The symbols are taken from the dynamic symbol table; you need the -rdynamic option to gcc, which makes it pass a flag to the linker which ensures that all symbols are placed in the table. (See the Link Options page of the GCC manual, and / or the Backtraces page of the glibc manual.)
Xdebug prints a backtrace table on errors, and you don’t have to write any PHP code to implement it. Downside is you have to install it as a PHP extension.
Alright, now I got it. : ) The problem was in the SYMBOL_INFO structure. It needs to be allocated on the heap, reserving space for the symbol name, and initialized properly. Here’s the final code: void printStack( void ); void printStack( void ) { unsigned int i; void * stack[ 100 ]; unsigned short frames; … Read more
The simplest way is: echo debug_backtrace()[1][‘function’]; As noted in the comments below, this can be further optimized by passing arguments to: omit both the object and args indices limit the number of stack frames returned echo debug_backtrace(!DEBUG_BACKTRACE_PROVIDE_OBJECT|DEBUG_BACKTRACE_IGNORE_ARGS,2)[1][‘function’];