Add .gnu_debugaltlink sections during fi_multifile phase.

diff --git a/dwz.c b/dwz.c
index 0e437a4c77b6cba549ab19eef95423b031a82343..a1fb8b66459db779be30c449945aebb9fdecee4c 100644 (file)
--- a/dwz.c
+++ b/dwz.c
@@ -346,6 +346,7 @@ static struct
 #define DEBUG_TYPES            12
 #define DEBUG_GDB_SCRIPTS      13
 #define GDB_INDEX              14
+#define GNU_DEBUGALTLINK       15
     { ".debug_info", NULL, NULL, 0, 0, 0 },
     { ".debug_abbrev", NULL, NULL, 0, 0, 0 },
     { ".debug_line", NULL, NULL, 0, 0, 0 },
@@ -361,6 +362,7 @@ static struct
     { ".debug_types", NULL, NULL, 0, 0, 0 },
     { ".debug_gdb_scripts", NULL, NULL, 0, 0, 0 },
     { ".gdb_index", NULL, NULL, 0, 0, 0 },
+    { ".gnu_debugaltlink", NULL, NULL, 0, 0, 0 },
     { NULL, NULL, NULL, 0, 0, 0 }
   };
 #define SAVED_SECTIONS (DEBUG_MACRO + 1)
@@ -5700,7 +5702,7 @@ read_macro (DSO *dso)
     {
       macro_htab = htab_try_create (50, macro_hash2, macro_eq2, NULL);
       if (macro_htab == NULL)
-        dwz_oom ();
+       dwz_oom ();
     }
 
   while (ptr < endsec)
@@ -5719,11 +5721,11 @@ read_macro (DSO *dso)
 
       version = read_16 (ptr);
       if (version != 4)
-        {
+       {
          error (0, 0, "%s: Unhandled .debug_macro version %d", dso->filename,
                 version);
          return 1;
-        }
+       }
       flags = read_8 (ptr);
       if ((flags & ~2U) != 0)
        {
@@ -5986,7 +5988,7 @@ handle_macro (void)
   macro_htab = htab_try_create (50, macro_hash, macro_eq, NULL);
   if (macro_htab == NULL)
     dwz_oom ();
-  
+
   endsec = debug_sections[DEBUG_MACRO].data + debug_sections[DEBUG_MACRO].size;
   if (op_multifile)
     {
@@ -8539,7 +8541,8 @@ read_dwarf (DSO *dso)
                                   dso->shdr[i].sh_name);
 
        if (strncmp (name, ".debug_", sizeof (".debug_") - 1) == 0
-           || strcmp (name, ".gdb_index") == 0)
+           || strcmp (name, ".gdb_index") == 0
+           || strcmp (name, ".gnu_debugaltlink") == 0)
          {
            for (j = 0; debug_sections[j].name; ++j)
              if (strcmp (name, debug_sections[j].name) == 0)
@@ -8617,6 +8620,13 @@ read_dwarf (DSO *dso)
       return 1;
     }
 
+  if (debug_sections[GNU_DEBUGALTLINK].data != NULL)
+    {
+      error (0, 0, "%s: .gnu_debugaltlink section already present",
+            dso->filename);
+      return 1;
+    }
+
   if (read_debug_info (dso))
     return 1;
 
@@ -8704,9 +8714,11 @@ write_dso (DSO *dso, const char *file, struct stat *st)
   Elf *elf = NULL;
   GElf_Ehdr ehdr;
   char *e_ident;
-  int fd, i, j;
+  int fd, i, j, addsec = -1;
   GElf_Off off, diff;
   char *filename = NULL;
+  GElf_Word shstrtabadd = 0;
+  char *shstrtab = NULL;
   bool remove_gdb_index = false;
 
