From 8f7a832961f9e30b0e30dbb7322a8a4e94fd2cbb Mon Sep 17 00:00:00 2001
From: mykola2312 <49044616+mykola2312@users.noreply.github.com>
Date: Sun, 25 Aug 2024 19:58:19 +0300
Subject: [PATCH] so, "string table index" is just an offset. implemented
 string resolving

---
 src/relf/relf.c | 39 +++++++++++++++++----------------------
 src/relf/relf.h | 13 +++++++++----
 2 files changed, 26 insertions(+), 26 deletions(-)

diff --git a/src/relf/relf.c b/src/relf/relf.c
index 76ad91f..cac439d 100644
--- a/src/relf/relf.c
+++ b/src/relf/relf.c
@@ -174,7 +174,7 @@ relf_value_t relf_open(relf_t* relf, const char* path)
             section->flags = hdr->sh_flags;
 
             // we will resolve names when string table is resolved
-            section->name = NULL;
+            section->si_name = hdr->sh_name;
 
             section->f_offset = hdr->sh_offset;
             section->f_size = hdr->sh_size;
@@ -185,8 +185,6 @@ relf_value_t relf_open(relf_t* relf, const char* path)
             section->info = hdr->sh_info;
 
             section->entsize = hdr->sh_entsize;
-
-            TRACE_SECTION(section);
         }
     }
     else
@@ -202,7 +200,7 @@ relf_value_t relf_open(relf_t* relf, const char* path)
             section->flags = hdr->sh_flags;
 
             // we will resolve names when string table is resolved
-            section->name = NULL;
+            section->si_name = hdr->sh_name;
 
             section->f_offset = hdr->sh_offset;
             section->f_size = hdr->sh_size;
@@ -213,8 +211,6 @@ relf_value_t relf_open(relf_t* relf, const char* path)
             section->info = hdr->sh_info;
 
             section->entsize = hdr->sh_entsize;
-
-            TRACE_SECTION(section);
         }
     }
 
@@ -225,27 +221,26 @@ relf_value_t relf_open(relf_t* relf, const char* path)
     else
         e_shstrndx = ((const Elf32_Ehdr*)relf->image)->e_shstrndx;
     
-    // NOTE: I should handle SHN_LORESERVE in e_phnum, e_shnum and e_shstrndx
-    // but that's non-existent use case when ELF has number of segments
-    // and sections that are exceeding uint16_t limit, so I don't care.
+    // resolve strings
     if (e_shstrndx != SHN_UNDEF)
     {
-        // we have string table, so to ease parsing
-        // we gonna allocate array of char pointers
-        // but first we need enumerate and find out
-        // how many strings there are
-        const char* cur = (const char*)
-            relf->image + relf->sections[e_shstrndx].f_offset;
-        const char* end = cur + relf->sections[e_shstrndx].f_size;
-        while (cur < end)
+        const char* strtab = (const char*)relf->image
+            + relf->sections[e_shstrndx].f_offset;
+        for (unsigned i = 0; i < relf->section_num; i++)
         {
-            TRACE("str %s\n", cur);
-            cur += strlen(cur) + 1;
-            relf->string_num++;
-        }
+            relf_section_t* section = &relf->sections[i];
+            section->name = strtab + section->si_name;
 
-        TRACE("string_num %u\n", relf->string_num);
+            TRACE_SECTION(section);
+        }
     }
     
     return RELF_ERROR(RELF_OK);
 }
+
+void relf_close(relf_t* relf)
+{
+    relf_unmap(relf);
+    free(relf->segments);
+    free(relf->sections);
+}
diff --git a/src/relf/relf.h b/src/relf/relf.h
index 473110c..4cdfebe 100644
--- a/src/relf/relf.h
+++ b/src/relf/relf.h
@@ -58,7 +58,10 @@ typedef struct {
     uint32_t type;
     uint32_t flags;
 
-    const char* name;
+    union {
+        uint32_t si_name; // index in string table
+        const char* name;
+    };
 
     uint64_t f_offset;
     uint64_t f_size;
@@ -72,6 +75,11 @@ typedef struct {
     uint64_t entsize;
 } relf_section_t;
 
+typedef struct {
+    const char** strings;
+    unsigned string_num;
+} relf_string_table_t;
+
 // relf instance
 typedef struct {
     void* image;
@@ -85,9 +93,6 @@ typedef struct {
 
     relf_section_t* sections;
     unsigned section_num;
-
-    const char** strings;
-    unsigned string_num;
 } relf_t;
 
 // opens ELF file, checks ELF magic and maps it into memory