019dc93ae0
Initially, ESP-IDF used the do_global_ctors() function to run global
constructors. This was done to accommodate Xtensa targets that emit
.ctors.* sections, which are ordered in descending order.
For RISC-V, compilation used .init_array.* sections, which are designed
to have ascending order. Priority constructors in .init_array.* sections
were correctly processed in ascending order. However, non-priority
.init_array section was processed in descending order, as it was done
for Xtensa .ctors.
Starting with ESP-IDF v6.0, the implementation switched to the standard
LibC behavior (__libc_init_array()), which processes both priority and
non-priority constructors in ascending order.
To achieve this, a breaking changes were introduced:
- Xtensa .ctors.* priority entries converted to .init_array.* format
(ascending), to be passed to __libc_init_array().
- Processing order of non-priority .init_array and .ctors sections was
changed from descending to ascending.
Also, this change introduces .preinit_array for linking. This may be
needed for some C++ or sanitizer features.
Related to https://github.com/espressif/esp-idf/issues/15529
| Supported Targets | ESP32 | ESP32-C2 | ESP32-C3 | ESP32-C5 | ESP32-C6 | ESP32-C61 | ESP32-H2 | ESP32-H21 | ESP32-H4 | ESP32-P4 | ESP32-S2 | ESP32-S3 | Linux |
|---|
Historical note
Initially, ESP-IDF used the do_global_ctors() function to run global constructors.
This was done to accommodate Xtensa targets that emit .ctors.* sections, which are ordered in descending order.
For RISC-V, compilation used .init_array.* sections, which are designed to have ascending order.
Priority constructors in .init_array.* sections were correctly processed in ascending order.
However, non-priority .init_array section was processed in descending order (as it was done for Xtensa .ctors).
Starting with ESP-IDF v6.0, the implementation switched to the standard LibC behavior (__libc_init_array()),
which processes both priority and non-priority constructors in ascending order.
To achieve this, a breaking changes were introduced:
- Xtensa
.ctors.*entries converted to.init_array.*format (ascending), to be passed to__libc_init_array(). - Processing order of non-priority
.init_arrayand.ctorssections was changed from descending to ascending.
This test ensures that the initialization order is correct and consistent between ESP-IDF and Linux targets.