1 /* This file is tc-avr.h
2    Copyright (C) 1999-2016 Free Software Foundation, Inc.
3 
4    Contributed by Denis Chertykov <denisc@overta.ru>
5 
6    This file is part of GAS, the GNU Assembler.
7 
8    GAS is free software; you can redistribute it and/or modify
9    it under the terms of the GNU General Public License as published by
10    the Free Software Foundation; either version 3, or (at your option)
11    any later version.
12 
13    GAS is distributed in the hope that it will be useful,
14    but WITHOUT ANY WARRANTY; without even the implied warranty of
15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16    GNU General Public License for more details.
17 
18    You should have received a copy of the GNU General Public License
19    along with GAS; see the file COPYING.  If not, write to the Free
20    Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
21    02110-1301, USA.  */
22 
23 /* By convention, you should define this macro in the `.h' file.  For
24    example, `tc-m68k.h' defines `TC_M68K'.  You might have to use this
25    if it is necessary to add CPU specific code to the object format
26    file.  */
27 #define TC_AVR
28 
29 /* This macro is the BFD target name to use when creating the output
30    file.  This will normally depend upon the `OBJ_FMT' macro.  */
31 #define TARGET_FORMAT "elf32-avr"
32 
33 /* This macro is the BFD architecture to pass to `bfd_set_arch_mach'.  */
34 #define TARGET_ARCH bfd_arch_avr
35 
36 /* This macro is the BFD machine number to pass to
37    `bfd_set_arch_mach'.  If it is not defined, GAS will use 0.  */
38 #define TARGET_MACH 0
39 
40 /* You should define this macro to be non-zero if the target is big
41    endian, and zero if the target is little endian.  */
42 #define TARGET_BYTES_BIG_ENDIAN 0
43 
44 /* If you define this macro, GAS will warn about the use of
45    nonstandard escape sequences in a string.  */
46 #define ONLY_STANDARD_ESCAPES
47 
48 #define DIFF_EXPR_OK    /* .-foo gets turned into PC relative relocs */
49 
50 /* GAS will call this function for any expression that can not be
51    recognized.  When the function is called, `input_line_pointer'
52    will point to the start of the expression.  */
53 #define md_operand(x)
54 
55 typedef struct
56 {
57   /* Name of the expression modifier allowed with .byte, .word, etc.  */
58   const char *name;
59 
60   /* Only allowed with n bytes of data.  */
61   int nbytes;
62 
63   /* Associated RELOC.  */
64   bfd_reloc_code_real_type reloc;
65 
66   /* Part of the error message.  */
67   const char *error;
68 } exp_mod_data_t;
69 
70 extern const exp_mod_data_t exp_mod_data[];
71 #define TC_PARSE_CONS_RETURN_TYPE const exp_mod_data_t *
72 #define TC_PARSE_CONS_RETURN_NONE exp_mod_data
73 
74 /* You may define this macro to parse an expression used in a data
75    allocation pseudo-op such as `.word'.  You can use this to
76    recognize relocation directives that may appear in such directives.  */
77 #define TC_PARSE_CONS_EXPRESSION(EXPR,N) avr_parse_cons_expression (EXPR, N)
78 extern const exp_mod_data_t *avr_parse_cons_expression (expressionS *, int);
79 
80 /* You may define this macro to generate a fixup for a data
81    allocation pseudo-op.  */
82 #define TC_CONS_FIX_NEW avr_cons_fix_new
83 extern void avr_cons_fix_new (fragS *,int, int, expressionS *,
84 			      const exp_mod_data_t *);
85 
86 /* This should just call either `number_to_chars_bigendian' or
87    `number_to_chars_littleendian', whichever is appropriate.  On
88    targets like the MIPS which support options to change the
