about summary refs log tree commit diff
path: root/src/libexpr/get-drvs.cc
blob: 88ea68a5f0bfb8a0e57785fa6dce7fda245ab0dc (plain) (blame)
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
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
#include "get-drvs.hh"
#include "util.hh"
#include "eval-inline.hh"

#include <cstring>


namespace nix {


string DrvInfo::queryDrvPath()
{
    if (drvPath == "" && attrs) {
        Bindings::iterator i = attrs->find(state->sDrvPath);
        PathSet context;
        drvPath = i != attrs->end() ? state->coerceToPath(*i->value, context) : "";
    }
    return drvPath;
}


string DrvInfo::queryOutPath()
{
    if (outPath == "" && attrs) {
        Bindings::iterator i = attrs->find(state->sOutPath);
        PathSet context;
        outPath = i != attrs->end() ? state->coerceToPath(*i->value, context) : "";
    }
    return outPath;
}


DrvInfo::Outputs DrvInfo::queryOutputs()
{
    if (outputs.empty()) {
        /* Get the ‘outputs’ list. */
        Bindings::iterator i;
        if (attrs && (i = attrs->find(state->sOutputs)) != attrs->end()) {
            state->forceList(*i->value, *i->pos);

            /* For each output... */
            for (unsigned int j = 0; j < i->value->list.length; ++j) {
                /* Evaluate the corresponding set. */
                string name = state->forceStringNoCtx(*i->value->list.elems[j], *i->pos);
                Bindings::iterator out = attrs->find(state->symbols.create(name));
                if (out == attrs->end()) continue; // FIXME: throw error?
                state->forceAttrs(*out->value);

                /* And evaluate its ‘outPath’ attribute. */
                Bindings::iterator outPath = out->value->attrs->find(state->sOutPath);
                if (outPath == out->value->attrs->end()) continue; // FIXME: throw error?
                PathSet context;
                outputs[name] = state->coerceToPath(*outPath->value, context);
            }
        } else
            outputs["out"] = queryOutPath();
    }
    return outputs;
}


string DrvInfo::queryOutputName()
{
    if (outputName == "" && attrs) {
        Bindings::iterator i = attrs->find(state->sOutputName);
        outputName = i != attrs->end() ? state->forceStringNoCtx(*i->value) : "";
    }
    return outputName;
}


Bindings * DrvInfo::getMeta()
{
    if (meta) return meta;
    if (!attrs) return 0;
    Bindings::iterator a = attrs->find(state->sMeta);
    if (a == attrs->end()) return 0;
    state->forceAttrs(*a->value, *a->pos);
    meta = a->value->attrs;
    return meta;
}


StringSet DrvInfo::queryMetaNames()
{
    StringSet res;
    if (!getMeta()) return res;
    foreach (Bindings::iterator, i, *meta)
        res.insert(i->name);
    return res;
}


bool DrvInfo::checkMeta(Value & v)
{
    state->forceValue(v);
    if (v.type == tList) {
        for (unsigned int n = 0; n < v.list.length; ++n)
            if (!checkMeta(*v.list.elems[n])) return false;
        return true;
    }
    else if (v.type == tAttrs) {
        Bindings::iterator i = v.attrs->find(state->sOutPath);
        if (i != v.attrs->end()) return false;
        foreach (Bindings::iterator, i, *v.attrs)
            if (!checkMeta(*i->value)) return false;
        return true;
    }
    else return v.type == tInt || v.type == tBool || v.type == tString;
}


Value * DrvInfo::queryMeta(const string & name)
{
    if (!getMeta()) return 0;
    Bindings::iterator a = meta->find(state->symbols.create(name));
    if (a == meta->end() || !checkMeta(*a->value)) return 0;
    return a->value;
}


string DrvInfo::queryMetaString(const string & name)
{
    Value * v = queryMeta(name);
    if (!v || v->type != tString) return "";
    return v->string.s;
}


int DrvInfo::queryMetaInt(const string & name, int def)
{
    Value * v = queryMeta(name);
    if (!v) return def;
    if (v->type == tInt) return v->integer;
    if (v->type == tString) {
        /* Backwards compatibility with before we had support for
           integer meta fields. */
        int n;
        if (string2Int(v->string.s, n)) return n;
    }
    return def;
}


bool DrvInfo::queryMetaBool(const string & name, bool def)
{
    Value * v = queryMeta(name);
    if (!v) return def;
    if (v->type == tBool) return v->boolean;
    if (v->type == tString) {
        /* Backwards compatibility with before we had support for
           Boolean meta fields. */
        if (strcmp(v->string.s, "true") == 0) return true;
        if (strcmp(v->string.s, "false") == 0) return false;
    }
    return def;
}


void DrvInfo::setMeta(const string & name, Value * v)
{
    getMeta();
    Bindings * old = meta;
    meta = new Bindings();
    Symbol sym = state->symbols.create(name);
    if (old)
        foreach (Bindings::iterator, i, *old)
            if (i->name != sym)
                meta->push_back(*i);
    if (v) meta->push_back(Attr(sym, v));
    meta->sort();
}


