It’s difficult to keep track of everything David Cronenberg is skewering in “Maps to the Stars”: The bloodshed, both literal and figurative, is nearly indiscriminate. But Hollywood and its monsters are prime targets.

Agatha Weiss (Mia Wasikowska), an odd-seeming teenage girl covered in burn scars, arrives in Hollywood on a bus from Florida with something like stars in her eyes. She splurges on a chauffeured limousine and asks her driver Jerome Fontana (Robert Pattinson) to take her on one of those “Maps to the Stars” tours one often sees advertised in certain parts of Los Angeles. He talks her out of it, but she’s able to find one star’s house on her own, or at least what’s left of it: The childhood home of Benji Weiss (Evan Bird), a teen superstar made famous by a popular film franchise called “Bad Babysitter.”

The attention-starved Agatha sets immediately to work on inserting herself into Benji’s world: By way of a previously established Twitter friendship with Carrie Fisher, Agatha lands a job at personal assistant for Havana Segrand (Julianne Moore), an entitled actress who is desperate to play her famous dead mother in a remake of the movie that made her famous. At the same time, she’s working out her issues -- stemming from what she says is childhood sexual abuse at the hands of that mother -- with Dr. Stafford Weiss (John Cusack), a caricature of a celebrity psychologist who also happens to be the father of Benji, the child star with a drug habit and a hell of a mean streak.

Everyone’s a mess, and the film itself is something of a train wreck, but a very enjoyable one, with Cronenberg as the twisted engineer, gleefully driving it off the rails. The chaos is controlled by deeply committed performances from just about every member of the cast, not only the one fantasizing about finally winning a first Academy Award after four nominations. Cronenberg (“The Fly,” “A History of Violence”) might be taking the p--- out of p--- itself, but his actors do admirable jobs of playing their roles as if they were not written for a movie from which satire gushes forth like the blood of a self-inflicted arterial wound.

Of course, Moore goes for broke, as does Cusack, who in “Maps” is as unrecognizable as Cusack could ever be. In fact, he appears to have been made up to look like he’s had not-spectacular cosmetic surgery. (Unless he actually has?) Wasikowska blossoms in a role that allows her to capitalize on her (forgive me) rather plain looks, and Bird is more than convincing as the worst-case scenario of what can happen to a child exploited by greedy, fame-hungry parents.

And in a film as meta as “Maps to the Stars,” casting is everything. Fisher (daughter of Debbie Reynolds and Eddie Fisher) makes a cameo as herself, dryly commenting that “everyone should have that opportunity” when Havana tells her how much she wants to play her mother in the movie. And in a discussion about that production, the possibility of Havana playing her mother’s role is dismissed as “stunt casting” -- a reference you might remember when you observe that Benji’s mom Clarissa Weiss (Olivia Williams of “The Sixth Sense”) is surrounded by relations who literally see dead people.

The real-life Moore appears to be a genuinely excellent person -- has there ever been a negative bit of gossip about her? -- but I have found that her capital-A Acting can sometimes take away more than it adds (e.g., “The Big Lebowski,” “A Single Man”). This is not the case in “Maps to the Stars.” If she didn’t overdo it, she wouldn’t have been doing her job. And it’s hard to imagine a better person for that job: Only an actress with a star and skin as bright as Moore’s could have pulled this off. Another with the same number of years behind her but who actually is fading, as Moore’s Havana is, probably wouldn’t have been able to dig her teeth into the role without her head getting in the way.

Perhaps by virtue of its shock value alone, incest is a preoccupation in Cronenberg's “Maps”: real, imagined, hidden and suspected. Evidence of incest purports to explain the pathologies of the film’s most messed-up characters, but it doesn’t explain it sufficiently to convince us of which came first, the chicken or the egg.

“Maps to the Stars” wears its heavy hand like a trophy -- the kind the people we meet in the movie might raise toward the ceiling of the Dolby Theater in triumph, or break over someone’s skull. From the start, it’s not a matter of if something terrible and violent will happen, it’s a matter of how and why and whodunnit. And because everyone is equally terrible and vulnerable in his or her own way, everyone is a potential suspect and victim, the promise of murder and mayhem threatening almost every scene.

Cronenberg makes good on this threat. Although you always know something is coming, you will likely not be prepared for what does. I inadvertently sat next to John Waters at a New York Film Festival screening, and can report that “Maps to the Stars” compelled Waters -- who not only directed a famous feces-eating scene in “Pink Flamingos” but also is a close personal friend of Manson Family member -- to cover his eyes.