Source: The Great Interpretation of Dreams (Ibn Sirin)
A friend crying in a dream (without screaming) indicates joy and happiness for him or the dreamer.
Source: Perfuming Humanity in the Expression of Dreams (Al-Nabulsi)
A friend crying indicates his need for help or that he is going through hardship.
Source: Signs in the Science of Expressions (Ibn Shaheen)
A friend crying is interpreted as relief and joy for him.