code | Source Code for Go In Action examples | Continous Integration library

I ran into the same issue today and came up with the following solution based on this very helpful article by Andrew Luca

In PrivateRoute.js:

I think the problem is that you are trying to use the deprecated babel-eslint parser, last updated a year ago, which looks like it doesn't support ES6 modules. Updating to the latest parser seems to work, at least for simple linting.

So, do this:

• In package.json, update the line "babel-eslint": "^10.0.2", to "@babel/eslint-parser": "^7.5.4",. This works with the code above but it may be better to use the latest version, which at the time of writing is 7.16.3.
• Run npm i from a terminal/command prompt in the folder
• In .eslintrc, update the parser line "parser": "babel-eslint", to "parser": "@babel/eslint-parser",
• In .eslintrc, add "requireConfigFile": false, to the parserOptions section (underneath "ecmaVersion": 8,) (I needed this or babel was looking for config files I don't have)
• Run the command to lint a file

Then, for me with just your two configuration files, the error goes away and I get appropriate linting errors.

Updating Navigation Safe Args

These lines are the important ones to look at:

I'm not sure what you're using to code, but in order to set it in Android Studio, open the manifest of your project and under the "activity" section, put android:exported="true"(or false if that is what you prefer). I have attached an example.

I am also stuck with the same problem because I installed the latest version of Node.js (v17.0.1).

Just go for node.js v14.18.1 and remove the latest version just use the stable version v14.18.1

Go to your package.json file and delete as many dependencies as you can until the project builds successfully. Then start adding back the dependencies one by one to detect which ones have troubles.

Then you can manually patch those dependencies by acceding them on node_modules/[dependencie]/android/build.gradle and setting androidx.core:core-ktx: or androidx.core:core: to a specific version (1.6.0 in my case).

It looks like GCC's naïveté about store-forwarding stalls is hurting its auto-vectorization strategy here. See also Store forwarding by example for some practical benchmarks on Intel with hardware performance counters, and What are the costs of failed store-to-load forwarding on x86? Also Agner Fog's x86 optimization guides.

(gcc -O3 enables -ftree-vectorize and a few other options not included by -O2, e.g. if-conversion to branchless cmov, which is another way -O3 can hurt with data patterns GCC didn't expect. By comparison, Clang enables auto-vectorization even at -O2, although some of its optimizations are still only on at -O3.)

It's doing 64-bit loads (and branching to store or not) on pairs of ints. This means, if we swapped the last iteration, this load comes half from that store, half from fresh memory, so we get a store-forwarding stall after every swap. But bubble sort often has long chains of swapping every iteration as an element bubbles far, so this is really bad.

(Bubble sort is bad in general, especially if implemented naively without keeping the previous iteration's second element around in a register. It can be interesting to analyze the asm details of exactly why it sucks, so it is fair enough for wanting to try.)

Anyway, this is pretty clearly an anti-optimization you should report on GCC Bugzilla with the "missed-optimization" keyword. Scalar loads are cheap, and store-forwarding stalls are costly. (Can modern x86 implementations store-forward from more than one prior store? no, nor can microarchitectures other than in-order Atom efficiently load when it partially overlaps with one previous store, and partially from data that has to come from the L1d cache.)

Even better would be to keep buf[x+1] in a register and use it as buf[x] in the next iteration, avoiding a store and load. (Like good hand-written asm bubble sort examples, a few of which exist on Stack Overflow.)

If it wasn't for the store-forwarding stalls (which AFAIK GCC doesn't know about in its cost model), this strategy might be about break-even. SSE 4.1 for a branchless pmind / pmaxd comparator might be interesting, but that would mean always storing and the C source doesn't do that.

If this strategy of double-width load had any merit, it would be better implemented with pure integer on a 64-bit machine like x86-64, where you can operate on just the low 32 bits with garbage (or valuable data) in the upper half. E.g.,

When exactly does segmentation fault happen (=when is SIGSEGV sent)?

When you attempt to access memory you don’t have access to, such as accessing an array out of bounds or dereferencing an invalid pointer. The signal SIGSEGV is standardized but different OS might implement it differently. "Segmentation fault" is mainly a term used in *nix systems, Windows calls it "access violation".

Why is the process in undefined behavior state after that point?

Because one or several of the variables in the program didn’t behave as expected. Let’s say you have some array that is supposed to store a number of values, but you didn’t allocate enough room for all them. So only those you allocated room for get written correctly, and the rest written out of bounds of the array can hold any values. How exactly is the OS to know how critical those out of bounds values are for your application to function? It knows nothing of their purpose.

Furthermore, writing outside allowed memory can often corrupt other unrelated variables, which is obviously dangerous and can cause any random behavior. Such bugs are often hard to track down. Stack overflows for example are such segmentation faults prone to overwrite adjacent variables, unless the error was caught by protection mechanisms.

If we look at the behavior of "bare metal" microcontroller systems without any OS and no virtual memory features, just raw physical memory - they will just silently do exactly as told - for example, overwriting unrelated variables and keep on going. Which in turn could cause disastrous behavior in case the application is mission-critical.

Why is it not recoverable?

Because the OS doesn’t know what your program is supposed to be doing.

Though in the "bare metal" scenario above, the system might be smart enough to place itself in a safe mode and keep going. Critical applications such as automotive and med-tech aren’t allowed to just stop or reset, as that in itself might be dangerous. They will rather try to "limp home" with limited functionality.

Why does this solution avoid that unrecoverable state? Does it even?

That solution is just ignoring the error and keeps on going. It doesn’t fix the problem that caused it. It’s a very dirty patch and setjmp/longjmp in general are very dangerous functions that should be avoided for any purpose.

We have to realize that a segmentation fault is a symptom of a bug, not the cause.

Comparison table: Operator != is not Original purpose Value inequality Negated pattern matching Can perform value inequality Yes Yes Can perform negated pattern matching No Yes Can invoke implicit operator on left-hand operand Yes No Can invoke implicit operator on right-hand operand(s) Yes Yes¹ Is its own operator Yes No² Overloadable Yes No Since C# 1.0 C# 9.0³ Value-type null-comparison branch elision⁴ Yes No_{[Citation needed]}⁵ Impossible comparisons Error Warning Left operand Any expression Any expression Right operand(s) Any expression Only constant expressions⁶ Syntax != is [not] [or|and ]*
and more Common examples: Example != is not Not null x != null x is not null Value inequality example x != 'a' x is not 'a' Runtime type (mis)match x.GetType() != typeof(Char) x is not Char⁷ SQL x NOT IN ( 1, 2, 3 ) x != 1 && x != 2 && x != 3 x is not 1 or 2 or 3

To answer the OP's question directly and specifically: