使用 C-Reduce 进行调试

brew install creduce

$ cat test.c
#include <stdio.h>

struct Stuff {
    char *name;
    int age;
}

main(int argc, char **argv) {
    printf("Hello, world!\n");
}

$ clang test.c
test.c:3:1: warning: return type of 'main' is not 'int' [-Wmain-return-type]
struct Stuff {
^
test.c:3:1: note: change return type to 'int'
struct Stuff {
^~~~~~~~~~~~
int
test.c:10:1: warning: control reaches end of non-void function [-Wreturn-type]
}
^
2 warnings generated.

#!/bin/bash

clang test.c &> output.txt
grep error output.txt && exit 1
grep "warning: return type of 'main' is not 'int'" output.txt &&
grep "struct Stuff" output.txt

$ creduce interestingness.sh test.c 
===< 4907 >===
running 3 interestingness tests in parallel
===< pass_includes :: 0 >===
(14.6 %, 111 bytes)

...lots of output...

===< pass_clex :: rename-toks >===
===< pass_clex :: delete-string >===
===< pass_indent :: final >===
(78.5 %, 28 bytes)
===================== done ====================

pass statistics:
  method pass_balanced :: parens-inside worked 1 times and failed 0 times
  method pass_includes :: 0 worked 1 times and failed 0 times
  method pass_blank :: 0 worked 1 times and failed 0 times
  method pass_indent :: final worked 1 times and failed 0 times
  method pass_indent :: regular worked 2 times and failed 0 times
  method pass_lines :: 3 worked 3 times and failed 30 times
  method pass_lines :: 8 worked 3 times and failed 30 times
  method pass_lines :: 10 worked 3 times and failed 30 times
  method pass_lines :: 6 worked 3 times and failed 30 times
  method pass_lines :: 2 worked 3 times and failed 30 times
  method pass_lines :: 4 worked 3 times and failed 30 times
  method pass_lines :: 0 worked 4 times and failed 20 times
  method pass_balanced :: curly-inside worked 4 times and failed 0 times
  method pass_lines :: 1 worked 6 times and failed 33 times

		 ******** .../test.c ********

struct Stuff {
} main() {
}

#import "AppDelegate.h"

@interface AppDelegate () {
    NSWindow *win;
}

@property (weak) IBOutlet NSWindow *window;
@end

@implementation AppDelegate

- (void)applicationDidFinishLaunching: (NSRect)visibleRect {
    NSLog(@"Starting up");
    visibleRect = NSInsetRect(visibleRect, 10, 10);
    visibleRect.size.height *= 2.0/3.0;
    win = [[NSWindow alloc] initWithContentRect: NSMakeRect(0, 0, 100, 100) styleMask:NSWindowStyleMaskTitled backing:NSBackingStoreBuffered defer:NO];
	
    [win makeKeyAndOrderFront: nil];
    NSLog(@"Off we go");
}

@end

* thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=EXC_I386_GPFLT)
	  * frame #0: 0x00007fff3ab3bf2d CoreFoundation`__CFNOTIFICATIONCENTER_IS_CALLING_OUT_TO_AN_OBSERVER__ + 13

function timeout() { perl -e 'alarm shift; exec @ARGV' "$@"; }

cp -a ~/Development/creduce-examples/Crasher .

cp AppDelegate.m Crasher/Crasher

cd Crasher
xcodebuild || exit 1

timeout 5 ./build/Release/Crasher.app/Contents/MacOS/Crasher

if [ $? -eq 139 ]; then
    exit 0
else
    exit 1
fi

$ creduce interestingness.sh Crasher/AppDelegate.m
...
(78.1 %, 151 bytes)
===================== done ====================

pass statistics:
  method pass_ints :: a worked 1 times and failed 2 times
  method pass_balanced :: curly worked 1 times and failed 3 times
  method pass_clex :: rm-toks-7 worked 1 times and failed 74 times
  method pass_clex :: rename-toks worked 1 times and failed 24 times
  method pass_clex :: delete-string worked 1 times and failed 3 times
  method pass_blank :: 0 worked 1 times and failed 1 times
  method pass_comments :: 0 worked 1 times and failed 0 times
  method pass_indent :: final worked 1 times and failed 0 times
  method pass_indent :: regular worked 2 times and failed 0 times
  method pass_lines :: 8 worked 3 times and failed 43 times
  method pass_lines :: 2 worked 3 times and failed 43 times
  method pass_lines :: 6 worked 3 times and failed 43 times
  method pass_lines :: 10 worked 3 times and failed 43 times
  method pass_lines :: 4 worked 3 times and failed 43 times
  method pass_lines :: 3 worked 3 times and failed 43 times
  method pass_lines :: 0 worked 4 times and failed 23 times
  method pass_lines :: 1 worked 6 times and failed 45 times

******** /Users/mikeash/Development/creduce-examples/Crasher/Crasher/AppDelegate.m ********

#import "AppDelegate.h"
@implementation AppDelegate
- (void)applicationDidFinishLaunching:(NSRect)a {
    a = NSInsetRect(a, 0, 10);
    NSLog(@"");
}
@end

- (void)applicationDidFinishLaunching:(NSNotification *)notification;

import Foundation

func crash() {
    let blah = ProblematicEnum.problematicCase.problematicMethod()
    NSLog("\(blah)")
}

enum ProblematicEnum {
    case first, second, problematicCase

    func problematicMethod() -> SomeClass {
    	let someVariable: SomeClass

    	switch self {
    	case .first:
    	    someVariable = SomeClass()
    	case .second:
    	    someVariable = SomeClass()
    	case .problematicCase:
    	    someVariable = SomeClass(someParameter: NSObject())
    	    _ = NSObject().description
    	    return someVariable // EXC_BAD_ACCESS (simulator: EXC_I386_GPFLT, device: code=1)
    	}

    	let _ = [someVariable]
    	return SomeClass(someParameter: NSObject())
    }

}

class SomeClass: NSObject {
    override init() {}
    init(someParameter: NSObject) {}
}

crash()

$ swift -O test.swift 
<unknown>:0: error: fatal error encountered during compilation; please file a bug report with your project and the crash log
<unknown>:0: note: Program used external function '__T04test15ProblematicEnumON' which could not be resolved!
...

swift -O test.swift
if [ $? -eq 134 ]; then
    exit 0
else
    exit 1
fi

enum a {
    case b, c, d
    func e() -> f {
    	switch self {
    	case .b:
    	    0
    	case .c:
    	    0
    	case .d:
    	    0
    	}
    	return f()
    }
}

class f{}