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 SpvOpExtInst:
58 // If it is a debug info instruction, we do not change the status to
59 // allow debug info instructions before OpVariable in a function.
60 // TODO(https://gitlab.khronos.org/spirv/SPIR-V/issues/533): We need
61 // to discuss the location of DebugScope, DebugNoScope, DebugDeclare,
62 // and DebugValue.
63 // NOTE: This does not apply to the non-semantic vulkan debug info.
64 if (!spvExtInstIsDebugInfo(inst.ext_inst_type()) ||
65 inst.ext_inst_type() ==
66 SPV_EXT_INST_TYPE_NONSEMANTIC_SHADER_DEBUGINFO_100) {
67 adjacency_status = PHI_AND_VAR_INVALID;
68 }
69 break;
70 case SpvOpPhi:
71 if (adjacency_status != PHI_VALID) {
72 return _.diag(SPV_ERROR_INVALID_DATA, &inst)
73 << "OpPhi must appear within a non-entry block before all "
74 << "non-OpPhi instructions "
75 << "(except for OpLine, which can be mixed with OpPhi).";
76 }
77 break;
78 case SpvOpLine:
79 case SpvOpNoLine:
80 break;
81 case SpvOpLoopMerge:
82 adjacency_status = PHI_AND_VAR_INVALID;
83 if (i != (instructions.size() - 1)) {
84 switch (instructions[i + 1].opcode()) {
85 case SpvOpBranch:
86 case SpvOpBranchConditional:
87 break;
88 default:
89 return _.diag(SPV_ERROR_INVALID_DATA, &inst)
90 << "OpLoopMerge must immediately precede either an "
91 << "OpBranch or OpBranchConditional instruction. "
92 << "OpLoopMerge must be the second-to-last instruction in "
93 << "its block.";
94 }
95 }
96 break;
97 case SpvOpSelectionMerge:
98 adjacency_status = PHI_AND_VAR_INVALID;
99 if (i != (instructions.size() - 1)) {
100 switch (instructions[i + 1].opcode()) {
101 case SpvOpBranchConditional:
102 case SpvOpSwitch:
103 break;
104 default:
105 return _.diag(SPV_ERROR_INVALID_DATA, &inst)
106 << "OpSelectionMerge must immediately precede either an "
107 << "OpBranchConditional or OpSwitch instruction. "
108 << "OpSelectionMerge must be the second-to-last "
109 << "instruction in its block.";
110 }
111 }
112 break;
113 case SpvOpVariable:
114 if (inst.GetOperandAs<SpvStorageClass>(2) == SpvStorageClassFunction &&
115 adjacency_status != IN_ENTRY_BLOCK) {
116 return _.diag(SPV_ERROR_INVALID_DATA, &inst)
117 << "All OpVariable instructions in a function must be the "
118 "first instructions in the first block.";
119 }
120 break;
121 default:
122 adjacency_status = PHI_AND_VAR_INVALID;
123 break;
124 }
125 }
126
127 return SPV_SUCCESS;
128 }
129
130 } // namespace val
131 } // namespace spvtools
132