• d-bugmail puremagic.com (52/52) Oct 12 2018 https://issues.dlang.org/show_bug.cgi?id=19305

d-bugmail puremagic.com writes:

https://issues.dlang.org/show_bug.cgi?id=19305

          Issue ID: 19305
           Summary: In symbol lookup, with statement becomes stronger than
                    an inner scope import statement
           Product: D
           Version: D2
          Hardware: All
                OS: All
            Status: NEW
          Severity: regression
          Priority: P1
         Component: dmd
          Assignee: nobody puremagic.com
          Reporter: shigekikarita gmail.com

I found a breaking change of symbol  from DMD2.073.0. I think this change comes
from a conflict between statement spec 4.3.2 and module spec 11.19.1.

see 4.3.2 in https://docarchives.dlang.io/v2.081.0/spec/module.html
see 11.19.1 in
https://docarchives.dlang.io/v2.081.0/spec/statement.html#with-statement


running example 
https://wandbox.org/permlink/5bDsMZeqKYh4runs
-------

module a;

enum f = "a";


module b;

enum f = "b";


module main;

import std.stdio;
import a;
import b;


void main() {
    with (a) {
        // 11.19.1 Within the with body the referenced object is searched first
for identifier symbols
        assert(f == "a");
        // 4.3.2 When a symbol name is used unqualified, a two-phase lookup
will happen. 
        // First, the module scope will be searched, starting from the
innermost scope. ...
        // Symbol lookup stops as soon as a symbol is found. 
        // If two symbols with the same name are found at the same lookup
phase,
        //  this ambiguity will result in a compilation error.
        import b;
        static if (__VERSION__ >= 2073) {
            assert(f == "a");
        } else {
            assert(f == "b");                    
        }
    }
}

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