Compile and run error troubleshooting methods

Compile-time header file is not found

• Compiler flags -v, displays all the header file search path
• Acer is open
• Specifies whether the compiler flags -I path
• Header file plus #error "xxxx", if the header files are compiled to, it will error

Compile-time symbol can not be found

• Whether the source file / header files are compiled into a
• Whether the symbol is the extern
• With c ++ compiler, whether to raise the extern "C"
• Is there a macro is not open
• Whether there is a header file that contains cross

Compile-time libraries can not be found

• Link flags -v, displays all library search path
• Specifies whether the link flags -L path
• -L under the presence of the library path
• The default DLL search path / lib, / usr / lib, / usr / local / lib and so the presence of the library
• Whether the current tool chain and libraries inconsistent

Runtime library can not be found

Runtime library search path order

1. Link, -Wl, -rpath = first_path: dynamic library search path specified second_path
2. LD_LIBRARY_PATH environment variable specified dynamic library search path
3. Specified in the configuration file /etc/ld.so.conf dynamic library search path
4. The default DLL search path / lib, / usr / lib

Runtime library search path View

• ldd program_name (ldd is a shell script)

ldd ./exe_json 
    linux-vdso.so.1 =>  (0x00007ffdfd3ed000)
    libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f2441ae6000)
    libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f24417dd000)
    libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f2441413000)
    /lib64/ld-linux-x86-64.so.2 (0x00007f2441d03000)

• strace -e trace=open program_name

(Part of embedded linux system when compiling the firmware, did not open this feature)

strace -e trace=open ./exe_json 
open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
open("/lib/x86_64-linux-gnu/libpthread.so.0", O_RDONLY|O_CLOEXEC) = 3
open("/lib/x86_64-linux-gnu/libm.so.6", O_RDONLY|O_CLOEXEC) = 3
open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
+++ exited with 0 +++

Different tool chains fit when symbol can not be found

• Chains of different tools with macro definitions of certain control symbols

eg：struct sockaddr_in结构体需要开启的宏
- linux PC: -D_GNU_SOURCE
- linux rk3308: -D_POSIX_C_SOURCE=200112L -D_DEFAULT_SOURCE

Different tool chains compile the run error

• The size of the end
• 32-bit / 64-bit
• -O2 optimization errors (such as encryption error message mbedtls communication network), change -O0

reference

• ldd principle https://www.cnblogs.com/kelamoyujuzhen/p/9823272.html
• -rpath-link action parameter https://blog.csdn.net/q1302182594/article/details/42102961