* Better error messages (especially wrt types).

This commit is contained in:
Eelco Dolstra 2006-07-19 15:36:15 +00:00
parent e10b830251
commit 4f3725b167
7 changed files with 96 additions and 62 deletions

View file

@ -41,7 +41,7 @@ static Expr substArgs(Expr body, ATermList formals, Expr arg)
if (!matchNoDefFormal(*i, name) && !matchDefFormal(*i, name, def))
abort(); /* can't happen */
if (subs[name] == 0) {
if (def == 0) throw Error(format("required function argument `%1%' missing")
if (def == 0) throw TypeError(format("the argument named `%1%' required by the function is missing")
% aterm2String(name));
defsUsed.push_back(name);
recAttrs = ATinsert(recAttrs, makeBind(name, def, makeNoPos()));
@ -68,7 +68,7 @@ static Expr substArgs(Expr body, ATermList formals, Expr arg)
matchNoDefFormal(*i, name) || matchDefFormal(*i, name, def);
subs.remove(name);
}
throw Error(format("unexpected function argument `%1%'")
throw TypeError(format("the function does not expect an argument named `%1%'")
% aterm2String(subs.begin()->key));
}
@ -133,7 +133,8 @@ string evalString(EvalState & state, Expr e)
{
e = evalExpr(state, e);
ATerm s;
if (!matchStr(e, s)) throw Error("string expected");
if (!matchStr(e, s))
throw TypeError(format("value is %1% while a string was expected") % showType(e));
return aterm2String(s);
}
@ -142,7 +143,8 @@ Path evalPath(EvalState & state, Expr e)
{
e = evalExpr(state, e);
ATerm s;
if (!matchPath(e, s)) throw Error("path expected");
if (!matchPath(e, s))
throw TypeError(format("value is %1% while a path was expected") % showType(e));
return aterm2String(s);
}
@ -152,7 +154,7 @@ bool evalBool(EvalState & state, Expr e)
e = evalExpr(state, e);
if (e == eTrue) return true;
else if (e == eFalse) return false;
else throw Error("boolean expected");
else throw TypeError(format("value is %1% while a boolean was expected") % showType(e));
}
@ -160,7 +162,8 @@ ATermList evalList(EvalState & state, Expr e)
{
e = evalExpr(state, e);
ATermList list;
if (!matchList(e, list)) throw Error("list expected");
if (!matchList(e, list))
throw TypeError(format("value is %1% while a list was expected") % showType(e));
return list;
}
@ -226,13 +229,13 @@ string coerceToStringWithContext(EvalState & state,
Expr a = attrs.get(toATerm("type"));
if (a && evalString(state, a) == "derivation") {
a = attrs.get(toATerm("outPath"));
if (!a) throw Error("output path missing from derivation");
if (!a) throw TypeError("output path missing from derivation");
context = ATinsert(context, e);
return evalPath(state, a);
}
}
throw Error("cannot coerce value to string");
throw TypeError(format("cannot coerce %1% to a string") % showType(e));
}
@ -294,7 +297,7 @@ Expr evalExpr2(EvalState & state, Expr e)
if (matchVar(e, name)) {
ATerm primOp = state.primOps.get(name);
if (!primOp)
throw Error(format("impossible: undefined variable `%1%'") % aterm2String(name));
throw EvalError(format("impossible: undefined variable `%1%'") % aterm2String(name));
int arity;
ATermBlob fun;
if (!matchPrimOpDef(primOp, arity, fun)) abort();
@ -355,7 +358,7 @@ Expr evalExpr2(EvalState & state, Expr e)
}
}
else throw Error("function or primop expected in function call");
else throw TypeError("the left-hand side of the function call is neither a function nor a primop (built-in operation)");
}
/* Attribute selection. */
@ -363,7 +366,7 @@ Expr evalExpr2(EvalState & state, Expr e)
ATerm pos;
string s1 = aterm2String(name);
Expr a = queryAttr(evalExpr(state, e1), s1, pos);
if (!a) throw Error(format("attribute `%1%' missing") % s1);
if (!a) throw EvalError(format("attribute `%1%' missing") % s1);
try {
return evalExpr(state, a);
} catch (Error & e) {
@ -451,26 +454,33 @@ Expr evalExpr2(EvalState & state, Expr e)
}
/* String or path concatenation. */
if (matchOpPlus(e, e1, e2)) {
ATermList es;
if (matchOpPlus(e, e1, e2) || matchConcatStrings(e, es)) {
ATermVector args;
args.push_back(e1);
args.push_back(e2);
return concatStrings(state, args);
if (matchOpPlus(e, e1, e2)) {
args.push_back(e1);
args.push_back(e2);
} else
for (ATermIterator i(es); i; ++i) args.push_back(*i);
try {
return concatStrings(state, args);
} catch (Error & e) {
e.addPrefix(format("in a string concatenation: "));
throw;
}
}
/* List concatenation. */
if (matchOpConcat(e, e1, e2)) {
ATermList l1 = evalList(state, e1);
ATermList l2 = evalList(state, e2);
return makeList(ATconcat(l1, l2));
}
/* String concatenation. */
ATermList es;
if (matchConcatStrings(e, es)) {
ATermVector args;
for (ATermIterator i(es); i; ++i) args.push_back(*i);
return concatStrings(state, args);
try {
ATermList l1 = evalList(state, e1);
ATermList l2 = evalList(state, e2);
return makeList(ATconcat(l1, l2));
} catch (Error & e) {
e.addPrefix(format("in a list concatenation: "));
throw;
}
}
/* Barf. */
@ -492,7 +502,7 @@ Expr evalExpr(EvalState & state, Expr e)
Expr nf = state.normalForms.get(e);
if (nf) {
if (nf == makeBlackHole())
throw Error("infinite recursion encountered");
throw EvalError("infinite recursion encountered");
state.nrCached++;
return nf;
}

