toolchain/binutils/patches/2.31.1/100-delay_evaluation_of_alignment_expressions_in_output_sections.patch

   1 From 3d9c8f6b3f033a6092425b7344647fb51dbed5c6 Mon Sep 17 00:00:00 2001
   2 From: Alan Modra <amodra@gmail.com>
   3 Date: Sun, 26 Aug 2018 14:23:38 +0930
   4 Subject: [PATCH] Delay evaluation of alignment expressions in output sections
   5
   6 git commit 702d16713 broke expressions using CONSTANT(COMMONPAGESIZE)
   7 in ALIGN or SUBALIGN of output section statements, because these
   8 optional fields were evaluated at script parse time and the patch in
   9 question delayed setting of config.commonpagesize.  The right thing to
  10 do is keep the tree representation of those fields for later
  11 evaluation.
  12
  13         PR 23571
  14         * ldlang.h (section_alignment): Make it an expression tree.
  15         (subsection_alignment): Likewise.
  16         * ldlang.c (topower): Delete.
  17         (output_section_statement_newfunc): Adjust initialization.
  18         (init_os): Evaluate section_alignment.
  19         (lang_size_sections_1): Likewise.
  20         (size_input_section): Evaluate subsection_alignment.
  21         (lang_enter_output_section_statement): Don't evaluate here.
  22         (lang_new_phdr): Use exp_get_vma rather than exp_get_value_int.
  23         * ldexp.h (exp_get_value_int): Delete.
  24         (exp_get_power): Declare.
  25         * ldexp.c (exp_get_value_int): Delete.
  26         (exp_get_power): New function.
  27         * emultempl/pe.em (place_orphan): Build expression for section
  28         alignment.
  29         * emultempl/pep.em (place_orphan): Likewise.
  30         * testsuite/ld-scripts/pr23571.d,
  31         * testsuite/ld-scripts/pr23571.t: New test.
  32         * testsuite/ld-scripts/align.exp: Run it.
  33 ---
  34  ld/ChangeLog                      | 23 +++++++++++++++++++
  35  ld/emultempl/pe.em                |  2 +-
  36  ld/emultempl/pep.em               |  2 +-
  37  ld/ldexp.c                        | 20 ++++++++++++++--
  38  ld/ldexp.h                        |  4 ++--
  39  ld/ldlang.c                       | 48 +++++++++++++--------------------------
  40  ld/ldlang.h                       |  4 ++--
  41  ld/testsuite/ld-scripts/align.exp |  4 ++++
  42  ld/testsuite/ld-scripts/pr23571.d | 10 ++++++++
  43  ld/testsuite/ld-scripts/pr23571.t | 11 +++++++++
  44  10 files changed, 88 insertions(+), 40 deletions(-)
  45  create mode 100644 ld/testsuite/ld-scripts/pr23571.d
  46  create mode 100644 ld/testsuite/ld-scripts/pr23571.t
  47
  48 --- a/ld/emultempl/pe.em
  49 +++ b/ld/emultempl/pe.em
  50 @@ -2165,7 +2165,7 @@ gld_${EMULATION_NAME}_place_orphan (asec
  51                                &add_child);
  52        if (bfd_link_relocatable (&link_info))
  53         {
  54 -         os->section_alignment = s->alignment_power;
  55 +         os->section_alignment = exp_intop (1U << s->alignment_power);
  56           os->bfd_section->alignment_power = s->alignment_power;
  57         }
  58      }
  59 --- a/ld/emultempl/pep.em
  60 +++ b/ld/emultempl/pep.em
  61 @@ -1962,7 +1962,7 @@ gld_${EMULATION_NAME}_place_orphan (asec
  62                                &add_child);
  63        if (bfd_link_relocatable (&link_info))
  64         {
  65 -         os->section_alignment = s->alignment_power;
  66 +         os->section_alignment = exp_intop (1U << s->alignment_power);
  67           os->bfd_section->alignment_power = s->alignment_power;
  68         }
  69      }
  70 --- a/ld/ldexp.c
  71 +++ b/ld/ldexp.c
  72 @@ -1522,10 +1522,26 @@ exp_get_vma (etree_type *tree, bfd_vma d
  73    return def;
  74  }
  75
  76 +/* Return the smallest non-negative integer such that two raised to
  77 +   that power is at least as large as the vma evaluated at TREE, if
