PowerPC disassembly of pcrel references

This adds some annotation to Power10 pcrel instructions, displaying
the target address (ie. pc + D34 field) plus a symbol if there is one
at exactly that target address.  pld from the .got or .plt will also
look up the entry and display it, symbolically if there is a dynamic
relocation on the entry.

include/
	* dis-asm.h (struct disassemble_info): Add dynrelbuf and dynrelcount.
binutils/
	* objdump.c (struct objdump_disasm_info): Delete dynrelbuf and
	dynrelcount.
	(find_symbol_for_address): Adjust for dynrelbuf and dynrelcount move.
	(disassemble_section, disassemble_data): Likewise.
opcodes/
	* ppc-dis.c (struct dis_private): Add "special".
	(POWERPC_DIALECT): Delete.  Replace uses with..
	(private_data): ..this.  New inline function.
	(disassemble_init_powerpc): Init "special" names.
	(skip_optional_operands): Add is_pcrel arg, set when detecting R
	field of prefix instructions.
	(bsearch_reloc, print_got_plt): New functions.
	(print_insn_powerpc): For pcrel instructions, print target address
	and symbol if known, and decode plt and got loads too.
gas/
	* testsuite/gas/ppc/prefix-pcrel.d: Update expected output.
	* testsuite/gas/ppc/prefix-reloc.d: Likewise.
	* gas/testsuite/gas/ppc/vsx_32byte.d: Likewise.
ld/
	* testsuite/ld-powerpc/inlinepcrel-1.d: Update expected output.
	* testsuite/ld-powerpc/inlinepcrel-2.d: Likewise.
	* testsuite/ld-powerpc/notoc2.d: Likewise.
	* testsuite/ld-powerpc/notoc3.d: Likewise.
	* testsuite/ld-powerpc/pcrelopt.d: Likewise.
	* testsuite/ld-powerpc/startstop.d: Likewise.
	* testsuite/ld-powerpc/tlsget.d: Likewise.
	* testsuite/ld-powerpc/tlsget2.d: Likewise.
	* testsuite/ld-powerpc/tlsld.d: Likewise.
	* testsuite/ld-powerpc/weak1.d: Likewise.
	* testsuite/ld-powerpc/weak1so.d: Likewise.

2 files changed, 143 insertions, 10 deletions

diff --git a/opcodes/ChangeLog b/opcodes/ChangeLog
index 9a94b9c..f6c5eef 100644
--- a/opcodes/ChangeLog
+++ b/opcodes/ChangeLog
@@ -1,3 +1,15 @@
+2021-04-09  Alan Modra  <amodra@gmail.com>
+
+	* ppc-dis.c (struct dis_private): Add "special".
+	(POWERPC_DIALECT): Delete.  Replace uses with..
+	(private_data): ..this.  New inline function.
+	(disassemble_init_powerpc): Init "special" names.
+	(skip_optional_operands): Add is_pcrel arg, set when detecting R
+	field of prefix instructions.
+	(bsearch_reloc, print_got_plt): New functions.
+	(print_insn_powerpc): For pcrel instructions, print target address
+	and symbol if known, and decode plt and got loads too.
+
 2021-04-08  Alan Modra  <amodra@gmail.com>
 
 	PR 27684
diff --git a/opcodes/ppc-dis.c b/opcodes/ppc-dis.c
index dc0825a..739195a 100644
--- a/opcodes/ppc-dis.c
+++ b/opcodes/ppc-dis.c
@@ -40,10 +40,20 @@ struct dis_private
 {
   /* Stash the result of parsing disassembler_options here.  */
   ppc_cpu_t dialect;
+
+  /* .got and .plt sections.  NAME is set to NULL if not present.  */
+  struct sec_buf {
+    asection *sec;
+    bfd_byte *buf;
+    const char *name;
+  } special[2];
 };
 
