1 /* Definitions for SOM assembler support.
2    Copyright (C) 1999-2018 Free Software Foundation, Inc.
3 
4 This file is part of GCC.
5 
6 GCC is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3, or (at your option)
9 any later version.
10 
11 GCC is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 GNU General Public License for more details.
15 
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING3.  If not see
18 <http://www.gnu.org/licenses/>.  */
19 
20 /* So we can conditionalize small amounts of code in pa.c or pa.md.  */
21 #undef TARGET_SOM
22 #define TARGET_SOM 1
23 
24 /* We do not use BINCL stabs in SOM.
25    ??? If it does not hurt, we probably should to avoid useless divergence
26    from other embedded stabs implementations.  */
27 #undef DBX_USE_BINCL
28 
29 #define DBX_LINES_FUNCTION_RELATIVE 1
30 
31 /* gdb needs a null N_SO at the end of each file for scattered loading.  */
32 
33 #define DBX_OUTPUT_NULL_N_SO_AT_MAIN_SOURCE_FILE_END
34 
35 /* HPUX has a program 'chatr' to list the dependencies of dynamically
36    linked executables and shared libraries.  */
37 #define LDD_SUFFIX "chatr"
38 /* Look for lines like "dynamic   /usr/lib/X11R5/libX11.sl"
39    or "static    /usr/lib/X11R5/libX11.sl".
40 
41    HPUX 10.20 also has lines like "static branch prediction ..."
42    so we filter that out explicitly.
43 
44    We also try to bound our search for libraries with marker
45    lines.  What a pain.  */
46 #define PARSE_LDD_OUTPUT(PTR)					\
47 do {								\
48   static int in_shlib_list = 0;					\
49   while (*PTR == ' ') PTR++;					\
50   if (strncmp (PTR, "shared library list:",			\
51 	       sizeof ("shared library list:") - 1) == 0)	\
52     {								\
53       PTR = 0;							\
54       in_shlib_list = 1;					\
55     }								\
56   else if (strncmp (PTR, "shared library binding:",		\
57 		    sizeof ("shared library binding:") - 1) == 0)\
58     {								\
59       PTR = 0;							\
60       in_shlib_list = 0;					\
61     }								\
62   else if (strncmp (PTR, "static branch prediction disabled",	\
63 		    sizeof ("static branch prediction disabled") - 1) == 0)\
64     {								\
65       PTR = 0;							\
66       in_shlib_list = 0;					\
67     }								\
68   else if (in_shlib_list					\
69 	   &&  strncmp (PTR, "dynamic", sizeof ("dynamic") - 1) == 0) \
70     {								\
71       PTR += sizeof ("dynamic") - 1;				\
72       while (*p == ' ') PTR++;					\
73     }								\
74   else if (in_shlib_list					\
75 	   && strncmp (PTR, "static", sizeof ("static") - 1) == 0) \
76     {								\
77       PTR += sizeof ("static") - 1;				\
78       while (*p == ' ') PTR++;					\
79     }								\
80   else								\
81     PTR = 0;							\
82 } while (0)
83 
84 /* Output the label for a function definition.  */
85 #ifndef HP_FP_ARG_DESCRIPTOR_REVERSED
86 #define ASM_DOUBLE_ARG_DESCRIPTORS(FILE, ARG0, ARG1)	\
87   do { fprintf (FILE, ",ARGW%d=FR", (ARG0));		\
88        fprintf (FILE, ",ARGW%d=FU", (ARG1));} while (0)
89 #define DFMODE_RETURN_STRING ",RTNVAL=FU"
90 #define SFMODE_RETURN_STRING ",RTNVAL=FR"
91 #else
92 #define ASM_DOUBLE_ARG_DESCRIPTORS(FILE, ARG0, ARG1)	\
93   do { fprintf (FILE, ",ARGW%d=FU", (ARG0));		\
94        fprintf (FILE, ",ARGW%d=FR", (ARG1));} while (0)
95 #define DFMODE_RETURN_STRING ",RTNVAL=FR"
96 #define SFMODE_RETURN_STRING ",RTNVAL=FU"
