[libc-commits] [libc] [libc] Add printf error handling (PR #162876)

[Michael Jones via libc-commits]

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@@ -132,14 +144,6 @@ template <typename T> LIBC_INLINE constexpr TypeDesc type_desc_from_type() {
 
 // This is the value to be returned by conversions when no error has occurred.
 constexpr int WRITE_OK = 0;
-// These are the printf return values for when an error has occurred. They are
-// all negative, and should be distinct.
-constexpr int FILE_WRITE_ERROR = -1;
-constexpr int FILE_STATUS_ERROR = -2;
-constexpr int NULLPTR_WRITE_ERROR = -3;
-constexpr int INT_CONVERSION_ERROR = -4;
-constexpr int FIXED_POINT_CONVERSION_ERROR = -5;
-constexpr int ALLOCATION_ERROR = -6;
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michaelrj-google wrote:

I'd prefer to use our own internal error numbers until we get to the entrypoint because the list of errno macros that are available depends on the platform. Specifically the C standard only defines 3: `EDOM`, `ERANGE`, and `EILSEQ`. Other error values like `ENOMEM` and `EINVAL` are actually from posix and might not be available on all platforms.

https://github.com/llvm/llvm-project/pull/162876