phoenix_dl.cpp

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/***************************************
        Auteur : Pierre Aubert
        Mail : pierre.aubert@lapp.in2p3.fr
        Licence : CeCILL-C
****************************************/
 
#include <stdio.h>
 
// DL includes
#include <link.h>
#include <stdlib.h>
#include <dlfcn.h>
#include <elf.h>
 
#include <iostream>
 
#include "phoenix_dl.h"


void phoenix_listLibrarySymbol(std::vector<std::string> & vecFunction, const std::string & libFileName){
        if(libFileName == ""){return;}
        void* library = dlopen(libFileName.c_str(), RTLD_LAZY | RTLD_GLOBAL);
        if(library == NULL){
                std::cerr << "phoenix_listLibrarySymbol : library '"<<libFileName<<"' not found" << std::endl;
                return;
        }
        struct link_map * map = NULL;
        dlinfo(library, RTLD_DI_LINKMAP, &map);
 
        Elf64_Sym * symtab = nullptr;
        char * strtab = nullptr;
        int symentries = 0;
        for(auto section = map->l_ld; section->d_tag != DT_NULL; ++section){
                if(section->d_tag == DT_SYMTAB){
                        symtab = (Elf64_Sym *)section->d_un.d_ptr;
                }
                if(section->d_tag == DT_STRTAB){
                        strtab = (char*)section->d_un.d_ptr;
                }
                if(section->d_tag == DT_SYMENT){
                        symentries = section->d_un.d_val;
                }
        }
        int size = strtab - (char *)symtab;
        for(int k = 0; k < size / symentries; ++k){
                auto sym = &symtab[k];
                // If sym is function
                if(ELF64_ST_TYPE(symtab[k].st_info) == STT_FUNC){
                        //str is name of each symbol
                        auto str = &strtab[sym->st_name];
                        vecFunction.push_back(std::string(str));
//                      printf("%s\n", str);
                }
        }
        dlclose(library);
}


std::string phoenix_mangleFunction(const std::string & functionPrototype, const std::string & extraInclude, const std::string & compiler){
        std::string command("echo \"#include <new>\\n#include <string>\\n"+extraInclude+"\\n"+functionPrototype+" {} \" | "+compiler+" -x c++ -S - -o- | grep \"@function\" | cut -d ',' -f 1 | sed -e \"s/.type//g\" | sed -s \"s/ //g\" | sed -e \"s/\t//g\"");
        FILE * fp = popen(command.c_str(), "r");
        if(fp == NULL){
                std::cerr << "phoenix_mangleFunction : cannot get result of command '"<<command<<"'" << std::endl;
                return "";
        }
        std::string mangledFunction("");
        int buffer;
        while(!feof(fp)){
                buffer = fgetc(fp);
                if(buffer != EOF){
                        char ch = (char)buffer;
                        if(ch != ' ' && ch != '\t' && ch != '\n'){
                                mangledFunction += ch;
                        }
                }
                else break;
        }
        pclose(fp);
        return mangledFunction;
}