forked from lix-project/lix
362 lines
8.9 KiB
C++
362 lines
8.9 KiB
C++
#ifndef __EVAL_H
|
|
#define __EVAL_H
|
|
|
|
#include "nixexpr.hh"
|
|
#include "symbol-table.hh"
|
|
#include "hash.hh"
|
|
|
|
#include <map>
|
|
|
|
#if HAVE_BOEHMGC
|
|
#include <gc/gc_allocator.h>
|
|
#endif
|
|
|
|
|
|
namespace nix {
|
|
|
|
|
|
class EvalState;
|
|
struct Env;
|
|
struct Value;
|
|
struct Attr;
|
|
|
|
|
|
/* Attribute sets are represented as a vector of attributes, sorted by
|
|
symbol (i.e. pointer to the attribute name in the symbol table). */
|
|
#if HAVE_BOEHMGC
|
|
typedef std::vector<Attr, gc_allocator<Attr> > BindingsBase;
|
|
#else
|
|
typedef std::vector<Attr> BindingsBase;
|
|
#endif
|
|
|
|
|
|
class Bindings : public BindingsBase
|
|
{
|
|
public:
|
|
iterator find(const Symbol & name);
|
|
void sort();
|
|
};
|
|
|
|
|
|
typedef enum {
|
|
tInt = 1,
|
|
tBool,
|
|
tString,
|
|
tPath,
|
|
tNull,
|
|
tAttrs,
|
|
tList,
|
|
tThunk,
|
|
tApp,
|
|
tLambda,
|
|
tBlackhole,
|
|
tPrimOp,
|
|
tPrimOpApp,
|
|
} ValueType;
|
|
|
|
|
|
typedef void (* PrimOpFun) (EvalState & state, Value * * args, Value & v);
|
|
|
|
|
|
struct PrimOp
|
|
{
|
|
PrimOpFun fun;
|
|
unsigned int arity;
|
|
Symbol name;
|
|
PrimOp(PrimOpFun fun, unsigned int arity, Symbol name)
|
|
: fun(fun), arity(arity), name(name) { }
|
|
};
|
|
|
|
|
|
struct Value
|
|
{
|
|
ValueType type;
|
|
union
|
|
{
|
|
int integer;
|
|
bool boolean;
|
|
|
|
/* Strings in the evaluator carry a so-called `context' (the
|
|
ATermList) which is a list of strings representing store
|
|
paths. This is to allow users to write things like
|
|
|
|
"--with-freetype2-library=" + freetype + "/lib"
|
|
|
|
where `freetype' is a derivation (or a source to be copied
|
|
to the store). If we just concatenated the strings without
|
|
keeping track of the referenced store paths, then if the
|
|
string is used as a derivation attribute, the derivation
|
|
will not have the correct dependencies in its inputDrvs and
|
|
inputSrcs.
|
|
|
|
The semantics of the context is as follows: when a string
|
|
with context C is used as a derivation attribute, then the
|
|
derivations in C will be added to the inputDrvs of the
|
|
derivation, and the other store paths in C will be added to
|
|
the inputSrcs of the derivations.
