xref: /freebsd/contrib/llvm-project/clang/lib/Analysis/FlowSensitive/Formula.cpp (revision 770cf0a5f02dc8983a89c6568d741fbc25baa999)
1 //===- Formula.cpp ----------------------------------------------*- 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 "clang/Analysis/FlowSensitive/Formula.h"
10 #include "clang/Basic/LLVM.h"
11 #include "llvm/ADT/STLExtras.h"
12 #include "llvm/ADT/StringRef.h"
13 #include "llvm/Support/Allocator.h"
14 #include "llvm/Support/ErrorHandling.h"
15 #include <cassert>
16 
17 namespace clang::dataflow {
18 
19 const Formula &Formula::create(llvm::BumpPtrAllocator &Alloc, Kind K,
20                                ArrayRef<const Formula *> Operands,
21                                unsigned Value) {
22   assert(Operands.size() == numOperands(K));
23   if (Value != 0) // Currently, formulas have values or operands, not both.
24     assert(numOperands(K) == 0);
25   void *Mem = Alloc.Allocate(sizeof(Formula) +
26                                  Operands.size() * sizeof(Operands.front()),
27                              alignof(Formula));
28   Formula *Result = new (Mem) Formula();
29   Result->FormulaKind = K;
30   Result->Value = Value;
31   // Operands are stored as `const Formula *`s after the formula itself.
32   // We don't need to construct an object as pointers are trivial types.
33   // Formula is alignas(const Formula *), so alignment is satisfied.
34   llvm::copy(Operands, reinterpret_cast<const Formula **>(Result + 1));
35   return *Result;
36 }
37 
38 static llvm::StringLiteral sigil(Formula::Kind K) {
39   switch (K) {
40   case Formula::AtomRef:
41   case Formula::Literal:
42     return "";
43   case Formula::Not:
44     return "!";
45   case Formula::And:
46     return " & ";
47   case Formula::Or:
48     return " | ";
49   case Formula::Implies:
50     return " => ";
51   case Formula::Equal:
52     return " = ";
53   }
54   llvm_unreachable("unhandled formula kind");
55 }
56 
57 void Formula::print(llvm::raw_ostream &OS, const AtomNames *Names) const {
58   if (Names && kind() == AtomRef)
59     if (auto It = Names->find(getAtom()); It != Names->end()) {
60       OS << It->second;
61       return;
62     }
63 
64   switch (numOperands(kind())) {
65   case 0:
66     switch (kind()) {
67     case AtomRef:
68       OS << getAtom();
69       break;
70     case Literal:
71       OS << (literal() ? "true" : "false");
72       break;
73     default:
74       llvm_unreachable("unhandled formula kind");
75     }
76     break;
77   case 1:
78     OS << sigil(kind());
79     operands()[0]->print(OS, Names);
80     break;
81   case 2:
82     OS << '(';
83     operands()[0]->print(OS, Names);
84     OS << sigil(kind());
85     operands()[1]->print(OS, Names);
86     OS << ')';
87     break;
88   default:
89     llvm_unreachable("unhandled formula arity");
90   }
91 }
92 
93 } // namespace clang::dataflow
94