1 //===--- LRTableTest.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-pseudo/grammar/LRTable.h"
10 #include "clang-pseudo/grammar/Grammar.h"
11 #include "clang/Basic/TokenKinds.h"
12 #include "llvm/Testing/Support/SupportHelpers.h"
13 #include "gmock/gmock.h"
14 #include "gtest/gtest.h"
15 #include <vector>
16
17 namespace clang {
18 namespace pseudo {
19 namespace {
20
21 using llvm::ValueIs;
22 using testing::ElementsAre;
23 using StateID = LRTable::StateID;
24
TEST(LRTable,Builder)25 TEST(LRTable, Builder) {
26 std::vector<std::string> GrammarDiags;
27 Grammar G = Grammar::parseBNF(R"bnf(
28 _ := expr # rule 0
29 expr := term # rule 1
30 expr := expr + term # rule 2
31 term := IDENTIFIER # rule 3
32 )bnf",
33 GrammarDiags);
34 EXPECT_THAT(GrammarDiags, testing::IsEmpty());
35
36 SymbolID Term = *G.findNonterminal("term");
37 SymbolID Eof = tokenSymbol(tok::eof);
38 SymbolID Identifier = tokenSymbol(tok::identifier);
39 SymbolID Plus = tokenSymbol(tok::plus);
40
41 LRTable::Builder B(G);
42 // eof IDENT term
43 // +-------+----+-------+------+
44 // |state0 | | s0 | |
45 // |state1 | | | g3 |
46 // |state2 | | | |
47 // +-------+----+-------+------+-------
48 B.Transition[{StateID{0}, Identifier}] = StateID{0};
49 B.Transition[{StateID{1}, Term}] = StateID{3};
50 B.Reduce[StateID{0}].insert(RuleID{0});
51 B.Reduce[StateID{1}].insert(RuleID{2});
52 B.Reduce[StateID{2}].insert(RuleID{1});
53 LRTable T = std::move(B).build();
54
55 EXPECT_EQ(T.getShiftState(0, Eof), llvm::None);
56 EXPECT_THAT(T.getShiftState(0, Identifier), ValueIs(0));
57 EXPECT_THAT(T.getReduceRules(0), ElementsAre(0));
58
59 EXPECT_EQ(T.getShiftState(1, Eof), llvm::None);
60 EXPECT_EQ(T.getShiftState(1, Identifier), llvm::None);
61 EXPECT_THAT(T.getGoToState(1, Term), ValueIs(3));
62 EXPECT_THAT(T.getReduceRules(1), ElementsAre(2));
63
64 // Verify the behaivor for other non-available-actions terminals.
65 SymbolID Int = tokenSymbol(tok::kw_int);
66 EXPECT_EQ(T.getShiftState(2, Int), llvm::None);
67
68 // Check follow sets.
69 EXPECT_TRUE(T.canFollow(Term, Plus));
70 EXPECT_TRUE(T.canFollow(Term, Eof));
71 EXPECT_FALSE(T.canFollow(Term, Int));
72 }
73
74 } // namespace
75 } // namespace pseudo
76 } // namespace clang
77