如何使 Qt Creator 在没有 return 语句时显示错误
事实证明，如果您在非 void 函数中没有 return 语句，g++ 编译器（默认在 Qt Creator 中使用）只会给出警告，即：
int* create_array(int n)
{
int* a = new int[n];
}
编译正常。
这种行为受到 g++ 本身无数错误报告的影响，但看起来开发人员认为这种行为符合 C++ 标准（这是有争议的，因为这部分有点令人困惑），如 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43943 ：
Flowing off the end of a function is equivalent to a return with no value;
this results in undefined behavior in a value-returning function.
然而，同一段开头是：
A return statement without an expression can be used only in functions
that do not return a value, that is, a function with the return type void,
a constructor (12.1), or a destructor (12.4).
所以除了这些（非）圣战之外标准解释 有没有任何选项可以让 Qt 在编译时将其标记为错误？
Turns out that g++ compiler (used in Qt Creator by default) gives a mere warning if you don't have return statement in the non-void function, i.e.:
int* create_array(int n)
{
int* a = new int[n];
}
compiles fine.
This behavior is subject to countless bug reports on g++ itself, but looks like developers consider this behavior conforming to C++ standard (which is debatable, cause it's a bit confusing in this part) as stated at http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43943 :
Flowing off the end of a function is equivalent to a return with no value;
this results in undefined behavior in a value-returning function.
However, the very same paragraph begins with:
A return statement without an expression can be used only in functions
that do not return a value, that is, a function with the return type void,
a constructor (12.1), or a destructor (12.4).
So aside from these (un)holy wars over the standard interpretation are there any options to make Qt flag this as an error at compile time?
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这与Qt无关，而是与g++有关。
在构建选项中，只需添加标志
-Werror，g++ 就会将任何警告视为错误。您可能还需要使用标志-Wall来使 g++ 生成额外的警告，因为默认情况下它不会针对缺少 return 语句（以及许多其他情况）生成警告。然而，无法根据每个警告来调整此设置，因此要么全部执行，要么什么都不执行。This is not related to Qt but to g++.
In the build options, simply add the flag
-Werrorand g++ will consider any warning as error. You may also need to use flag-Wallto make g++ generate additional warnings, as it doesn't generate warnings for missing return statements (and many other situations) by default. There's no way to tune this setting on a per-warning basis however, so it's either everything or nothing.您可以使用
-Werror=warning_name语法将特定警告视为错误。对于您的情况，您可以使用-Werror=return-type（其中return-type是“控件到达非 void 函数末尾”警告的名称）。根据 https://gcc.gnu.org/onlinedocs/gcc/Warning-选项.html。You can use
-Werror=warning_namesyntax to treat a specific warning as an error. For your case you can use-Werror=return-type(wherereturn-typeis the name of the "control reaches end of non-void function" warning). According to https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html.