[Issue 14831] New: Each function local symbols should have unique mangled name

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=14831

          Issue ID: 14831
           Summary: Each function local symbols should have unique mangled
                    name
           Product: D
           Version: D2
          Hardware: All
                OS: All
            Status: NEW
          Severity: major
          Priority: P1
         Component: dmd
          Assignee: nobody at puremagic.com
          Reporter: k.hara.pg at gmail.com
            Blocks: 9748, 10619, 14820

Typical example:

module test;
void main()
{
    { int x; pragma(msg, x.mangleof); } // _D4test4mainFZ1xi
    { int x; pragma(msg, x.mangleof); } // _D4test4mainFZ1xi
}

Even if two or more different function local symbols have same name, their
mangled name should be unique.

---

Currently the mangling issue causes many pragmatic problems.

https://issues.dlang.org/show_bug.cgi?id=10619
If the same name symbols are captured by TemplateAliasParameter, the
corresponding template instances will be entangled.

https://issues.dlang.org/show_bug.cgi?id=14820
If the symbols declared in unrolled loop (compile-time iterated foreach)
statement, they're easily entangled.

https://issues.dlang.org/show_bug.cgi?id=9748
The problem is not only for variables, but also function local templates and
template functions.

---

Currently function local functions, type definitions, and static variables are
not allowed.

module test;
void main()
{
    { void f() {} pragma(msg, f.mangleof); }
    { void f() {} pragma(msg, f.mangleof); }        // error

    { struct S {} pragma(msg, S.mangleof); }
    { struct S {} pragma(msg, S.mangleof); }        // ICE

    { class C {} pragma(msg, C.mangleof); }
    { class C {} pragma(msg, C.mangleof); }         // ICE

    { enum E { a } pragma(msg, E.mangleof); }
    { enum E { a } pragma(msg, E.mangleof); }       // error

    { static int v = 0; pragma(msg, v.mangleof); }
    { static int v = 1; pragma(msg, v.mangleof); }  // error
}

However, I think the rejections are not so meaningful. I cannot see any reason
to limit such the static function local symbols to unique.

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