h"
18 #include "clang/AST/GlobalDecl.h"
19
20 using namespace clang;
21 using namespace clang::CIRGen;
22
~CIRGenCXXABI()23 CIRGenCXXABI::~CIRGenCXXABI() {}
24
buildThisParam(CIRGenFunction & cgf,FunctionArgList & params)25 void CIRGenCXXABI::buildThisParam(CIRGenFunction &cgf,
26 FunctionArgList ¶ms) {
27 const auto *md = cast<CXXMethodDecl>(cgf.curGD.getDecl());
28
29 // FIXME: I'm not entirely sure I like using a fake decl just for code
30 // generation. Maybe we can come up with a better way?
31 auto *thisDecl =
32 ImplicitParamDecl::Create(cgm.getASTContext(), nullptr, md->getLocation(),
33 &cgm.getASTContext().Idents.get("this"),
34 md->getThisType(), ImplicitParamKind::CXXThis);
35 params.push_back(thisDecl);
36 cgf.cxxabiThisDecl = thisDecl;
37
38 // Classic codegen computes the alignment of thisDecl and saves it in
39 // CodeGenFunction::CXXABIThisAlignment, but it is only used in emitTypeCheck
40 // in CodeGenFunction::StartFunction().
41 assert(!cir::MissingFeatures::cxxabiThisAlignment());
42 }
43
getCXXDestructorLinkage(GVALinkage linkage,const CXXDestructorDecl * dtor,CXXDtorType dt) const44 cir::GlobalLinkageKind CIRGenCXXABI::getCXXDestructorLinkage(
45 GVALinkage linkage, const CXXDestructorDecl *dtor, CXXDtorType dt) const {
46 // Delegate back to cgm by default.
47 return cgm.getCIRLinkageForDeclarator(dtor, linkage,
48 /*isConstantVariable=*/false);
49 }
50
loadIncomingCXXThis(CIRGenFunction & cgf)51 mlir::Value CIRGenCXXABI::loadIncomingCXXThis(CIRGenFunction &cgf) {
52 ImplicitParamDecl *vd = getThisDecl(cgf);
53 Address addr = cgf.getAddrOfLocalVar(vd);
54 return cgf.getBuilder().create<cir::LoadOp>(
55 cgf.getLoc(vd->getLocation()), addr.getElementType(), addr.getPointer());
56 }
57
setCXXABIThisValue(CIRGenFunction & cgf,mlir::Value thisPtr)58 void CIRGenCXXABI::setCXXABIThisValue(CIRGenFunction &cgf,
59 mlir::Value thisPtr) {
60 /// Initialize the 'this' slot.
61 assert(getThisDecl(cgf) && "no 'this' variable for function");
62 cgf.cxxabiThisValue = thisPtr;
63 }
64