/* Cache for already considered attrsets. */
typedef set<Bindings *> Done;


/* Evaluate value `v'.  If it evaluates to a set of type `derivation',
   then put information about it in `drvs' (unless it's already in
   `doneExprs').  The result boolean indicates whether it makes sense
   for the caller to recursively search for derivations in `v'. */
static bool getDerivation(EvalState & state, Value & v,
    const string & attrPath, DrvInfos & drvs, Done & done,
    bool ignoreAssertionFailures)
{
    try {
        state.forceValue(v);
        if (!state.isDerivation(v)) return true;

        /* Remove spurious duplicates (e.g., a set like `rec { x =
           derivation {...}; y = x;}'. */
        if (done.find(v.attrs) != done.end()) return false;
        done.insert(v.attrs);

        Bindings::iterator i = v.attrs->find(state.sName);
        /* !!! We really would like to have a decent back trace here. */
        if (i == v.attrs->end()) throw TypeError("derivation name missing");

        Bindings::iterator i2 = v.attrs->find(state.sSystem);

        DrvInfo drv(state, state.forceStringNoCtx(*i->value), attrPath,
            i2 == v.attrs->end() ? "unknown" : state.forceStringNoCtx(*i2->value, *i2->pos),
            v.attrs);

        drvs.push_back(drv);
        return false;

    } catch (AssertionError & e) {
        if (ignoreAssertionFailures) return false;
        throw;
    }
}


bool getDerivation(EvalState & state, Value & v, DrvInfo & drv,
    bool ignoreAssertionFailures)
{
    Done done;
    DrvInfos drvs;
    getDerivation(state, v, "", drvs, done, ignoreAssertionFailures);
    if (drvs.size() != 1) return false;
    drv = drvs.front();
    return true;
}


static string addToPath(const string & s1, const string & s2)
{
    return s1.empty() ? s2 : s1 + "." + s2;
}


static void getDerivations(EvalState & state, Value & vIn,
    const string & pathPrefix, Bindings & autoArgs,
    DrvInfos & drvs, Done & done,
    bool ignoreAssertionFailures)
{
    Value v;
    state.autoCallFunction(autoArgs, vIn, v);

    /* Process the expression. */
    if (!getDerivation(state, v, pathPrefix, drvs, done, ignoreAssertionFailures)) ;

    else if (v.type == tAttrs) {

        /* !!! undocumented hackery to support combining channels in
           nix-env.cc. */
        bool combineChannels = v.attrs->find(state.symbols.create("_combineChannels")) != v.attrs->end();

        /* Consider the attributes in sorted order to get more
           deterministic behaviour in nix-env operations (e.g. when
           there are names clashes between derivations, the derivation
           bound to the attribute with the "lower" name should take
           precedence). */
        typedef std::map<string, Symbol> SortedSymbols;
        SortedSymbols attrs;
        foreach (Bindings::iterator, i, *v.attrs)
            attrs.insert(std::pair<string, Symbol>(i->name, i->name));

        foreach (SortedSymbols::iterator, i, attrs) {
            startNest(nest, lvlDebug, format("evaluating attribute `%1%'") % i->first);
            string pathPrefix2 = addToPath(pathPrefix, i->first);
            Value & v2(*v.attrs->find(i->second)->value);
            if (combineChannels)
                getDerivations(state, v2, pathPrefix2, autoArgs, drvs, done, ignoreAssertionFailures);
            else if (getDerivation(state, v2, pathPrefix2, drvs, done, ignoreAssertionFailures)) {
                /* If the value of this attribute is itself a set,
                   should we recurse into it?  => Only if it has a
                   `recurseForDerivations = true' attribute. */
                if (v2.type == tAttrs) {
                    Bindings::iterator j = v2.attrs->find(state.symbols.create("recurseForDerivations"));
                    if (j != v2.attrs->end() && state.forceBool(*j->value))
                        getDerivations(state, v2, pathPrefix2, autoArgs, drvs, done, ignoreAssertionFailures);
                }
            }
        }
    }

    else if (v.type == tList) {
        for (unsigned int n = 0; n < v.list.length; ++n) {
            startNest(nest, lvlDebug,
                format("evaluating list element"));
            string pathPrefix2 = addToPath(pathPrefix, (format("%1%") % n).str());
            if (getDerivation(state, *v.list.elems[n], pathPrefix2, drvs, done, ignoreAssertionFailures))
                getDerivations(state, *v.list.elems[n], pathPrefix2, autoArgs, drvs, done, ignoreAssertionFailures);
        }
    }

    else throw TypeError("expression does not evaluate to a derivation (or a set or list of those)");
}


void getDerivations(EvalState & state, Value & v, const string & pathPrefix,
    Bindings & autoArgs, DrvInfos & drvs, bool ignoreAssertionFailures)
{
    Done done;
    getDerivations(state, v, pathPrefix, autoArgs, drvs, done, ignoreAssertionFailures);
}


}