D issues are now tracked on GitHub. This Bugzilla instance remains as a read-only archive.
Issue 6344 - [CTFE] Assertion Failure in interpret.c when create an empty slice from null pointer
Summary: [CTFE] Assertion Failure in interpret.c when create an empty slice from null ...
Status: RESOLVED FIXED
Alias: None
Product: D
Classification: Unclassified
Component: dmd (show other issues)
Version: D2
Hardware: Other Windows
: P2 major
Assignee: No Owner
URL:
Keywords: ice-on-valid-code
Depends on:
Blocks:
 
Reported: 2011-07-18 12:07 UTC by Andrej Mitrovic
Modified: 2011-07-21 20:33 UTC (History)
2 users (show)

See Also:

Attachments
Add an attachment (proposed patch, testcase, etc.)

Note You need to log in before you can comment on or make changes to this issue.
Description Andrej Mitrovic 2011-07-18 12:07:58 UTC 
DMD 2.054, XP32:

import std.array;
import std.stdio;
import std.conv;
import std.traits;

enum Foo
{
    pre_x,
    pre_y,
    pre_z,
}  

mixin(wrapEnum!(Foo)("NewEnum", "pre_"));  // fails

private string wrapEnum(Type)(string newName, string prefix)
{
    string result = "enum " ~ newName ~ " {";
    
    foreach (member; EnumMembers!Type)
    {
        result ~= to!string(member).replace(prefix, "") ~ ",";
    }

    return result ~ "}";
}

void main()
{
    // writeln(wrapEnum!(Foo)("NewEnum", "pre_"));  // writes: enum NewEnum {x,y,z,}
}

Output:

Assertion failure: 'se->e1->op == TOKarrayliteral || se->e1->op == TOKstring' on line 4957 in file 'interpret.c'

abnormal program termination
Comment 1 kennytm 2011-07-18 13:01:40 UTC 
First reduction:

--------------------------------
import std.array;

string rp(string subject) {
    auto app = appender!string();
    app.put(subject[0 .. 0]); 
    auto m = app.data;
    return m;
}

enum e = rp("pre_x");
--------------------------------
Comment 2 kennytm 2011-07-18 13:16:45 UTC 
Ultimate cause: create an empty slice from a 'null' pointer.

----------------------
static assert({
    char* c = null;
    auto m = c[0..0];
    return true;
}());
----------------------