kpdev wrote: > What is it about this change that is defeating the ValueObject printer from > compressing this output onto one line? It looks like the contents that get > printed are the same, so there's something about switching from a Summary > provider to a child provider that's causing problems. We should fix that as > people are really picky about variable printing being as space efficient as > possible.
> To clear up terminology... Strings had data formatters before AND after this > change. The difference is that you've switched from a "Summary Provider" data > formatter to a "Synthetic Child Provider" data formatter. > > It looks like you've made the printing of std::strings less space efficient. > That shouldn't be necessary, and isn't desirable. We should figure out why > that's happening and fix that before this change is going to not cause > complaints. As there is mentioned in a comment for `FormatManager::ShouldPrintAsOneLiner` ( https://github.com/llvm/llvm-project/blob/main/lldb/source/DataFormatters/FormatManager.cpp#L498 ): ``` // if we decided to define synthetic children for a type, we probably care // enough to show them, but avoid nesting children in children ``` So, there is a condition for that: ``` // but if we only have them to provide a value, keep going if (!synth_sp->MightHaveChildren() && synth_sp->DoesProvideSyntheticValue()) is_synth_val = true; else return false; ``` This patch adds StringSynthetic and this synthetic `MightHaveChildren()` is `true`, therefore `ShouldPrintAsOneLiner` returns `false`. And the printer will use `"()"` or `"{\n ... \n}"` according to whether we return `true` or `false` from this function. If we would like to avoid unnecessary output we probably may ask SyntheticFrontend directly if it would like to print expanded info or not, what do you think about it? https://github.com/llvm/llvm-project/pull/67782 _______________________________________________ lldb-commits mailing list lldb-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
