compiler/analyzer does not catch init methods returning null with nonnull

Originator:nobrien
Number:rdar://31262790 Date Originated:03/26/2017
Status:Open Resolved:
Product:Xcode Product Version:8.2
Classification:Serious Bug Reproducible:Always
 
Summary:
compiler/analyzer does not catch init methods returning null with nonnull - very simple

This means we can't catch bugs at compile time due to nullability contracts being broken

See attached screenshot for crystal clear repro

Steps to Reproduce:

1) Have this init method:

- (nonnull instancetype)initWithCondition:(BOOL)condition
{
    if (condition) {
        return nil;
    }
    return [self init];
}

2) set CLANG_ANALYZER_NONNULL to YES for the project being analyzed

Expected Results:

static analyzer (or, even better, the compiler) will have warning where "return nil" line happens:
"nil returned from a method that is expected to return a non-null value"

Actual Results:
No such warning, expect crashing in production when nil is returned and Swift is the consumer language

Comments

Screenshot is of the following:

- (nonnull instancetype)initWithCondition:(BOOL)condition
{
    if (condition) {
        return nil; // no warning
    }
    return [self init];
}

- (nonnull instancetype)methodWithCondition:(BOOL)condition
{
    if (condition) {
        return nil; // warning is present
    }
    return [self init];
}
By nobrien at March 26, 2017, 3:39 p.m. (reply...)

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