-#define POWERPC_DIALECT(INFO) \
-  (((struct dis_private *) ((INFO)->private_data))->dialect)
+static inline struct dis_private *
+private_data (struct disassemble_info *info)
+{
+  return (struct dis_private *) info->private_data;
+}
 
 struct ppc_mopt {
   /* Option string, without -m or -M prefix.  */
@@ -270,7 +280,7 @@ get_powerpc_dialect (struct disassemble_info *info)
   ppc_cpu_t dialect = 0;
 
   if (info->private_data)
-    dialect = POWERPC_DIALECT (info);
+    dialect = private_data (info)->dialect;
 
   /* Disassemble according to the section headers flags for VLE-mode.  */
   if (dialect & PPC_OPCODE_VLE
@@ -387,7 +397,7 @@ powerpc_init_dialect (struct disassemble_info *info)
     }
 
   info->private_data = priv;
-  POWERPC_DIALECT(info) = dialect;
+  private_data (info)->dialect = dialect;
 }
 
 #define PPC_OPCD_SEGS (1 + PPC_OP (-1))
@@ -409,7 +419,7 @@ ppc_symbol_is_valid (asymbol *sym,
     return false;
 
   est = elf_symbol_from (sym);
-  
+
   /* Ignore ELF hidden, local, no-type symbols.
      These are generated by annobin.  */
   if (est != NULL
@@ -477,6 +487,11 @@ disassemble_init_powerpc (struct disassemble_info *info)
     }
 
   powerpc_init_dialect (info);
+  if (info->private_data != NULL)
+    {
+      private_data (info)->special[0].name = ".got";
+      private_data (info)->special[1].name = ".plt";
+    }
 }
 
 /* Print a big endian PowerPC instruction.  */
@@ -532,7 +547,7 @@ operand_value_powerpc (const struct powerpc_operand *operand,
 
 static bool
 skip_optional_operands (const unsigned char *opindex,
-			uint64_t insn, ppc_cpu_t dialect)
+			uint64_t insn, ppc_cpu_t dialect, bool *is_pcrel)
 {
   const struct powerpc_operand *operand;
   int num_optional;
@@ -544,11 +559,15 @@ skip_optional_operands (const unsigned char *opindex,
 	return false;
       if ((operand->flags & PPC_OPERAND_OPTIONAL) != 0)
 	{
+	  int64_t value = operand_value_powerpc (operand, insn, dialect);
+
+	  if (operand->shift == 52)
+	    *is_pcrel = value != 0;
+
 	  /* Negative count is used as a flag to extract function.  */
 	  --num_optional;
-	  if (operand_value_powerpc (operand, insn, dialect)
-	      != ppc_optional_operand_value (operand, insn, dialect,
-					     num_optional))
+	  if (value != ppc_optional_operand_value (operand, insn, dialect,
+						   num_optional))
 	    return false;
 	}
     }
@@ -764,6 +783,75 @@ lookup_spe2 (uint64_t insn)
   return NULL;
 }
 
