The following program segfaults my LDC (hg r757):
module blaat;
struct MatchResult {
private size_t data;
}
MatchResult ABCD(alias Alias)(char[]) {
return MatchResult(1);
}
MatchResult A(alias Alias)(char[]) {
return MatchResult(1);
}
MatchResult ABCDE(dchar[] chars)(char[]) {
return MatchResult(1);
}
// The mangled name of A's template parameter needs to be >= 126 chars
// for it to segfault.
// (125 may segfault also, 124 doesn't)
alias A!(ABCD!(ABCDE!("012345678")))
MangleMatcher;
$ dmd -c blaat.d
$ gdc -c blaat.d
$ ldc -c blaat.d
Segmentation fault
I'm running x86-64 Ubuntu 8.04.
As you can see, DMD (v1.036) and GDC ((prerelease gdc 0.25, using dmd 1.021) (Ubuntu 0.25-4.1.2-16ubuntu1), x86-64) compile it without error but LDC segfaults.
GDB backtrace (slighly cleaned up for readability):
#0 0x00007ffaed157060 in strlen () from /lib/libc.so.6
#1 0x00007ffaed123e1a in vfprintf () from /lib/libc.so.6
#2 0x00007ffaed1479ea in vsnprintf () from /lib/libc.so.6
#3 0x000000000057f446 in OutBuffer::vprintf () at ldc/dmd/root.c:1627
#4 0x000000000057f556 in OutBuffer::printf () at ldc/dmd/root.c:1677
#5 0x00000000005b11fd in TemplateInstance::genIdent () at ldc/dmd/template.c:3644
#6 0x00000000005b4f35 in TemplateInstance::semantic () at ldc/dmd/template.c:2964
#7 0x0000000000571dea in TypeInstance::resolve () at ldc/dmd/mtype.c:3667
#8 0x0000000000549d9d in AliasDeclaration::semantic () at ldc/dmd/declaration.c:460
#9 0x0000000000555d18 in Module::semantic () at ldc/dmd/module.c:654
#10 0x000000000056c45e in main () at ldc/dmd/mars.c:1136
Investigating further, it seems strlen is passed an invalid pointer: its value is 0x686374614d313174, which translates to "t11Match" (that substring appears around the middle of the mangled name TemplateInstance::genIdent is trying to print).
Something is very wrong here, probably something to do with the mess that is C(++) varargs...
(Unless that format string it uses is incorrect?)
