Merge branch 'master' of git.mesalab.cn:zhangyang/variable_monitor

1 files changed, 37 insertions, 22 deletions

diff --git a/source/ucli/elf.cc b/source/ucli/elf.cc
index f742e87..af4f801 100644
--- a/source/ucli/elf.cc
+++ b/source/ucli/elf.cc
@@ -10,6 +10,8 @@
 
 // #include <dwarf.h>
 // #include <elfutils/libdw.h>
+// #include <dwarf.h>
+// #include <elfutils/libdw.h>
 
 #define NS_NAME_LEN 128
 
@@ -81,14 +83,14 @@ static int get_symbols_in_section(sym_section_ctx *sym, Elf *elf, Elf_Scn *sec,
     return -1;
   }
 
-  sym->symstrs = elf_getdata(symstrs_sec, NULL);
+  sym->symstrs = elf_getdata(symstrs_sec, NULL); // 获取section data
   if (!sym->symstrs) {
     return -1;
   }
 
-  sym->sym_count = shdr->sh_size / shdr->sh_entsize;
+  sym->sym_count = shdr->sh_size / shdr->sh_entsize; // 获取section中的symbol数量
   sym->is_plt = 0;
-  sym->is_reloc = is_reloc;
+  sym->is_reloc = is_reloc; // 是否是可重定位文件
 
   return 0;
 }
@@ -118,7 +120,7 @@ static int get_plt_symbols_in_section(sym_section_ctx *sym, Elf *elf,
   sym->is_plt = 1;
   sym->plt_entsize = plt->plt.hdr->sh_type;
   sym->plt_offset = plt->plt.hdr->sh_offset;
-  sym->sym_count = plt->plt_rel.hdr->sh_size / plt->plt_rel.hdr->sh_entsize;
+  sym->sym_count = plt->plt_rel.hdr->sh_size / plt->plt_rel.hdr->sh_entsize; // 获取section中的symbol数量
   sym->plt_rel_type = plt->plt_rel.hdr->sh_type;
 
   return 0;
@@ -161,6 +163,7 @@ static void __get_symbol_without_plt(std::set<symbol> &ss, sym_section_ctx *tab,
     s.end = s.start + sym.st_size;
     s.ip = s.start;
     s.name = sym_name;
+    printf("name: %s, start: %lx, end: %lx\n", s.name.c_str(), s.start, s.end);
     ss.insert(s);
   }
 }
@@ -217,6 +220,7 @@ static void __get_plt_symbol(std::set<symbol> &ss, symbol_sections_ctx *si,
     s.end = s.start + si->dynsymtab.plt_entsize;
     s.ip = s.start;
     s.name = sym_name;
+    printf("name: %s, start: %lx, end: %lx\n", s.name.c_str(), s.start, s.end);
     ss.insert(s);
   }
 }
@@ -230,19 +234,25 @@ static void get_all_symbols(std::set<symbol> &ss, symbol_sections_ctx *si,
 // static void get_debug_symbols(std::set<symbol>& ss, Dwarf* dw) {
 //   Dwarf_Off die_offset = 0, next_offset;
 //   size_t header_size;
+//   printf("1\n");
 //   while (dwarf_nextcu(dw, die_offset, &next_offset, &header_size, NULL, NULL, NULL) == 0) {
+//     printf("2\n");
 //     Dwarf_Die cudie;
+//     printf("3\n");
 //     if (dwarf_offdie(dw, die_offset + header_size, &cudie) == NULL) {
+//       printf("4\n");
 //       continue;
 //     }
-
+//     printf("4\n");
 //     Dwarf_Die die;
 //     if (dwarf_child(&cudie, &die) != 0) {
+//       printf("5\n");
 //       continue;
 //     }
 
 //     do {
 //       const char* die_name = dwarf_diename(&die);
+//       printf("6\n");
 //       if (!die_name) {
 //         continue;
 //       }
@@ -252,12 +262,13 @@ static void get_all_symbols(std::set<symbol> &ss, symbol_sections_ctx *si,
 //       if (attr) {
 //         Dwarf_Addr low_pc;
 //         if (dwarf_formaddr(attr, &low_pc) == 0) {
-//           symbol s;
-//           s.name = die_name;
-//           s.start = low_pc;
-//           s.end = s.start; // You need to find the high_pc to set the end.
+//           printf("name: %s, low_pc: %lx\n", die_name, low_pc);
+//           // symbol s;
+//           // s.name = die_name;
+//           // s.start = low_pc;
+//           // s.end = s.start; // You need to find the high_pc to set the end.
 
