Report overflow on PowerPC64 @h and @ha relocations.

This changes the behaviour of @h and @ha on PowerPC64 to report errors
on 32-bit overflow.  The motivation for this change is that on
PowerPC64, most uses of @h and @ha modifiers and their corresponding
relocations are to build up 32-bit offsets.  We'd like to know when
such offsets overflow.  Only rarely do people use @h or @ha with the
high 32-bit modifiers to build a 64-bit constant.  Those uses will now
need to use two new modifiers, @high and @higha, if the constant isn't
known at assembly time.  For now, we won't report overflow at assembly
time..

This also fixes an error when applying some of the HIGHER and HIGHEST
relocations.

include/elf/
	* ppc64.h (R_PPC64_ADDR16_HIGH, R_PPC64_ADDR16_HIGHA,
	R_PPC64_TPREL16_HIGH, R_PPC64_TPREL16_HIGHA,
	R_PPC64_DTPREL16_HIGH, R_PPC64_DTPREL16_HIGHA): New.
	(IS_PPC64_TLS_RELOC): Match new tls relocs.
bfd/
	* reloc.c (BFD_RELOC_PPC64_ADDR16_HIGH, BFD_RELOC_PPC64_ADDR16_HIGHA,
	BFD_RELOC_PPC64_TPREL16_HIGH, BFD_RELOC_PPC64_TPREL16_HIGHA,
	BFD_RELOC_PPC64_DTPREL16_HIGH, BFD_RELOC_PPC64_DTPREL16_HIGHA): New.
	* elf64-ppc.c (ppc64_elf_howto_raw): Add entries for new relocs.
	Make all _HA and _HI relocs report signed overflow.
	(ppc64_elf_reloc_type_lookup): Handle new relocs.
	(must_be_dyn_reloc, ppc64_elf_check_relocs): Likewise.
	(dec_dynrel_count, ppc64_elf_relocate_section): Likewise.
	(ppc64_elf_relocate_section): Don't apply 0x8000 adjust to
	R_PPC64_TPREL16_HIGHER, R_PPC64_TPREL16_HIGHEST,
	R_PPC64_DTPREL16_HIGHER, and R_PPC64_DTPREL16_HIGHEST.
	* libbfd.h: Regenerate.
	* bfd-in2.h: Regenerate.
gas/
	* config/tc-ppc.c (SEX16): Don't mask.
	(REPORT_OVERFLOW_HI): Define as zero.
	(ppc_elf_suffix): Support @high, @higha, @dtprel@high, @dtprel@higha,
	@tprel@high, and @tprel@higha modifiers.
	(md_assemble): Ignore X_unsigned when applying 16-bit insn fields.
	Add (disabled) code to check @h and @ha reloc overflow for powerpc64.
	Handle new relocs.
	(md_apply_fix): Similarly.
elfcpp/
	* powerpc.h (R_PPC64_ADDR16_HIGH, R_PPC64_ADDR16_HIGHA,
	R_PPC64_TPREL16_HIGH, R_PPC64_TPREL16_HIGHA,
	R_PPC64_DTPREL16_HIGH, R_PPC64_DTPREL16_HIGHA): Define.
gold/
	* powerpc.cc (Target_powerpc::Scan::check_non_pic): Handle new relocs.
	(Target_powerpc::Scan::global, local): Likewise.
	(Target_powerpc::Relocate::relocate): Likewise.  Check for overflow
	on all ppc64 @h and @ha relocs.

2 files changed, 114 insertions, 36 deletions

diff --git a/gas/ChangeLog b/gas/ChangeLog
index 1490eea..a1b71b0 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,3 +1,14 @@
+2013-10-30  Alan Modra  <amodra@gmail.com>
+
+	* config/tc-ppc.c (SEX16): Don't mask.
+	(REPORT_OVERFLOW_HI): Define as zero.
+	(ppc_elf_suffix): Support @high, @higha, @dtprel@high, @dtprel@higha,
+	@tprel@high, and @tprel@higha modifiers.
+	(md_assemble): Ignore X_unsigned when applying 16-bit insn fields.
+	Add (disabled) code to check @h and @ha reloc overflow for powerpc64.
+	Handle new relocs.
+	(md_apply_fix): Similarly.
+
 2013-10-18  Chao-ying Fu  <Chao-ying.Fu@imgtec.com>
 
 	* config/tc-mips.c (fpr_read_mask): Test MSA registers.
diff --git a/gas/config/tc-ppc.c b/gas/config/tc-ppc.c
index 6b54f5a..34afc91 100644
--- a/gas/config/tc-ppc.c
+++ b/gas/config/tc-ppc.c
@@ -86,7 +86,11 @@ static int set_target_endian = 0;
    compensating for #lo being treated as a signed number.  */
 #define PPC_HIGHESTA(v) PPC_HIGHEST ((v) + 0x8000)
 
