## Writing Analyzers

### 1. Create the code

Analyzers need to implement the Analyzer interface ( in the `galley/pkg/config/analysis` package). They should be created under the analyzers subdirectory, and given their own appropriate subpackage.

An annotated example:

```go
package virtualservice

// <imports here>

	default:
	}
}

// RetryAfter ensures that the function will run again after no later than interval. This
// can be called from inside a run of the BoundedFrequencyRunner's function, or
// asynchronously.
func (bfr *BoundedFrequencyRunner) RetryAfter(interval time.Duration) {
	// This could be called either with or without bfr.mu held, so we can't grab that
	// lock, and therefore we can't update the timer directly.

	JMP	crosscall2(SB)

// Called by C code generated by cmd/cgo.
// func crosscall2(fn, a unsafe.Pointer, n int32, ctxt uintptr)
// Saves C callee-saved registers and calls cgocallback with three arguments.
// fn is the PC of a func(a unsafe.Pointer) function.
TEXT crosscall2(SB),NOSPLIT|NOFRAME,$0
	/*
	 * Push arguments for fn (X10, X11, X13), along with all callee-save

// SIGSEGV, and our runtime.sigtramp don't even know we
// are in external code, and will continue to use R10,
// this might as well result in another SIGSEGV.
// Note: both functions will clobber R0 and R11 and
// can be called from 5c ABI code.

// On android, runtime.tls_g is a normal variable.
// TLS offset is computed in x_cgo_inittls.
#ifdef GOOS_android
#define TLSG_IS_VARIABLE
#endif

/**< Message handler called at the start of a suite. pSuite will not be null. */

typedef void (*CU_TestStartMessageHandler)(const CU_pTest pTest, const CU_pSuite pSuite);
/**< Message handler called at the start of a test.
 *  The parameters are the test and suite being run.  The test run is 
 *  considered in progress when the message handler is called.  
 *  Neither pTest nor pSuite may be null.
 */

	// call target function
	MOVD	0(R26), R0
	CALL	(R0)

	// should never return
	CALL	runtime·abort(SB)
	UNDEF

/*
 * support for morestack
 */

// Called during function prolog when more stack is needed.
// Caller has already loaded:
// R3 prolog's LR (R30)
//
// The traceback routines see morestack on a g0 as being
// the top of a stack (for example, morestack calling newstack

//
// Closing the file may or may not release the lock promptly. Callers should
// ensure that Unlock is always called if RLock succeeds.
func RLock(f File) error {
	return lock(f, readLock)
}

// Unlock removes an advisory lock placed on f by this process.
//
// The caller must not attempt to unlock a file that is not locked.
func Unlock(f File) error {
	return unlock(f)
}

TEXT _rt0_riscv64_linux(SB),NOSPLIT|NOFRAME,$0
	MOV	0(X2), A0	// argc
	ADD	$8, X2, A1	// argv
	JMP	main(SB)

// When building with -buildmode=c-shared, this symbol is called when the shared
// library is loaded.
TEXT _rt0_riscv64_linux_lib(SB),NOSPLIT,$224
	// Preserve callee-save registers, along with X1 (LR).
	MOV	X1, (8*3)(X2)
	MOV	X8, (8*4)(X2)
	MOV	X9, (8*5)(X2)
	MOV	X18, (8*6)(X2)
	MOV	X19, (8*7)(X2)
	MOV	X20, (8*8)(X2)

            // This is because we cannot tell the difference between:
            // - a validation exception thrown in user code that is called from other user code, where the caller should be blamed
            // - an unexpected exception thrown in user code that is called from other user code, where the called code should be blamed
            // So, for now, just blame the first user code that can be identified. This gives the user some clues for where to start

// the signal handler (it cannot block, allocate memory, or use locks)
// so the handler communicates with a processing goroutine
// via struct sig, below.
//
// sigsend is called by the signal handler to queue a new signal.
// signal_recv is called by the Go program to receive a newly queued signal.
//
// Synchronization between sigsend and signal_recv is based on the sig.state
// variable. It can be in three states: