dwarf2.h (DW_EH_PE_aligned): New.

        * dwarf2.h (DW_EH_PE_aligned): New.
        * dwarf2asm.c (eh_data_format_name): Name it.
        (dw2_asm_output_encoded_addr_rtx): Align for it.
        * dwarf2out.c (output_call_frame_info): Handle it for personality
        routine and LSDA pointers.

        * unwind-pe.h (DW_EH_PE_aligned): New.
        (base_of_encoded_value): Handle it.
        (read_encoded_value_with_base): Likewise.
        * unwind-dw2-fde.c (base_from_object): Likewise.
        (get_cie_encoding): Likewise.

        * config/alpha/elf.h: Remove ecoff commentary.
        * config/alpha/osf.h (ASM_PREFERRED_EH_DATA_FORMAT): New.

From-SVN: r42926

gcc/ChangeLog

+2001-06-05  Richard Henderson  <rth@redhat.com>
+
+	* dwarf2.h (DW_EH_PE_aligned): New.
+	* dwarf2asm.c (eh_data_format_name): Name it.
+	(dw2_asm_output_encoded_addr_rtx): Align for it.
+	* dwarf2out.c (output_call_frame_info): Handle it for personality
+	routine and LSDA pointers.
+
+	* unwind-pe.h (DW_EH_PE_aligned): New.
+	(base_of_encoded_value): Handle it.
+	(read_encoded_value_with_base): Likewise.
+	* unwind-dw2-fde.c (base_from_object): Likewise.
+	(get_cie_encoding): Likewise.
+
+	* config/alpha/elf.h: Remove ecoff commentary.
+	* config/alpha/osf.h (ASM_PREFERRED_EH_DATA_FORMAT): New.
+
 2001-06-05  David O'Brien  <obrien@FreeBSD.org>
 
 	* config.gcc, config/i386/bsd386.h:  Do not directly include

gcc/config/alpha/elf.h

@@ -686,8 +686,6 @@ void FN ()					\
 #undef UNALIGNED_INT_ASM_OP
 #undef UNALIGNED_DOUBLE_INT_ASM_OP
 
-/* ??? This should be possible for ECOFF as well, since the relocations
-   exist.  But the assembler doesn't seem to create them.  */
 /* Select a format to encode pointers in exception handling data.  CODE
    is 0 for data, 1 for code labels, 2 for function pointers.  GLOBAL is
    true if the symbol may be affected by dynamic relocations.

gcc/config/alpha/osf.h

@@ -153,3 +153,17 @@ __enable_execute_stack (addr)						\
 #define HAS_INIT_SECTION
 #define LD_INIT_SWITCH "-init"
 #define LD_FINI_SWITCH "-fini"
+
+/* Select a format to encode pointers in exception handling data.  CODE
+   is 0 for data, 1 for code labels, 2 for function pointers.  GLOBAL is
+   true if the symbol may be affected by dynamic relocations.
+   
+   We really ought to be using the SREL32 relocations that ECOFF has,
+   but no version of the native assembler supports creating such things,
+   and Compaq has no plans to rectify this.  Worse, the dynamic loader
+   cannot handle unaligned relocations, so we have to make sure that
+   things get padded appropriately.  */
+#define ASM_PREFERRED_EH_DATA_FORMAT(CODE,GLOBAL)			     \
+  (TARGET_GAS								     \
+   ? (((GLOBAL) ? DW_EH_PE_indirect : 0) | DW_EH_PE_pcrel | DW_EH_PE_sdata4) \
+   : DW_EH_PE_aligned)

gcc/dwarf2.h

@@ -580,5 +580,6 @@ enum dwarf_macinfo_record_type
 #define DW_EH_PE_textrel	0x20
 #define DW_EH_PE_datarel	0x30
 #define DW_EH_PE_funcrel	0x40
+#define DW_EH_PE_aligned	0x50
 
 #define DW_EH_PE_indirect	0x80

gcc/dwarf2asm.c

@@ -490,6 +490,7 @@ eh_data_format_name (format)
 
   S(DW_EH_PE_absptr, "absolute")
   S(DW_EH_PE_omit, "omit")
+  S(DW_EH_PE_aligned, "aligned absolute")
 
   S(DW_EH_PE_uleb128, "uleb128")
   S(DW_EH_PE_udata2, "udata2")
@@ -947,6 +948,12 @@ dw2_asm_output_encoded_addr_rtx VPARAMS ((int encoding,
 
   size = size_of_encoded_value (encoding);
 
