From 91a2ae2a30a7935807a7d138de8cfa9e4613e797 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Sat, 10 Feb 2001 01:42:04 +0000 Subject: [PATCH] * config/tc-ia64.h (md_elf_section_type): New macro. (ELF_TC_SPECIAL_SECTIONS): Drop .IA_64.unwind and .IA_64.unwind_info (they're now handled via ia64_elf_section_type. * config/tc-ia64.c (unwind): New members saved_text_seg, saved_text_subseg, and force_unwind_entry. (optimize_unw_records): New function to optimize away unnecessary unwind directives. (ia64_elf_section_type): New function. (output_unw_records): Generate unwind info only if the size is non-zero or if it's forced for some other reason (e.g., handlerdata or a personality routine). (generate_unwind_image): Don't switch back to previous section---stay inside the unwind info section instead so that handlerdata that may follow goes into the right place. (dot_handlerdata): Force generation of unwind entry and save the current active text segment before generating unwind image. (dot_unwentry): Force generation of unwind entry. (dot_personality): Ditto. (dot_endp): Generate unwind table entry only if there is some unwind info or the unwind entry was forced. * config/tc-ia64.c (make_unw_section_name): New macro to form unwind section name. (generate_unwind_image): Add "text_name" argument. Use it to form unwind section name. (dot_handlerdata): Determine current segment (section) name and pass it to generate_unwind_image(). (dot_endp): Determine current segment (section) name and use it to determine the appropriate unwind section name. (ia64_md_do_align): Add missing ATTRIBUTE_UNUSED declarations to n, fill, and max arguments. --- gas/ChangeLog | 35 ++++++ gas/config/tc-ia64.c | 265 +++++++++++++++++++++++++++++++++---------- gas/config/tc-ia64.h | 8 +- 3 files changed, 246 insertions(+), 62 deletions(-) diff --git a/gas/ChangeLog b/gas/ChangeLog index f3f38006a72..6fbf67c0b47 100644 --- a/gas/ChangeLog +++ b/gas/ChangeLog @@ -1,3 +1,38 @@ +2001-02-08 David Mosberger + + * config/tc-ia64.h (md_elf_section_type): New macro. + (ELF_TC_SPECIAL_SECTIONS): Drop .IA_64.unwind and .IA_64.unwind_info + (they're now handled via ia64_elf_section_type. + + * config/tc-ia64.c (unwind): New members saved_text_seg, + saved_text_subseg, and force_unwind_entry. + (optimize_unw_records): New function to optimize away unnecessary + unwind directives. + (ia64_elf_section_type): New function. + (output_unw_records): Generate unwind info only if the size is + non-zero or if it's forced for some other reason (e.g., + handlerdata or a personality routine). + (generate_unwind_image): Don't switch back to previous + section---stay inside the unwind info section instead so that + handlerdata that may follow goes into the right place. + (dot_handlerdata): Force generation of unwind entry and save the + current active text segment before generating unwind image. + (dot_unwentry): Force generation of unwind entry. + (dot_personality): Ditto. + (dot_endp): Generate unwind table entry only if there is + some unwind info or the unwind entry was forced. + + * config/tc-ia64.c (make_unw_section_name): New macro to form + unwind section name. + (generate_unwind_image): Add "text_name" argument. Use it to + form unwind section name. + (dot_handlerdata): Determine current segment (section) name and + pass it to generate_unwind_image(). + (dot_endp): Determine current segment (section) name and use + it to determine the appropriate unwind section name. + (ia64_md_do_align): Add missing ATTRIBUTE_UNUSED declarations to + n, fill, and max