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[libc++][NFC] Update the documentation for _LIBCPP_OVERRIDABLE_FUNCTION (#140121)

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Louis Dionne
2025-05-16 07:29:46 -04:00
committed by GitHub
parent e5f8998ac8
commit e829963a4f
1 changed files with 5 additions and 5 deletions
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10
libcxx/src/include/overridable_function.h
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@@ -29,14 +29,14 @@
// This is a low-level utility which does not work on all platforms, since it needs
// to make assumptions about the object file format in use. Furthermore, it requires
// the "base definition" of the function (the one we want to check whether it has been
// overridden) to be annotated with the _LIBCPP_MAKE_OVERRIDABLE_FUNCTION_DETECTABLE macro.
// overridden) to be defined using the _LIBCPP_OVERRIDABLE_FUNCTION macro.
//
// This currently works with Mach-O files (used on Darwin) and with ELF files (used on Linux
// and others). On platforms where we know how to implement this detection, the macro
// _LIBCPP_CAN_DETECT_OVERRIDDEN_FUNCTION is defined to 1, and it is defined to 0 on
// other platforms. The _LIBCPP_MAKE_OVERRIDABLE_FUNCTION_DETECTABLE macro is defined to
// nothing on unsupported platforms so that it can be used to decorate functions regardless
// of whether detection is actually supported.
// other platforms. The _LIBCPP_OVERRIDABLE_FUNCTION macro is defined to perform a normal
// function definition on unsupported platforms so that it can be used to define functions
// regardless of whether detection is actually supported.
//
// How does this work?
// -------------------
@@ -44,7 +44,7 @@
// Let's say we want to check whether a weak function `f` has been overridden by the user.
// The general mechanism works by placing `f`'s definition (in the libc++ built library)
// inside a special section, which we do using the `__section__` attribute via the
// _LIBCPP_MAKE_OVERRIDABLE_FUNCTION_DETECTABLE macro.
// _LIBCPP_OVERRIDABLE_FUNCTION macro.
//
// Then, when comes the time to check whether the function has been overridden, we take
// the address of the function and we check whether it falls inside the special function