|
|
|
|
For canonicity, the store paths should be in sorted order. */
|
|
struct {
|
|
const char * s;
|
|
const char * * context; // must be in sorted order
|
|
} string;
|
|
|
|
const char * path;
|
|
Bindings * attrs;
|
|
struct {
|
|
unsigned int length;
|
|
Value * * elems;
|
|
} list;
|
|
struct {
|
|
Env * env;
|
|
Expr * expr;
|
|
} thunk;
|
|
struct {
|
|
Value * left, * right;
|
|
} app;
|
|
struct {
|
|
Env * env;
|
|
ExprLambda * fun;
|
|
} lambda;
|
|
PrimOp * primOp;
|
|
struct {
|
|
Value * left, * right;
|
|
} primOpApp;
|
|
};
|
|
};
|
|
|
|
|
|
struct Env
|
|
{
|
|
Env * up;
|
|
unsigned int prevWith; // nr of levels up to next `with' environment
|
|
Value * values[0];
|
|
};
|
|
|
|
|
|
struct Attr
|
|
{
|
|
Symbol name;
|
|
Value * value;
|
|
Pos * pos;
|
|
Attr(Symbol name, Value * value, Pos * pos = &noPos)
|
|
: name(name), value(value), pos(pos) { };
|
|
Attr() : pos(&noPos) { };
|
|
bool operator < (const Attr & a) const
|
|
{
|
|
return name < a.name;
|
|
}
|
|
};
|
|
|
|
|
|
/* After overwriting an app node, be sure to clear pointers in the
|
|
Value to ensure that the target isn't kept alive unnecessarily. */
|
|
static inline void clearValue(Value & v)
|
|
{
|
|
v.app.right = 0;
|
|
}
|
|
|
|
|
|
static inline void mkInt(Value & v, int n)
|
|
{
|
|
clearValue(v);
|
|
v.type = tInt;
|
|
v.integer = n;
|
|
}
|
|
|
|
|
|
static inline void mkBool(Value & v, bool b)
|
|
{
|
|
clearValue(v);
|
|
v.type = tBool;
|
|
v.boolean = b;
|
|
}
|
|
|
|
|
|
static inline void mkApp(Value & v, Value & left, Value & right)
|
|
{
|
|
v.type = tApp;
|
|
v.app.left = &left;
|
|
v.app.right = &right;
|
|
}
|
|
|
|
|
|
void mkString(Value & v, const char * s);
|
|
void mkString(Value & v, const string & s, const PathSet & context = PathSet());
|
|
void mkPath(Value & v, const char * s);
|
|
|
|
void copyContext(const Value & v, PathSet & context);
|
|
|
|
|
|
/* Cache for calls to addToStore(); maps source paths to the store
|
|
paths. */
|
|
typedef std::map<Path, Path> SrcToStore;
|
|
|
|
struct EvalState;
|
|
|
|
|
|
std::ostream & operator << (std::ostream & str, const Value & v);
|
|
|
|
|
|
class EvalState
|
|
{
|
|
public:
|
|
SymbolTable symbols;
|
|
|
|
const Symbol sWith, sOutPath, sDrvPath, sType, sMeta, sName,
|
|
sSystem, sOverrides;
|
|
|
|
private:
|
|
SrcToStore srcToStore;
|
|
|
|
bool allowUnsafeEquality;
|
|
|
|
std::map<Path, Expr *> parseTrees;
|
|
|
|
public:
|
|
|
|
EvalState();
|
|
~EvalState();
|
|
|
|
/* Parse a Nix expression from the specified file. If `path'
|
|
refers to a directory, then "/default.nix" is appended. */
|
|
Expr * parseExprFromFile(Path path);
|
|
|
|
/* Parse a Nix expression from the specified string. */
|
|
Expr * parseExprFromString(const string & s, const Path & basePath);
|
|
|
|
/* Evaluate an expression read from the given file to normal
|
|
form. */
|
|
void evalFile(const Path & path, Value & v);
|
|
|
|
/* Evaluate an expression to normal form, storing the result in
|
|
value `v'. */
|
|
void eval(Expr * e, Value & v);
|
|
void eval(Env & env, Expr * e, Value & v);
|
|
|
|
/* Evaluation the expression, then verify that it has the expected
|
|
type. */
|
|
bool evalBool(Env & env, Expr * e);
|
|
void evalAttrs(Env & env, Expr * e, Value & v);
|
|
|
|
/* If `v' is a thunk, enter it and overwrite `v' with the result
|
|
of the evaluation of the thunk. If `v' is a delayed function
|
|
application, call the function and overwrite `v' with the
|
|
result. Otherwise, this is a no-op. */
|
|