+  if (encoding == DW_EH_PE_aligned)
+    {
+      assemble_align (POINTER_SIZE);
+      encoding = DW_EH_PE_absptr;
+    }
+
   /* NULL is _always_ represented as a plain zero.  */
   if (addr == const0_rtx)
     assemble_integer (addr, size, 1);

gcc/dwarf2out.c

@@ -1820,6 +1820,28 @@ output_call_frame_info (for_eh)
 	  augmentation[0] = 'z';
           *p = '\0';
 	}
+
+      /* Ug.  Some platforms can't do unaligned dynamic relocations at all.  */
+      if (eh_personality_libfunc && per_encoding == DW_EH_PE_aligned)
+	{
+	  int offset = (  4		/* Length */
+			+ 4		/* CIE Id */
+			+ 1		/* CIE version */
+			+ strlen (augmentation) + 1	/* Augmentation */
+			+ size_of_uleb128 (1)		/* Code alignment */
+			+ size_of_sleb128 (DWARF_CIE_DATA_ALIGNMENT)
+			+ 1		/* RA column */
+			+ 1		/* Augmentation size */
+			+ 1		/* Personality encoding */ );
+	  int pad = -offset & (PTR_SIZE - 1);
+
+	  augmentation_size += pad;
+
+	  /* Augmentations should be small, so there's scarce need to
+	     iterate for a solution.  Die if we exceed one uleb128 byte.  */
+	  if (size_of_uleb128 (augmentation_size) != 1)
+	    abort ();
+	}
     }
   dw2_asm_output_nstring (augmentation, -1, "CIE Augmentation");
 
@@ -1909,8 +1931,22 @@ output_call_frame_info (for_eh)
 	{
 	  if (any_lsda_needed)
 	    {
-	      dw2_asm_output_data_uleb128 (
-		size_of_encoded_value (lsda_encoding), "Augmentation size");
+	      int size = size_of_encoded_value (lsda_encoding);
+
+	      if (lsda_encoding == DW_EH_PE_aligned)
+		{
+		  int offset = (  4		/* Length */
+				+ 4		/* CIE offset */
+				+ 2 * size_of_encoded_value (fde_encoding)
+				+ 1		/* Augmentation size */ );
+		  int pad = -offset & (PTR_SIZE - 1);
+
+		  size += pad;
+		  if (size_of_uleb128 (size) != 1)
+		    abort ();
+		}
+
+	      dw2_asm_output_data_uleb128 (size, "Augmentation size");
 
 	      if (fde->uses_eh_lsda)
 	        {
@@ -1921,9 +1957,13 @@ output_call_frame_info (for_eh)
 		 	"Language Specific Data Area");
 	        }
 	      else
+		{
+		  if (lsda_encoding == DW_EH_PE_aligned)
+		    ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (PTR_SIZE));
 		  dw2_asm_output_data (size_of_encoded_value (lsda_encoding),
 				       0, "Language Specific Data Area (none)");
 		}
+	    }
 	  else
 	    dw2_asm_output_data_uleb128 (0, "Augmentation size");
 	}

gcc/unwind-dw2-fde.c

@@ -233,6 +233,7 @@ base_from_object (unsigned char encoding, struct object *ob)
     {
     case DW_EH_PE_absptr:
     case DW_EH_PE_pcrel:
+    case DW_EH_PE_aligned:
       return 0;
 
     case DW_EH_PE_textrel:
@@ -270,7 +271,12 @@ get_cie_encoding (struct dwarf_cie *cie)
 	return *p;
       /* Personality encoding and pointer.  */
       else if (*aug == 'P')
-	p = read_encoded_value_with_base (*p & 0xF, 0, p + 1, &dummy);
+	{
+	  /* ??? Avoid dereferencing indirect pointers, since we're
+	     faking the base address.  Gotta keep DW_EH_PE_aligned
+	     intact, however.  */
+	  p = read_encoded_value_with_base (*p & 0x7F, 0, p + 1, &dummy);
+	}
       /* LSDA encoding.  */
       else if (*aug == 'L')
 	p++;

gcc/unwind-pe.h

@@ -40,6 +40,7 @@
 #define DW_EH_PE_textrel        0x20
 #define DW_EH_PE_datarel        0x30
 #define DW_EH_PE_funcrel        0x40
+#define DW_EH_PE_aligned        0x50
 
 #define DW_EH_PE_indirect	0x80
 
@@ -83,6 +84,7 @@ base_of_encoded_value (unsigned char encoding, struct _Unwind_Context *context)
     {
     case DW_EH_PE_absptr:
     case DW_EH_PE_pcrel:
+    case DW_EH_PE_aligned:
       return 0;
 
     case DW_EH_PE_textrel:
@@ -117,6 +119,15 @@ read_encoded_value_with_base (unsigned char encoding, _Unwind_Ptr base,
   union unaligned *u = (union unaligned *) p;
   _Unwind_Ptr result;
 
+  if (encoding == DW_EH_PE_aligned)
+    {
+      _Unwind_Ptr a = (_Unwind_Ptr)p;
+      a = (a + sizeof (void *) - 1) & - sizeof(void *);
+      result = *(_Unwind_Ptr *) a;
+      p = (const unsigned char *)(a + sizeof (void *));
+    }
+  else
+    {
       switch (encoding & 0x0f)
 	{
 	case DW_EH_PE_absptr:
@@ -191,10 +202,12 @@ read_encoded_value_with_base (unsigned char encoding, _Unwind_Ptr base,
 
       if (result != 0)
 	{
-      result += ((encoding & 0x70) == DW_EH_PE_pcrel ? (_Unwind_Ptr)u : base);
+	  result += ((encoding & 0x70) == DW_EH_PE_pcrel
+		     ? (_Unwind_Ptr)u : base);
 	  if (encoding & DW_EH_PE_indirect)
 	    result = *(_Unwind_Ptr *)result;
 	}
+    }
 
   *val = result;
   return p;