  78 +   TREE is a non-NULL expression that can be resolved.  If TREE is
  79 +   NULL or cannot be resolved, return -1.  */
  80 +
  81  int
  82 -exp_get_value_int (etree_type *tree, int def, char *name)
  83 +exp_get_power (etree_type *tree, char *name)
  84  {
  85 -  return exp_get_vma (tree, def, name);
  86 +  bfd_vma x = exp_get_vma (tree, -1, name);
  87 +  bfd_vma p2;
  88 +  int n;
  89 +
  90 +  if (x == (bfd_vma) -1)
  91 +    return -1;
  92 +
  93 +  for (n = 0, p2 = 1; p2 < x; ++n, p2 <<= 1)
  94 +    if (p2 == 0)
  95 +      break;
  96 +
  97 +  return n;
  98  }
  99
 100  fill_type *
 101 --- a/ld/ldexp.h
 102 +++ b/ld/ldexp.h
 103 @@ -229,8 +229,8 @@ void exp_print_tree
 104    (etree_type *);
 105  bfd_vma exp_get_vma
 106    (etree_type *, bfd_vma, char *);
 107 -int exp_get_value_int
 108 -  (etree_type *, int, char *);
 109 +int exp_get_power
 110 +  (etree_type *, char *);
 111  fill_type *exp_get_fill
 112    (etree_type *, fill_type *, char *);
 113  bfd_vma exp_get_abs_int
 114 --- a/ld/ldlang.c
 115 +++ b/ld/ldlang.c
 116 @@ -1199,8 +1199,8 @@ output_section_statement_newfunc (struct
 117    ret = (struct out_section_hash_entry *) entry;
 118    memset (&ret->s, 0, sizeof (ret->s));
 119    ret->s.header.type = lang_output_section_statement_enum;
 120 -  ret->s.output_section_statement.subsection_alignment = -1;
 121 -  ret->s.output_section_statement.section_alignment = -1;
 122 +  ret->s.output_section_statement.subsection_alignment = NULL;
 123 +  ret->s.output_section_statement.section_alignment = NULL;
 124    ret->s.output_section_statement.block_value = 1;
 125    lang_list_init (&ret->s.output_section_statement.children);
 126    lang_statement_append (stat_ptr, &ret->s, &ret->s.header.next);
 127 @@ -2193,8 +2193,9 @@ init_os (lang_output_section_statement_t
 128      exp_init_os (s->load_base);
 129
 130    /* If supplied an alignment, set it.  */
 131 -  if (s->section_alignment != -1)
 132 -    s->bfd_section->alignment_power = s->section_alignment;
 133 +  if (s->section_alignment != NULL)
 134 +    s->bfd_section->alignment_power = exp_get_power (s->section_alignment,
 135 +                                                    "section alignment");
 136  }
 137
 138  /* Make sure that all output sections mentioned in an expression are
 139 @@ -4706,8 +4707,10 @@ size_input_section
 140          is greater than any seen before, then record it too.  Perform
 141          the alignment by inserting a magic 'padding' statement.  */
 142
 143 -      if (output_section_statement->subsection_alignment != -1)
 144 -       i->alignment_power = output_section_statement->subsection_alignment;
 145 +      if (output_section_statement->subsection_alignment != NULL)
 146 +       i->alignment_power
 147 +         = exp_get_power (output_section_statement->subsection_alignment,
 148 +                          "subsection alignment");
 149
 150        if (o->alignment_power < i->alignment_power)
 151         o->alignment_power = i->alignment_power;
 152 @@ -5147,7 +5150,8 @@ lang_size_sections_1
 153                     section_alignment = os->bfd_section->alignment_power;
 154                   }
 155                 else
 156 -                 section_alignment = os->section_alignment;
 157 +                 section_alignment = exp_get_power (os->section_alignment,
 158 +                                                    "section alignment");
 159
 160                 /* Align to what the section needs.  */
 161                 if (section_alignment > 0)
 162 @@ -5225,7 +5229,8 @@ lang_size_sections_1
 163                        only align according to the value in the output
 164                        statement.  */
 165                     if (os->lma_region != os->region)
