| 1 | // Copyright 2013 The Go Authors. All rights reserved. |
|---|---|
| 2 | // Use of this source code is governed by a BSD-style |
| 3 | // license that can be found in the LICENSE file. |
| 4 | |
| 5 | package pointer |
| 6 | |
| 7 | import "go/types" |
| 8 | |
| 9 | type constraint interface { |
| 10 | // For a complex constraint, returns the nodeid of the pointer |
| 11 | // to which it is attached. For addr and copy, returns dst. |
| 12 | ptr() nodeid |
| 13 | |
| 14 | // renumber replaces each nodeid n in the constraint by mapping[n]. |
| 15 | renumber(mapping []nodeid) |
| 16 | |
| 17 | // presolve is a hook for constraint-specific behaviour during |
| 18 | // pre-solver optimization. Typical implementations mark as |
| 19 | // indirect the set of nodes to which the solver will add copy |
| 20 | // edges or PTS labels. |
| 21 | presolve(h *hvn) |
| 22 | |
| 23 | // solve is called for complex constraints when the pts for |
| 24 | // the node to which they are attached has changed. |
| 25 | solve(a *analysis, delta *nodeset) |
| 26 | |
| 27 | String() string |
| 28 | } |
| 29 | |
| 30 | // dst = &src |
| 31 | // pts(dst) ⊇ {src} |
| 32 | // A base constraint used to initialize the solver's pt sets |
| 33 | type addrConstraint struct { |
| 34 | dst nodeid // (ptr) |
| 35 | src nodeid |
| 36 | } |
| 37 | |
| 38 | func (c *addrConstraint) ptr() nodeid { return c.dst } |
| 39 | func (c *addrConstraint) renumber(mapping []nodeid) { |
| 40 | c.dst = mapping[c.dst] |
| 41 | c.src = mapping[c.src] |
| 42 | } |
| 43 | |
| 44 | // dst = src |
| 45 | // A simple constraint represented directly as a copyTo graph edge. |
| 46 | type copyConstraint struct { |
| 47 | dst nodeid // (ptr) |
| 48 | src nodeid |
| 49 | } |
| 50 | |
| 51 | func (c *copyConstraint) ptr() nodeid { return c.dst } |
| 52 | func (c *copyConstraint) renumber(mapping []nodeid) { |
| 53 | c.dst = mapping[c.dst] |
| 54 | c.src = mapping[c.src] |
| 55 | } |
| 56 | |
| 57 | // dst = src[offset] |
| 58 | // A complex constraint attached to src (the pointer) |
| 59 | type loadConstraint struct { |
| 60 | offset uint32 |
| 61 | dst nodeid |
| 62 | src nodeid // (ptr) |
| 63 | } |
| 64 | |
| 65 | func (c *loadConstraint) ptr() nodeid { return c.src } |
| 66 | func (c *loadConstraint) renumber(mapping []nodeid) { |
| 67 | c.dst = mapping[c.dst] |
| 68 | c.src = mapping[c.src] |
| 69 | } |
| 70 | |
| 71 | // dst[offset] = src |
| 72 | // A complex constraint attached to dst (the pointer) |
| 73 | type storeConstraint struct { |
| 74 | offset uint32 |
| 75 | dst nodeid // (ptr) |
| 76 | src nodeid |
| 77 | } |
| 78 | |
| 79 | func (c *storeConstraint) ptr() nodeid { return c.dst } |
| 80 | func (c *storeConstraint) renumber(mapping []nodeid) { |
| 81 | c.dst = mapping[c.dst] |
| 82 | c.src = mapping[c.src] |
| 83 | } |
| 84 | |
| 85 | // dst = &src.f or dst = &src[0] |
| 86 | // A complex constraint attached to dst (the pointer) |
| 87 | type offsetAddrConstraint struct { |
| 88 | offset uint32 |
| 89 | dst nodeid |
| 90 | src nodeid // (ptr) |
| 91 | } |
| 92 | |
| 93 | func (c *offsetAddrConstraint) ptr() nodeid { return c.src } |
| 94 | func (c *offsetAddrConstraint) renumber(mapping []nodeid) { |
| 95 | c.dst = mapping[c.dst] |
| 96 | c.src = mapping[c.src] |
| 97 | } |
| 98 | |
| 99 | // dst = src.(typ) where typ is an interface |
| 100 | // A complex constraint attached to src (the interface). |
| 101 | // No representation change: pts(dst) and pts(src) contains tagged objects. |
| 102 | type typeFilterConstraint struct { |
| 103 | typ types.Type // an interface type |
| 104 | dst nodeid |
| 105 | src nodeid // (ptr) |
| 106 | } |
| 107 | |
| 108 | func (c *typeFilterConstraint) ptr() nodeid { return c.src } |
| 109 | func (c *typeFilterConstraint) renumber(mapping []nodeid) { |
| 110 | c.dst = mapping[c.dst] |
| 111 | c.src = mapping[c.src] |
| 112 | } |
| 113 | |
| 114 | // dst = src.(typ) where typ is a concrete type |
| 115 | // A complex constraint attached to src (the interface). |
| 116 | // |
| 117 | // If exact, only tagged objects identical to typ are untagged. |
| 118 | // If !exact, tagged objects assignable to typ are untagged too. |
| 119 | // The latter is needed for various reflect operators, e.g. Send. |
| 120 | // |
| 121 | // This entails a representation change: |
| 122 | // pts(src) contains tagged objects, |
| 123 | // pts(dst) contains their payloads. |
| 124 | type untagConstraint struct { |
| 125 | typ types.Type // a concrete type |
| 126 | dst nodeid |
| 127 | src nodeid // (ptr) |
| 128 | exact bool |
| 129 | } |
| 130 | |
| 131 | func (c *untagConstraint) ptr() nodeid { return c.src } |
| 132 | func (c *untagConstraint) renumber(mapping []nodeid) { |
| 133 | c.dst = mapping[c.dst] |
| 134 | c.src = mapping[c.src] |
| 135 | } |
| 136 | |
| 137 | // src.method(params...) |
| 138 | // A complex constraint attached to iface. |
| 139 | type invokeConstraint struct { |
| 140 | method *types.Func // the abstract method |
| 141 | iface nodeid // (ptr) the interface |
| 142 | params nodeid // the start of the identity/params/results block |
| 143 | } |
| 144 | |
| 145 | func (c *invokeConstraint) ptr() nodeid { return c.iface } |
| 146 | func (c *invokeConstraint) renumber(mapping []nodeid) { |
| 147 | c.iface = mapping[c.iface] |
| 148 | c.params = mapping[c.params] |
| 149 | } |
| 150 |
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