/* * This file is part of libFirm. * Copyright (C) 2012 University of Karlsruhe. */ /** * @file * @brief Dumps global variables and constants as gas assembler. * @author Christian Wuerdig, Matthias Braun * @date 04.11.2005 */ #include "begnuas.h" #include "be_t.h" #include "bearch.h" #include "beemithlp.h" #include "beemitter.h" #include "bemodule.h" #include "betranshlp.h" #include "dbginfo.h" #include "entity_t.h" #include "execfreq.h" #include "iredges_t.h" #include "irnode_t.h" #include "irtools.h" #include "lc_opts_enum.h" #include "panic.h" #include "platform_t.h" #include "util.h" #include #include /** by default, we generate assembler code for GNU as */ elf_variant_t be_gas_elf_variant = ELF_VARIANT_NORMAL; bool be_gas_emit_types = true; char be_gas_elf_type_char = '@'; static be_gas_section_t current_section = (be_gas_section_t) -1; static pmap *block_numbers; static unsigned next_block_nr; static bool is_macho(void) { return ir_platform.object_format == OBJECT_FORMAT_MACH_O; } static void emit_section_macho(be_gas_section_t const section) { if (current_section == section) return; current_section = section; be_gas_section_t const base = section & GAS_SECTION_TYPE_MASK; be_gas_section_t const flags = section & ~GAS_SECTION_TYPE_MASK; static char const *const macho_shortforms[] = { [GAS_SECTION_CONSTRUCTORS] = "mod_init_func", [GAS_SECTION_DESTRUCTORS] = "mod_term_func", }; if (flags == 0 && base < ARRAY_SIZE(macho_shortforms)) { char const *const shortform = macho_shortforms[base]; if (shortform) { be_emit_irprintf("\t.%s\n", shortform); be_emit_write_line(); return; } } typedef struct { const char *segment_section; const char *flags; } macho_sectioninfo_t; static const macho_sectioninfo_t macho_sectioninfos[] = { [GAS_SECTION_TEXT] = { "__TEXT,__text", "regular,pure_instructions" }, [GAS_SECTION_DATA] = { "__DATA,__data", NULL }, [GAS_SECTION_RODATA] = { "__TEXT,__const", NULL }, [GAS_SECTION_REL_RO] = { "__DATA,__const", NULL }, [GAS_SECTION_REL_RO_LOCAL] = { "__DATA,__const", NULL }, [GAS_SECTION_BSS] = { "__DATA,__bss", NULL }, [GAS_SECTION_CSTRING] = { "__TEXT,__cstring", "cstring_literals" }, [GAS_SECTION_PIC_TRAMPOLINES] = { "__IMPORT,__jump_table", "symbol_stubs,self_modifying_code+pure_instructions,5" }, [GAS_SECTION_PIC_SYMBOLS] = { "__IMPORT,__pointers", "non_lazy_symbol_pointers" }, [GAS_SECTION_DEBUG_INFO] = { "__DWARF,__debug_info", "regular,debug" }, [GAS_SECTION_DEBUG_ABBREV] = { "__DWARF,__debug_abbrev", "regular,debug" }, [GAS_SECTION_DEBUG_LINE] = { "__DWARF,__debug_line", "regular,debug" }, [GAS_SECTION_DEBUG_PUBNAMES] = { "__DWARF,__debug_pubnames", "regular,debug" }, [GAS_SECTION_DEBUG_FRAME] = { "__DWARF,__debug_frame", "regular,debug" }, }; static const macho_sectioninfo_t macho_sectioninfos_coalesce[] = { [GAS_SECTION_TEXT] = { "__TEXT,__textcoal_nt", "coalesced,pure_instructions" }, [GAS_SECTION_DATA] = { "__DATA,__datacoal_nt", "coalesced" }, [GAS_SECTION_BSS] = { "__DATA,__datacoal_nt", "coalesced" }, [GAS_SECTION_RODATA] = { "__TEXT,__const_coal", "coalesced" }, [GAS_SECTION_CSTRING] = { "__TEXT,__const_coal", "coalesced" }, }; if (flags & GAS_SECTION_FLAG_TLS) panic("thread local storage not supported on macho (section 0x%X)", section); macho_sectioninfo_t const *info; if (flags & GAS_SECTION_FLAG_COMDAT) { assert(base < ARRAY_SIZE(macho_sectioninfos_coalesce)); info = &macho_sectioninfos_coalesce[base]; } else { assert(base < ARRAY_SIZE(macho_sectioninfos)); info = &macho_sectioninfos[base]; } if (!info->segment_section) panic("Unsupported macho section requested"); be_emit_irprintf("\t.section\t%s", info->segment_section); if (info->flags) be_emit_irprintf(",%s", info->flags); be_emit_char('\n'); be_emit_write_line(); } typedef struct { const char *name; const char *type; const char *flags; } elf_sectioninfo_t; static const elf_sectioninfo_t elf_sectioninfos[] = { [GAS_SECTION_TEXT] = { "text", "progbits", "ax" }, [GAS_SECTION_DATA] = { "data", "progbits", "aw" }, [GAS_SECTION_RODATA] = { "rodata", "progbits", "a" }, [GAS_SECTION_REL_RO_LOCAL] = { "data.rel.ro.local", "progbits", "aw" }, [GAS_SECTION_REL_RO] = { "data.rel.ro", "progbits", "aw" }, [GAS_SECTION_BSS] = { "bss", "nobits", "aw" }, [GAS_SECTION_CONSTRUCTORS] = { "ctors", "progbits", "aw" }, [GAS_SECTION_DESTRUCTORS] = { "dtors", "progbits", "aw" }, [GAS_SECTION_JCR] = { "jcr", "progbits", "aw" }, [GAS_SECTION_DEBUG_INFO] = { "debug_info", "progbits", "" }, [GAS_SECTION_DEBUG_ABBREV] = { "debug_abbrev", "progbits", "" }, [GAS_SECTION_DEBUG_LINE] = { "debug_line", "progbits", "" }, [GAS_SECTION_DEBUG_PUBNAMES] = { "debug_pubnames", "progbits", "" }, [GAS_SECTION_DEBUG_FRAME] = { "debug_frame", "progbits", "" }, }; static void emit_section_sparc(be_gas_section_t section, const ir_entity *entity) { if (current_section == section && !(section & GAS_SECTION_FLAG_COMDAT)) return; current_section = section; be_gas_section_t const base = section & GAS_SECTION_TYPE_MASK; be_gas_section_t const flags = section & ~GAS_SECTION_TYPE_MASK; be_emit_cstring("\t.section\t\"."); /* Part1: section-name */ if (flags & GAS_SECTION_FLAG_TLS) be_emit_char('t'); assert((size_t)base < ARRAY_SIZE(elf_sectioninfos)); char const *const name = elf_sectioninfos[base].name; assert(name != NULL); be_emit_string(name); if (flags & GAS_SECTION_FLAG_COMDAT) { be_emit_char('.'); be_gas_emit_entity(entity); } be_emit_char('"'); /* for the simple sections we're done here */ if (flags != 0) { be_emit_cstring(",#alloc"); switch (base) { case GAS_SECTION_TEXT: be_emit_cstring(",#execinstr"); break; case GAS_SECTION_DATA: case GAS_SECTION_BSS: be_emit_cstring(",#write"); break; default: /* nothing */ break; } if (flags & GAS_SECTION_FLAG_TLS) be_emit_cstring(",#tls"); } be_emit_char('\n'); be_emit_write_line(); } static void emit_section_elf_coff(be_gas_section_t const section, ir_entity const *const entity) { if (current_section == section && !(section & GAS_SECTION_FLAG_COMDAT)) return; current_section = section; be_gas_section_t const base = section & GAS_SECTION_TYPE_MASK; be_gas_section_t const flags = section & ~GAS_SECTION_TYPE_MASK; /* shortforms */ if (flags == 0) { switch (base) { case GAS_SECTION_TEXT: be_emit_cstring("\t.text\n"); be_emit_write_line(); return; case GAS_SECTION_DATA: be_emit_cstring("\t.data\n"); be_emit_write_line(); return; case GAS_SECTION_RODATA: be_emit_cstring("\t.section\t.rodata\n"); be_emit_write_line(); return; case GAS_SECTION_BSS: be_emit_cstring("\t.bss\n"); be_emit_write_line(); return; default: break; } } assert((size_t)base < ARRAY_SIZE(elf_sectioninfos)); elf_sectioninfo_t const *const info = &elf_sectioninfos[base]; assert(info->name != NULL); be_emit_cstring("\t.section\t."); /* section name */ if (flags & GAS_SECTION_FLAG_TLS) be_emit_char('t'); be_emit_string(info->name); if (flags & GAS_SECTION_FLAG_COMDAT) { be_emit_char('.'); be_gas_emit_entity(entity); } /* section flags */ be_emit_irprintf(",\"%s", info->flags); if (flags & GAS_SECTION_FLAG_TLS) be_emit_char('T'); if (flags & GAS_SECTION_FLAG_COMDAT) be_emit_char('G'); /* section