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INT64_MIN/MAX not defined for newer g++ #3722
Description
Description
While cross compiling for arm w/ newer versions of g++ INT64_MAX, INT64_MIN, UINT64, INT32_MIN, INT32_MAX, UINT32_MAX aren't defined. I found the following:
/* The ISO C99 standard specifies that in C++ implementations these
macros should only be defined if explicitly requested. */
#if !defined __cplusplus || defined __STDC_LIMIT_MACROS
Rather than adding the #define to make this work I created a patch that uses the std::numeric_limits<int64_t>::max()
I guess a "compatibility" include file could be created to work around this issue; but it wasn't obvious to me how to do this.
After applying the patch I ran all the tests and they all passed.
int64_min_max.patch.txt
Reproduction steps
git clone https://github.com/nlohmann/json.git
cd json
git checkout v3.11.2
mkdir build
cd build
cmake -DCMAKE_TOOLCHAIN_FILE=../../aarch64.cmake -DCMAKE_INSTALL_PREFIX=/opt/nxpimx8/usr/local ..
make
Expected vs. actual results
See compiler errors below.
Minimal code example
No response
Error messages
json/tests/src/unit-to_chars.cpp:466:23: error: 'INT64_MIN' was not declared in this scope
466 | check_integer(INT64_MIN, "-9223372036854775808");
| ^~~~~~~~~
/home/priestwilliaml/newbuild/build/json/tests/src/unit-to_chars.cpp:467:23: error: 'INT64_MAX' was not declared in this scope
467 | check_integer(INT64_MAX, "9223372036854775807");
| ^~~~~~~~~
json/tests/src/unit-cbor.cpp: In function 'void _DOCTEST_ANON_FUNC_7()':
/home/priestwilliaml/newbuild/build/json/tests/src/unit-cbor.cpp:176:39: error: 'INT64_MIN' was not declared in this scope
176 | numbers.push_back(INT64_MIN);
| ^~~~~~~~~
json/tests/src/unit-msgpack.cpp:511:39: error: 'INT64_MIN' was not declared in this scope
511 | numbers.push_back(INT64_MIN);
| ^~~~~~~~~
json/tests/src/unit-regression1.cpp: In function 'void _DOCTEST_ANON_FUNC_7()':
/home/priestwilliaml/newbuild/build/json/tests/src/unit-regression1.cpp:880:51: error: 'INT64_MIN' was not declared in this scope
880 | CHECK(j1.get<json::number_integer_t>() == INT64_MIN);
| ^~~~~~~~~Compiler and operating system
linux g++ 11.2.0 crosscompiling for ARM 64
Library version
v3.11.2 from github
Validation
- The bug also occurs if the latest version from the
developbranch is used. - I can successfully compile and run the unit tests.
Activity
falbrechtskirchinger commentedon Sep 4, 2022
We should be using
std::numeric_limitsanyway.falbrechtskirchinger commentedon Sep 13, 2022
The problem is usually older compilers (or standard libraries, technically). C++11 (and C11) removed the need for
__STDC_LIMIT_MACROS.Even after replacing these limit macros, we still depend on
SIZE_MAXfor conditional code and can't easily replace those uses withstd::numeric_limitsbecause of enabled compiler warnings.I wonder why your compiler doesn't seem to complain about that? (
SIZE_MAXis defined within the same conditional block in my header files.)