Can't compile for libcamera

[ojio-san]

Hello there,

I'm trying to build the libcamera project (0.2.0+rpt20240215) but this libpisp is causing me an issue :

165.0 ninja: job failed: g++ -Isubprojects/libpisp/src/libpisp.so.1.0.4.p -Isubprojects/libpisp/src -I../subprojects/libpisp/src -Isubprojects/libpisp/src/libpisp -I../subprojects/libpisp/src/libpisp -I../subprojects/nlohmann_json-3.11.2/single_include -I/usr/include -fdiagnostics-color=always -D_FILE_OFFSET_BITS=64 -Wall -Winvalid-pch -Wextra -Werror -std=c++17 -O0 -g -DPISP_LOGGING_ENABLE=1 -DBOOST_BIND_GLOBAL_PLACEHOLDERS -Os -fstack-clash-protection -Wformat -Werror=format-security -D_GLIBCXX_ASSERTIONS=1 -D_LIBCPP_ENABLE_THREAD_SAFETY_ANNOTATIONS=1 -D_LIBCPP_ENABLE_HARDENED_MODE=1 -fPIC -pthread -DBOOST_LOG_DYN_LINK=1 -DBOOST_LOG_SETUP_DYN_LINK=1 -DBOOST_THREAD_BUILD_DLL=1 -DBOOST_THREAD_USE_DLL=1 -DBOOST_SYSTEM_DYN_LINK=1 -DBOOST_ALL_NO_LIB -MD -MQ subprojects/libpisp/src/libpisp.so.1.0.4.p/libpisp_backend_backend_default_config.cpp.o -MF subprojects/libpisp/src/libpisp.so.1.0.4.p/libpisp_backend_backend_default_config.cpp.o.d -o subprojects/libpisp/src/libpisp.so.1.0.4.p/libpisp_backend_backend_default_config.cpp.o -c ../subprojects/libpisp/src/libpisp/backend/backend_default_config.cpp
165.0 ../subprojects/libpisp/src/libpisp/backend/backend_default_config.cpp: In function 'bool {anonymous}::is_installed()':
165.0 ../subprojects/libpisp/src/libpisp/backend/backend_default_config.cpp:37:32: error: '_DYNAMIC' was not declared in this scope; did you mean 'PT_DYNAMIC'?
165.0 37 | const ElfW(Dyn) *dyn = _DYNAMIC;
165.0 | ^~~~~~~~
165.0 | PT_DYNAMIC
221.7 ninja: subcommand failed

More output here : https://pastebin.com/raw/3hbXBdVh and here https://pastebin.com/raw/yTvEfUVG

Environment : alpine 3.19 on armv6

Any advices ? Thank you :)

[naushir]

_DYNAMIC is defined in link.h, which is #included in the file. Not sure why you are seeing this error message. Can you check the contents of /usr/include/link.h and see if the definition exists?

[ojio-san]

Hello and thank you for your reply :)

Unfortunately, I can't find the _DYNAMIC in the file : /usr/include/link.h

You can download the musl-dev package on the alpine repository here : https://dl-cdn.alpinelinux.org/alpine/v3.19/main/armv7/musl-dev-1.2.4_git20230717-r4.apk which contains the /usr/include/link.h file.

Nevertheless, this is the content of this file :

#ifndef _LINK_H
#define _LINK_H

#ifdef __cplusplus
extern "C" {
#endif

#include <elf.h>
#define __NEED_size_t
#define __NEED_uint32_t
#include <bits/alltypes.h>

#if UINTPTR_MAX > 0xffffffff
#define ElfW(type) Elf64_ ## type
#else
#define ElfW(type) Elf32_ ## type
#endif

#include <bits/link.h>

struct dl_phdr_info {
	ElfW(Addr) dlpi_addr;
	const char *dlpi_name;
	const ElfW(Phdr) *dlpi_phdr;
	ElfW(Half) dlpi_phnum;
	unsigned long long int dlpi_adds;
	unsigned long long int dlpi_subs;
	size_t dlpi_tls_modid;
	void *dlpi_tls_data;
};

struct link_map {
	ElfW(Addr) l_addr;
	char *l_name;
	ElfW(Dyn) *l_ld;
	struct link_map *l_next, *l_prev;
};

struct r_debug {
	int r_version;
	struct link_map *r_map;
	ElfW(Addr) r_brk;
	enum { RT_CONSISTENT, RT_ADD, RT_DELETE } r_state;
	ElfW(Addr) r_ldbase;
};

int dl_iterate_phdr(int (*)(struct dl_phdr_info *, size_t, void *), void *);

#ifdef __cplusplus
}
#endif

#endif

[pinchartl]

In libcamera, we have

/* musl doesn't declare _DYNAMIC in link.h, declare it manually. */
extern ElfW(Dyn) _DYNAMIC[];

[naushir]

Thanks @pinchartl I'll add that declaration and hopefully it should fix this issue.

[naushir]

#26 is now merged. Please do give it a try and let me know if it is fixed.

Environment : alpine 3.19 on armv7

I'm curious what platform you are running this on? libpisp is only really relevant for Pi 5 (armv8). So perhaps your libcamera meson build config should not include rpi/pisp support?

[ojio-san]

=> This is now building fine with your last commit on main branch!

So, I am building packages for https://github.com/raspberrypi/rpicam-apps and https://github.com/raspberrypi/libcamera

And I am trying to cross compiling from amd64 (debian) with docker buildx to armv6 on alpine linux (sorry I said armv7 in the first post) : for a rpi0 on alpine linux. Sadly no one seems to distribute packages for alpine, only for rpi os.

I have successfully built v1.2.1 and libcamera 0.1.0+rpt20231122, but thoses new versions are giving me quite a hard time.

You said that maybe I don't need this, so now I am trying to rebuild the libcamera package with :

meson setup --prefix=/usr build --buildtype=release -Dpipelines=rpi/vc4 -Dipas=rpi/vc4 -Dv4l2=true -Dgstreamer=disabled -Dtest=false -Dlc-compliance=disabled -Dcam=disabled -Dqcam=disabled -Ddocumentation=disabled -Dpycamera=disabled

If it will work, that should mean that this is a false issue and the last commit on the main branch should maybe not be there

--
EDIT : building works fine with meson setup line up here, and building rpicam-apps with this dependency too. thank you !