dwarf_get_fde_info_for_cfa_reg3(3) [freebsd man page]

DWARF_GET_FDE_INFO_FOR_CFA_REGS3(3)			   BSD Library Functions Manual 		       DWARF_GET_FDE_INFO_FOR_CFA_REGS3(3)

NAME

     dwarf_get_fde_info_for_cfa_regs3 -- retrieve a CFA register rule

LIBRARY

     DWARF Access Library (libdwarf, -ldwarf)

SYNOPSIS

     #include <libdwarf.h>

     int
     dwarf_get_fde_info_for_cfa_regs3(Dwarf_Fde fde, Dwarf_Addr pc, Dwarf_Small *type, Dwarf_Signed *offset_relevant, Dwarf_Signed *register_num,
	 Dwarf_Signed *offset_or_block_len, Dwarf_Ptr *block_ptr, Dwarf_Addr *row_pc, Dwarf_Error *err);

DESCRIPTION

     Function dwarf_get_fde_info_for_cfa_reg3() retrieves the CFA register rule for a given program counter address from the register rule table
     associated with an FDE descriptor.

     Argument fde should reference a valid DWARF FDE descriptor.

     Argument pc should hold the program counter address to be used to locate the desired register rule row.

     On successful execution, dwarf_get_fde_info_for_cfa_reg3() stores information about the CFA register rule found into the locations pointed to
     by the arguments type, offset_relevant, register_num, offset_or_block_len, block_ptr and row_pc.

     Argument type should point to a location which will hold the type code of the register rule found.  The returned value is one of the
     DW_EXPR_* contants defined in the header file <libdwarf.h>.

     If there is an offset value associated with the CFA register rule, the location pointed to by argument offset_relevant will be set to 1.

     Argument register_num should point to a location which will hold the register number associated with the CFA register rule.

     If the CFA register rule is of type DW_EXPR_OFFSET or DW_EXPR_VAL_OFFSET, the location pointed to by argument offset_or_block_len will be set
     to the offset value associated with the register rule, or to 0 if the register rule does not have an offset value.  If the type code is
     DW_EXPR_EXPRESSION or DW_EXPR_VAL_EXPRESSION, the location pointed to by argument offset_or_block_len will be set to the length in bytes of
     the DWARF expression block associated with the register rule.

     Argument block_ptr should point to a location which will be set to a pointer to the content of the DWARF expression block associated with the
     CFA register rule.

     Argument row_pc should point to a location which will be set to the lowest program counter address associated with the register rule found.

     If argument err is not NULL, it will be used to return an error descriptor in case of an error.

RETURN VALUES

     Function dwarf_get_fde_info_for_cfa_reg3() returns DW_DLV_OK when it succeeds.  In case of an error, it returns DW_DLV_ERROR and sets the
     argument err.

ERRORS

     Function dwarf_get_fde_info_for_cfa_reg3() can fail with:

     [DW_DLE_ARGUMENT]		   One of the arguments block_ptr, fde, offset_or_block_len, offset_relevant, register_num, row_pc, or type was
				   NULL.

     [DW_DLE_PC_NOT_IN_FDE_RANGE]  The program counter value provided in argument pc did not fall in the range covered by argument fde.

SEE ALSO

     dwarf(3), dwarf_get_fde_at_pc(3), dwarf_get_fde_info_for_all_regs(3), dwarf_get_fde_info_for_all_regs3(3), dwarf_get_fde_info_for_reg(3),
     dwarf_get_fde_info_for_reg3(3), dwarf_get_fde_n(3), dwarf_set_frame_cfa_value(3), dwarf_set_frame_rule_table_size(3),
     dwarf_set_frame_rule_initial_value(3), dwarf_set_frame_same_value(3), dwarf_set_frame_undefined_value(3)

BSD
								   June 12, 2011							       BSD

DWARF_GET_FDE_INFO_FOR_REG3(3)				   BSD Library Functions Manual 			    DWARF_GET_FDE_INFO_FOR_REG3(3)

NAME

     dwarf_get_fde_info_for_reg3 -- retrieve register rule

LIBRARY

     DWARF Access Library (libdwarf, -ldwarf)

SYNOPSIS

     #include <libdwarf.h>

     int
     dwarf_get_fde_info_for_reg3(Dwarf_Fde fde, Dwarf_Half table_column, Dwarf_Addr pc, Dwarf_Small *type, Dwarf_Signed *offset_relevant,
	 Dwarf_Signed *register_num, Dwarf_Signed *offset_or_block_len, Dwarf_Ptr *block_ptr, Dwarf_Addr *row_pc, Dwarf_Error *error);

DESCRIPTION

     Function dwarf_get_fde_info_for_reg3() retrieves a register rule from the register rule table associated with a given FDE descriptor, given a
     program counter address and rule column number.