89    endianness, which function to call is a runtime decision.  On
90    other targets, `md_number_to_chars' can be a simple macro.  */
91 #define md_number_to_chars number_to_chars_littleendian
92 
93 /* `md_short_jump_size'
94    `md_long_jump_size'
95    `md_create_short_jump'
96    `md_create_long_jump'
97    If `WORKING_DOT_WORD' is defined, GAS will not do broken word
98    processing (*note Broken words::.).  Otherwise, you should set
99    `md_short_jump_size' to the size of a short jump (a jump that is
100    just long enough to jump around a long jmp) and
101    `md_long_jump_size' to the size of a long jump (a jump that can go
102    anywhere in the function), You should define
103    `md_create_short_jump' to create a short jump around a long jump,
104    and define `md_create_long_jump' to create a long jump.  */
105 #define WORKING_DOT_WORD
106 
107 /* If you define this macro, it means that `tc_gen_reloc' may return
108    multiple relocation entries for a single fixup.  In this case, the
109    return value of `tc_gen_reloc' is a pointer to a null terminated
110    array.  */
111 #undef RELOC_EXPANSION_POSSIBLE
112 
113 /* No shared lib support, so we don't need to ensure externally
114    visible symbols can be overridden.  */
115 #define EXTERN_FORCE_RELOC 0
116 
117 /* If defined, this macro allows control over whether fixups for a
118    given section will be processed when the linkrelax variable is
119    set. Define it to zero and handle things in md_apply_fix instead.*/
120 #define TC_LINKRELAX_FIXUP(SEG) 0
121 
122 /* If this macro returns non-zero, it guarantees that a relocation will be emitted
123    even when the value can be resolved locally. Do that if linkrelax is turned on */
124 #define TC_FORCE_RELOCATION(fix)	avr_force_relocation (fix)
125 #define TC_FORCE_RELOCATION_SUB_SAME(fix, seg) \
126   (! SEG_NORMAL (seg) || avr_force_relocation (fix))
127 extern int avr_force_relocation (struct fix *);
128 
129 /* Values passed to md_apply_fix don't include the symbol value.  */
130 #define MD_APPLY_SYM_VALUE(FIX) 0
131 
132 /* If you define this macro, it should return the offset between the
133    address of a PC relative fixup and the position from which the PC
134    relative adjustment should be made.  On many processors, the base
135    of a PC relative instruction is the next instruction, so this
136    macro would return the length of an instruction.  */
137 #define MD_PCREL_FROM_SECTION(FIX, SEC) md_pcrel_from_section (FIX, SEC)
138 extern long md_pcrel_from_section (struct fix *, segT);
139 
140 /* The number of bytes to put into a word in a listing.  This affects
141    the way the bytes are clumped together in the listing.  For
142    example, a value of 2 might print `1234 5678' where a value of 1
143    would print `12 34 56 78'.  The default value is 4.  */
144 #define LISTING_WORD_SIZE 2
145 
146 /* AVR port uses `$' as a logical line separator.  */
147 #define LEX_DOLLAR 0
148 
149 /* An `.lcomm' directive with no explicit alignment parameter will
150    use this macro to set P2VAR to the alignment that a request for
151    SIZE bytes will have.  The alignment is expressed as a power of
152    two.  If no alignment should take place, the macro definition
153    should do nothing.  Some targets define a `.bss' directive that is
154    also affected by this macro.  The default definition will set
155    P2VAR to the truncated power of two of sizes up to eight bytes.  */
156 #define TC_IMPLICIT_LCOMM_ALIGNMENT(SIZE, P2VAR) (P2VAR) = 0
157 
158 /* We don't want gas to fixup the following program memory related relocations.