-#define SEX16(val) ((((val) & 0xffff) ^ 0x8000) - 0x8000)
+#define SEX16(val) (((val) ^ 0x8000) - 0x8000)
+
+/* For the time being on ppc64, don't report overflow on @h and @ha
+   applied to constants.  */
+#define REPORT_OVERFLOW_HI 0
 
 static bfd_boolean reg_names_p = TARGET_REG_NAMES_P;
 
@@ -1923,6 +1927,8 @@ ppc_elf_suffix (char **str_p, expressionS *exp_p)
     MAP32 ("bitfld",		BFD_RELOC_PPC_EMB_BIT_FLD),
     MAP32 ("relsda",		BFD_RELOC_PPC_EMB_RELSDA),
     MAP32 ("xgot",		BFD_RELOC_PPC_TOC16),
+    MAP64 ("high",		BFD_RELOC_PPC64_ADDR16_HIGH),
+    MAP64 ("higha",		BFD_RELOC_PPC64_ADDR16_HIGHA),
     MAP64 ("higher",		BFD_RELOC_PPC64_HIGHER),
     MAP64 ("highera",		BFD_RELOC_PPC64_HIGHER_S),
     MAP64 ("highest",		BFD_RELOC_PPC64_HIGHEST),
@@ -1932,10 +1938,14 @@ ppc_elf_suffix (char **str_p, expressionS *exp_p)
     MAP64 ("toc@l",		BFD_RELOC_PPC64_TOC16_LO),
     MAP64 ("toc@h",		BFD_RELOC_PPC64_TOC16_HI),
     MAP64 ("toc@ha",		BFD_RELOC_PPC64_TOC16_HA),
+    MAP64 ("dtprel@high",	BFD_RELOC_PPC64_DTPREL16_HIGH),
+    MAP64 ("dtprel@higha",	BFD_RELOC_PPC64_DTPREL16_HIGHA),
     MAP64 ("dtprel@higher",	BFD_RELOC_PPC64_DTPREL16_HIGHER),
     MAP64 ("dtprel@highera",	BFD_RELOC_PPC64_DTPREL16_HIGHERA),
     MAP64 ("dtprel@highest",	BFD_RELOC_PPC64_DTPREL16_HIGHEST),
     MAP64 ("dtprel@highesta",	BFD_RELOC_PPC64_DTPREL16_HIGHESTA),
+    MAP64 ("tprel@high",	BFD_RELOC_PPC64_TPREL16_HIGH),
+    MAP64 ("tprel@higha",	BFD_RELOC_PPC64_TPREL16_HIGHA),
     MAP64 ("tprel@higher",	BFD_RELOC_PPC64_TPREL16_HIGHER),
     MAP64 ("tprel@highera",	BFD_RELOC_PPC64_TPREL16_HIGHERA),
     MAP64 ("tprel@highest",	BFD_RELOC_PPC64_TPREL16_HIGHEST),
@@ -2810,55 +2820,76 @@ md_assemble (char *str)
 		break;
 
 	      case BFD_RELOC_LO16:
-		/* X_unsigned is the default, so if the user has done
-		   something which cleared it, we always produce a
-		   signed value.  */
-		if (ex.X_unsigned && ! (operand->flags & PPC_OPERAND_SIGNED))
-		  ex.X_add_number &= 0xffff;
-		else
+		ex.X_add_number &= 0xffff;
+		if ((operand->flags & PPC_OPERAND_SIGNED) != 0)
 		  ex.X_add_number = SEX16 (ex.X_add_number);
 		break;
 
 	      case BFD_RELOC_HI16:
-		if (ex.X_unsigned && ! (operand->flags & PPC_OPERAND_SIGNED))
-		  ex.X_add_number = PPC_HI (ex.X_add_number);
-		else
-		  ex.X_add_number = SEX16 (PPC_HI (ex.X_add_number));
+		if (REPORT_OVERFLOW_HI && ppc_obj64)
+		  {
+		    /* PowerPC64 @h is tested for overflow.  */
+		    ex.X_add_number = (addressT) ex.X_add_number >> 16;
+		    if ((operand->flags & PPC_OPERAND_SIGNED) != 0)
+		      {
+			addressT sign = (((addressT) -1 >> 16) + 1) >> 1;
+			ex.X_add_number
+			  = ((addressT) ex.X_add_number ^ sign) - sign;
+		      }
+		    break;
+		  }
+		/* Fall thru */
+
+	      case BFD_RELOC_PPC64_ADDR16_HIGH:
+		ex.X_add_number = PPC_HI (ex.X_add_number);
+		if ((operand->flags & PPC_OPERAND_SIGNED) != 0)
+		  ex.X_add_number = SEX16 (ex.X_add_number);
 		break;
 
