The ThinLTO index bitcode writer uses a helper forEachSummary to manage preparation and writing of summaries needed for each distributed index file. For alias summaries, it invokes the provided callback for the aliasee as well, as we at least need to produce a value id for the alias's summary. However, all summary generation for the aliasee itself should be skipped on calls when IsAliasee is true. We invoke the callback again if that value's summary is to be written as well. We were asserting in debug mode when invoking collectMemProfCallStacks, because a given stack id index was not in the StackIdIndicesToIndex map. It was not added because the forEachSummary invocation that records these ids in the map (invoked from the IndexBitcodeWriter constructor) was correctly skipping this handling when invoked for aliasees. We need the same guard in the invocation that calls collectMemProfCallStacks. Note that this doesn't cause any real problems in a non-asserts build as the missing map lookup will return the default 0 value from the map, which isn't used since we don't actually write the corresponding summary.
222 KiB
222 KiB