 166 -                     section_alignment = os->section_alignment;
 167 +                     section_alignment = exp_get_power (os->section_alignment,
 168 +                                                        "section alignment");
 169                     if (section_alignment > 0)
 170                       lma = align_power (lma, section_alignment);
 171                   }
 172 @@ -6673,25 +6678,6 @@ lang_add_output (const char *name, int f
 173      }
 174  }
 175
 176 -static int
 177 -topower (int x)
 178 -{
 179 -  unsigned int i = 1;
 180 -  int l;
 181 -
 182 -  if (x < 0)
 183 -    return -1;
 184 -
 185 -  for (l = 0; l < 32; l++)
 186 -    {
 187 -      if (i >= (unsigned int) x)
 188 -       return l;
 189 -      i <<= 1;
 190 -    }
 191 -
 192 -  return 0;
 193 -}
 194 -
 195  lang_output_section_statement_type *
 196  lang_enter_output_section_statement (const char *output_section_statement_name,
 197                                      etree_type *address_exp,
 198 @@ -6727,10 +6713,8 @@ lang_enter_output_section_statement (con
 199      einfo (_("%F%P:%pS: error: align with input and explicit align specified\n"),
 200            NULL);
 201
 202 -  os->subsection_alignment =
 203 -    topower (exp_get_value_int (subalign, -1, "subsection alignment"));
 204 -  os->section_alignment =
 205 -    topower (exp_get_value_int (align, -1, "section alignment"));
 206 +  os->subsection_alignment = subalign;
 207 +  os->section_alignment = align;
 208
 209    os->load_base = ebase;
 210    return os;
 211 @@ -7748,7 +7732,7 @@ lang_new_phdr (const char *name,
 212    n = (struct lang_phdr *) stat_alloc (sizeof (struct lang_phdr));
 213    n->next = NULL;
 214    n->name = name;
 215 -  n->type = exp_get_value_int (type, 0, "program header type");
 216 +  n->type = exp_get_vma (type, 0, "program header type");
 217    n->filehdr = filehdr;
 218    n->phdrs = phdrs;
 219    n->at = at;
 220 --- a/ld/ldlang.h
 221 +++ b/ld/ldlang.h
 222 @@ -143,6 +143,8 @@ typedef struct lang_output_section_state
 223    fill_type *fill;
 224    union etree_union *addr_tree;
 225    union etree_union *load_base;
 226 +  union etree_union *section_alignment;
 227 +  union etree_union *subsection_alignment;
 228
 229    /* If non-null, an expression to evaluate after setting the section's
 230       size.  The expression is evaluated inside REGION (above) with '.'
 231 @@ -153,8 +155,6 @@ typedef struct lang_output_section_state
 232    lang_output_section_phdr_list *phdrs;
 233
 234    unsigned int block_value;
 235 -  int subsection_alignment;    /* Alignment of components.  */
 236 -  int section_alignment;       /* Alignment of start of section.  */
 237    int constraint;
 238    flagword flags;
 239    enum section_type sectype;
 240 --- a/ld/testsuite/ld-scripts/align.exp
 241 +++ b/ld/testsuite/ld-scripts/align.exp
 242 @@ -53,3 +53,7 @@ if ![is_aout_format] {
 243  }
 244  run_dump_test align2c
 245  set LDFLAGS "$saved_LDFLAGS"
 246 +
 247 +if { [is_elf_format] && ![is_generic_elf] } {
 248 +    run_dump_test pr23571
 249 +}
 250 --- /dev/null
 251 +++ b/ld/testsuite/ld-scripts/pr23571.d
 252 @@ -0,0 +1,10 @@
 253 +#source: align2a.s
 254 +#ld: -T pr23571.t -z common-page-size=0x1000
 255 +#objdump: -h -w
 256 +
 257 +.*: +file format .*
 258 +
 259 +Sections:
 260 +Idx Name +Size +VMA +LMA +File off +Algn +Flags
 261 + +0 \.text +[0-9a-f]* +0+1000 +0+1000 .*
 262 + +1 \.data +[0-9a-f]* +0+2000 +0+2000 +[0-9a-f]* +2\*\*12 .*
 263 --- /dev/null
 264 +++ b/ld/testsuite/ld-scripts/pr23571.t
 265 @@ -0,0 +1,11 @@
 266 +SECTIONS
 267 +{
 268 +  .text CONSTANT(COMMONPAGESIZE) : {
 269 +    *(.text)
 270 +  }
 271 +
 272 +  .data : ALIGN(CONSTANT(COMMONPAGESIZE)) {
 273 +    *(.data)
 274 +  }
 275 +  /DISCARD/ : {*(*)}
 276 +}