arguments. + 2001-02-09 Schwidefsky * Makefile.am: Add linux target for S/390. diff --git a/gas/config/tc-ia64.c b/gas/config/tc-ia64.c index 0b31a556dea..8f827393b3e 100644 --- a/gas/config/tc-ia64.c +++ b/gas/config/tc-ia64.c @@ -1,5 +1,5 @@ /* tc-ia64.c -- Assembler for the HP/Intel IA-64 architecture. - Copyright (C) 1998, 1999, 2000 Free Software Foundation. + Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation. Contributed by David Mosberger-Tang This file is part of GAS, the GNU Assembler. @@ -617,6 +617,9 @@ static struct symbolS *proc_end; symbolS *info; /* pointer to unwind info */ symbolS *personality_routine; + segT saved_text_seg; + subsegT saved_text_subseg; + unsigned int force_unwind_entry : 1; /* force generation of unwind entry? */ /* TRUE if processing unwind directives in a prologue region. */ int prologue; @@ -825,11 +828,28 @@ static void set_imask PARAMS ((unw_rec_list *, unsigned long, unsigned long, uns static int count_bits PARAMS ((unsigned long)); static unsigned long slot_index PARAMS ((unsigned long, fragS *, unsigned long, fragS *)); +static unw_rec_list *optimize_unw_records PARAMS ((unw_rec_list *)); static void fixup_unw_records PARAMS ((unw_rec_list *)); static int output_unw_records PARAMS ((unw_rec_list *, void **)); static int convert_expr_to_ab_reg PARAMS ((expressionS *, unsigned int *, unsigned int *)); static int convert_expr_to_xy_reg PARAMS ((expressionS *, unsigned int *, unsigned int *)); -static int generate_unwind_image PARAMS ((void)); +static int generate_unwind_image PARAMS ((const char *)); + +/* Build the unwind section name by appending the (possibly stripped) + text section NAME to the unwind PREFIX. The resulting string + pointer is assigned to RESULT. The string is allocated on the + stack, so this must be a macro... */ +#define make_unw_section_name(special, text_name, result) \ + { \ + char *_prefix = special_section_name[special]; \ + size_t _prefix_len = strlen (_prefix), _text_len = strlen (text_name); \ + char *_result = alloca (_prefix_len + _text_len + 1); \ + memcpy(_result, _prefix, _prefix_len); \ + memcpy(_result + _prefix_len, text_name, _text_len); \ + _result[_prefix_len + _text_len] = '\0'; \ + result = _result; \ + } \ +while (0) /* Determine if application register REGNUM resides in the integer unit (as opposed to the memory unit). */ @@ -874,6 +894,22 @@ ia64_elf_section_flags (flags, attr, type) return flags; } +int +ia64_elf_section_type (str, len) + const char *str; + size_t len; +{ + len = sizeof (ELF_STRING_ia64_unwind_info) - 1; + if (strncmp (str, ELF_STRING_ia64_unwind_info, len) == 0) + return SHT_PROGBITS; + + len = sizeof (ELF_STRING_ia64_unwind) - 1; + if (strncmp (str, ELF_STRING_ia64_unwind, len) == 0) + return SHT_IA_64_UNWIND; + + return -1; +} + static unsigned int set_regstack (ins, locs, outs, rots) unsigned int ins, locs, outs, rots; @@ -2495,6 +2531,25 @@ slot_index (slot_addr, slot_frag, first_addr, first_frag) return index; } +/* Optimize unwind record directives. */ + +static unw_rec_list * +optimize_unw_records (list) + unw_rec_list *list; +{ + if (!list) + return NULL; + + /* If the only unwind record is ".prologue" or ".prologue" followed + by ".body", then we can optimize the unwind directives away. */ + if (list->r.type == prologue + && (list->next == NULL + || (list->next->r.type == body && list->next->next == NULL))) + return NULL; + + return list; +} + /* Given a complete record list, process any records which have unresolved fields, (ie length counts for a prologue). After this has been run, all neccessary information should be available @@ -2681,6 +2736,9 @@ output_unw_records (list, ptr) int size, x, extra = 0; unsigned char *mem; + *ptr = NULL; + + list = optimize_unw_records (list); fixup_unw_records (list); size = calc_record_size (list); @@ -2688,24 +2746,33 @@ output_unw_records (list, ptr) x = size % 8; if (x != 0) extra = 8 - x; - /* Add 8 for the header + 8 more bytes for the personality offset. */ - mem = xmalloc (size + extra + 16); - vbyte_mem_ptr = mem + 8; - /* Clear the padding area and personality. */ - memset (mem + 8 + size, 0 , extra + 8); - /* Initialize the header area. */ - md_number_to_chars (mem, (((bfd_vma) 1 << 48) /* version */ - | (unwind.personality_routine - ? ((bfd_vma) 3 << 32) /* U & E handler flags */ - : 0) - | ((size + extra) / 8)), /* length (dwords) */ - 8); + if (size > 0 || unwind.force_unwind_entry) + { + unwind.force_unwind_entry = 0; + + /* Add 8 for the header + 8 more bytes for the personality offset. */ + mem = xmalloc (size + extra + 16); - process_unw_records (list, output_vbyte_mem); + vbyte_mem_ptr = mem + 8; + /* Clear the padding area and personality. */ + memset (mem + 8 + size, 0 , extra + 8); + /* Initialize the header area. */ + md_number_to_chars (mem, + (((bfd_vma) 1 << 48) /* version */ + | (unwind.personality_routine + ? ((bfd_vma) 3 << 32) /* U & E handler flags */ + : 0) + | ((size + extra) / 8)), /* length (dwords) */ + 8); - *ptr = mem; - return size + extra + 16; + process_unw_records (list, output_vbyte_mem); + + *ptr = mem; + + size += extra + 16; + } + return size; } static int @@ -3053,7 +3120,8 @@ dot_restorereg_p (dummy) } static int -generate_unwind_image () +generate_unwind_image (text_name) + const char *text_name; { int size; unsigned char *unw_rec; @@ -3071,8 +3139,13 @@ generate_unwind_image () if (size != 0) { unsigned char *where; + char *sec_name; expressionS exp; - set_section ((char *) special_section_name[SPECIAL_SECTION_UNWIND_INFO]); + + make_unw_section_name (SPECIAL_SECTION_UNWIND_INFO, text_name, sec_name); + set_section (sec_name); + bfd_set_section_flags (stdoutput, now_seg, + SEC_LOAD | SEC_ALLOC | SEC_READONLY); /* Make sure the section has 8 byte alignment. */ record_alignment (now_seg, 3); @@ -3088,6 +3161,7 @@ generate_unwind_image () /* Copy the information from the unwind record into this section. The data is already in the correct byte order. */ memcpy (where, unw_rec, size); + /* Add the personality address to the image. */ if (unwind.personality_routine != 0) { @@ -3098,7 +3172,6 @@ generate_unwind_image () &exp, 0, BFD_RELOC_IA64_LTOFF_FPTR64LSB); unwind.personality_routine = 0; } - obj_elf_previous (0); } free_list_records (unwind.list); @@ -3111,7 +3184,23 @@ static void dot_handlerdata (dummy) int dummy ATTRIBUTE_UNUSED; { - generate_unwind_image (); + const char *text_name = segment_name (now_seg); + + /* If text section name starts with ".text" (which it should), + strip this prefix off. */ + if (strcmp (text_name, ".text") == 0) + text_name = ""; + + unwind.force_unwind_entry = 1; + + /* Remember which segment we're in so we can switch back after .endp */ + unwind.saved_text_seg = now_seg; + unwind.saved_text_subseg = now_subseg; + + /* Generate unwind info into unwind-info section and then leave that + section as the currently active one so dataXX directives go into + the language specific data area of the unwind info block. */ + generate_unwind_image (text_name); demand_empty_rest_of_line (); } @@ -3119,6 +3208,7 @@ static void dot_unwentry (dummy) int dummy