type */ if (ir_platform.object_format != OBJECT_FORMAT_PE_COFF) be_emit_irprintf("\",%c%s", be_gas_elf_type_char, info->type); if (flags & GAS_SECTION_FLAG_COMDAT) { be_emit_char(','); be_gas_emit_entity(entity); be_emit_cstring(",comdat"); } be_emit_char('\n'); be_emit_write_line(); } static void emit_section(be_gas_section_t const section, ir_entity const *const entity) { if (is_macho()) { emit_section_macho(section); } else if (be_gas_elf_variant == ELF_VARIANT_SPARC) { emit_section_sparc(section, entity); } else { emit_section_elf_coff(section, entity); } } void be_gas_emit_switch_section(be_gas_section_t section) { /* you have to produce a switch_section call with entity manually * for comdat sections */ assert(!(section & GAS_SECTION_FLAG_COMDAT)); emit_section(section, NULL); } static ir_tarval *get_initializer_tarval(const ir_initializer_t *initializer) { if (initializer->kind == IR_INITIALIZER_TARVAL) return initializer->tarval.value; if (initializer->kind == IR_INITIALIZER_CONST) { ir_node *node = initializer->consti.value; if (is_Const(node)) { return get_Const_tarval(node); } } return get_tarval_unknown(); } static bool initializer_is_string_const(const ir_initializer_t *initializer, bool only_suffix_null) { if (initializer->kind != IR_INITIALIZER_COMPOUND) return false; size_t len = initializer->compound.n_initializers; if (len < 1) return false; bool found_printable = false; for (size_t i = 0; i < len; ++i) { ir_initializer_t *sub_initializer = initializer->compound.initializers[i]; ir_tarval *tv = get_initializer_tarval(sub_initializer); if (!tarval_is_constant(tv)) return false; ir_mode *mode = get_tarval_mode(tv); if (!mode_is_int(mode) || get_mode_size_bits(mode) != 8) return false; int c = get_tarval_long(tv); if (i == len-1) { if (c != '\0') return false; } else { if (isgraph(c) || isspace(c)) found_printable = true; else if (c != 0 || only_suffix_null) return false; } } return found_printable; } static bool initializer_is_null(const ir_initializer_t *initializer) { switch (initializer->kind) { case IR_INITIALIZER_NULL: return true; case IR_INITIALIZER_TARVAL: { ir_tarval *tv = initializer->tarval.value; return tarval_is_null(tv); } case IR_INITIALIZER_CONST: { ir_node *value = initializer->consti.value; if (!is_Const(value)) return false; return is_Const_null(value); } case IR_INITIALIZER_COMPOUND: { for (size_t i = 0; i < initializer->compound.n_initializers; ++i) { ir_initializer_t *subinitializer = initializer->compound.initializers[i]; if (!initializer_is_null(subinitializer)) return false; } return true; } } panic("invalid initializer in initializer_is_null"); } /** * Determine if an entity is a string constant * @param ent The entity * @param only_suffix_null if true '\0' is only legal at the end of the * string. */ static bool entity_is_string_const(const ir_entity *ent, bool only_suffix_null) { /* if it's an array */ ir_type *type = get_entity_type(ent); if (!is_Array_type(type)) return false; /* and the array's element type is primitive */ ir_type *element_type = get_array_element_type(type); if (!is_Primitive_type(element_type)) return false; /* and the mode of the element type is an int of * the same size as the byte mode */ ir_mode *mode = get_type_mode(element_type); if (!mode_is_int(mode) || get_mode_size_bits(mode) != 8) return false; ir_initializer_t const *const init = get_entity_initializer(ent); if (!init) return false; return initializer_is_string_const(init, only_suffix_null); } static bool