xref: /llvm-project/clang/lib/AST/ByteCode/Function.cpp (revision dec6324cb05ac1d339c1b2bd43add968f2931c62)
1 //===--- Function.h - Bytecode function for the VM --------------*- C++ -*-===//
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 #include "Function.h"
10 #include "Program.h"
11 #include "clang/AST/Decl.h"
12 #include "clang/AST/DeclCXX.h"
13 #include "clang/Basic/Builtins.h"
14 
15 using namespace clang;
16 using namespace clang::interp;
17 
18 Function::Function(Program &P, FunctionDeclTy Source, unsigned ArgSize,
19                    llvm::SmallVectorImpl<PrimType> &&ParamTypes,
20                    llvm::DenseMap<unsigned, ParamDescriptor> &&Params,
21                    llvm::SmallVectorImpl<unsigned> &&ParamOffsets,
22                    bool HasThisPointer, bool HasRVO, unsigned BuiltinID)
23     : P(P), Source(Source), ArgSize(ArgSize), ParamTypes(std::move(ParamTypes)),
24       Params(std::move(Params)), ParamOffsets(std::move(ParamOffsets)),
25       HasThisPointer(HasThisPointer), HasRVO(HasRVO), BuiltinID(BuiltinID) {
26   if (const auto *F = Source.dyn_cast<const FunctionDecl *>())
27     Variadic = F->isVariadic();
28 }
29 
30 Function::ParamDescriptor Function::getParamDescriptor(unsigned Offset) const {
31   auto It = Params.find(Offset);
32   assert(It != Params.end() && "Invalid parameter offset");
33   return It->second;
34 }
35 
36 SourceInfo Function::getSource(CodePtr PC) const {
37   assert(PC >= getCodeBegin() && "PC does not belong to this function");
38   assert(PC <= getCodeEnd() && "PC Does not belong to this function");
39   assert(hasBody() && "Function has no body");
40   unsigned Offset = PC - getCodeBegin();
41   using Elem = std::pair<unsigned, SourceInfo>;
42   auto It = llvm::lower_bound(SrcMap, Elem{Offset, {}}, llvm::less_first());
43   if (It == SrcMap.end())
44     return SrcMap.back().second;
45   return It->second;
46 }
47 
48 bool Function::isVirtual() const {
49   if (const auto *M = dyn_cast_if_present<CXXMethodDecl>(
50           Source.dyn_cast<const FunctionDecl *>()))
51     return M->isVirtual();
52   return false;
53 }
54 
55 /// Unevaluated builtins don't get their arguments put on the stack
56 /// automatically. They instead operate on the AST of their Call
57 /// Expression.
58 /// Similar information is available via ASTContext::BuiltinInfo,
59 /// but that is not correct for our use cases.
60 static bool isUnevaluatedBuiltin(unsigned BuiltinID) {
61   return BuiltinID == Builtin::BI__builtin_classify_type ||
62          BuiltinID == Builtin::BI__builtin_os_log_format_buffer_size ||
63          BuiltinID == Builtin::BI__builtin_constant_p ||
64          BuiltinID == Builtin::BI__noop;
65 }
66 
67 bool Function::isUnevaluatedBuiltin() const {
68   return ::isUnevaluatedBuiltin(BuiltinID);
69 }
70