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151 lines
3.9 KiB
151 lines
3.9 KiB
/* Function return value location for Linux/m68k ABI. |
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This file is part of elfutils. |
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This file is free software; you can redistribute it and/or modify |
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it under the terms of either |
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* the GNU Lesser General Public License as published by the Free |
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Software Foundation; either version 3 of the License, or (at |
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your option) any later version |
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or |
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* the GNU General Public License as published by the Free |
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Software Foundation; either version 2 of the License, or (at |
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your option) any later version |
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or both in parallel, as here. |
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elfutils is distributed in the hope that it will be useful, but |
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WITHOUT ANY WARRANTY; without even the implied warranty of |
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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General Public License for more details. |
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You should have received copies of the GNU General Public License and |
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the GNU Lesser General Public License along with this program. If |
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not, see <http://www.gnu.org/licenses/>. */ |
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#ifdef HAVE_CONFIG_H |
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# include <config.h> |
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#endif |
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#include <assert.h> |
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#include <dwarf.h> |
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#define BACKEND m68k_ |
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#include "libebl_CPU.h" |
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/* %d0, or pair %d0, %d1. */ |
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static const Dwarf_Op loc_intreg[] = |
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{ |
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{ .atom = DW_OP_reg0 }, { .atom = DW_OP_piece, .number = 4 }, |
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{ .atom = DW_OP_reg1 }, { .atom = DW_OP_piece, .number = 4 }, |
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}; |
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#define nloc_intreg 1 |
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#define nloc_intregpair 4 |
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/* %a0. */ |
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static const Dwarf_Op loc_ptrreg[] = |
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{ |
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{ .atom = DW_OP_reg8 } |
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}; |
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#define nloc_ptrreg 1 |
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/* %fp0. */ |
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static const Dwarf_Op loc_fpreg[] = |
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{ |
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{ .atom = DW_OP_reg16 } |
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}; |
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#define nloc_fpreg 1 |
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/* The return value is a structure and is actually stored in stack space |
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passed in a hidden argument by the caller. But, the compiler |
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helpfully returns the address of that space in %a0. */ |
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static const Dwarf_Op loc_aggregate[] = |
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{ |
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{ .atom = DW_OP_reg8 } |
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}; |
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#define nloc_aggregate 1 |
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int |
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m68k_return_value_location (Dwarf_Die *functypedie, const Dwarf_Op **locp) |
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{ |
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/* Start with the function's type, and get the DW_AT_type attribute, |
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which is the type of the return value. */ |
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Dwarf_Die die_mem, *typedie = &die_mem; |
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int tag = dwarf_peeled_die_type (functypedie, typedie); |
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if (tag <= 0) |
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return tag; |
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switch (tag) |
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{ |
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case -1: |
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return -1; |
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case DW_TAG_subrange_type: |
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if (! dwarf_hasattr_integrate (typedie, DW_AT_byte_size)) |
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{ |
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Dwarf_Attribute attr_mem, *attr; |
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attr = dwarf_attr_integrate (typedie, DW_AT_type, &attr_mem); |
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typedie = dwarf_formref_die (attr, &die_mem); |
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tag = DWARF_TAG_OR_RETURN (typedie); |
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} |
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FALLTHROUGH; |
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case DW_TAG_base_type: |
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case DW_TAG_enumeration_type: |
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case DW_TAG_pointer_type: |
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case DW_TAG_ptr_to_member_type: |
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{ |
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Dwarf_Word size; |
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Dwarf_Attribute attr_mem; |
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if (dwarf_formudata (dwarf_attr_integrate (typedie, DW_AT_byte_size, |
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&attr_mem), &size) != 0) |
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{ |
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if (tag == DW_TAG_pointer_type || tag == DW_TAG_ptr_to_member_type) |
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size = 4; |
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else |
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return -1; |
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} |
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if (tag == DW_TAG_base_type) |
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{ |
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Dwarf_Word encoding; |
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if (dwarf_formudata (dwarf_attr_integrate (typedie, DW_AT_encoding, |
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&attr_mem), |
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&encoding) != 0) |
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return -1; |
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if (encoding == DW_ATE_float) |
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{ |
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if (size > 12) |
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return -2; |
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*locp = loc_fpreg; |
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return nloc_fpreg; |
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} |
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} |
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if (tag == DW_TAG_pointer_type || tag == DW_TAG_ptr_to_member_type) |
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{ |
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*locp = loc_ptrreg; |
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return nloc_ptrreg; |
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} |
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*locp = loc_intreg; |
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if (size <= 4) |
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return nloc_intreg; |
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if (size <= 8) |
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return nloc_intregpair; |
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} |
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FALLTHROUGH; |
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case DW_TAG_structure_type: |
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case DW_TAG_class_type: |
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case DW_TAG_union_type: |
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case DW_TAG_array_type: |
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*locp = loc_aggregate; |
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return nloc_aggregate; |
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} |
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/* XXX We don't have a good way to return specific errors from ebl calls. |
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This value means we do not understand the type, but it is well-formed |
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DWARF and might be valid. */ |
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return -2; |
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}
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