Question

因此，我现在完成的程序可以按预期工作，除了当我按下'p'时发生的崩溃外，该崩溃仅应将if语句切换到else部分，但是会崩溃并显示“非法指令（内核已转储）”消息。

#include <stdio.h>
// include the UFCFGL301's standard library
#include <ufcfgl-30-1.h>
// uncomment if you want to use the graphics library
#include <graphics.h>


const uint32 window_Width = 600;
const uint32 window_Height = 400;

using namespace uwe;

struct Rect{
  int x,y,width,height,r,g,b;
};

struct Circle{
  int x,y,radius,r,g,b;
};

union CircleorRect{
  Rect rect;
Circle circle;
};

Rect createRect() {
  int x = rand() % window_Width;
  int y = rand() % window_Height;
  int width = rand() % 200;
  int height = rand() % 200;
  int r = rand()%256;
  int g = rand()%256;
  int b = rand()%256;
  return Rect{x, y, width, height, r, g, b};
};

Circle createCirc() {
  int x = rand() % window_Width;
  int y = rand() % window_Height;
  int radius = rand() % 200;
  int r = rand()%256;
  int g = rand()%256;
  int b = rand()%256;
  return Circle{x, y, radius, r, g, b};
};

Rect createRect();
Circle createCirc();

int main(void) {
// graphics window
initialiseGraphics(window_Width,window_Height);
// variables
int count = 0,pressedcount;
Circle circle[1000];
Rect rects[1000];
bool stopCircs = false;
// creating distinct shapes then mapping them.
loop(
  [&](){

    rects[count] = createRect();
    //if circles = create new circle and paint it
    if (stopCircs == false) {
      circle[count] = createCirc();
      for (size_t i = 0; i < count; i++) {
        setColour(circle[i].r,circle[i].g,circle[i].b);
        drawFilledCircle(circle[i].x,circle[i].y,circle[i].radius);
      }
    }
    else {
      for (size_t i = 0; i < pressedcount; i++) {
        setColour(circle[i].r,circle[i].g,circle[i].b);
        drawFilledCircle(circle[i].x,circle[i].y,circle[i].radius);
      }}

    for (size_t i = 0; i < count; i++) {
      setColour(rects[i].r,rects[i].g,rects[i].b);
      drawFilledRect(rects[i].x,rects[i].y,rects[i].width,rects[i].height);
    }

      count++;
      if (count >= 1000) {
        count = 0;
      }
  },
  [&](KeyPress keyPress){
    if (getTextCharacter(keyPress) == 'q') {
      return true;
    }
    else if (getTextCharacter(keyPress) == 'p') {
      stopCircs = true;
      pressedcount = count;
    }
    else {
      return false;
    }
  });
return 0;
}

“ p”印刷机只能从生成新的圆切换到仅加载旧的圆，不知道为什么会导致崩溃。这就是整个过程，所以如果有人想尝试运行它或告诉我如何获得比尝试失败的帮助更好的调试器，将不胜感激。

Answer 1

在此lambda中，并非所有控制路径都具有return语句（编译时具有较高的错误/警告级别可能会诊断出这种错误）。

[&](KeyPress keyPress){
    if (getTextCharacter(keyPress) == 'q') {
      return true;
    }
    else if (getTextCharacter(keyPress) == 'p') {
      stopCircs = true;
      pressedcount = count;
      //here maybe missing return
    }
    else {
      return false;
    }
// or here maybe missing return
}

C ++非法指令（核心已转储）

1 个答案: