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digitalmars.D.bugs - [Issue 2474] New: Recursive lazy arguments are inlined incorrectly

reply d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=2474

           Summary: Recursive lazy arguments are inlined incorrectly
           Product: D
           Version: 2.021
          Platform: PC
        OS/Version: Windows
            Status: NEW
          Keywords: rejects-valid
          Severity: normal
          Priority: P2
         Component: DMD
        AssignedTo: bugzilla digitalmars.com
        ReportedBy: snake.scaly gmail.com


This code:

--8<-----------
int foo(lazy int x)
{
  int bar()
  {
    return foo(bar());
  }
  return bar();
}
--8<-----------

produces the following output when compiled:

 dmd inlinebug.d -c -inline

and cannot be accessed from foo Without the -inline flag this code compiles and works as expected. The same bug is present in DMD 1.037. --
Nov 26 2008
next sibling parent d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=2474


smjg iname.com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |smjg iname.com
            Version|2.021                       |1.036




------- Comment #1 from smjg iname.com  2008-11-27 09:42 -------
 dmd inlinebug.d -c -inline

and cannot be accessed from foo

Presumably, inlining changes return bar(); to return foo(bar()); after which it tries to TRO the foo call, but gets mixed up as it relies on the nested function bar. I'm not sure if the compiler is actually within its rights to complain about this, as it's bad code even though not technically illegal. And if such bad code interferes with optimisation, should the compiler error or just not bother with the optimisation?
 Without the -inline flag this code compiles and works as expected.

As in throws a stack overflow?
 The same bug is present in DMD 1.037.

And 1.036 and 2.020. AIUI if the same bug occurs in both D1 and D2, it is preferred to file it under the D1 version. --
Nov 27 2008
prev sibling next sibling parent d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=2474





------- Comment #2 from snake.scaly gmail.com  2008-11-27 10:51 -------
 I'm not sure if the compiler is actually within its rights to complain about
 this, as it's bad code even though not technically illegal...
 
 Without the -inline flag this code compiles and works as expected.

As in throws a stack overflow?

This is a reduced version of Knuth's "Man or Boy" test: --8<---------------- import std.stdio; int a(int k, lazy int x1, lazy int x2, lazy int x3, lazy int x4, lazy int x5) { int b() { k--; return a(k, b(), x1, x2, x3, x4); } return k <= 0 ? x4 + x5 : b(); } void main() { writefln(a(10, 1, -1, -1, 1, 0)); } --8<----------------
dmd manorboy.d

manorboy

dmd -inline manorboy.d

cannot be accessed from a manorboy.d(8): delegate manorboy.a.b.__dgliteral2 is a nested function and cannot be accessed from a manorboy.d(8): delegate manorboy.a.b.__dgliteral3 is a nested function and cannot be accessed from a manorboy.d(8): delegate manorboy.a.b.__dgliteral4 is a nested function and cannot be accessed from a manorboy.d(8): delegate manorboy.a.b.__dgliteral5 is a nested function and cannot be accessed from a See also the issue 2475, it's the same. --
Nov 27 2008
prev sibling next sibling parent d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=2474


smjg iname.com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |bugzilla digitalmars.com




------- Comment #3 from smjg iname.com  2009-01-11 16:47 -------
*** Bug 2475 has been marked as a duplicate of this bug. ***


-- 
Jan 11 2009
prev sibling parent d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=2474


Don <clugdbug yahoo.com.au> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |fawzi gmx.ch


--- Comment #4 from Don <clugdbug yahoo.com.au> 2010-09-13 23:55:41 PDT ---
*** Issue 3244 has been marked as a duplicate of this issue. ***

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