1 // Copyright (c) 2018 LunarG Inc.
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 // http://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14
15 // Validates correctness of the intra-block preconditions of SPIR-V
16 // instructions.
17
18 #include "source/val/validate.h"
19
20 #include <string>
21
22 #include "source/diagnostic.h"
23 #include "source/opcode.h"
24 #include "source/val/instruction.h"
25 #include "source/val/validation_state.h"
26
27 namespace spvtools {
28 namespace val {
29
30 enum {
31 // Status right after meeting OpFunction.
32 IN_NEW_FUNCTION,
33 // Status right after meeting the entry block.
34 IN_ENTRY_BLOCK,
35 // Status right after meeting non-entry blocks.
36 PHI_VALID,
37 // Status right after meeting non-OpVariable instructions in the entry block
38 // or non-OpPhi instructions in non-entry blocks, except OpLine.
39 PHI_AND_VAR_INVALID,
40 };
41
ValidateAdjacency(ValidationState_t & _)42 spv_result_t ValidateAdjacency(ValidationState_t& _) {
43 const auto& instructions = _.ordered_instructions();
44 int adjacency_status = PHI_AND_VAR_INVALID;
45
46 for (size_t i = 0; i < instructions.size(); ++i) {
47 const auto& inst = instructions[i];
48 switch (inst.opcode()) {
49 case SpvOpFunction:
50 case SpvOpFunctionParameter:
51 adjacency_status = IN_NEW_FUNCTION;
52 break;
53 case SpvOpLabel:
54 adjacency_status =
55 adjacency_status == IN_NEW_FUNCTION ? IN_ENTRY_BLOCK : PHI_VALID;
56 break;
57 case SpvOpPhi:
58 if (adjacency_status != PHI_VALID) {
59 return _.diag(SPV_ERROR_INVALID_DATA, &inst)
60 << "OpPhi must appear within a non-entry block before all "
61 << "non-OpPhi instructions "
62 << "(except for OpLine, which can be mixed with OpPhi).";
63 }
64 break;
65 case SpvOpLine:
66 case SpvOpNoLine:
67 break;
68 case SpvOpLoopMerge:
69 adjacency_status = PHI_AND_VAR_INVALID;
70 if (i != (instructions.size() - 1)) {
71 switch (instructions[i + 1].opcode()) {
72 case SpvOpBranch:
73 case SpvOpBranchConditional:
74 break;
75 default:
76 return _.diag(SPV_ERROR_INVALID_DATA, &inst)
77 << "OpLoopMerge must immediately precede either an "
78 << "OpBranch or OpBranchConditional instruction. "
79 << "OpLoopMerge must be the second-to-last instruction in "
80 << "its block.";
81 }
82 }
83 break;
84 case SpvOpSelectionMerge:
85 adjacency_status = PHI_AND_VAR_INVALID;
86 if (i != (instructions.size() - 1)) {
87 switch (instructions[i + 1].opcode()) {
88 case SpvOpBranchConditional:
89 case SpvOpSwitch:
90 break;
91 default:
92 return _.diag(SPV_ERROR_INVALID_DATA, &inst)
93 << "OpSelectionMerge must immediately precede either an "
94 << "OpBranchConditional or OpSwitch instruction. "
95 << "OpSelectionMerge must be the second-to-last "
96 << "instruction in its block.";
97 }
98 }
99 break;
100 case SpvOpVariable:
101 if (inst.GetOperandAs<SpvStorageClass>(2) == SpvStorageClassFunction &&
102 adjacency_status != IN_ENTRY_BLOCK) {
103 return _.diag(SPV_ERROR_INVALID_DATA, &inst)
104 << "All OpVariable instructions in a function must be the "
105 "first instructions in the first block.";
106 }
107 break;
108 default:
109 adjacency_status = PHI_AND_VAR_INVALID;
110 break;
111 }
112 }
113
114 return SPV_SUCCESS;
115 }
116
117 } // namespace val
118 } // namespace spvtools
119