View file

@ -41,10 +41,6 @@ struct EvalState
};
MakeError(EvalError, Error)
MakeError(AssertionError, EvalError)
/* Evaluate an expression to normal form. */
Expr evalExpr(EvalState & state, Expr e);

View file

@ -16,7 +16,7 @@ string DrvInfo::queryOutPath(EvalState & state) const
{
if (outPath == "") {
Expr a = attrs->get(toATerm("outPath"));
if (!a) throw Error("output path missing");
if (!a) throw TypeError("output path missing");
(string &) outPath = evalPath(state, a);
}
return outPath;
@ -81,7 +81,7 @@ static bool getDerivation(EvalState & state, Expr e,
a = attrs->get(toATerm("name"));
/* !!! We really would like to have a decent back trace here. */
if (!a) throw Error("derivation name missing");
if (!a) throw TypeError("derivation name missing");
drv.name = evalString(state, a);
a = attrs->get(toATerm("system"));
@ -123,7 +123,7 @@ static void getDerivations(EvalState & state, Expr e,
for (ATermIterator i(formals); i; ++i) {
Expr name, def;
if (matchNoDefFormal(*i, name))
throw Error(format("expression evaluates to a function with no-default arguments (`%1%')")
throw TypeError(format("cannot auto-call a function that has an argument without a default value (`%1%')")
% aterm2String(name));
else if (!matchDefFormal(*i, name, def))
abort(); /* can't happen */
@ -224,7 +224,7 @@ static void getDerivations(EvalState & state, Expr e,
return;
}
throw Error("expression does not evaluate to a derivation (or a set or list of those)");
throw TypeError("expression does not evaluate to a derivation (or a set or list of those)");
}

View file

@ -50,7 +50,7 @@ void queryAllAttrs(Expr e, ATermMap & attrs, bool withPos)
{
ATermList bnds;
if (!matchAttrs(e, bnds))
throw Error("attribute set expected");
throw TypeError("attribute set expected");
for (ATermIterator i(bnds); i; ++i) {
ATerm name;
@ -73,7 +73,7 @@ Expr queryAttr(Expr e, const string & name, ATerm & pos)
{
ATermList bnds;
if (!matchAttrs(e, bnds))
throw Error("attribute set expected");
throw TypeError("attribute set expected");
for (ATermIterator i(bnds); i; ++i) {
ATerm name2, pos2;
@ -214,7 +214,7 @@ static void checkVarDefs2(set<Expr> & done, const ATermMap & defs, Expr e)
if (matchVar(e, name)) {
if (!defs.get(name))
throw Error(format("undefined variable `%1%'")
throw EvalError(format("undefined variable `%1%'")
% aterm2String(name));
}
@ -289,3 +289,24 @@ Expr makeBool(bool b)
{
return b ? eTrue : eFalse;
}
string showType(Expr e)
{
ATerm t1, t2, t3;
ATermList l1;
int i1;
if (matchStr(e, t1)) return "a string";
if (matchPath(e, t1)) return "a path";
if (matchUri(e, t1)) return "a path";
if (matchNull(e)) return "null";
if (matchInt(e, i1)) return "an integer";
if (matchBool(e, t1)) return "a boolean";
if (matchFunction(e, l1, t1, t2)) return "a function";
if (matchFunction1(e, t1, t2, t3)) return "a function";
if (matchAttrs(e, l1)) return "an attribute set";
if (matchList(e, l1)) return "a list";
if (matchContext(e, l1, t1)) return "a context containing " + showType(t1);
return "an unknown type";
}

View file

@ -9,6 +9,11 @@
#include "util.hh"
MakeError(EvalError, Error)
MakeError(AssertionError, EvalError)
MakeError(TypeError, EvalError)
/* Nix expressions are represented as ATerms. The maximal sharing
property of the ATerm library allows us to implement caching of
normals forms efficiently. */
@ -82,5 +87,7 @@ void checkVarDefs(const ATermMap & def, Expr e);
/* Create an expression representing a boolean. */
Expr makeBool(bool b);
string showType(Expr e);
#endif /* !__NIXEXPR_H */

View file

@ -103,7 +103,7 @@ static void checkAttrs(ATermMap & names, ATermList bnds)
ATerm pos;
if (!matchBind(*i, name, e, pos)) abort(); /* can't happen */
if (names.get(name))
throw Error(format("duplicate attribute `%1%' at %2%")
throw EvalError(format("duplicate attribute `%1%' at %2%")
% aterm2String(name) % showPos(pos));
names.set(name, name);
}
@ -123,7 +123,7 @@ static void checkAttrSets(ATerm e)
!matchDefFormal(*i, name, deflt))
abort();
if (names.get(name))
throw Error(format("duplicate formal function argument `%1%' at %2%")
throw EvalError(format("duplicate formal function argument `%1%' at %2%")
% aterm2String(name) % showPos(pos));
names.set(name, name);
}
@ -168,12 +168,12 @@ static Expr parse(EvalState & state,
int res = yyparse(scanner, &data);
yylex_destroy(scanner);
if (res) throw Error(data.error);
if (res) throw EvalError(data.error);
try {
checkVarDefs(state.primOps, data.result);
} catch (Error & e) {
throw Error(format("%1%, in `%2%'") % e.msg() % path);
throw EvalError(format("%1%, in `%2%'") % e.msg() % path);
}
checkAttrSets(data.result);