ATTRIBUTE_UNUSED; { + unwind.force_unwind_entry = 1; demand_empty_rest_of_line (); } @@ -3583,6 +3673,7 @@ dot_personality (dummy) c = get_symbol_end (); p = input_line_pointer; unwind.personality_routine = symbol_find_or_make (name); + unwind.force_unwind_entry = 1; *p = c; SKIP_WHITESPACE (); demand_empty_rest_of_line (); @@ -3685,57 +3776,115 @@ dot_endp (dummy) long where; segT saved_seg; subsegT saved_subseg; + const char *sec_name, *text_name; - saved_seg = now_seg; - saved_subseg = now_subseg; + if (unwind.saved_text_seg) + { + saved_seg = unwind.saved_text_seg; + saved_subseg = unwind.saved_text_subseg; + unwind.saved_text_seg = NULL; + } + else + { + saved_seg = now_seg; + saved_subseg = now_subseg; + } + + /* + Use a slightly ugly scheme to derive the unwind section names from + the text section name: + + text sect. unwind table sect. + name: name: comments: + ---------- ----------------- -------------------------------- + .text .IA_64.unwind + .text.foo .IA_64.unwind.text.foo + .foo .IA_64.unwind.foo + _info .IA_64.unwind_info gas issues error message (ditto) + _infoFOO .IA_64.unwind_infoFOO gas issues error message (ditto) + + This mapping is done so that: + + (a) An object file with unwind info only in .text will use + unwind section names .IA_64.unwind and .IA_64.unwind_info. + This follows the letter of the ABI and also ensures backwards + compatibility with older toolchains. + + (b) An object file with unwind info in multiple text sections + will use separate unwind sections for each text section. + This allows us to properly set the "sh_info" and "sh_link" + fields in SHT_IA_64_UNWIND as required by the ABI and also + lets GNU ld support programs with multiple segments + containing unwind info (as might be the case for certain + embedded applications). + + (c) An error is issued if there would be a name clash. + */ + text_name = segment_name (saved_seg); + if (strncmp (text_name, "_info", 5) == 0) + { + as_bad ("Illegal section name `%s' (causes unwind section name clash)", + text_name); + ignore_rest_of_line (); + return; + } + if (strcmp (text_name, ".text") == 0) + text_name = ""; expression (&e); demand_empty_rest_of_line (); insn_group_break (1, 0, 0); - /* If there was a .handlerdata, we haven't generated an image yet. */ - if (unwind.info == 0) - { - generate_unwind_image (); - } + /* If there wasn't a .handlerdata, we haven't generated an image yet. */ + if (!unwind.info) + generate_unwind_image (text_name); - subseg_set (md.last_text_seg, 0); - unwind.proc_end = expr_build_dot (); - - set_section ((char *) special_section_name[SPECIAL_SECTION_UNWIND]); + if (unwind.info || unwind.force_unwind_entry) + { + subseg_set (md.last_text_seg, 0); + unwind.proc_end = expr_build_dot (); - /* Make sure the section has 8 byte alignment. */ - record_alignment (now_seg, 3); + make_unw_section_name (SPECIAL_SECTION_UNWIND, text_name, sec_name); + set_section ((char *) sec_name); + bfd_set_section_flags (stdoutput, now_seg, + SEC_LOAD | SEC_ALLOC | SEC_READONLY); - ptr = frag_more (24); - where = frag_now_fix () - 24; - bytes_per_address = bfd_arch_bits_per_address (stdoutput) / 8; + /* Make sure the section has 8 byte alignment. */ + record_alignment (now_seg, 3); - /* Issue the values of a) Proc Begin, b) Proc End, c) Unwind Record. */ - e.X_op = O_pseudo_fixup; - e.X_op_symbol = pseudo_func[FUNC_SEG_RELATIVE].u.sym; - e.X_add_number = 0; - e.X_add_symbol = unwind.proc_start; - ia64_cons_fix_new (frag_now, where, bytes_per_address, &e); + ptr = frag_more (24); + where = frag_now_fix () - 24; + bytes_per_address = bfd_arch_bits_per_address (stdoutput) / 8; - e.X_op = O_pseudo_fixup; - e.X_op_symbol = pseudo_func[FUNC_SEG_RELATIVE].u.sym; - e.X_add_number = 0; - e.X_add_symbol = unwind.proc_end; - ia64_cons_fix_new (frag_now, where + bytes_per_address, bytes_per_address, &e); + /* Issue the values of a) Proc Begin, b) Proc End, c) Unwind Record. */ + e.X_op = O_pseudo_fixup; + e.X_op_symbol = pseudo_func[FUNC_SEG_RELATIVE].u.sym; + e.X_add_number = 0; + e.X_add_symbol = unwind.proc_start; + ia64_cons_fix_new (frag_now, where, bytes_per_address, &e); - if (unwind.info != 0) - { e.X_op = O_pseudo_fixup; e.X_op_symbol = pseudo_func[FUNC_SEG_RELATIVE].u.sym; e.X_add_number = 0; - e.X_add_symbol = unwind.info; - ia64_cons_fix_new (frag_now, where + (bytes_per_address * 2), bytes_per_address, &e); - } - else - md_number_to_chars (ptr + (bytes_per_address * 2), 0, bytes_per_address); + e.X_add_symbol = unwind.proc_end; + ia64_cons_fix_new (frag_now, where + bytes_per_address, + bytes_per_address, &e); + + if (unwind.info) + { + e.X_op = O_pseudo_fixup; + e.X_op_symbol = pseudo_func[FUNC_SEG_RELATIVE].u.sym; + e.X_add_number = 0; + e.X_add_symbol = unwind.info; + ia64_cons_fix_new (frag_now, where + (bytes_per_address * 2), + bytes_per_address, &e); + } + else + md_number_to_chars (ptr + (bytes_per_address * 2), 0, + bytes_per_address); + } subseg_set (saved_seg, saved_subseg); unwind.proc_start = unwind.proc_end = unwind.info = 0; } @@ -9791,10 +9940,10 @@ md_section_align (seg, size) void ia64_md_do_align (n, fill, len, max) - int n; - const char *fill; + int n ATTRIBUTE_UNUSED; + const char *fill ATTRIBUTE_UNUSED; int len ATTRIBUTE_UNUSED; - int max; + int max ATTRIBUTE_UNUSED; { if (subseg_text_p (now_seg)) ia64_flush_insns (); diff --git a/gas/config/tc-ia64.h b/gas/config/tc-ia64.h index 05e30c64f96..f2b9fe43e8f 100644 --- a/gas/config/tc-ia64.h +++ b/gas/config/tc-ia64.h @@ -1,5 +1,5 @@ /* tc-ia64.h -- Header file for tc-ia64.c. - Copyright (C) 1998, 1999, 2000 Free Software Foundation, Inc. + Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc. Contributed by David Mosberger-Tang This file is part of GAS, the GNU Assembler. @@ -82,6 +82,7 @@ extern void ia64_cons_fix_new PARAMS ((fragS *f, int where, int nbytes, extern void ia64_validate_fix PARAMS ((struct fix *fix)); extern char * ia64_canonicalize_symbol_name PARAMS ((char *)); extern flagword ia64_elf_section_flags PARAMS ((flagword, int, int)); +extern int ia64_elf_section_type PARAMS ((const char *, size_t len)); extern long ia64_pcrel_from_section PARAMS ((struct fix *fix, segT sec)); extern void ia64_md_do_align PARAMS ((int, const char *, int, int)); extern void ia64_handle_align PARAMS ((fragS *f)); @@ -111,6 +112,7 @@ extern void ia64_handle_align PARAMS ((fragS *f)); #define MD_PCREL_FROM_SECTION(fix,sec) ia64_pcrel_from_section (fix, sec) #define md_do_align(n,f,l,m,j) ia64_md_do_align (n,f,l,m) #define HANDLE_ALIGN(f) ia64_handle_align (f) +#define md_elf_section_type(str,len) ia64_elf_section_type (str, len) #define MAX_MEM_FOR_RS_ALIGN_CODE (15 + 16) @@ -121,9 +123,7 @@ extern void ia64_handle_align PARAMS ((fragS *f)); #define ELF_TC_SPECIAL_SECTIONS \ { ".sbss", SHT_NOBITS, SHF_ALLOC + SHF_WRITE + SHF_IA_64_SHORT }, \ -{ ".sdata", SHT_PROGBITS, SHF_ALLOC + SHF_WRITE + SHF_IA_64_SHORT }, \ -{ ".IA_64.unwind", SHT_IA_64_UNWIND, SHF_ALLOC }, \ -{ ".IA_64.unwind_info", SHT_PROGBITS, SHF_ALLOC }, +{ ".sdata", SHT_PROGBITS, SHF_ALLOC + SHF_WRITE + SHF_IA_64_SHORT }, #define DWARF2_LINE_MIN_INSN_LENGTH 1 /* so slot-multipliers can be 1 */ -- 2.30.2