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* Check for duplicate attributes in fixAttrs, rather than doing a

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separate traversal after parsing.  Likewise, check for duplicate
  pattern variables right away.
This commit is contained in:
Eelco Dolstra 2009-05-14 14:29:45 +00:00
parent 50d11b90ca
commit e42975490f
1 changed files with 63 additions and 94 deletions
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157
src/libexpr/parser.y
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@ -44,28 +44,77 @@ struct ParseData
Path path;
string error;
};
static void duplicateAttr(ATerm name, ATerm pos, ATerm prevPos)
{
throw EvalError(format("duplicate attribute `%1%' at %2% (previously defined at %3%)")
% aterm2String(name) % showPos(pos) % showPos (prevPos));
}
static Expr fixAttrs(int recursive, ATermList as)
static Expr fixAttrs(bool recursive, ATermList as)
{
ATermList bs = ATempty, cs = ATempty;
ATermList * is = recursive ? &cs : &bs;
ATermMap used;
for (ATermIterator i(as); i; ++i) {
ATermList names;
Expr src;
ATerm pos;
ATermList names; Expr src, e; ATerm name, pos;
if (matchInherit(*i, src, names, pos)) {
bool fromScope = matchScope(src);
for (ATermIterator j(names); j; ++j) {
Expr rhs = fromScope ? makeVar(*j) : makeSelect(src, *j);
if (used.get(*j)) duplicateAttr(*j, pos, used[*j]);
used.set(*j, pos);
*is = ATinsert(*is, makeBind(*j, rhs, pos));
}
} else bs = ATinsert(bs, *i);
} else if (matchBind(*i, name, e, pos)) {
if (used.get(name)) duplicateAttr(name, pos, used[name]);
used.set(name, pos);
bs = ATinsert(bs, *i);
} else abort(); /* can't happen */
}
if (recursive)
return makeRec(bs, cs);
else
return makeAttrs(bs);
return recursive? makeRec(bs, cs) : makeAttrs(bs);
}
static void checkPatternVars(ATerm pos, ATermMap & map, Pattern pat)
{
ATerm name;
ATermList formals;
Pattern pat1, pat2;
ATermBool ellipsis;
if (matchVarPat(pat, name)) {
if (map.get(name))
throw EvalError(format("duplicate formal function argument `%1%' at %2%")
% aterm2String(name) % showPos(pos));
map.set(name, name);
}
else if (matchAttrsPat(pat, formals, ellipsis)) {
for (ATermIterator i(formals); i; ++i) {
ATerm d1;
if (!matchFormal(*i, name, d1)) abort();
if (map.get(name))
throw EvalError(format("duplicate formal function argument `%1%' at %2%")
% aterm2String(name) % showPos(pos));
map.set(name, name);
}
}
else if (matchAtPat(pat, pat1, pat2)) {
checkPatternVars(pos, map, pat1);
checkPatternVars(pos, map, pat2);
}
else abort();
}
static void checkPatternVars(ATerm pos, Pattern pat)
{
ATermMap map;
checkPatternVars(pos, map, pat);
}
@ -245,13 +294,13 @@ expr: expr_function;
expr_function
: pattern ':' expr_function
{ $$ = makeFunction($1, $3, CUR_POS); }
{ checkPatternVars(CUR_POS, $1); $$ = makeFunction($1, $3, CUR_POS); }
| ASSERT expr ';' expr_function
{ $$ = makeAssert($2, $4, CUR_POS); }
| WITH expr ';' expr_function
{ $$ = makeWith($2, $4, CUR_POS); }
| LET binds IN expr_function
{ $$ = makeSelect(fixAttrs(1, ATinsert($2, makeBind(toATerm("<let-body>"), $4, CUR_POS))), toATerm("<let-body>")); }
{ $$ = makeSelect(fixAttrs(true, ATinsert($2, makeBind(toATerm("<let-body>"), $4, CUR_POS))), toATerm("<let-body>")); }
| expr_if
;
@ -306,11 +355,11 @@ expr_simple
/* Let expressions `let {..., body = ...}' are just desugared
into `(rec {..., body = ...}).body'. */
| LET '{' binds '}'
{ $$ = makeSelect(fixAttrs(1, $3), toATerm("body")); }
{ $$ = makeSelect(fixAttrs(true, $3), toATerm("body")); }
| REC '{' binds '}'
{ $$ = fixAttrs(1, $3); }
{ $$ = fixAttrs(true, $3); }
| '{' binds '}'
{ $$ = fixAttrs(0, $2); }
{ $$ = fixAttrs(false, $2); }
| '[' expr_list ']' { $$ = makeList(ATreverse($2)); }
;
@ -390,84 +439,6 @@ formal
namespace nix {
static void checkAttrs(ATermMap & names, ATermList bnds)
{
for (ATermIterator i(bnds); i; ++i) {
ATerm name;
Expr e;
ATerm pos;
if (!matchBind(*i, name, e, pos)) abort(); /* can't happen */
if (names.get(name))
throw EvalError(format("duplicate attribute `%1%' at %2%")
% aterm2String(name) % showPos(pos));
names.set(name, name);
}
}
static void checkPatternVars(ATerm pos, ATermMap & map, Pattern pat)
{
ATerm name;
ATermList formals;
Pattern pat1, pat2;
ATermBool ellipsis;
if (matchVarPat(pat, name)) {
if (map.get(name))
throw EvalError(format("duplicate formal function argument `%1%' at %2%")
% aterm2String(name) % showPos(pos));
map.set(name, name);
}
else if (matchAttrsPat(pat, formals, ellipsis)) {
for (ATermIterator i(formals); i; ++i) {
ATerm d1;
if (!matchFormal(*i, name, d1)) abort();
if (map.get(name))
throw EvalError(format("duplicate formal function argument `%1%' at %2%")
% aterm2String(name) % showPos(pos));
map.set(name, name);
}
}
else if (matchAtPat(pat, pat1, pat2)) {
checkPatternVars(pos, map, pat1);
checkPatternVars(pos, map, pat2);
}
else abort();
}
static void checkAttrSets(ATerm e)
{
ATerm pat, body, pos;
if (matchFunction(e, pat, body, pos)) {
ATermMap map(16);
checkPatternVars(pos, map, pat);
}
ATermList bnds;
if (matchAttrs(e, bnds)) {
ATermMap names(ATgetLength(bnds));
checkAttrs(names, bnds);
}
ATermList rbnds, nrbnds;
if (matchRec(e, rbnds, nrbnds)) {
ATermMap names(ATgetLength(rbnds) + ATgetLength(nrbnds));
checkAttrs(names, rbnds);
checkAttrs(names, nrbnds);
}
if (ATgetType(e) == AT_APPL) {
int arity = ATgetArity(ATgetAFun(e));
for (int i = 0; i < arity; ++i)
checkAttrSets(ATgetArgument(e, i));
}
else if (ATgetType(e) == AT_LIST)
for (ATermIterator i((ATermList) e); i; ++i)
checkAttrSets(*i);
}
static Expr parse(EvalState & state,
const char * text, const Path & path,
const Path & basePath)
@ -490,8 +461,6 @@ static Expr parse(EvalState & state,
throw EvalError(format("%1%, in `%2%'") % e.msg() % path);
}
checkAttrSets(data.result);
return data.result;
}