 	      case BFD_RELOC_HI16_S:
-		if (ex.X_unsigned && ! (operand->flags & PPC_OPERAND_SIGNED))
-		  ex.X_add_number = PPC_HA (ex.X_add_number);
-		else
-		  ex.X_add_number = SEX16 (PPC_HA (ex.X_add_number));
+		if (REPORT_OVERFLOW_HI && ppc_obj64)
+		  {
+		    /* PowerPC64 @ha is tested for overflow.  */
+		    ex.X_add_number
+		      = ((addressT) ex.X_add_number + 0x8000) >> 16;
+		    if ((operand->flags & PPC_OPERAND_SIGNED) != 0)
+		      {
+			addressT sign = (((addressT) -1 >> 16) + 1) >> 1;
+			ex.X_add_number
+			  = ((addressT) ex.X_add_number ^ sign) - sign;
+		      }
+		    break;
+		  }
+		/* Fall thru */
+
+	      case BFD_RELOC_PPC64_ADDR16_HIGHA:
+		ex.X_add_number = PPC_HA (ex.X_add_number);
+		if ((operand->flags & PPC_OPERAND_SIGNED) != 0)
+		  ex.X_add_number = SEX16 (ex.X_add_number);
 		break;
 
 	      case BFD_RELOC_PPC64_HIGHER:
-		if (ex.X_unsigned && ! (operand->flags & PPC_OPERAND_SIGNED))
-		  ex.X_add_number = PPC_HIGHER (ex.X_add_number);
-		else
-		  ex.X_add_number = SEX16 (PPC_HIGHER (ex.X_add_number));
+		ex.X_add_number = PPC_HIGHER (ex.X_add_number);
+		if ((operand->flags & PPC_OPERAND_SIGNED) != 0)
+		  ex.X_add_number = SEX16 (ex.X_add_number);
 		break;
 
 	      case BFD_RELOC_PPC64_HIGHER_S:
-		if (ex.X_unsigned && ! (operand->flags & PPC_OPERAND_SIGNED))
-		  ex.X_add_number = PPC_HIGHERA (ex.X_add_number);
-		else
-		  ex.X_add_number = SEX16 (PPC_HIGHERA (ex.X_add_number));
+		ex.X_add_number = PPC_HIGHERA (ex.X_add_number);
+		if ((operand->flags & PPC_OPERAND_SIGNED) != 0)
+		  ex.X_add_number = SEX16 (ex.X_add_number);
 		break;
 
 	      case BFD_RELOC_PPC64_HIGHEST:
-		if (ex.X_unsigned && ! (operand->flags & PPC_OPERAND_SIGNED))
-		  ex.X_add_number = PPC_HIGHEST (ex.X_add_number);
-		else
-		  ex.X_add_number = SEX16 (PPC_HIGHEST (ex.X_add_number));
+		ex.X_add_number = PPC_HIGHEST (ex.X_add_number);
+		if ((operand->flags & PPC_OPERAND_SIGNED) != 0)
+		  ex.X_add_number = SEX16 (ex.X_add_number);
 		break;
 
 	      case BFD_RELOC_PPC64_HIGHEST_S:
-		if (ex.X_unsigned && ! (operand->flags & PPC_OPERAND_SIGNED))
-		  ex.X_add_number = PPC_HIGHESTA (ex.X_add_number);
-		else
-		  ex.X_add_number = SEX16 (PPC_HIGHESTA (ex.X_add_number));
+		ex.X_add_number = PPC_HIGHESTA (ex.X_add_number);
+		if ((operand->flags & PPC_OPERAND_SIGNED) != 0)
+		  ex.X_add_number = SEX16 (ex.X_add_number);
 		break;
 	      }
 #endif /* OBJ_ELF */
@@ -6390,25 +6421,51 @@ md_apply_fix (fixS *fixP, valueT *valP, segT seg ATTRIBUTE_UNUSED)
       fieldval = value & 0xffff;
     sign_extend_16:
       if (operand != NULL && (operand->flags & PPC_OPERAND_SIGNED) != 0)
-	fieldval = (fieldval ^ 0x8000) - 0x8000;
+	fieldval = SEX16 (fieldval);
       fixP->fx_no_overflow = 1;
       break;
 