     Argument fde should reference a valid DWARF FDE descriptor.

     Arugment table_column should hold the column number of the register rule desired.

     Argument pc should hold the program counter address to be used to locate the desired register rule row.

     On successful execution, dwarf_get_fde_info_for_reg3() stores information about the register rule found into the locations pointed to by the
     arguments type, offset_relevant, register_num, offset_or_block_len, block_ptr and row_pc.

     Argument type should point to a location which will hold the type code of the register rule found.  The returned value is one of the
     DW_EXPR_* contants defined in the header file <libdwarf.h>.

     If there is an offset value associated with the register rule, the location pointed to by argument offset_relevant will be set to 1.

     Argument register_num should point to a location which will hold the register number associated with the register rule.

     If the register rule is of type DW_EXPR_OFFSET or DW_EXPR_VAL_OFFSET, the location pointed to by argument offset_or_block_len will be set to
     the offset value associated with the register rule, or to 0 if the register rule does not have an offset value.  If the type code is
     DW_EXPR_EXPRESSION or DW_EXPR_VAL_EXPRESSION, the location pointed to by argument offset_or_block_len will be set to the length in bytes of
     the DWARF expression block associated with the register rule.

     Argument block_ptr should point to a location which will be set to a pointer to the content of the DWARF expression block associated with the
     register rule.

     Argument row_pc should point to a location which will be set to the lowest program counter address associated with the register rule found.

     If argument err is not NULL, it will be used to return an error descriptor in case of an error.

RETURN VALUES

     Function dwarf_get_fde_info_for_reg3() returns DW_DLV_OK when it succeeds.  In case of an error, it returns DW_DLV_ERROR and sets the argu-
     ment err.

ERRORS

     Function dwarf_get_fde_info_for_reg3() can fail with:

     [DW_DLE_ARGUMENT]		   One of the arguments block_ptr, fde, offset_or_block_len, offset_relevant, register_num, row_pc, or type was
				   NULL.

     [DW_DLE_FRAME_TABLE_COL_BAD]  The column number provided in argument table_column was too large.

     [DW_DLE_PC_NOT_IN_FDE_RANGE]  The program counter value provided in argument pc did not fall in the range covered by argument fde.

EXAMPLE

     To retrieve the register rules at column 3 from a rule table associated with a FDE descriptor:

	   Dwarf_Fde fde;
	   Dwarf_Off fde_offset, cie_offset;
	   Dwarf_Unsigned func_len, fde_length;
	   Dwarf_Signed cie_index, offset_relevant, register_num;
	   Dwarf_Signed offset_or_block_len;
	   Dwarf_Addr low_pc, row_pc;
	   Dwarf_Ptr fde_addr, block_ptr;
	   Dwarf_Small type;
	   Dwarf_Error de;

	   /* ... assuming `fde` references a valid FDE descriptor... */
	   if (dwarf_get_fde_range(fde, &low_pc, &func_len, &fde_addr,
	       &fde_length, &cie_offset, &cie_index, &fde_offset,
	       &de) != DW_DLV_OK)
		   errx(EXIT_FAILURE, "dwarf_get_fde_range failed: %s",
		       dwarf_errmsg(de));

	   /* Iterate all the table rows. */
	   for (pc = low_pc; pc < low_pc + func_len; pc++) {
		   if (dwarf_get_fde_info_for_reg3(fde, 3, pc, &type,
		       &offset_relevant, &register_num, &offset_or_block_len,
		       &block_ptr, &row_pc, &de) != DW_DLV_OK) {
			   warnx("dwarf_get_fde_info_for_reg3 failed: %s",
			       dwarf_errmsg(de));
			   continue;
		   }
		   /* ... use the retrieved register rule ... */
	   }

SEE ALSO

     dwarf(3), dwarf_get_fde_at_pc(3), dwarf_get_fde_info_for_all_regs(3), dwarf_get_fde_info_for_all_regs3(3),
     dwarf_get_fde_info_for_cfa_reg3(3), dwarf_get_fde_info_for_reg(3), dwarf_get_fde_n(3), dwarf_set_frame_cfa_value(3),
     dwarf_set_frame_rule_table_size(3), dwarf_set_frame_rule_initial_value(3), dwarf_set_frame_same_value(3), dwarf_set_frame_undefined_value(3)

BSD
								 November 9, 2011							       BSD