Bug 3719 – forward references can cause out-of-memory error

If there are forward references that are not resolved for a long time, dmd can waste a lot of memory and cpu-cycles. It's not easy to create a small test case, but qtd fails to compile with "out of memory" without the following patch: Module::runDeferredSemantic() should not retry between every new symbol in a class or struct, but only when some sensible progress is made (e.g. if Module::dprogress > 0). runDeferredSemantic() must then be forced to run once before running semantic2() on the modules. Index: mars.c =================================================================== --- mars.c (revision 336) +++ mars.c (working copy) @@ -1109,6 +1109,12 @@ if (global.errors) fatal(); + if(modules.dim) + { // last chance to resolve deferred symbols + Module::dprogress = 1; + ((Module *)modules.data[0])->runDeferredSemantic(); // should be static instead + } + // Do pass 2 semantic analysis for (i = 0; i < modules.dim; i++) { Index: module.c =================================================================== --- module.c (revision 336) +++ module.c (working copy) @@ -938,6 +938,8 @@ { size_t len; + if(dprogress == 0) + return; static int nested; if (nested) return;

Changeset 342

fixed dmd 1.056 and 2.040