[Enh] add -profile="gc" switch

[WalterBright]

This is the start of a memory profiler, i.e. throw the switch and the compiler emits code to log all calls to allocate memory. This one only does it for calls to new a class. The following shows how it works:

import core.stdc.stdio;

class C { }

void main() {
    auto b = new C();
}

extern (C) Object _d_newclass(const ClassInfo ci);

extern (C) Object _d_newclassTrace(string file, int line, string funcname, const ClassInfo ci) {
    printf("_d_newclassTrace class = %s file = '%.*s' line = %d function = '%.*s'\n",
    cast(char *)ci.name,
    file.length, file.ptr,
    line,
    funcname.length, funcname.ptr
    );
    return _d_newclass(ci);
}

[WalterBright]

Corresponding issue:
https://issues.dlang.org/show_bug.cgi?id=14527

[WalterBright]

The failure is another heisenbug, nothing to do with this PR.

[yebblies]

If you go on this page and click the 'deprecate' link it will re-run it.

[WalterBright]

Where is that link? I can't find it.

[yebblies]

Where is that link? I can't find it.

Are you logged into the autotester? It should be there, although it disappears once clicked.

[WalterBright]

Here's what I see:

[yebblies]

Yes, the "Deleted: 1" means that it has already been done (happens automatically when the branch is pushed to). Opening a more recent run should show the deprecate link.

[WalterBright]

Makes sense. Thanks for the tip.

[andralex]

noice

[andralex]

Auto-merge toggled on

[MartinNowak]

When does a NewExpression not have a location? It kind of defeats the point when some allocations aren't accounted for.

[WalterBright]

Sometimes internally generated code doesn't have a location that would make any sense.