summaryrefslogtreecommitdiffstats
path: root/gfx/angle/checkout/src/compiler/translator/ValidateGlobalInitializer.cpp
blob: 126e8d785423d02cd8100e250f01f52f015a6faf (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
//
// Copyright 2002 The ANGLE Project Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
//

#include "compiler/translator/ValidateGlobalInitializer.h"

#include "compiler/translator/tree_util/IntermTraverse.h"

namespace sh
{

namespace
{

const int kMaxAllowedTraversalDepth = 256;

class ValidateGlobalInitializerTraverser : public TIntermTraverser
{
  public:
    ValidateGlobalInitializerTraverser(int shaderVersion,
                                       bool isWebGL,
                                       bool hasExtNonConstGlobalInitializers);

    void visitSymbol(TIntermSymbol *node) override;
    void visitConstantUnion(TIntermConstantUnion *node) override;
    bool visitAggregate(Visit visit, TIntermAggregate *node) override;
    bool visitBinary(Visit visit, TIntermBinary *node) override;
    bool visitUnary(Visit visit, TIntermUnary *node) override;

    bool isValid() const { return mIsValid && mMaxDepth < mMaxAllowedDepth; }
    bool issueWarning() const { return mIssueWarning; }

  private:
    ANGLE_INLINE void onNonConstInitializerVisit(bool accept)
    {
        if (accept)
        {
            if (!mExtNonConstGlobalInitializers)
            {
                mIssueWarning = true;
            }
        }
        else
        {
            mIsValid = false;
        }
    }

    int mShaderVersion;
    bool mIsWebGL;
    bool mExtNonConstGlobalInitializers;
    bool mIsValid;
    bool mIssueWarning;
};

void ValidateGlobalInitializerTraverser::visitSymbol(TIntermSymbol *node)
{
    // ESSL 1.00 section 4.3 (or ESSL 3.00 section 4.3):
    // Global initializers must be constant expressions.
    switch (node->getType().getQualifier())
    {
        case EvqConst:
            break;
        case EvqGlobal:
        case EvqTemporary:
        case EvqUniform:
            // We allow these cases to be compatible with legacy ESSL 1.00 content.
            // Implement stricter rules for ESSL 3.00 since there's no legacy content to deal
            // with.
            onNonConstInitializerVisit(mExtNonConstGlobalInitializers ||
                                       ((mShaderVersion < 300) && mIsWebGL));
            break;
        default:
            mIsValid = false;
    }
}

void ValidateGlobalInitializerTraverser::visitConstantUnion(TIntermConstantUnion *node)
{
    // Constant unions that are not constant expressions may result from folding a ternary
    // expression.
    switch (node->getType().getQualifier())
    {
        case EvqConst:
            break;
        case EvqTemporary:
            onNonConstInitializerVisit(mExtNonConstGlobalInitializers ||
                                       ((mShaderVersion < 300) && mIsWebGL));
            break;
        default:
            UNREACHABLE();
    }
}

bool ValidateGlobalInitializerTraverser::visitAggregate(Visit visit, TIntermAggregate *node)
{
    // Disallow calls to user-defined functions and texture lookup functions in global variable
    // initializers.  For simplicity, all non-math built-in calls are disallowed.
    if (node->isFunctionCall() ||
        (BuiltInGroup::IsBuiltIn(node->getOp()) && !BuiltInGroup::IsMath(node->getOp())))
    {
        onNonConstInitializerVisit(mExtNonConstGlobalInitializers);
    }
    return true;
}

bool ValidateGlobalInitializerTraverser::visitBinary(Visit visit, TIntermBinary *node)
{
    if (node->isAssignment())
    {
        onNonConstInitializerVisit(mExtNonConstGlobalInitializers);
    }
    return true;
}

bool ValidateGlobalInitializerTraverser::visitUnary(Visit visit, TIntermUnary *node)
{
    if (node->isAssignment())
    {
        onNonConstInitializerVisit(mExtNonConstGlobalInitializers);
    }
    return true;
}

ValidateGlobalInitializerTraverser::ValidateGlobalInitializerTraverser(
    int shaderVersion,
    bool isWebGL,
    bool hasExtNonConstGlobalInitializers)
    : TIntermTraverser(true, false, false, nullptr),
      mShaderVersion(shaderVersion),
      mIsWebGL(isWebGL),
      mExtNonConstGlobalInitializers(hasExtNonConstGlobalInitializers),
      mIsValid(true),
      mIssueWarning(false)
{
    setMaxAllowedDepth(kMaxAllowedTraversalDepth);
}

}  // namespace

bool ValidateGlobalInitializer(TIntermTyped *initializer,
                               int shaderVersion,
                               bool isWebGL,
                               bool hasExtNonConstGlobalInitializers,
                               bool *warning)
{
    ValidateGlobalInitializerTraverser validate(shaderVersion, isWebGL,
                                                hasExtNonConstGlobalInitializers);
    initializer->traverse(&validate);
    ASSERT(warning != nullptr);
    *warning = validate.issueWarning();
    return validate.isValid();
}

}  // namespace sh