1 //===- Constraint.cpp - Constraint class ----------------------------------===//
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 // Constraint wrapper to simplify using TableGen Record for constraints.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "mlir/TableGen/Constraint.h"
14 #include "llvm/TableGen/Record.h"
15 
16 using namespace mlir;
17 using namespace mlir::tblgen;
18 
19 Constraint::Constraint(const llvm::Record *record)
20     : Constraint(record, CK_Uncategorized) {
21   // Look through OpVariable's to their constraint.
22   if (def->isSubClassOf("OpVariable"))
23     def = def->getValueAsDef("constraint");
24 
25   if (def->isSubClassOf("TypeConstraint")) {
26     kind = CK_Type;
27   } else if (def->isSubClassOf("AttrConstraint")) {
28     kind = CK_Attr;
29   } else if (def->isSubClassOf("RegionConstraint")) {
30     kind = CK_Region;
31   } else if (def->isSubClassOf("SuccessorConstraint")) {
32     kind = CK_Successor;
33   } else {
34     assert(def->isSubClassOf("Constraint"));
35   }
36 }
37 
38 Pred Constraint::getPredicate() const {
39   auto *val = def->getValue("predicate");
40 
41   // If no predicate is specified, then return the null predicate (which
42   // corresponds to true).
43   if (!val)
44     return Pred();
45 
46   const auto *pred = dyn_cast<llvm::DefInit>(val->getValue());
47   return Pred(pred);
48 }
49 
50 std::string Constraint::getConditionTemplate() const {
51   return getPredicate().getCondition();
52 }
53 
54 StringRef Constraint::getSummary() const {
55   if (Optional<StringRef> summary = def->getValueAsOptionalString("summary"))
56     return *summary;
57   return def->getName();
58 }
59 
60 StringRef Constraint::getDescription() const {
61   return def->getValueAsOptionalString("description").value_or("");
62 }
63 
64 StringRef Constraint::getDefName() const {
65   if (Optional<StringRef> baseDefName = getBaseDefName())
66     return *baseDefName;
67   return def->getName();
68 }
69 
70 std::string Constraint::getUniqueDefName() const {
71   std::string defName = def->getName().str();
72 
73   // Non-anonymous classes already have a unique name from the def.
74   if (!def->isAnonymous())
75     return defName;
76 
77   // Otherwise, this is an anonymous class. In these cases we still use the def
78   // name, but we also try attach the name of the base def when present to make
79   // the name more obvious.
80   if (Optional<StringRef> baseDefName = getBaseDefName())
81     return (*baseDefName + "(" + defName + ")").str();
82   return defName;
83 }
84 
85 Optional<StringRef> Constraint::getBaseDefName() const {
86   // Functor used to check a base def in the case where the current def is
87   // anonymous.
88   auto checkBaseDefFn = [&](StringRef baseName) -> Optional<StringRef> {
89     if (const auto *defValue = def->getValue(baseName)) {
90       if (const auto *defInit = dyn_cast<llvm::DefInit>(defValue->getValue()))
91         return Constraint(defInit->getDef(), kind).getDefName();
92     }
93     return llvm::None;
94   };
95 
96   switch (kind) {
97   case CK_Attr:
98     if (def->isAnonymous())
99       return checkBaseDefFn("baseAttr");
100     return llvm::None;
101   case CK_Type:
102     if (def->isAnonymous())
103       return checkBaseDefFn("baseType");
104     return llvm::None;
105   default:
106     return llvm::None;
107   }
108 }
109 
110 AppliedConstraint::AppliedConstraint(Constraint &&constraint,
111                                      llvm::StringRef self,
112                                      std::vector<std::string> &&entities)
113     : constraint(constraint), self(std::string(self)),
114       entities(std::move(entities)) {}
115 
116 Constraint DenseMapInfo<Constraint>::getEmptyKey() {
117   return Constraint(RecordDenseMapInfo::getEmptyKey(),
118                     Constraint::CK_Uncategorized);
119 }
120 
121 Constraint DenseMapInfo<Constraint>::getTombstoneKey() {
122   return Constraint(RecordDenseMapInfo::getTombstoneKey(),
123                     Constraint::CK_Uncategorized);
124 }
125 
126 unsigned DenseMapInfo<Constraint>::getHashValue(Constraint constraint) {
127   if (constraint == getEmptyKey())
128     return RecordDenseMapInfo::getHashValue(RecordDenseMapInfo::getEmptyKey());
129   if (constraint == getTombstoneKey()) {
130     return RecordDenseMapInfo::getHashValue(
131         RecordDenseMapInfo::getTombstoneKey());
132   }
133   return llvm::hash_combine(constraint.getPredicate(), constraint.getSummary());
134 }
135 
136 bool DenseMapInfo<Constraint>::isEqual(Constraint lhs, Constraint rhs) {
137   if (lhs == rhs)
138     return true;
139   if (lhs == getEmptyKey() || lhs == getTombstoneKey())
140     return false;
141   if (rhs == getEmptyKey() || rhs == getTombstoneKey())
142     return false;
143   return lhs.getPredicate() == rhs.getPredicate() &&
144          lhs.getSummary() == rhs.getSummary();
145 }
146