From 8fdaeaeadc0d0c88c4e5b89bdce93f82e9e6bf32 Mon Sep 17 00:00:00 2001
From: zy <zhangyang@geedgenetworks.com>
Date: Thu, 7 Dec 2023 03:46:57 -0500
Subject: [PATCH] dwarf

---
 source/ucli/Makefile |  2 +-
 source/ucli/elf.cc   | 50 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 51 insertions(+), 1 deletion(-)

diff --git a/source/ucli/Makefile b/source/ucli/Makefile
index b94ef76..7b5fd9a 100644
--- a/source/ucli/Makefile
+++ b/source/ucli/Makefile
@@ -5,7 +5,7 @@ OBJECTS=$(SOURCES:.cc=.o)
 
 CFLAGS=-g -O0
 INCLUDES=-I/usr/include/elf
-LIBS=-lunwind-x86_64 -lunwind -lelf
+LIBS=-lunwind-x86_64 -lunwind -lelf -ldwarf -ldw
 
 %.o: %.cc
 		$(CXX) $(CFLAGS) $(INCLUDES) -c $< -o $@
diff --git a/source/ucli/elf.cc b/source/ucli/elf.cc
index 7be03f1..b0c1d70 100644
--- a/source/ucli/elf.cc
+++ b/source/ucli/elf.cc
@@ -8,6 +8,9 @@
 #include <sys/utsname.h>
 #include <unistd.h>
 
+#include <dwarf.h>
+#include <elfutils/libdw.h>
+
 #define NS_NAME_LEN 128
 
 struct sym_section_ctx {
@@ -224,6 +227,45 @@ static void get_all_symbols(std::set<symbol> &ss, symbol_sections_ctx *si,
   __get_plt_symbol(ss, si, elf);
 }
 
+static void get_debug_symbols(std::set<symbol>& ss, Dwarf* dw) {
+  Dwarf_Off die_offset = 0, next_offset;
+  size_t header_size;
+  while (dwarf_nextcu(dw, die_offset, &next_offset, &header_size, NULL, NULL, NULL) == 0) {
+    Dwarf_Die cudie;
+    if (dwarf_offdie(dw, die_offset + header_size, &cudie) == NULL) {
+      continue;
+    }
+
+    Dwarf_Die die;
+    if (dwarf_child(&cudie, &die) != 0) {
+      continue;
+    }
+
+    do {
+      const char* die_name = dwarf_diename(&die);
+      if (!die_name) {
+        continue;
+      }
+
+      Dwarf_Attribute attr_mem;
+      Dwarf_Attribute* attr = dwarf_attr(&die, DW_AT_low_pc, &attr_mem);
+      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.
+
+          ss.insert(s);
+        }
+      }
+    } while (dwarf_siblingof(&die, &die) == 0);
+
+    die_offset = next_offset;
+  }
+}
+
 bool get_symbol_from_elf(std::set<symbol> &ss, const char *path) {
   static int first_init = 0;
 
@@ -331,6 +373,14 @@ bool get_symbol_from_elf(std::set<symbol> &ss, const char *path) {
 
   get_all_symbols(ss, &si, elf);
   elf_end(elf);
+
+  // After getting all symbols from .symtab and .dynsym
+  Dwarf *dw = dwarf_begin(fd, DWARF_C_READ);
+  if (dw) {
+    get_debug_symbols(ss, dw);
+    dwarf_end(dw);
+  }
+
   close(fd);
   return true;
 }
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