Store Nix integers as longs

So on 64-bit systems, integers are now 64-bit.

Fixes #158.

src/libexpr/eval.cc

@@ -968,7 +968,7 @@ void ExprConcatStrings::eval(EvalState & state, Env & env, Value & v)
 {
     PathSet context;
     std::ostringstream s;
-    int n = 0;
+    NixInt n = 0;
 
     bool first = true;
     ValueType firstType;
@@ -1021,7 +1021,7 @@ void EvalState::strictForceValue(Value & v)
 }
 
 
-int EvalState::forceInt(Value & v)
+NixInt EvalState::forceInt(Value & v)
 {
     forceValue(v);
     if (v.type != tInt)

src/libexpr/eval.hh

@@ -159,7 +159,7 @@ public:
     void strictForceValue(Value & v);
 
     /* Force `v', and then verify that it has the expected type. */
-    int forceInt(Value & v);
+    NixInt forceInt(Value & v);
     bool forceBool(Value & v);
     inline void forceAttrs(Value & v);
     inline void forceList(Value & v);

src/libexpr/lexer.l

@@ -110,8 +110,10 @@ or          { return OR_KW; }
 \+\+        { return CONCAT; }
 
 {ID}        { yylval->id = strdup(yytext); return ID; }
-{INT}       { int n = atoi(yytext); /* !!! overflow */
-              yylval->n = n;
+{INT}       { errno = 0;
+              yylval->n = strtol(yytext, 0, 10);
+              if (errno != 0)
+                  throw ParseError(format("invalid integer `%1%'") % yytext);
               return INT;
             }
 

src/libexpr/nixexpr.hh

@@ -75,9 +75,9 @@ std::ostream & operator << (std::ostream & str, Expr & e);
 
 struct ExprInt : Expr
 {
-    int n;
+    NixInt n;
     Value v;
-    ExprInt(int n) : n(n) { mkInt(v, n); };
+    ExprInt(NixInt n) : n(n) { mkInt(v, n); };
     COMMON_METHODS
     Value * maybeThunk(EvalState & state, Env & env);
 };

src/libexpr/parser.y

@@ -238,7 +238,7 @@ void yyerror(YYLTYPE * loc, yyscan_t scanner, ParseData * data, const char * err
   nix::ExprAttrs * attrs;
   nix::Formals * formals;
   nix::Formal * formal;
-  int n;
+  nix::NixInt n;
   char * id; // !!! -> Symbol
   char * path;
   char * uri;

src/libexpr/primops.cc

@@ -1024,7 +1024,7 @@ static void prim_mul(EvalState & state, Value * * args, Value & v)
 
 static void prim_div(EvalState & state, Value * * args, Value & v)
 {
-    int i2 = state.forceInt(*args[1]);
+    NixInt i2 = state.forceInt(*args[1]);
     if (i2 == 0) throw EvalError("division by zero");
     mkInt(v, state.forceInt(*args[0]) / i2);
 }

src/libexpr/value.hh

@@ -31,12 +31,15 @@ struct PrimOp;
 struct Symbol;
 
 
+typedef long NixInt;
+
+
 struct Value
 {
     ValueType type;
     union
     {
-        int integer;
+        NixInt integer;
         bool boolean;
 
         /* Strings in the evaluator carry a so-called `context' which
@@ -97,7 +100,7 @@ static inline void clearValue(Value & v)
 }
 
 
-static inline void mkInt(Value & v, int n)
+static inline void mkInt(Value & v, NixInt n)
 {
     clearValue(v);
     v.type = tInt;

src/libutil/util.cc

@@ -1083,14 +1083,6 @@ bool statusOk(int status)
 }
 
 
-string int2String(int n)
-{
-    std::ostringstream str;
-    str << n;
-    return str.str();
-}
-
-
 bool hasSuffix(const string & s, const string & suffix)
 {
     return s.size() >= suffix.size() && string(s, s.size() - suffix.size()) == suffix;

src/libutil/util.hh

@@ -319,7 +319,12 @@ template<class N> bool string2Int(const string & s, N & n)
     return str && str.get() == EOF;
 }
 
-string int2String(int n);
+template<class N> string int2String(N n)
+{
+    std::ostringstream str;
+    str << n;
+    return str.str();
+}
 
 
 /* Return true iff `s' ends in `suffix'. */