97 #endif
98 
99 
100 #define ASM_DECLARE_FUNCTION_NAME(FILE, NAME, DECL) \
101     do { tree fntype = TREE_TYPE (TREE_TYPE (DECL));			\
102 	 tree tree_type = TREE_TYPE (DECL);				\
103 	 tree parm;							\
104 	 int i;								\
105 	 if (TREE_PUBLIC (DECL) || TARGET_GAS)				\
106 	   { 								\
107 	     if (TREE_PUBLIC (DECL))					\
108 	       {							\
109 		 fputs ("\t.EXPORT ", FILE);				\
110 		 assemble_name (FILE, NAME);				\
111 		 fputs (",ENTRY,PRIV_LEV=3", FILE);			\
112 	       }							\
113 	     else							\
114 	       {							\
115 		 fputs ("\t.PARAM ", FILE);				\
116 		 assemble_name (FILE, NAME);				\
117 		 fputs (",PRIV_LEV=3", FILE);				\
118 	       }							\
119 	     for (parm = DECL_ARGUMENTS (DECL), i = 0; parm && i < 4;	\
120 		  parm = DECL_CHAIN (parm))				\
121 	       {							\
122 		 tree type = DECL_ARG_TYPE (parm);			\
123 		 machine_mode mode = TYPE_MODE (type);			\
124 		 if (mode == SFmode && ! TARGET_SOFT_FLOAT)		\
125 		   fprintf (FILE, ",ARGW%d=FR", i++);			\
126 		 else if (mode == DFmode && ! TARGET_SOFT_FLOAT)	\
127 		   {							\
128 		     if (i <= 2)					\
129 		       {						\
130 			 if (i == 1) i++;				\
131 			 ASM_DOUBLE_ARG_DESCRIPTORS (FILE, i++, i++);	\
132 		       }						\
133 		     else						\
134 		       break;						\
135 		   }							\
136 		 else							\
137 		   {							\
138 		     int arg_size = pa_function_arg_size (mode, type);	\
139 		     /* Passing structs by invisible reference uses	\
140 			one general register.  */			\
141 		     if (arg_size > 2 || TREE_ADDRESSABLE (type))	\
142 		       arg_size = 1;					\
143 		     if (arg_size == 2 && i <= 2)			\
144 		       {						\
145 			 if (i == 1) i++;				\
146 			 fprintf (FILE, ",ARGW%d=GR", i++);		\
147 			 fprintf (FILE, ",ARGW%d=GR", i++);		\
148 		       }						\
149 		     else if (arg_size == 1)				\
150 		       fprintf (FILE, ",ARGW%d=GR", i++);		\
151 		     else						\
152 		       i += arg_size;					\
153 		   }							\
154 	       }							\
155 	     /* anonymous args */					\
156 	     if (stdarg_p (tree_type))					\
157 	       {							\
158 		 for (; i < 4; i++)					\
159 		   fprintf (FILE, ",ARGW%d=GR", i);			\
160 	       }							\
161 	     if (TYPE_MODE (fntype) == DFmode && ! TARGET_SOFT_FLOAT)	\
162 	       fputs (DFMODE_RETURN_STRING, FILE);			\
163 	     else if (TYPE_MODE (fntype) == SFmode && ! TARGET_SOFT_FLOAT) \
164 	       fputs (SFMODE_RETURN_STRING, FILE);			\
165 	     else if (fntype != void_type_node)				\
166 	       fputs (",RTNVAL=GR", FILE);				\
167 	     fputs ("\n", FILE);					\
168 	   }} while (0)
169 
170 #define TARGET_ASM_FILE_START pa_som_file_start
171 #define TARGET_ASM_INIT_SECTIONS pa_som_asm_init_sections
172 
173 /* String to output before writable data.  */
174 #define DATA_SECTION_ASM_OP "\t.SPACE $PRIVATE$\n\t.SUBSPA $DATA$\n"
175 
176 /* String to output before uninitialized data.  */
177 #define BSS_SECTION_ASM_OP "\t.SPACE $PRIVATE$\n\t.SUBSPA $BSS$\n"
178 
179 /* This is how to output a command to make the user-level label
180    named NAME defined for reference from other files.  We use
181    assemble_name_raw instead of assemble_name since a symbol in
182    a .IMPORT directive that isn't otherwise referenced is not
183    placed in the symbol table of the assembled object.