   ehdr = dso->ehdr;
@@ -8716,9 +8728,48 @@ write_dso (DSO *dso, const char *file, struct stat *st)
   for (i = 0; debug_sections[i].name; i++)
     if (debug_sections[i].new_size != debug_sections[i].size)
       {
-       diff = (GElf_Off) debug_sections[i].new_size
-              - (GElf_Off) dso->shdr[debug_sections[i].sec].sh_size;
-       off = dso->shdr[debug_sections[i].sec].sh_offset;
+       if (debug_sections[i].size == 0
+           && debug_sections[i].sec == 0)
+         {
+           unsigned int len;
+           if (addsec == -1)
+             for (j = 0; debug_sections[j].name; j++)
+               if (debug_sections[j].new_size
+                   && debug_sections[j].sec
+                   && debug_sections[j].sec > addsec)
+                 addsec = debug_sections[j].sec;
+           ehdr.e_shnum++;
+           for (j = 1; j < dso->ehdr.e_shnum; ++j)
+             {
+               if (dso->shdr[j].sh_offset > ehdr.e_shoff)
+                 dso->shdr[j].sh_offset += ehdr.e_shentsize;
+               if (dso->shdr[j].sh_link > (unsigned int) addsec)
+                 dso->shdr[j].sh_link++;
+               if ((dso->shdr[j].sh_type == SHT_REL
+                    || dso->shdr[j].sh_type == SHT_RELA
+                    || (dso->shdr[j].sh_flags & SHF_INFO_LINK))
+                   && dso->shdr[j].sh_info
+                      > (unsigned int) addsec)
+                 dso->shdr[j].sh_info++;
+             }
+           if (ehdr.e_shstrndx > addsec)
+             ehdr.e_shstrndx++;
+           len = strlen (debug_sections[i].name) + 1;
+           dso->shdr[dso->ehdr.e_shstrndx].sh_size += len;
+           for (j = dso->ehdr.e_shstrndx + 1; j < dso->ehdr.e_shnum; ++j)
+             dso->shdr[j].sh_offset += len;
+           if (ehdr.e_shoff > dso->shdr[dso->ehdr.e_shstrndx].sh_offset)
+             ehdr.e_shoff += len;
+           shstrtabadd += len;
+           diff = debug_sections[i].new_size;
+           off = dso->shdr[addsec].sh_offset;
+         }
+       else
+         {
+           diff = (GElf_Off) debug_sections[i].new_size
+                  - (GElf_Off) dso->shdr[debug_sections[i].sec].sh_size;
+           off = dso->shdr[debug_sections[i].sec].sh_offset;
+         }
        for (j = 1; j < dso->ehdr.e_shnum; ++j)
          if (dso->shdr[j].sh_offset > off)
            dso->shdr[j].sh_offset += diff;
@@ -8750,6 +8801,17 @@ write_dso (DSO *dso, const char *file, struct stat *st)
          }
       }
 
+  if (shstrtabadd != 0)
+    {
+      shstrtab = (char *) malloc (dso->shdr[dso->ehdr.e_shstrndx].sh_size);
+      if (shstrtab == NULL)
+       {
+         error (0, ENOMEM, "Failed to adjust .shstrtab for %s",
+                dso->filename);
+         return 1;
+       }
+    }
+
   if (file == NULL)
     {
       size_t len = strlen (dso->filename);
@@ -8762,6 +8824,7 @@ write_dso (DSO *dso, const char *file, struct stat *st)
        {
          error (0, errno, "Failed to create temporary file for %s",
                 dso->filename);
+         free (shstrtab);
          return 1;
        }
     }
@@ -8771,6 +8834,7 @@ write_dso (DSO *dso, const char *file, struct stat *st)
       if (fd == -1)
        {
          error (0, errno, "Failed to open %s for writing", file);
+         free (shstrtab);
          return 1;
        }
     }
@@ -8781,6 +8845,7 @@ write_dso (DSO *dso, const char *file, struct stat *st)
       error (0, 0, "cannot open ELF file: %s", elf_errmsg (-1));
       unlink (file);
       close (fd);
+      free (shstrtab);
       return 1;
     }
 
