Bug 18296 – [Reg2.078.1] invalid code with coverage and copy construction

cat > bug.d << CODE alias AliasSeq(Args...) = Args; struct Duration { this(long hnsecs) { _hnsecs = hnsecs; } long _hnsecs; } void main() { foreach(U; AliasSeq!(Duration, const Duration)) { const Duration t = 42; U u = t; assert(t._hnsecs == u._hnsecs); } } CODE dmd -cov -run bug.d

Only occurs with PIC enabled, guess this happens as a result of https://github.com/dlang/dmd/pull/7654 whereby coverage symbols no longer have local linkage.

FYI the discussion happens at this PR: https://github.com/dlang/druntime/pull/2048

Commit pushed to master at https://github.com/dlang/druntime https://github.com/dlang/druntime/commit/2d45fcbbd7a734bb6ecf8ba3d60897e8fefc4d44 use more specific workaround for Issue 18296

Commits pushed to master at https://github.com/dlang/dmd https://github.com/dlang/dmd/commit/0146d2be4298f15416a4f0bee08876934ed2200c fix Issue 18296 - make __coverage a hidden symbol - external linkage only for current DSO, but not across DSOs - avoids GOT indirection on every access - thus avoids codegen bugs related to those - uses SCstatic with SFLhidden flag as the access is the same as for static symbols, even though linkage is between SCglobal and SCstatic In the long-run (and with more usage) a separate SChidden might be cleaner. - no changes to OMF code as LPUBDEF isn't used https://github.com/dlang/dmd/commit/eb2bf7713cd46d49a9ea75999188d84b410b45d5 Merge pull request #7772 from MartinNowak/fix18296 fix Issue 18296 - make __coverage a hidden symbol