184 
185    Failure to import a function reference can cause the HP linker
186    to segmentation fault!
187 
188    Note that the SOM based tools need the symbol imported as a
189    CODE symbol, while the ELF based tools require the symbol to
190    be imported as an ENTRY symbol.  */
191 
192 #define ASM_OUTPUT_EXTERNAL(FILE, DECL, NAME) \
193   pa_hpux_asm_output_external ((FILE), (DECL), (NAME))
194 #define ASM_OUTPUT_EXTERNAL_REAL(FILE, DECL, NAME) \
195   do { fputs ("\t.IMPORT ", FILE);					\
196        assemble_name_raw (FILE, NAME);					\
197        if (FUNCTION_NAME_P (NAME))					\
198 	 fputs (",CODE\n", FILE);					\
199        else								\
200 	 fputs (",DATA\n", FILE);					\
201      } while (0)
202 
203 /* The bogus HP assembler requires ALL external references to be
204    "imported", even library calls.  They look a bit different, so
205    here's this macro.
206 
207    Also note not all libcall names are passed to pa_encode_section_info
208    (__main for example).  To make sure all libcall names have section
209    info recorded in them, we do it here.
210 
211    We must also ensure that a libcall that has been previously
212    exported is not subsequently imported since the HP assembler may
213    change the type from an ENTRY to a CODE symbol.  This would make
214    the symbol local.  We are forced to use the identifier node
215    associated with the real assembler name for this check as the
216    symbol_ref available in ASM_DECLARE_FUNCTION_NAME is not the
217    same as the one used here.  As a result, we can't use flags
218    in the symbol_ref for this check.  The identifier check assumes
219    assemble_external_libcall is called before the symbol is used.  */
220 
221 #define ASM_OUTPUT_EXTERNAL_LIBCALL(FILE, RTL) \
222   do { const char *name;						\
223        tree id;								\
224 									\
225        if (!function_label_operand (RTL, VOIDmode))			\
226 	 pa_encode_label (RTL);						\
227 									\
228        name = targetm.strip_name_encoding (XSTR ((RTL), 0));		\
229        id = maybe_get_identifier (name);				\
230        if (!id || !TREE_SYMBOL_REFERENCED (id))				\
231 	 {								\
232 	   fputs ("\t.IMPORT ", FILE);					\
233 	   assemble_name_raw (FILE, XSTR ((RTL), 0));		       	\
234 	   fputs (",CODE\n", FILE);					\
235 	 }								\
236      } while (0)
237 
238 /* We want __gcc_plt_call to appear in every program built by
239    gcc, so we make a reference to it out of __main.
240    We use the asm statement to fool the optimizer into not
241    removing the dead (but important) initialization of
242    REFERENCE.  */
243 
244 #define DO_GLOBAL_DTORS_BODY			\
245 do {						\
246   extern void __gcc_plt_call (void);		\
247   void (*reference)(void) = &__gcc_plt_call;	\
248   func_ptr *p;					\
249   __asm__ ("" : : "r" (reference));		\
250   for (p = __DTOR_LIST__ + 1; *p; )		\
251     (*p++) ();					\
252 } while (0)
253 
254 /* This macro specifies the biggest alignment supported by the object
255    file format of this machine.
256 
257    The .align directive in the HP assembler allows alignments up to 4096
258    bytes.  However, the maximum alignment of a global common symbol is 8
259    bytes for objects smaller than the page size (4096 bytes).  For larger
260    objects, the linker provides an alignment of 32 bytes.  Unfortunately,
261    this macro doesn't provide a mechanism to test for common symbols.  */
262 #define MAX_OFILE_ALIGNMENT 32768
263 
264 /* The SOM linker hardcodes paths into binaries.  As a result, dotdots
265    must be removed from library prefixes to prevent binaries from depending
266    on the location of the GCC tool directory.  The downside is GCC
267    cannot be moved after installation using a symlink.  */
268 #undef TARGET_ALWAYS_STRIP_DOTDOT
269 #define TARGET_ALWAYS_STRIP_DOTDOT true
270 
271 /* If GAS supports weak, we can support weak when we have working linker
272    support for secondary definitions and are generating code for GAS.
