From 5f18cd2e84bb4d7405f7dbcc8b6554365556a3a1 Mon Sep 17 00:00:00 2001 From: Eelco Dolstra Date: Fri, 8 Feb 2013 19:49:24 +0100 Subject: [PATCH] Make "${./path} ..." evaluate to a string, not a path MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Wacky string coercion semantics caused expressions like exec = "${./my-script} params..."; to evaluate to a path (‘/path/my-script params’), because anti-quotations are desuged to string concatenation: exec = ./my-script + " params..."; By constrast, adding a space at the start would yield a string as expected: exec = " ${./my-script} params..."; Now the first example also evaluates to a string. --- src/libexpr/eval.cc | 2 +- src/libexpr/nixexpr.hh | 4 +++- src/libexpr/parser.y | 6 +++--- 3 files changed, 7 insertions(+), 5 deletions(-) diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc index 676dd3ac4..a1613a420 100644 --- a/src/libexpr/eval.cc +++ b/src/libexpr/eval.cc @@ -966,7 +966,7 @@ void ExprConcatStrings::eval(EvalState & state, Env & env, Value & v) since paths are copied when they are used in a derivation), and none of the strings are allowed to have contexts. */ if (first) { - isPath = vStr.type == tPath; + isPath = !forceString && vStr.type == tPath; first = false; } diff --git a/src/libexpr/nixexpr.hh b/src/libexpr/nixexpr.hh index bc6c3287c..86a7bfd50 100644 --- a/src/libexpr/nixexpr.hh +++ b/src/libexpr/nixexpr.hh @@ -277,8 +277,10 @@ MakeBinOp(OpConcatLists, "++") struct ExprConcatStrings : Expr { + bool forceString; vector * es; - ExprConcatStrings(vector * es) : es(es) { }; + ExprConcatStrings(bool forceString, vector * es) + : forceString(forceString), es(es) { }; COMMON_METHODS }; diff --git a/src/libexpr/parser.y b/src/libexpr/parser.y index 1819da5e1..66edfb548 100644 --- a/src/libexpr/parser.y +++ b/src/libexpr/parser.y @@ -203,7 +203,7 @@ static Expr * stripIndentation(SymbolTable & symbols, vector & es) es2->push_back(new ExprString(symbols.create(s2))); } - return es2->size() == 1 ? (*es2)[0] : new ExprConcatStrings(es2); + return es2->size() == 1 ? (*es2)[0] : new ExprConcatStrings(true, es2); } @@ -318,7 +318,7 @@ expr_op { vector * l = new vector; l->push_back($1); l->push_back($3); - $$ = new ExprConcatStrings(l); + $$ = new ExprConcatStrings(false, l); } | expr_op CONCAT expr_op { $$ = new ExprOpConcatLists($1, $3); } | expr_app @@ -349,7 +349,7 @@ expr_simple /* For efficiency, and to simplify parse trees a bit. */ if ($2->empty()) $$ = new ExprString(data->symbols.create("")); else if ($2->size() == 1) $$ = $2->front(); - else $$ = new ExprConcatStrings($2); + else $$ = new ExprConcatStrings(true, $2); } | IND_STRING_OPEN ind_string_parts IND_STRING_CLOSE { $$ = stripIndentation(data->symbols, *$2);