159    We will need them in case that we want to do linker relaxation.
160    We could in principle keep these fixups in gas when not relaxing.
161    However, there is no serious performance penalty when making the linker
162    make the fixup work.  Check also that fx_addsy is not NULL, in order to make
163    sure that the fixup refers to some sort of label.  */
164 #define TC_VALIDATE_FIX(FIXP,SEG,SKIP)                       \
165   if (   (FIXP->fx_r_type == BFD_RELOC_AVR_7_PCREL           \
166        || FIXP->fx_r_type == BFD_RELOC_AVR_13_PCREL          \
167        || FIXP->fx_r_type == BFD_RELOC_AVR_LO8_LDI_PM        \
168        || FIXP->fx_r_type == BFD_RELOC_AVR_LO8_LDI_GS        \
169        || FIXP->fx_r_type == BFD_RELOC_AVR_HI8_LDI_PM        \
170        || FIXP->fx_r_type == BFD_RELOC_AVR_HI8_LDI_GS        \
171        || FIXP->fx_r_type == BFD_RELOC_AVR_HH8_LDI_PM        \
172        || FIXP->fx_r_type == BFD_RELOC_AVR_LO8_LDI_PM_NEG    \
173        || FIXP->fx_r_type == BFD_RELOC_AVR_HI8_LDI_PM_NEG    \
174        || FIXP->fx_r_type == BFD_RELOC_AVR_HH8_LDI_PM_NEG    \
175        || FIXP->fx_r_type == BFD_RELOC_AVR_8_LO              \
176        || FIXP->fx_r_type == BFD_RELOC_AVR_8_HI              \
177        || FIXP->fx_r_type == BFD_RELOC_AVR_8_HLO             \
178        || FIXP->fx_r_type == BFD_RELOC_AVR_16_PM)            \
179       && FIXP->fx_addsy != NULL				     \
180       && FIXP->fx_subsy == NULL)			     \
181     {							     \
182       symbol_mark_used_in_reloc (FIXP->fx_addsy);	     \
183       goto SKIP;					     \
184     }
185 
186 /* This macro is evaluated for any fixup with a fx_subsy that
187    fixup_segment cannot reduce to a number.  If the macro returns
188    false an error will be reported. */
189 #define TC_VALIDATE_FIX_SUB(fix, seg)   avr_validate_fix_sub (fix)
190 extern int avr_validate_fix_sub (struct fix *);
191 
192 /* This target is buggy, and sets fix size too large.  */
193 #define TC_FX_SIZE_SLACK(FIX) 2
194 
195 /* AVR instructions are 2 or 4 bytes long.  */
196 #define DWARF2_LINE_MIN_INSN_LENGTH 	2
197 
198 /* 32 bits pseudo-addresses are used on AVR.  */
199 #define DWARF2_ADDR_SIZE(bfd) 4
200 
201 /* Enable cfi directives.  */
202 #define TARGET_USE_CFIPOP 1
203 
204 /* The stack grows down, and is only byte aligned.  */
205 #define DWARF2_CIE_DATA_ALIGNMENT -1
206 
207 /* Define the column that represents the PC.  */
208 #define DWARF2_DEFAULT_RETURN_COLUMN  36
209 
210 /* Define a hook to setup initial CFI state.  */
211 extern void tc_cfi_frame_initial_instructions (void);
212 #define tc_cfi_frame_initial_instructions tc_cfi_frame_initial_instructions
213 
214 /* The difference between same-section symbols may be affected by linker
215    relaxation, so do not resolve such expressions in the assembler.  */
216 #define md_allow_local_subtract(l,r,s) avr_allow_local_subtract (l, r, s)
217 extern bfd_boolean avr_allow_local_subtract (expressionS *, expressionS *, segT);
218 
219 #define elf_tc_final_processing 	avr_elf_final_processing
220 extern void avr_elf_final_processing (void);
221 
222 #define md_post_relax_hook avr_post_relax_hook ()
223 extern void avr_post_relax_hook (void);
224 
225 #define HANDLE_ALIGN(fragP) avr_handle_align (fragP)
226 extern void avr_handle_align (fragS *fragP);
227 
228 struct avr_frag_data
229 {
230   unsigned is_org : 1;
231   unsigned is_align : 1;
232   unsigned has_fill : 1;
233 
234   char fill;
235   offsetT alignment;
236 };
237 #define TC_FRAG_TYPE			struct avr_frag_data
238