-//           ss.insert(s);
+//           // ss.insert(s);
 //         }
 //       }
 //     } while (dwarf_siblingof(&die, &die) == 0);
@@ -265,6 +276,9 @@ static void get_all_symbols(std::set<symbol> &ss, symbol_sections_ctx *si,
 //     die_offset = next_offset;
 //   }
 // }
+//     die_offset = next_offset;
+//   }
+// }
 
 bool is_stripped(const char* path) {
   char command[256];
@@ -334,30 +348,30 @@ bool get_symbol_from_elf(std::set<symbol> &ss, const char *path) {
 
   int fd = open(path, O_RDONLY);
 
-  Elf *elf = elf_begin(fd, ELF_C_READ, NULL);
+  Elf *elf = elf_begin(fd, ELF_C_READ, NULL); // 指向elf文件的指针
   if (elf == NULL) {
     close(fd);
     return false;
   }
 
-  Elf_Kind ek = elf_kind(elf);
+  Elf_Kind ek = elf_kind(elf); // 获取elf文件类型
   if (ek != ELF_K_ELF) {
     elf_end(elf);
     close(fd);
     return false;
   }
-  GElf_Ehdr hdr;
+  GElf_Ehdr hdr; // elf文件头
   if (gelf_getehdr(elf, &hdr) == NULL) {
     elf_end(elf);
     close(fd);
     return false;
   }
 
-  if (hdr.e_type == ET_EXEC) {
+  if (hdr.e_type == ET_EXEC) { // 可执行文件
     is_reloc = 1;
   }
 
-  if (!elf_rawdata(elf_getscn(elf, hdr.e_shstrndx), NULL)) {
+  if (!elf_rawdata(elf_getscn(elf, hdr.e_shstrndx), NULL)) { //
     elf_end(elf);
     close(fd);
     return false;
@@ -379,25 +393,26 @@ bool get_symbol_from_elf(std::set<symbol> &ss, const char *path) {
   Elf_Scn *symtab_sec = NULL;
   Elf_Scn *plt_sec = NULL;
   Elf_Scn *plt_rel_sec = NULL;
-
+  Elf_Scn *debug_sec = NULL;
+  // 遍历elf文件的section header table
   while ((sec = elf_nextscn(elf, sec)) != NULL) {
     char *str;
-    gelf_getshdr(sec, &shdr);
+    gelf_getshdr(sec, &shdr); // 获取section header
     str = elf_strptr(elf, hdr.e_shstrndx, shdr.sh_name);
 
-    if (str && strcmp(".symtab", str) == 0) {
+    if (str && strcmp(".symtab", str) == 0) { // .symtab section
       symtab_sec = sec;
-      memcpy(&symtab_shdr, &shdr, sizeof(dynsym_shdr));
+      memcpy(&symtab_shdr, &shdr, sizeof(dynsym_shdr)); 
     }
-    if (str && strcmp(".dynsym", str) == 0) {
+    if (str && strcmp(".dynsym", str) == 0) { // .dynsym section
       dynsym_sec = sec;
       memcpy(&dynsym_shdr, &shdr, sizeof(dynsym_shdr));
     }
-    if (str && strcmp(".rela.plt", str) == 0) {
+    if (str && strcmp(".rela.plt", str) == 0) { // .rela.plt section
       plt_rel_sec = sec;
       memcpy(&plt_rel_shdr, &shdr, sizeof(plt_rel_shdr));
     }
-    if (str && strcmp(".plt", str) == 0) {
+    if (str && strcmp(".plt", str) == 0) { // .plt section
       plt_sec = sec;
       memcpy(&plt_shdr, &shdr, sizeof(plt_shdr));
     }