[ObjC] Propagate type information from calls to `[super init]`

Calls to `objc_msgSendSuper2` with a selector in the `init` family are
detected and their arguments are analyzed to determine the receiver
class. A call type adjustment is added to update the return type.

This handles most calls to `[super init]` from Objective-C code as the
compiler generates a straightforward code sequence for these calls. Some
calls from Swift are handled, but the Swift compiler generates more varied
code so additional work is needed for complete coverage.

1 files changed, 11 insertions, 4 deletions

diff --git a/plugins/workflow_objc/src/error.rs b/plugins/workflow_objc/src/error.rs
index 75328226..8353d015 100644
--- a/plugins/workflow_objc/src/error.rs
+++ b/plugins/workflow_objc/src/error.rs
@@ -11,13 +11,20 @@ impl From<()> for WorkflowRegistrationError {
     }
 }
 
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub enum ILLevel {
+    Low,
+    Medium,
+    High,
+}
+
 #[derive(Error, Debug)]
 pub enum Error {
-    #[error("Unable to retrieve low-level IL for function at {func_start:#x}")]
-    MissingLowLevelIL { func_start: u64 },
+    #[error("Unable to retrieve {level:?} IL for function at {func_start:#x}")]
+    MissingIL { level: ILLevel, func_start: u64 },
 
-    #[error("Unable to retrieve low-level SSA IL for function at {func_start:#x}")]
-    MissingSsaForm { func_start: u64 },
+    #[error("Unable to retrieve {level:?} SSA IL for function at {func_start:#x}")]
+    MissingSsaForm { level: ILLevel, func_start: u64 },
 
     #[error("Unexpected LLIL operation at address {address:#x} (expected {expected})")]
     UnexpectedLlilOperation { address: u64, expected: String },