+static arelent *
+bsearch_reloc (arelent **lo, arelent **hi, bfd_vma vma)
+{
+  while (lo < hi)
+    {
+      arelent **mid = lo + (hi - lo) / 2;
+      arelent *rel = *mid;
+
+      if (vma < rel->address)
+	hi = mid;
+      else if (vma > rel->address)
+	lo = mid + 1;
+      else
+	return rel;
+    }
+  return NULL;
+}
+
+static bool
+print_got_plt (struct sec_buf *sb, uint64_t vma, struct disassemble_info *info)
+{
+  if (sb->name != NULL)
+    {
+      asection *s = sb->sec;
+      if (s == NULL)
+	{
+	  s = bfd_get_section_by_name (info->section->owner, sb->name);
+	  sb->sec = s;
+	  if (s == NULL)
+	    sb->name = NULL;
+	}
+      if (s != NULL
+	  && vma >= s->vma
+	  && vma < s->vma + s->size)
+	{
+	  asymbol *sym = NULL;
+	  uint64_t ent = 0;
+	  if (info->dynrelcount > 0)
+	    {
+	      arelent **lo = info->dynrelbuf;
+	      arelent **hi = lo + info->dynrelcount;
+	      arelent *rel = bsearch_reloc (lo, hi, vma);
+	      if (rel != NULL && rel->sym_ptr_ptr != NULL)
+		sym = *rel->sym_ptr_ptr;
+	    }
+	  if (sym == NULL && (s->flags & SEC_HAS_CONTENTS) != 0)
+	    {
+	      if (sb->buf == NULL
+		  && !bfd_malloc_and_get_section (s->owner, s, &sb->buf))
+		sb->name = NULL;
+	      if (sb->buf != NULL)
+		{
+		  ent = bfd_get_64 (s->owner, sb->buf + (vma - s->vma));
+		  if (ent != 0)
+		    sym = (*info->symbol_at_address_func) (ent, info);
+		}
+	    }
+	  if (sym != NULL)
+	    (*info->fprintf_func) (info->stream, " [%s@%s]",
+				   bfd_asymbol_name (sym), sb->name + 1);
+	  else
+	    (*info->fprintf_func) (info->stream, " [%" PRIx64 "@%s]",
+				   ent, sb->name + 1);
+	  return true;
+	}
+    }
+  return false;
+}
+
 /* Print a PowerPC or POWER instruction.  */
 
 static int
@@ -862,6 +950,8 @@ print_insn_powerpc (bfd_vma memaddr,
 	need_paren
       } op_separator;
       bool skip_optional;
+      bool is_pcrel;
+      uint64_t d34;
       int blanks;
 
       (*info->fprintf_func) (info->stream, "%s", opcode->name);
@@ -873,6 +963,8 @@ print_insn_powerpc (bfd_vma memaddr,
       /* Now extract and print the operands.  */
       op_separator = blanks;
       skip_optional = false;
+      is_pcrel = false;
+      d34 = 0;
       for (opindex = opcode->operands; *opindex != 0; opindex++)
 	{
 	  int64_t value;
@@ -886,7 +978,8 @@ print_insn_powerpc (bfd_vma memaddr,
 	      && (dialect & PPC_OPCODE_RAW) == 0)
 	    {
 	      if (!skip_optional)
-		skip_optional = skip_optional_operands (opindex, insn, dialect);
+		skip_optional = skip_optional_operands (opindex, insn,
+							dialect, &is_pcrel);
 	      if (skip_optional)
 		continue;
 	    }
@@ -945,6 +1038,11 @@ print_insn_powerpc (bfd_vma memaddr,
 	  else
 	    (*info->fprintf_func) (info->stream, "%" PRId64, value);
 
+	  if (operand->shift == 52)
+	    is_pcrel = value != 0;
+	  else if (operand->bitm == UINT64_C (0x3ffffffff))
+	    d34 = value;
+
 	  if (op_separator == need_paren)
 	    (*info->fprintf_func) (info->stream, ")");
 
@@ -953,6 +1051,29 @@ print_insn_powerpc (bfd_vma memaddr,
 	    op_separator = need_paren;
 	}
 
+      if (is_pcrel)
+	{
+	  d34 += memaddr;
+	  (*info->fprintf_func) (info->stream, "\t# %" PRIx64, d34);
+	  asymbol *sym = (*info->symbol_at_address_func) (d34, info);
+	  if (sym)
+	    (*info->fprintf_func) (info->stream, " <%s>",
+				   bfd_asymbol_name (sym));
+
+	  if (info->private_data != NULL
+	      && info->section != NULL
+	      && info->section->owner != NULL
+	      && (bfd_get_file_flags (info->section->owner)
+		  & (EXEC_P | DYNAMIC)) != 0
+	      && ((insn & ((-1ULL << 50) | (0x3fULL << 26)))
+		  == ((1ULL << 58) | (1ULL << 52) | (57ULL << 26)) /* pld */))
+	    {
+	      for (int i = 0; i < 2; i++)
+		if (print_got_plt (private_data (info)->special + i, d34, info))
+		  break;
+	    }
+	}
+
       /* We have found and printed an instruction.  */
       return insn_length;
     }