From 4c82b003420fabbb95e077866784badc1a49189b Mon Sep 17 00:00:00 2001
From: herman ten brugge <hermantenbrugge@home.nl>
Date: Tue, 17 May 2022 07:34:10 +0200
Subject: [PATCH] Update for elflint problems

tccgen.c:
- When __FUNCTION__ is used and no code is generated use symbol len = 0.

tccelf.c:
- If library is present in verneed it should be in DT_NEEDED.
- @plt symbols should have size 0
- set _GLOBAL_OFFSET_TABLE_ st_size correct
- Remove version symbol if new value present

reported by elflint:

__FUNCTION__ problem:
  section [19] '.symtab': symbol 2134 (L.195) does not fit completely in referenced section [14] '.data.ro'
DT_NEEDED problem:
  section [26] '.gnu.version_r': entry 2 references unknown dependency
@plt symbols should have size 0:
  section [22] '.symtab': symbol 36557 (r_core_config_init@plt) does not fit completely in referenced section [14] '.plt'
_GLOBAL_OFFSET_TABLE_ size:
  section [44] '.symtab': _GLOBAL_OFFSET_TABLE_ symbol size 4 does not match .got section size 736
Remove version symbol:
  section [25] '.gnu.version': symbol 86: version index 3 is for requested version
  This happened for example with bounds checking symbol malloc
---
 tccelf.c | 33 ++++++++++++++++++++++++++++++---
 tccgen.c |  2 +-
 2 files changed, 31 insertions(+), 4 deletions(-)

diff --git a/tccelf.c b/tccelf.c
index ceb54b61..3f44a1cc 100644
--- a/tccelf.c
+++ b/tccelf.c
@@ -547,7 +547,7 @@ LIBTCCAPI void tcc_list_symbols(TCCState *s, void *ctx,
 static void
 version_add (TCCState *s1)
 {
-    int i;
+    int i, j;
     ElfW(Sym) *sym;
     ElfW(Verneed) *vn = NULL;
     Section *symtab;
@@ -593,6 +593,14 @@ version_add (TCCState *s1)
             ElfW(Vernaux) *vna = 0;
             if (sv->out_index < 1)
               continue;
+	    /* If present in verneed it should be in DT_NEEDED */
+	    for (j = 0; j < s1->nb_loaded_dlls; j++) {
+		DLLReference *dllref = s1->loaded_dlls[j];
+		if (!strcmp(sv->lib, dllref->name)) {
+		    dllref->level = 0;
+		    break;
+		}
+	    }
             vnofs = section_add(verneed_section, sizeof(*vn), 1);
             vn = (ElfW(Verneed)*)(verneed_section->data + vnofs);
             vn->vn_version = 1;
@@ -1137,7 +1145,7 @@ static struct sym_attr * put_got_entry(TCCState *s1, int dyn_reloc_type,
             len = sizeof plt_name - 5;
         memcpy(plt_name, name, len);
         strcpy(plt_name + len, "@plt");
-        attr->plt_sym = put_elf_sym(s1->symtab, attr->plt_offset, sym->st_size,
+        attr->plt_sym = put_elf_sym(s1->symtab, attr->plt_offset, 0,
             ELFW(ST_INFO)(STB_GLOBAL, STT_FUNC), 0, s1->plt->sh_num, plt_name);
     } else {
         attr->got_offset = got_offset;
@@ -2526,6 +2534,14 @@ static Section *create_bsd_note_section(TCCState *s1,
 }
 #endif
 
+static void elf_patch_global_offset_size(TCCState *s1, Section *s)
+{
+    int sym_index;
+
+    if ((sym_index = find_elf_sym(s, "_GLOBAL_OFFSET_TABLE_")))
+	((ElfW(Sym) *)s->data)[sym_index].st_size = s1->got->data_offset;
+}
+
 /* Output an elf, coff or binary file */
 /* XXX: suppress unneeded sections */
 static int elf_output_file(TCCState *s1, const char *filename)
@@ -2589,7 +2605,8 @@ static int elf_output_file(TCCState *s1, const char *filename)
             dynamic->link = dynstr;
             dynamic->sh_entsize = sizeof(ElfW(Dyn));
 
-            build_got(s1);
+            if (!s1->got)
+                build_got(s1);
 
             if (file_type == TCC_OUTPUT_EXE) {
                 bind_exe_dynsyms(s1);
@@ -2602,6 +2619,8 @@ static int elf_output_file(TCCState *s1, const char *filename)
             }
         }
         build_got_entries(s1);
+	elf_patch_global_offset_size(s1, symtab_section);
+	elf_patch_global_offset_size(s1, s1->dynsym);
 	version_add (s1);
     }
 
@@ -3065,6 +3084,14 @@ ST_FUNC int tcc_load_object_file(TCCState *s1,
                                 sym->st_info, sym->st_other,
                                 sym->st_shndx, name);
         old_to_new_syms[i] = sym_index;
+#ifndef ELF_OBJ_ONLY
+	/* Remove version symbol if new value present */
+	sym_index = find_elf_sym(s1->dynsymtab_section, name);
+	if (sym_index && sym_index < nb_sym_to_version &&
+	    sym->st_shndx != SHN_UNDEF &&
+	    ELFW(ST_BIND)(sym->st_info) != STB_LOCAL)
+	    sym_to_version[sym_index] = -1;
+#endif
     }
 
     /* third pass to patch relocation entries */
diff --git a/tccgen.c b/tccgen.c
index 98295348..01afd89e 100644
--- a/tccgen.c
+++ b/tccgen.c
@@ -5328,7 +5328,7 @@ ST_FUNC void unary(void)
             type.t |= VT_ARRAY;
             type.ref->c = len;
             sec = rodata_section;
-            vpush_ref(&type, sec, sec->data_offset, len);
+            vpush_ref(&type, sec, sec->data_offset, NODATA_WANTED ? 0 : len);
             if (!NODATA_WANTED)
                 memcpy(section_ptr_add(sec, len), funcname, len);
             next();