summary refs log tree commit diff
path: root/src/libexpr/get-drvs.cc
blob: d2d01072f61d1f72e06a8efd571982601017d9a2 (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
#include "get-drvs.hh"
#include "nixexpr-ast.hh"
#include "util.hh"


namespace nix {


string DrvInfo::queryDrvPath(EvalState & state) const
{
    if (drvPath == "") {
        Expr a = attrs->get(toATerm("drvPath"));

        /* Backwards compatibility hack with user environments made by
           Nix <= 0.10: these contain illegal Path("") expressions. */
        ATerm t;
        if (a && matchPath(evalExpr(state, a), t))
            return aterm2String(t);
        
        PathSet context;
        (string &) drvPath = a ? coerceToPath(state, a, context) : "";
    }
    return drvPath;
}


string DrvInfo::queryOutPath(EvalState & state) const
{
    if (outPath == "") {
        Expr a = attrs->get(toATerm("outPath"));
        if (!a) throw TypeError("output path missing");
        PathSet context;
        (string &) outPath = coerceToPath(state, a, context);
    }
    return outPath;
}


MetaInfo DrvInfo::queryMetaInfo(EvalState & state) const
{
    MetaInfo meta;
    
    Expr a = attrs->get(toATerm("meta"));
    if (!a) return meta; /* fine, empty meta information */

    ATermMap attrs2;
    queryAllAttrs(evalExpr(state, a), attrs2);

    for (ATermMap::const_iterator i = attrs2.begin(); i != attrs2.end(); ++i) {
        Expr e = evalExpr(state, i->value);
        string s;
        PathSet context;
        if (matchStr(e, s, context))
            meta[aterm2String(i->key)] = s;
        /* For future compatibility, ignore attribute values that are
           not strings. */
    }

    return meta;
}


string DrvInfo::queryMetaInfo(EvalState & state, const string & name) const
{
    /* !!! evaluates all meta attributes => inefficient */
    MetaInfo meta = queryMetaInfo(state);
    MetaInfo::iterator i = meta.find(name);
    return i == meta.end() ? "" : i->second;
}


void DrvInfo::setMetaInfo(const MetaInfo & meta)
{
    ATermMap metaAttrs;
    for (MetaInfo::const_iterator i = meta.begin(); i != meta.end(); ++i)
        metaAttrs.set(toATerm(i->first),
            makeAttrRHS(makeStr(i->second), makeNoPos()));
    attrs->set(toATerm("meta"), makeAttrs(metaAttrs));
}


/* Cache for already evaluated derivations.  Usually putting ATerms in
   a STL container is unsafe (they're not scanning for GC roots), but
   here it doesn't matter; everything in this set is reachable from
   the stack as well. */
typedef set<Expr> Exprs;


/* Evaluate expression `e'.  If it evaluates to an attribute 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 `e'. */
static bool getDerivation(EvalState & state, Expr e,
    const string & attrPath, DrvInfos & drvs, Exprs & doneExprs)
{
    try {
        
        ATermList es;
        e = evalExpr(state, e);
        if (!matchAttrs(e, es)) return true;

        boost::shared_ptr<ATermMap> attrs(new ATermMap());
        queryAllAttrs(e, *attrs, false);
    
        Expr a = attrs->get(toATerm("type"));
        if (!a || evalStringNoCtx(state, a) != "derivation") return true;

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

        DrvInfo drv;
    
        a = attrs->get(toATerm("name"));
        /* !!! We really would like to have a decent back trace here. */
        if (!a) throw TypeError("derivation name missing");
        drv.name = evalStringNoCtx(state, a);

        a = attrs->get(toATerm("system"));
        if (!a)
            drv.system = "unknown";
        else
            drv.system = evalStringNoCtx(state, a);

        drv.attrs = attrs;

        drv.attrPath = attrPath;

        drvs.push_back(drv);
        return false;
    
    } catch (AssertionError & e) {
        return false;
    }
}


bool getDerivation(EvalState & state, Expr e, DrvInfo & drv)
{
    Exprs doneExprs;
    DrvInfos drvs;
    getDerivation(state, e, "", drvs, doneExprs);
    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, Expr e,
    const string & pathPrefix, const ATermMap & autoArgs,
    DrvInfos & drvs, Exprs & doneExprs)
{
    e = evalExpr(state, autoCallFunction(evalExpr(state, e), autoArgs));

    /* Process the expression. */
    ATermList es;
    DrvInfo drv;

    if (!getDerivation(state, e, pathPrefix, drvs, doneExprs))
        return;

    if (matchAttrs(e, es)) {
        ATermMap drvMap(ATgetLength(es));
        queryAllAttrs(e, drvMap);

        /* !!! undocumented hackery to support
           corepkgs/channels/unpack.sh. */
        Expr e2 = drvMap.get(toATerm("_combineChannels"));
        bool combineChannels = e2 && evalBool(state, e2);
        
        for (ATermMap::const_iterator i = drvMap.begin(); i != drvMap.end(); ++i) {
            startNest(nest, lvlDebug,
                format("evaluating attribute `%1%'") % aterm2String(i->key));
            string pathPrefix2 = addToPath(pathPrefix, aterm2String(i->key));
            if (combineChannels) {
                if (((string) aterm2String(i->key)) != "_combineChannels")
                    getDerivations(state, i->value, pathPrefix2, autoArgs, drvs, doneExprs);
            }
            else if (getDerivation(state, i->value, pathPrefix2, drvs, doneExprs)) {
                /* If the value of this attribute is itself an
                   attribute set, should we recurse into it?  => Only
                   if it has a `recurseForDerivations = true'
                   attribute. */
                ATermList es;
                Expr e = evalExpr(state, i->value);
                if (matchAttrs(e, es)) {
                    ATermMap attrs(ATgetLength(es));
                    queryAllAttrs(e, attrs, false);
                    if (((e2 = attrs.get(toATerm("recurseForDerivations")))
                            && evalBool(state, e2)))
                        getDerivations(state, e, pathPrefix2, autoArgs, drvs, doneExprs);
                }
            }
        }
        
        return;
    }

    if (matchList(e, es)) {
        int n = 0;
        for (ATermIterator i(es); i; ++i, ++n) {
            startNest(nest, lvlDebug,
                format("evaluating list element"));
            string pathPrefix2 = addToPath(pathPrefix, (format("%1%") % n).str());
            if (getDerivation(state, *i, pathPrefix2, drvs, doneExprs))
                getDerivations(state, *i, pathPrefix2, autoArgs, drvs, doneExprs);
        }
        return;
    }

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


void getDerivations(EvalState & state, Expr e, const string & pathPrefix,
    const ATermMap & autoArgs, DrvInfos & drvs)
{
    Exprs doneExprs;
    getDerivations(state, e, pathPrefix, autoArgs, drvs, doneExprs);
}

 
}