c++ - GCC mangling 的变化会影响 ABI 兼容性吗？

Question

Documentation对于

-fabi-version

这样说[这里只有一部分]:

[...]
Version 11, which first appeared in G++ 7, corrects the mangling ofsizeof... expressions and operator names. For multiple entities withthe same name within a function, that are declared in differentscopes, the mangling now changes starting with the twelfth occurrence.It also implies -fnew-inheriting-ctors.

Version 12, which first appeared in G++ 8, corrects the callingconventions for empty classes on the x86_64 target and for classeswith only deleted copy/move constructors. It accidentally changes thecalling convention for classes with a deleted copy constructor and atrivial move constructor.

Version 13, which first appeared in G++ 8.2, fixes the accidentalchange in version 12.

Version 14, which first appeared in G++ 10, corrects the mangling ofthe nullptr expression.

Version 15, which first appeared in G++ 11, changes the mangling of__ alignof __ to be distinct from that of alignof, and dependent operator names.

我的问题是这种修改更改(例如不是调用约定更改，而是 Version14 和 Version15 中的更改)是否会影响 ABI 兼容性，链接器是否会在链接时只选择一个，一切都会很好？

注意:假设我正在使用这些东西，尽管我怀疑大多数人在 API 边界内使用它们。

Answer 1

是的，每个 ABI 版本都是不兼容的，但大多数更改只影响极少数情况，希望像 12 这样的某些版本很少见，因为它们很快就被修复了。进行此类更改的原因通常是某些东西会破坏为相同名称，即使只有一个组件使用它而不是需要两个不兼容，它也会中断。