1// Copyright 2015 Google Inc. All Rights Reserved.
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#include "dyndep.h"
16
17#include <assert.h>
18#include <stdio.h>
19
20#include "debug_flags.h"
21#include "disk_interface.h"
22#include "dyndep_parser.h"
23#include "graph.h"
24#include "state.h"
25#include "util.h"
26
27using namespace std;
28
29bool DyndepLoader::LoadDyndeps(Node* node, std::string* err) const {
30 DyndepFile ddf;
31 return LoadDyndeps(node, &ddf, err);
32}
33
34bool DyndepLoader::LoadDyndeps(Node* node, DyndepFile* ddf,
35 std::string* err) const {
36 // We are loading the dyndep file now so it is no longer pending.
37 node->set_dyndep_pending(false);
38
39 // Load the dyndep information from the file.
40 EXPLAIN("loading dyndep file '%s'", node->path().c_str());
41 if (!LoadDyndepFile(node, ddf, err))
42 return false;
43
44 // Update each edge that specified this node as its dyndep binding.
45 std::vector<Edge*> const& out_edges = node->out_edges();
46 for (std::vector<Edge*>::const_iterator oe = out_edges.begin();
47 oe != out_edges.end(); ++oe) {
48 Edge* const edge = *oe;
49 if (edge->dyndep_ != node)
50 continue;
51
52 DyndepFile::iterator ddi = ddf->find(edge);
53 if (ddi == ddf->end()) {
54 *err = ("'" + edge->outputs_[0]->path() + "' "
55 "not mentioned in its dyndep file "
56 "'" + node->path() + "'");
57 return false;
58 }
59
60 ddi->second.used_ = true;
61 Dyndeps const& dyndeps = ddi->second;
62 if (!UpdateEdge(edge, &dyndeps, err)) {
63 return false;
64 }
65 }
66
67 // Reject extra outputs in dyndep file.
68 for (DyndepFile::const_iterator oe = ddf->begin(); oe != ddf->end();
69 ++oe) {
70 if (!oe->second.used_) {
71 Edge* const edge = oe->first;
72 *err = ("dyndep file '" + node->path() + "' mentions output "
73 "'" + edge->outputs_[0]->path() + "' whose build statement "
74 "does not have a dyndep binding for the file");
75 return false;
76 }
77 }
78
79 return true;
80}
81
82bool DyndepLoader::UpdateEdge(Edge* edge, Dyndeps const* dyndeps,
83 std::string* err) const {
84 // Add dyndep-discovered bindings to the edge.
85 // We know the edge already has its own binding
86 // scope because it has a "dyndep" binding.
87 if (dyndeps->restat_)
88 edge->env_->AddBinding("restat", "1");
89
90 // Add the dyndep-discovered outputs to the edge.
91 edge->outputs_.insert(edge->outputs_.end(),
92 dyndeps->implicit_outputs_.begin(),
93 dyndeps->implicit_outputs_.end());
94 edge->implicit_outs_ += dyndeps->implicit_outputs_.size();
95
96 // Add this edge as incoming to each new output.
97 for (std::vector<Node*>::const_iterator i =
98 dyndeps->implicit_outputs_.begin();
99 i != dyndeps->implicit_outputs_.end(); ++i) {
100 if (Edge* old_in_edge = (*i)->in_edge()) {
101 // This node already has an edge producing it. Fail with an error
102 // unless the edge was generated by ImplicitDepLoader, in which
103 // case we can replace it with the now-known real producer.
104 if (!old_in_edge->generated_by_dep_loader_) {
105 *err = "multiple rules generate " + (*i)->path();
106 return false;
107 }
108 old_in_edge->outputs_.clear();
109 }
110 (*i)->set_in_edge(edge);
111 }
112
113 // Add the dyndep-discovered inputs to the edge.
114 edge->inputs_.insert(edge->inputs_.end() - edge->order_only_deps_,
115 dyndeps->implicit_inputs_.begin(),
116 dyndeps->implicit_inputs_.end());
117 edge->implicit_deps_ += dyndeps->implicit_inputs_.size();
118
119 // Add this edge as outgoing from each new input.
120 for (std::vector<Node*>::const_iterator i =
121 dyndeps->implicit_inputs_.begin();
122 i != dyndeps->implicit_inputs_.end(); ++i)
123 (*i)->AddOutEdge(edge);
124
125 return true;
126}
127
128bool DyndepLoader::LoadDyndepFile(Node* file, DyndepFile* ddf,
129 std::string* err) const {
130 DyndepParser parser(state_, disk_interface_, ddf);
131 return parser.Load(file->path(), err);
132}
133