View file

@ -26,19 +26,19 @@ static Expr primImport(EvalState & state, const ATermVector & args)
Nix expression created at the derivation's output path. */
if (a && evalString(state, a) == "derivation") {
a = queryAttr(arg, "drvPath");
if (!a) throw Error("bad derivation in import");
if (!a) throw EvalError("bad derivation in import");
Path drvPath = evalPath(state, a);
buildDerivations(singleton<PathSet>(drvPath));
a = queryAttr(arg, "outPath");
if (!a) throw Error("bad derivation in import");
if (!a) throw EvalError("bad derivation in import");
path = evalPath(state, a);
}
}
if (path == "")
throw Error("path or derivation expected in import");
throw TypeError("`import' requires a path or derivation as its argument");
return evalFile(state, path);
}
@ -133,11 +133,11 @@ static void processBinding(EvalState & state, Expr e, Derivation & drv,
if (a && evalString(state, a) == "derivation") {
a = queryAttr(e, "drvPath");
if (!a) throw Error("derivation name missing");
if (!a) throw EvalError("derivation name missing");
Path drvPath = evalPath(state, a);
a = queryAttr(e, "outPath");
if (!a) throw Error("output path missing");
if (!a) throw EvalError("output path missing");
/* !!! supports only single output path */
Path outPath = evalPath(state, a);
@ -148,7 +148,7 @@ static void processBinding(EvalState & state, Expr e, Derivation & drv,
else if (a && evalString(state, a) == "storePath") {
a = queryAttr(e, "outPath");
if (!a) throw Error("output path missing");
if (!a) throw EvalError("output path missing");
/* !!! supports only single output path */
Path outPath = evalPath(state, a);
@ -156,7 +156,7 @@ static void processBinding(EvalState & state, Expr e, Derivation & drv,
ss.push_back(outPath);
}
else throw Error("invalid derivation attribute");
else throw TypeError("attribute sets in derivations must either be derivations or store paths");
}
else if (matchPath(e, s)) {
@ -171,7 +171,7 @@ static void processBinding(EvalState & state, Expr e, Derivation & drv,
else {
if (isDerivation(srcPath))
throw Error(format("file names are not allowed to end in `%1%'")
throw EvalError(format("file names are not allowed to end in `%1%'")
% drvExtension);
Path dstPath;
if (state.srcToStore[srcPath] != "")
@ -200,14 +200,14 @@ static void processBinding(EvalState & state, Expr e, Derivation & drv,
Strings ss2;
processBinding(state, evalExpr(state, e1), drv, ss2);
if (ss2.size() != 1)
throw Error("left-hand side of `~' operator cannot be a list");
throw TypeError("left-hand side of `~' operator cannot be a list");
e2 = evalExpr(state, e2);
if (!(matchStr(e2, s) || matchPath(e2, s)))
throw Error("right-hand side of `~' operator must be a path or string");
throw TypeError("right-hand side of `~' operator must be a path or string");
ss.push_back(canonPath(ss2.front() + "/" + aterm2String(s)));
}
else throw Error("invalid derivation attribute");
else throw TypeError(format("%1% is not allowed as a derivation argument") % showType(e));
}
@ -240,7 +240,7 @@ static Expr primDerivationStrict(EvalState & state, const ATermVector & args)
/* Figure out the name already (for stack backtraces). */
Expr eDrvName = attrs.get(toATerm("name"));
if (!eDrvName)
throw Error("required attribute `name' missing");
throw EvalError("required attribute `name' missing");
ATerm posDrvName;
if (!matchAttrRHS(eDrvName, eDrvName, posDrvName)) abort();
string drvName = evalString(state, eDrvName);
@ -291,16 +291,16 @@ static Expr primDerivationStrict(EvalState & state, const ATermVector & args)
else if (key == "outputHashMode") {
if (s == "recursive") outputHashRecursive = true;
else if (s == "flat") outputHashRecursive = false;
else throw Error(format("invalid value `%1%' for `outputHashMode' attribute") % s);
else throw EvalError(format("invalid value `%1%' for `outputHashMode' attribute") % s);
}
}
}
/* Do we have all required attributes? */
if (drv.builder == "")
throw Error("required attribute `builder' missing");
throw EvalError("required attribute `builder' missing");
if (drv.platform == "")
throw Error("required attribute `system' missing");
throw EvalError("required attribute `system' missing");
/* If an output hash was given, check it. */
if (outputHash == "")
@ -308,7 +308,7 @@ static Expr primDerivationStrict(EvalState & state, const ATermVector & args)
else {
HashType ht = parseHashType(outputHashAlgo);
if (ht == htUnknown)
throw Error(format("unknown hash algorithm `%1%'") % outputHashAlgo);
throw EvalError(format("unknown hash algorithm `%1%'") % outputHashAlgo);
Hash h;
if (outputHash.size() == Hash(ht).hashSize * 2)
/* hexadecimal representation */
@ -326,7 +326,7 @@ static Expr primDerivationStrict(EvalState & state, const ATermVector & args)
alphanumerics and some other characters appear. */
checkStoreName(drvName);
if (isDerivation(drvName))
throw Error(format("derivation names are not allowed to end in `%1%'")
throw EvalError(format("derivation names are not allowed to end in `%1%'")
% drvExtension);
/* !!! the name should not end in the derivation extension (.drv).
@ -457,7 +457,7 @@ static Expr primIsNull(EvalState & state, const ATermVector & args)
static Path findDependency(Path dir, string dep)
{
if (dep[0] == '/') throw Error(
if (dep[0] == '/') throw EvalError(
format("illegal absolute dependency `%1%'") % dep);
Path p = canonPath(dir + "/" + dep);
@ -515,7 +515,7 @@ static Expr primDependencyClosure(EvalState & state, const ATermVector & args)
/* Get the start set. */
Expr startSet = queryAttr(attrs, "startSet");
if (!startSet) throw Error("attribute `startSet' required");
if (!startSet) throw EvalError("attribute `startSet' required");
ATermList startSet2 = evalList(state, startSet);
Path pivot;
@ -538,7 +538,7 @@ static Expr primDependencyClosure(EvalState & state, const ATermVector & args)
}
Expr scanner = queryAttr(attrs, "scanner");
if (!scanner) throw Error("attribute `scanner' required");
if (!scanner) throw EvalError("attribute `scanner' required");
/* Construct the dependency closure by querying the dependency of
each path in `workSet', adding the dependencies to