@@ -8811,6 +8876,7 @@ write_dso (DSO *dso, const char *file, struct stat *st)
       unlink (file);
       elf_end (elf);
       close (fd);
+      free (shstrtab);
       return 1;
     }
   elf_flagelf (elf, ELF_C_SET, ELF_F_LAYOUT | ELF_F_PERMISSIVE);
@@ -8845,6 +8911,47 @@ write_dso (DSO *dso, const char *file, struct stat *st)
              }
            break;
          }
+      if (i == dso->ehdr.e_shstrndx && shstrtabadd)
+       {
+         memcpy (shstrtab, data1->d_buf,
+                 dso->shdr[dso->ehdr.e_shstrndx].sh_size
+                 - shstrtabadd);
+         data2->d_buf = shstrtab;
+         data2->d_size = dso->shdr[i].sh_size;
+       }
+      if (i == addsec)
+       {
+         GElf_Word sh_name = dso->shdr[dso->ehdr.e_shstrndx].sh_size
+                             - shstrtabadd;
+         GElf_Shdr shdr;
+
+         off = dso->shdr[i].sh_offset + dso->shdr[i].sh_size;
+         for (j = 0; debug_sections[j].name; j++)
+           if (debug_sections[j].new_size
+               && debug_sections[j].size == 0
+               && debug_sections[j].sec == 0)
+             {
+               scn = elf_newscn (elf);
+               elf_flagscn (scn, ELF_C_SET, ELF_F_DIRTY);
+               memset (&shdr, '\0', sizeof (shdr));
+               shdr.sh_name = sh_name;
+               sh_name += strlen (debug_sections[j].name) + 1;
+               strcpy (shstrtab + shdr.sh_name, debug_sections[j].name);
+               shdr.sh_type = SHT_PROGBITS;
+               shdr.sh_offset = off;
+               shdr.sh_size = debug_sections[j].new_size;
+               shdr.sh_addralign = 1;
+               off += shdr.sh_size;
+               gelf_update_shdr (scn, &shdr);
+               data2 = elf_newdata (scn);
+               data2->d_buf = debug_sections[j].new_data;
+               data2->d_type = ELF_T_BYTE;
+               data2->d_version = EV_CURRENT;
+               data2->d_size = shdr.sh_size;
+               data2->d_off = 0;
+               data2->d_align = 1;
+             }
+       }
     }
 
   if (elf_update (elf, ELF_C_WRITE_MMAP) == -1)
@@ -8853,6 +8960,7 @@ write_dso (DSO *dso, const char *file, struct stat *st)
       unlink (file);
       elf_end (elf);
       close (fd);
+      free (shstrtab);
       return 1;
     }
 
@@ -8862,9 +8970,11 @@ write_dso (DSO *dso, const char *file, struct stat *st)
       unlink (file);
       elf_end (elf);
       close (fd);
+      free (shstrtab);
       return 1;
     }
 
+  free (shstrtab);
   fchown (fd, st->st_uid, st->st_gid);
   fchmod (fd, st->st_mode & 07777);
   close (fd);
@@ -9506,7 +9616,19 @@ dwz (const char *file, const char *outfile)
       else
        {
          if (unlikely (fi_multifile))
-           write_macro ();
+           {
+             size_t len = strlen (multifile) + 1;
+             debug_sections[GNU_DEBUGALTLINK].new_size = len + 0x14;
+             debug_sections[GNU_DEBUGALTLINK].new_data
+               = malloc (debug_sections[GNU_DEBUGALTLINK].new_size);
+             if (debug_sections[GNU_DEBUGALTLINK].new_data == NULL)
+               dwz_oom ();
+             memcpy (debug_sections[GNU_DEBUGALTLINK].new_data, multifile,
+                     len);
+             memcpy (debug_sections[GNU_DEBUGALTLINK].new_data + len,
+                     multifile_sha1, 0x14);
+             write_macro ();
+           }
          write_abbrev ();
          write_info ();
          write_loc ();