273    This is primarily for one-only support as SOM doesn't allow undefined
274    weak symbols.  */
275 #ifdef HAVE_GAS_WEAK
276 #define TARGET_SUPPORTS_WEAK (TARGET_SOM_SDEF && TARGET_GAS)
277 #else
278 #define TARGET_SUPPORTS_WEAK 0
279 #endif
280 
281 /* CVS GAS as of 4/28/04 supports a comdat parameter for the .nsubspa
282    directive.  This provides one-only linkage semantics even though we
283    don't have weak support.  */
284 #ifdef HAVE_GAS_NSUBSPA_COMDAT
285 #define SUPPORTS_SOM_COMDAT (TARGET_GAS)
286 #else
287 #define SUPPORTS_SOM_COMDAT 0
288 #endif
289 
290 /* We can support one only if we support weak or comdat.  */
291 #define SUPPORTS_ONE_ONLY (TARGET_SUPPORTS_WEAK || SUPPORTS_SOM_COMDAT)
292 
293 /* We use DECL_COMMON for uninitialized one-only variables as we don't
294    have linkonce .bss.  We use SOM secondary definitions or comdat for
295    initialized variables and functions.  */
296 #define MAKE_DECL_ONE_ONLY(DECL) \
297   do {									\
298     if (TREE_CODE (DECL) == VAR_DECL					\
299         && (DECL_INITIAL (DECL) == 0					\
300             || DECL_INITIAL (DECL) == error_mark_node))			\
301       DECL_COMMON (DECL) = 1;						\
302     else if (TARGET_SUPPORTS_WEAK)					\
303       DECL_WEAK (DECL) = 1;						\
304   } while (0)
305 
306 /* This is how we tell the assembler that a symbol is weak.  The SOM
307    weak implementation uses the secondary definition (sdef) flag.
308 
309    The behavior of sdef symbols is similar to ELF weak symbols in that
310    multiple definitions can occur without incurring a link error.
311    However, they differ in the following ways:
312      1) Undefined sdef symbols are not allowed.
313      2) The linker searches for undefined sdef symbols and will load an
314 	archive library member to resolve an undefined sdef symbol.
315      3) The exported symbol from a shared library is a primary symbol
316         rather than a sdef symbol.  Thus, more care is needed in the
317 	ordering of libraries.
318 
319    It appears that the linker discards extra copies of "weak" functions
320    when linking shared libraries, independent of whether or not they
321    are in their own section.  In linking final executables, -Wl,-O can
322    be used to remove dead procedures.  Thus, support for named sections
323    is not needed and in previous testing caused problems with various
324    HP tools.  */
325 #define ASM_WEAKEN_LABEL(FILE,NAME) \
326   do { fputs ("\t.weak\t", FILE);				\
327        assemble_name (FILE, NAME);				\
328        fputc ('\n', FILE);					\
329        targetm.asm_out.globalize_label (FILE, NAME);		\
330   } while (0)
331 
332 /* We can't handle weak aliases, and therefore can't support pragma weak.
333    Suppress the use of pragma weak in gthr-dce.h and gthr-posix.h.  */
334 #define GTHREAD_USE_WEAK 0
335 
336 /* Shared library suffix.  Collect2 strips the version string after
337    this suffix when generating constructor/destructor names.  */
338 #define SHLIB_SUFFIX ".sl"
339 
340 /* We don't have named sections.  */
341 #define TARGET_HAVE_NAMED_SECTIONS false
342 
343 #define TARGET_ASM_TM_CLONE_TABLE_SECTION pa_som_tm_clone_table_section
344 
345 /* Generate specially named labels to identify DWARF 2 frame unwind
346    information.  */
347 #define EH_FRAME_THROUGH_COLLECT2
348