Escape \U and \u in generated stubs

[alcaeus]

This fixes an issue where a namespaced class beginning with "U" or "u" would yield an invalid arginfo file due to the occurrence of a unicode escape sequence, causing a compile error.

Note: waiting for CI test results due to the absence of a local test environment.

[kocsismate]

Hmm, I registered the UnlikelyCompileError class you added in this PR and everything seems to be working just fine without your fix. 🤔 Do you have an idea what makes the difference? Do we use different platform (I'm on a Mac)?

[alcaeus]

That's a good question. I'm compiling on MacOS as well. This is the macro that first caused the issue:

ZEND_BEGIN_ARG_WITH_RETURN_OBJ_INFO_EX(arginfo_class_MongoDB_BSON_UTCDateTime___set_state, 0, 1, MongoDB\\BSON\\UTCDateTime, 0)

Replacing the U with \125 fixed the error for me:

ZEND_BEGIN_ARG_WITH_RETURN_OBJ_INFO_EX(arginfo_class_MongoDB_BSON_UTCDateTime___set_state, 0, 1, MongoDB\\BSON\\\125TCDateTime, 0)

For reference, here's the compiler output:

In file included from src/BSON/UTCDateTime.c:28:
src/BSON/UTCDateTime_arginfo.h:22:112: error: \U used with no following hex digits; treating as '\' followed by identifier [-Werror,-Wunicode]
ZEND_BEGIN_ARG_WITH_RETURN_OBJ_INFO_EX(arginfo_class_MongoDB_BSON_UTCDateTime___set_state, 0, 1, MongoDB\\BSON\\UTCDateTime, 0)
                                                                                                               ^
1 error generated.
make: *** [src/BSON/UTCDateTime.lo] Error 1

Let me know if I can provide any other information to help figure it out. I'll hold off on fixing the tests in the meantime so we can confirm whether this is a general issue or just something weird happening on my machine.

[guilliamxavier]

This seems to vary by compiler (at least GCC vs Clang vs MSVC), e.g. https://godbolt.org/z/vYh87Ghd4 (or https://godbolt.org/z/46PPb14f5)
(to be clear: this PR looks good)

[guilliamxavier]

A couple nits

[cmb69]

This seems to vary by compiler (at least GCC vs Clang vs MSVC) , e.g. https://godbolt.org/z/vYh87Ghd4

Interesting! Using the new conformant preprocessor (/Zc:preprocessor) with MSVC, I get:

Foo??
Foo??
---
Foo\U0001F600
Foo\U0001F600
Foo\Unlikely
Foo\Unlikely
===
Foo\U0001F600
Foo\U0001F600
Foo\Unlikely
Foo\Unlikely

So a bit more conforming to GCC and clang.

[cmb69]

Thank you!