Cannot build with -flto

[ZeroChaos-]

Link time optimization is increasingly common across linux distros, but this fails to build on gentoo when lto is enabled.

I would expect this is easy to replicate with CFLAGS=-flto -Werror=odr -Werror=lto-type-mismatch -Werror=strict-aliasing

Gentoo Bug https://bugs.gentoo.org/861872

[ZeroChaos-]

Min test case to reproduce CFLAGS="-flto" cmake .. will show the warning
Min test case to make it a build failure so it doesn't get lost by accident CFLAGS="-flto -Werror=lto-type-mismatch" cmake ..

[  4%] Linking C shared library ../../output/libbladeRF.so
/home/zero/development/bladeRF/host/libraries/libbladeRF/src/board/bladerf2/common.h:200:25: warning: type of ‘bladerf2_rfic_init_params_fastagc_burst’ does not match original declaration [-Wlto-type-mismatch]
  200 | extern AD9361_InitParam bladerf2_rfic_init_params_fastagc_burst;
      |                         ^
/home/zero/development/bladeRF/fpga_common/src/ad936x_params.c:308:18: note: ‘bladerf2_rfic_init_params_fastagc_burst’ was previously declared here
  308 | AD9361_InitParam bladerf2_rfic_init_params_fastagc_burst = {
      |                  ^
/home/zero/development/bladeRF/fpga_common/src/ad936x_params.c:308:18: note: code may be misoptimized unless ‘-fno-strict-aliasing’ is used
/home/zero/development/bladeRF/host/libraries/libbladeRF/src/board/bladerf2/common.h:199:25: warning: type of ‘bladerf2_rfic_init_params’ does not match original declaration [-Wlto-type-mismatch]
  199 | extern AD9361_InitParam bladerf2_rfic_init_params;
      |                         ^
/home/zero/development/bladeRF/fpga_common/src/ad936x_params.c:20:18: note: ‘bladerf2_rfic_init_params’ was previously declared here
   20 | AD9361_InitParam bladerf2_rfic_init_params = {
      |                  ^
/home/zero/development/bladeRF/fpga_common/src/ad936x_params.c:20:18: note: code may be misoptimized unless ‘-fno-strict-aliasing’ is used
lto-wrapper: warning: using serial compilation of 6 LTRANS jobs
lto-wrapper: note: see the ‘-flto’ option documentation for more information

[Jannik2099]

The definitions of AD9361_InitParam differ.

thirdparty/analogdevicesinc/no-OS/ad9361/sw/ad9361_api.h : size 528 bytes.
fpga_common/include/ad936x.h : size 536 bytes.

diff between small and big (comments removed):

88d87
<     uint32_t fagc_lock_level;
170a170,175
>     uint8_t clk_out_drive;
>     uint8_t dataclk_drive;
>     uint8_t data_port_drive;
>     uint8_t clk_out_slew;
>     uint8_t dataclk_slew;
>     uint8_t data_port_slew;

[rghilduta]

Yup that's it! Thanks for spotting it!

[ZeroChaos-]

How we doing @rghilduta ? Any chance a fix is on the horizon?