mirror of
https://github.com/nlohmann/json.git
synced 2026-09-07 16:57:59 +00:00
Niels Lohmann
3d89ac50a0
Linking test-regression2 with clang and MinGW fails with
relocation truncated to fit: IMAGE_REL_AMD64_REL32 against `.rdata'
once the translation unit grows past a certain size: the code can no longer
reach the read-only data it references within the range of a 32-bit
relocation. The file is one of the largest in the test suite and had been
sitting just under that limit, so an unrelated change elsewhere in the
library is enough to tip it over. It is already the second such file --
unit-regression1.cpp was split for size before -- and windows.yml already
carries a workaround for the same limit hitting the debug sections of this
same target, where -g0 was enough because that relocation was against
`.debug_line'. This one is against `.rdata', which no compiler flag avoids.
Move the second half of the regression tests, and the helper types only they
use, into unit-regression3.cpp. The sections are independent -- every
statement in "regression tests 2" was already inside a SECTION -- so they
move unchanged, and the counts confirm nothing was lost: 168 assertions
before the split, 50 plus 118 after.
The result is that both files are comfortably smaller than the one that used
to link, measured with clang at -O1 for C++20:
read-only data text object
before 58,233 1,287,764 3,158,120
unit-regression2.cpp 48,161 1,012,988 2,522,296
unit-regression3.cpp 41,710 772,704 1,878,880
No CMake change is needed: tests/CMakeLists.txt globs src/unit-*.cpp, so the
new file is picked up and built for every standard like its siblings.
CONTRIBUTING.md pointed contributors at unit-regression2.cpp for new bug
tests; it now points at the smaller file and says why the two exist, so the
split does not quietly undo itself.
Signed-off-by: Niels Lohmann <mail@nlohmann.me>