+    case BFD_RELOC_HI16:
+    case BFD_RELOC_HI16_PCREL:
 #ifdef OBJ_ELF
+      if (REPORT_OVERFLOW_HI && ppc_obj64)
+	{
+	  fieldval = value >> 16;
+	  if (operand != NULL && (operand->flags & PPC_OPERAND_SIGNED) != 0)
+	    {
+	      valueT sign = (((valueT) -1 >> 16) + 1) >> 1;
+	      fieldval = ((valueT) fieldval ^ sign) - sign;
+	    }
+	  break;
+	}
+      /* Fall thru */
+
     case BFD_RELOC_PPC_VLE_HI16A:
     case BFD_RELOC_PPC_VLE_HI16D:
+    case BFD_RELOC_PPC64_ADDR16_HIGH:
 #endif
-    case BFD_RELOC_HI16:
-    case BFD_RELOC_HI16_PCREL:
       fieldval = PPC_HI (value);
       goto sign_extend_16;
 
+    case BFD_RELOC_HI16_S:
+    case BFD_RELOC_HI16_S_PCREL:
 #ifdef OBJ_ELF
+      if (REPORT_OVERFLOW_HI && ppc_obj64)
+	{
+	  fieldval = (value + 0x8000) >> 16;
+	  if (operand != NULL && (operand->flags & PPC_OPERAND_SIGNED) != 0)
+	    {
+	      valueT sign = (((valueT) -1 >> 16) + 1) >> 1;
+	      fieldval = ((valueT) fieldval ^ sign) - sign;
+	    }
+	  break;
+	}
+      /* Fall thru */
+
     case BFD_RELOC_PPC_VLE_HA16A:
     case BFD_RELOC_PPC_VLE_HA16D:
+    case BFD_RELOC_PPC64_ADDR16_HIGHA:
 #endif
-    case BFD_RELOC_HI16_S:
-    case BFD_RELOC_HI16_S_PCREL:
       fieldval = PPC_HA (value);
       goto sign_extend_16;
 
@@ -6471,10 +6528,14 @@ md_apply_fix (fixS *fixP, valueT *valP, segT seg ATTRIBUTE_UNUSED)
 	case BFD_RELOC_PPC_GOT_DTPREL16_HA:
 	case BFD_RELOC_PPC64_TPREL16_DS:
 	case BFD_RELOC_PPC64_TPREL16_LO_DS:
+	case BFD_RELOC_PPC64_TPREL16_HIGH:
+	case BFD_RELOC_PPC64_TPREL16_HIGHA:
 	case BFD_RELOC_PPC64_TPREL16_HIGHER:
 	case BFD_RELOC_PPC64_TPREL16_HIGHERA:
 	case BFD_RELOC_PPC64_TPREL16_HIGHEST:
 	case BFD_RELOC_PPC64_TPREL16_HIGHESTA:
+	case BFD_RELOC_PPC64_DTPREL16_HIGH:
+	case BFD_RELOC_PPC64_DTPREL16_HIGHA:
 	case BFD_RELOC_PPC64_DTPREL16_DS:
 	case BFD_RELOC_PPC64_DTPREL16_LO_DS:
 	case BFD_RELOC_PPC64_DTPREL16_HIGHER:
@@ -6660,6 +6721,8 @@ md_apply_fix (fixS *fixP, valueT *valP, segT seg ATTRIBUTE_UNUSED)
 	case BFD_RELOC_PPC64_HIGHER_S:
 	case BFD_RELOC_PPC64_HIGHEST:
 	case BFD_RELOC_PPC64_HIGHEST_S:
+	case BFD_RELOC_PPC64_ADDR16_HIGH:
+	case BFD_RELOC_PPC64_ADDR16_HIGHA:
 	  break;
 
 	case BFD_RELOC_PPC_DTPMOD:
@@ -6736,10 +6799,14 @@ md_apply_fix (fixS *fixP, valueT *valP, segT seg ATTRIBUTE_UNUSED)
 	case BFD_RELOC_PPC64_TOC16_LO:
 	case BFD_RELOC_PPC64_TOC16_HI:
 	case BFD_RELOC_PPC64_TOC16_HA:
+	case BFD_RELOC_PPC64_DTPREL16_HIGH:
+	case BFD_RELOC_PPC64_DTPREL16_HIGHA:
 	case BFD_RELOC_PPC64_DTPREL16_HIGHER:
 	case BFD_RELOC_PPC64_DTPREL16_HIGHERA:
 	case BFD_RELOC_PPC64_DTPREL16_HIGHEST:
 	case BFD_RELOC_PPC64_DTPREL16_HIGHESTA:
+	case BFD_RELOC_PPC64_TPREL16_HIGH:
+	case BFD_RELOC_PPC64_TPREL16_HIGHA:
 	case BFD_RELOC_PPC64_TPREL16_HIGHER:
 	case BFD_RELOC_PPC64_TPREL16_HIGHERA:
 	case BFD_RELOC_PPC64_TPREL16_HIGHEST: