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Fix the string scans on big-endian targets with Zig 0.16 - #6
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Zig 0.16 bit-casts element 0 of a bool vector to the most significant bit on big-endian targets, while 0.17 always puts it in the least significant one. With the mask reversed, @ctz pointed at the wrong byte in both string scans, so decoding failed and encoding could leave characters unescaped. Detect the bit order at compile time and reverse the mask when needed. Also run the tests on s390x under qemu in CI.
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Zig 0.16 bit-casts element 0 of a bool vector to the most significant bit on big-endian targets, while 0.17 always puts it in the least significant one. Both string scans (
scanStringEndin the decoder,writeStringin the encoder) bit-cast the match vector to au16and take@ctz, so on a big-endian target with 0.16 they pointed at the wrong byte.On
main,zig build test -Dtarget=s390x-linux -fqemuwith 0.16 fails 4 tests: decoding escapes, encoding escapes, the struct round trip and skipping unknown fields. With 0.17 it passes. zt hit the same thing (lalinsky/zt#42).compat.vectorMaskdetects the bit order at compile time and reverses the mask when needed, so both versions see elementiin biti. On little-endian targets it compiles to the plain bit-cast.CI now also runs the tests on s390x under qemu.
Tested on 0.16 and 0.17, natively and on s390x.