void forceValue(Value & v);
|
|
|
|
/* Force a value, then recursively force list elements and
|
|
attributes. */
|
|
void strictForceValue(Value & v);
|
|
|
|
/* Force `v', and then verify that it has the expected type. */
|
|
int forceInt(Value & v);
|
|
bool forceBool(Value & v);
|
|
void forceAttrs(Value & v);
|
|
void forceList(Value & v);
|
|
void forceFunction(Value & v); // either lambda or primop
|
|
string forceString(Value & v);
|
|
string forceString(Value & v, PathSet & context);
|
|
string forceStringNoCtx(Value & v);
|
|
|
|
/* Return true iff the value `v' denotes a derivation (i.e. a
|
|
set with attribute `type = "derivation"'). */
|
|
bool isDerivation(Value & v);
|
|
|
|
/* String coercion. Converts strings, paths and derivations to a
|
|
string. If `coerceMore' is set, also converts nulls, integers,
|
|
booleans and lists to a string. If `copyToStore' is set,
|
|
referenced paths are copied to the Nix store as a side effect.q */
|
|
string coerceToString(Value & v, PathSet & context,
|
|
bool coerceMore = false, bool copyToStore = true);
|
|
|
|
/* Path coercion. Converts strings, paths and derivations to a
|
|
path. The result is guaranteed to be a canonicalised, absolute
|
|
path. Nothing is copied to the store. */
|
|
Path coerceToPath(Value & v, PathSet & context);
|
|
|
|
private:
|
|
|
|
/* The base environment, containing the builtin functions and
|
|
values. */
|
|
Env & baseEnv;
|
|
|
|
unsigned int baseEnvDispl;
|
|
|
|
public:
|
|
|
|
/* The same, but used during parsing to resolve variables. */
|
|
StaticEnv staticBaseEnv; // !!! should be private
|
|
|
|
private:
|
|
|
|
void createBaseEnv();
|
|
|
|
void addConstant(const string & name, Value & v);
|
|
|
|
void addPrimOp(const string & name,
|
|
unsigned int arity, PrimOpFun primOp);
|
|
|
|
Value * lookupVar(Env * env, const VarRef & var);
|
|
|
|
friend class ExprVar;
|
|
friend class ExprAttrs;
|
|
friend class ExprLet;
|
|
|
|
Expr * parse(const char * text,
|
|
const Path & path, const Path & basePath);
|
|
|
|
public:
|
|
|
|
/* Do a deep equality test between two values. That is, list
|
|
elements and attributes are compared recursively. */
|
|
bool eqValues(Value & v1, Value & v2);
|
|
|
|
void callFunction(Value & fun, Value & arg, Value & v);
|
|
|
|
/* Automatically call a function for which each argument has a
|
|
default value or has a binding in the `args' map. */
|
|
void autoCallFunction(Bindings & args, Value & fun, Value & res);
|
|
|
|
/* Allocation primitives. */
|
|
Value * allocValue();
|
|
Env & allocEnv(unsigned int size);
|
|
|
|
Value * allocAttr(Value & vAttrs, const Symbol & name);
|
|
|
|
void mkList(Value & v, unsigned int length);
|
|
void mkAttrs(Value & v, unsigned int expected);
|
|
void mkThunk_(Value & v, Expr * expr);
|
|
|
|
Value * maybeThunk(Env & env, Expr * expr);
|
|
|
|
/* Print statistics. */
|
|
void printStats();
|
|
|
|
private:
|
|
|
|
unsigned long nrEnvs;
|
|
unsigned long nrValuesInEnvs;
|
|
unsigned long nrValues;
|
|
unsigned long nrListElems;
|
|
unsigned long nrEvaluated;
|
|
unsigned long nrAttrsets;
|
|
unsigned long nrOpUpdates;
|
|
unsigned long nrOpUpdateValuesCopied;
|
|
unsigned int recursionDepth;
|
|
unsigned int maxRecursionDepth;
|
|
char * deepestStack; /* for measuring stack usage */
|
|
|
|
friend class RecursionCounter;
|
|
friend class ExprOpUpdate;
|
|
};
|
|
|
|
|
|
/* Return a string representing the type of the value `v'. */
|
|
string showType(const Value & v);
|
|
|
|
|
|
}
|
|
|
|
|
|
#endif /* !__EVAL_H */
|