xref: /freebsd/contrib/llvm-project/clang/lib/Analysis/FlowSensitive/Formula.cpp (revision aa1a8ff2d6dbc51ef058f46f3db5a8bb77967145)
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 #include <type_traits>
17 
18 namespace clang::dataflow {
19 
20 const Formula &Formula::create(llvm::BumpPtrAllocator &Alloc, Kind K,
21                                ArrayRef<const Formula *> Operands,
22                                unsigned Value) {
23   assert(Operands.size() == numOperands(K));
24   if (Value != 0) // Currently, formulas have values or operands, not both.
25     assert(numOperands(K) == 0);
26   void *Mem = Alloc.Allocate(sizeof(Formula) +
27                                  Operands.size() * sizeof(Operands.front()),
28                              alignof(Formula));
29   Formula *Result = new (Mem) Formula();
30   Result->FormulaKind = K;
31   Result->Value = Value;
32   // Operands are stored as `const Formula *`s after the formula itself.
33   // We don't need to construct an object as pointers are trivial types.
34   // Formula is alignas(const Formula *), so alignment is satisfied.
35   llvm::copy(Operands, reinterpret_cast<const Formula **>(Result + 1));
36   return *Result;
37 }
38 
39 static llvm::StringLiteral sigil(Formula::Kind K) {
40   switch (K) {
41   case Formula::AtomRef:
42   case Formula::Literal:
43     return "";
44   case Formula::Not:
45     return "!";
46   case Formula::And:
47     return " & ";
48   case Formula::Or:
49     return " | ";
50   case Formula::Implies:
51     return " => ";
52   case Formula::Equal:
53     return " = ";
54   }
55   llvm_unreachable("unhandled formula kind");
56 }
57 
58 void Formula::print(llvm::raw_ostream &OS, const AtomNames *Names) const {
59   if (Names && kind() == AtomRef)
60     if (auto It = Names->find(getAtom()); It != Names->end()) {
61       OS << It->second;
62       return;
63     }
64 
65   switch (numOperands(kind())) {
66   case 0:
67     switch (kind()) {
68     case AtomRef:
69       OS << getAtom();
70       break;
71     case Literal:
72       OS << (literal() ? "true" : "false");
73       break;
74     default:
75       llvm_unreachable("unhandled formula kind");
76     }
77     break;
78   case 1:
79     OS << sigil(kind());
80     operands()[0]->print(OS, Names);
81     break;
82   case 2:
83     OS << '(';
84     operands()[0]->print(OS, Names);
85     OS << sigil(kind());
86     operands()[1]->print(OS, Names);
87     OS << ')';
88     break;
89   default:
90     llvm_unreachable("unhandled formula arity");
91   }
92 }
93 
94 } // namespace clang::dataflow