GCC
Previous GCC version was 8.4.0
Official GNU porting guides for your code
Espressif Toolchain changes
int32_t and uint32_t for Xtensa compiler
The types int32_t and uint32_t have been changed from int and unsigned int to long and unsigned long. Upstream GCC uses long integers for int32_t/uint32_t on Xtensa, RISC-V and other architectures.
2021r2 and older, GCC 8 |
2022r1, GCC 11 |
|
|---|---|---|
xtensa |
(unsigned) int |
(unsigned) long |
riscv32 |
(unsigned) long |
(unsigned) long |
The most cases in code are related to the formatting. Using %i, %x, etc., should be replaced to PRIi32, PRIxx, and others from <inttypes.h>.
In other cases it should be noted that enums have int type.
In common, int32_t and int are different types, as well as uint32_t and unsigned int.
Removing of CONFIG_COMPILER_DISABLE_GCC8_WARNINGS build option
CONFIG_COMPILER_DISABLE_GCC8_WARNINGS option was introduced to help transition from rigid GCC 5 toolchain to new ones with helping build ancient code. Enough time has passed to fix the warnings.
For now in GCC 11, the suggestion is to review your own code to comply compiler warnings.
Common cases in code
-Wstringop-overflow, -Wstringop-overread, -Wstringop-truncation, and -Warray-bounds warnings
Warning details: https://gcc.gnu.org/onlinedocs/gcc-11.2.0/gcc/Warning-Options.html
Double check your code then fix please. Unfortunately, not all seemingly simple ways to satisfy the compiler will work. You can supress such warnings if the compiler worried for nothing.
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wstringop-overflow"
#pragma GCC diagnostic ignored "-Warray-bounds"
memset(RTC_SLOW_MEM, 0, CONFIG_ULP_COPROC_RESERVE_MEM); // <<-- This line leads to warnings
#pragma GCC diagnostic pop
#pragma GCC diagnostic push
#if __GNUC__ >= 11
#pragma GCC diagnostic ignored "-Wstringop-overread" // <<-- This key had been introduced since GCC 11
#endif
#pragma GCC diagnostic ignored "-Warray-bounds"
memcpy(backup_write_data, (void *)EFUSE_PGM_DATA0_REG, sizeof(backup_write_data)); // <<-- This line leads to warnings
#pragma GCC diagnostic pop
-Waddress-of-packed-member warning
Warning details: https://gcc.gnu.org/onlinedocs/gcc-11.2.0/gcc/Warning-Options.html
Double check your code then fix please.
Unaligned pointer value for data doesn’t have penalty for xtensa and riscv32 Espressif chips so we can ignore it in most cases.
components/bt/host/bluedroid/btc/profile/std/gatt/btc_gatt_util.c: In function 'btc_to_bta_gatt_id':
components/bt/host/bluedroid/btc/profile/std/gatt/btc_gatt_util.c:105:21: warning: taking address of packed member of 'struct <anonymous>' may result in an unaligned pointer value [-Waddress-of-packed-member]
105 | btc_to_bta_uuid(&p_dest->uuid, &p_src->uuid);
| ^~~~~~~~~~~~~
on CMake level for tons of cases:
set_source_files_properties(
"host/bluedroid/bta/gatt/bta_gattc_act.c"
"host/bluedroid/bta/gatt/bta_gattc_cache.c"
"host/bluedroid/btc/profile/std/gatt/btc_gatt_util.c"
"host/bluedroid/btc/profile/std/gatt/btc_gatts.c"
PROPERTIES COMPILE_FLAGS -Wno-address-of-packed-member)
or on code level:
#pragma GCC diagnostic push
#if __GNUC__ >= 9
#pragma GCC diagnostic ignored "-Waddress-of-packed-member" <<-- This key had been introduced since GCC 9
#endif
uint32_t* reg_ptr = (uint32_t*)src;
#pragma GCC diagnostic pop
llabs() for 64-bit integers
The function abs() from stdlib.h takes int argument. Please use llabs() for types that intended to be 64-bit. In particular it’s important for time_t.