Rich shale and some carbonates qualify. Most shale does not: it lacks the organic content, or it was never heated enough, or it was heated so far that it generated and then stopped. The hydrocarbons in a conventional reservoir usually migrated out of a source rock. They were not formed in the reservoir sand.
A source rock that still holds what it generated is the target of a shale development, which produces from the source itself. Calling every shale in a well a source rock, because it is dark, overstates the charge available to the traps above it.