entity_is_zero_initialized(ir_entity const *entity) { if (is_alias_entity(entity)) return false; ir_initializer_t *initializer = get_entity_initializer(entity); return initializer != NULL && initializer_is_null(initializer); } static bool is_comdat(const ir_entity *entity) { ir_linkage linkage = get_entity_linkage(entity); return (linkage & IR_LINKAGE_MERGE) && (linkage & IR_LINKAGE_GARBAGE_COLLECT); } typedef enum reloc_class_t { NO_RELOCATIONS, ONLY_LOCAL_RELOCATIONS, ANY_RELOCATIONS, } reloc_class_t; static reloc_class_t classify_expr_relocs(ir_node const *const node) { switch (get_irn_opcode(node)) { case iro_Conv: return classify_expr_relocs(get_Conv_op(node)); case iro_Address: { ir_entity const *const entity = get_Address_entity(node); ir_visibility const visibility = get_entity_visibility(entity); return visibility == ir_visibility_local || visibility == ir_visibility_private ? ONLY_LOCAL_RELOCATIONS : ANY_RELOCATIONS; } case iro_Offset: case iro_Align: case iro_Const: case iro_Size: case iro_Unknown: return NO_RELOCATIONS; case iro_Add: case iro_Sub: case iro_Mul: return MAX(classify_expr_relocs(get_binop_left(node)), classify_expr_relocs(get_binop_right(node))); default: panic("unsupported IR-node %+F in initializer", node); } } static reloc_class_t classify_initializer_relocs( ir_initializer_t const *const init) { switch (get_initializer_kind(init)) { case IR_INITIALIZER_NULL: case IR_INITIALIZER_TARVAL: return NO_RELOCATIONS; case IR_INITIALIZER_CONST: return classify_expr_relocs(get_initializer_const_value(init)); case IR_INITIALIZER_COMPOUND: { reloc_class_t result = NO_RELOCATIONS; for (size_t i = 0, n = get_initializer_compound_n_entries(init); i < n; ++i) { ir_initializer_t const *const subinit = get_initializer_compound_value(init, i); result = MAX(result, classify_initializer_relocs(subinit)); } return result; } } panic("invalid initializer"); } static be_gas_section_t determine_basic_section(const ir_entity *entity) { if (is_method_entity(entity) || is_alias_entity(entity)) return GAS_SECTION_TEXT; if (get_entity_linkage(entity) & IR_LINKAGE_CONSTANT) { /* mach-o is the only one with a cstring section */ if (is_macho() && get_entity_linkage(entity) & IR_LINKAGE_NO_IDENTITY && entity_is_string_const(entity, true)) return GAS_SECTION_CSTRING; if (ir_platform.pic_style != BE_PIC_NONE) { ir_initializer_t const *const init = get_entity_initializer(entity); switch (classify_initializer_relocs(init)) { case ONLY_LOCAL_RELOCATIONS: return GAS_SECTION_REL_RO_LOCAL; case ANY_RELOCATIONS: return GAS_SECTION_REL_RO; case NO_RELOCATIONS: return GAS_SECTION_RODATA; } panic("invalid relocation class"); } else { return GAS_SECTION_RODATA; } } if (entity_is_zero_initialized(entity)) return GAS_SECTION_BSS; return GAS_SECTION_DATA; } static be_gas_section_t determine_section(be_main_env_t const *const main_env, ir_entity const *const entity) { ir_type *owner = get_entity_owner(entity); if (owner == get_segment_type(IR_SEGMENT_GLOBAL)) { be_gas_section_t section = determine_basic_section(entity); if (is_comdat(entity)) section |= GAS_SECTION_FLAG_COMDAT; return section; } else if (main_env && owner == main_env->pic_symbols_type) { return GAS_SECTION_PIC_SYMBOLS; } else if (main_env && owner == main_env->pic_trampolines_type) { return GAS_SECTION_PIC_TRAMPOLINES; } else if (owner == get_segment_type(IR_SEGMENT_CONSTRUCTORS)) { return GAS_SECTION_CONSTRUCTORS; } else if (owner == get_segment_type(IR_SEGMENT_DESTRUCTORS)) { return GAS_SECTION_DESTRUCTORS; } else if (owner == get_segment_type(IR_SEGMENT_JCR)) { return GAS_SECTION_JCR; } else if (owner == get_segment_type(IR_SEGMENT_THREAD_LOCAL)) { be_gas_section_t section = determine_basic_section(entity); if (is_comdat(entity)) section |= GAS_SECTION_FLAG_COMDAT; return section | GAS_SECTION_FLAG_TLS; } /* the java frontend keeps some functions inside classes */ if (is_Class_type(owner)) { return determine_basic_section(entity); } panic("couldn't determine section for %+F", entity); } static void emit_symbol_directive(const char *directive, const ir_entity *entity) { be_emit_irprintf("\t%s ", directive); be_gas_emit_entity(entity); be_emit_char('\n'); be_emit_write_line(); } static void emit_weak(const ir_entity *entity) { char const *const directive = !is_macho() ? ".weak" : entity_has_definition(entity) ? ".weak_definition" : /* */ ".weak_reference"; emit_symbol_directive(directive, entity); } static const char *get_visibility_directive(const ir_entity *entity, bool *output_global) { switch (get_entity_visibility(entity)) { case ir_visibility_external: return NULL; case ir_visibility_external_private: { switch (ir_platform.object_format) { case OBJECT_FORMAT_MACH_O: *output_global = false; return ".private_extern"; case OBJECT_FORMAT_ELF: return ".hidden"; case OBJECT_FORMAT_PE_COFF: panic("ir_visibility_external_private not supported for COFF"); } panic("invalid object file format"); } case ir_visibility_external_protected: { switch (ir_platform.object_format) { case OBJECT_FORMAT_MACH_O: return NULL; case OBJECT_FORMAT_ELF: return ".protected"; case OBJECT_FORMAT_PE_COFF: panic("ir_visibility_external_protected not supported for COFF"); } panic("invalid object file format"); } case ir_visibility_local: case ir_visibility_private: *output_global = false; return NULL; } panic("invalid visibility"); } static void emit_visibility(const ir_entity *entity, bool implicit_globl) { ir_linkage const linkage = get_entity_linkage(entity); if (linkage & IR_LINKAGE_WEAK) emit_weak(entity); bool output_global = !implicit_globl; const char *const directive = get_visibility_directive(entity, &output_global); if (output_global) emit_symbol_directive(".globl", entity); if (directive != NULL) emit_symbol_directive(directive, entity); if (is_macho() && (linkage & IR_LINKAGE_HIDDEN_USER) && get_entity_ld_name(entity)[0] != '\0') { emit_symbol_directive(".no_dead_strip", entity); } } void be_gas_emit_function_prolog(const ir_entity *entity, unsigned po2alignment, const parameter_dbg_info_t *parameter_infos) { be_dwarf_function_before(entity, parameter_infos); be_gas_section_t const section = determine_section(NULL, entity); emit_section(section, entity); /* write the begin line (makes the life easier for scripts parsing the * assembler) */ if (be_options.verbose_asm) { be_emit_cstring("# -- Begin "); be_gas_emit_entity(entity); be_emit_char('\n'); be_emit_write_line(); } if (po2alignment > 0) { /* gcc fills space between function with 0x90... */ char const *const fill_byte = is_macho() ? "0x90" : ""; unsigned const maximum_skip = (1U << po2alignment) - 1; be_emit_irprintf("\t.p2align %u,%s,%u\n", po2alignment, fill_byte, maximum_skip); be_emit_write_line(); } emit_visibility(entity, false); switch (ir_platform.object_format) { case OBJECT_FORMAT_ELF: be_emit_cstring("\t.type\t"); be_gas_emit_entity(entity); be_emit_irprintf(", %cfunction\n", be_gas_elf_type_char); be_emit_write_line(); break; case OBJECT_FORMAT_PE_COFF: be_emit_cstring("\t.def\t"); be_gas_emit_entity(entity); char const vis = get_entity_visibility(entity) == ir_visibility_local ? '3' : '2'; be_emit_irprintf(";\t.scl\t%c;\t.type\t32;\t.endef\n", vis); be_emit_write_line(); break; case OBJECT_FORMAT_MACH_O: if (section == (GAS_SECTION_TEXT | GAS_SECTION_FLAG_COMDAT)) emit_symbol_directive(".weak_definition", entity); break; } be_gas_emit_entity(entity); be_emit_cstring(":\n"); be_emit_write_line(); be_dwarf_function_begin(); } void be_gas_emit_function_epilog(ir_entity const *const entity) { be_dwarf_function_end(); if (ir_platform.object_format == OBJECT_FORMAT_ELF) { be_emit_cstring("\t.size\t"); be_gas_emit_entity(entity); be_emit_cstring(", .-"); be_gas_emit_entity(entity); be_emit_char('\n'); be_emit_write_line(); } if (be_options.verbose_asm) { be_emit_cstring("# -- End "); be_gas_emit_entity(entity); be_emit_char('\n'); be_emit_write_line(); } be_emit_char('\n'); be_emit_write_line(); next_block_nr += 199; next_block_nr -= next_block_nr % 100; } /** * Output parts of a tarval. * * @param tv The tarval * @param offset The byte offst to start at * @param n How many bytes to output */ static void emit_tv(ir_tarval *const tv, unsigned const offset, unsigned const n) { be_emit_cstring("0x"); for (unsigned i = n; i-- != 0;) { be_emit_irprintf("%02x", get_tarval_sub_bits(tv, offset + i)); } } /** * Return the label prefix for labeled instructions. */ const char *be_gas_insn_label_prefix(void) { return ".LE"; } /** * Dump an atomic value. * * @param init a node representing the atomic value (on the const code irg) */ static void emit_init_expression(ir_node *const init) { ir_mode *mode = get_irn_mode(init); switch (get_irn_opcode(init)) { case iro_Conv: emit_init_expression(get_Conv_op(init)); return; case iro_Const: { /* it's an arithmetic value */ int const bytes = get_mode_size_bytes(mode); ir_tarval *const tv = get_Const_tarval(init); emit_tv(tv, 0, bytes); return; } case iro_Address: be_gas_emit_entity(get_Address_entity(init)); return; case iro_Offset: be_emit_irprintf("%d", get_entity_offset(get_Offset_entity(init))); return; case iro_Align: be_emit_irprintf("%u", get_type_alignment(get_Align_type(init))); return; case iro_Size: be_emit_irprintf("%u", get_type_size(get_Size_type(init))); return; case iro_Add: if (!be_mode_needs_gp_reg(mode)) panic("constant must be int or pointer for '+' to work"); emit_init_expression(get_Add_left(init)); be_emit_cstring(" + "); emit_init_expression(get_Add_right(init)); return; case iro_Sub: if (!be_mode_needs_gp_reg(mode)) panic("constant must be int or pointer for '-' to work"); emit_init_expression(get_Sub_left(init)); be_emit_cstring(" - "); emit_init_expression(get_Sub_right(init)); return; case iro_Mul: if (!mode_is_int(mode)) panic("constant must be int for '*' to work"); emit_init_expression(get_Mul_left(init)); be_emit_cstring(" * "); emit_init_expression(get_Mul_right(init)); return; case iro_Unknown: be_emit_cstring("0"); return; default: panic("unsupported IR-node %+F", init); } } /** * Dumps the type for given size (.byte, .long, ...) * * @param size the size in bytes */ static void emit_size_type(size_t size) { switch (size) { case 1: be_emit_cstring("\t.byte\t"); break; case 2: be_emit_cstring("\t.short\t"); break; case 4: be_emit_cstring("\t.long\t"); break; case 8: be_emit_cstring("\t.quad\t"); break; default: panic("try to dump a type with %u bytes", (unsigned)size); } } static void emit_string_char(int c) { switch (c) { case '"' : be_emit_cstring("\\\""); break; case '\n': be_emit_cstring("\\n"); break; case '\r': be_emit_cstring("\\r"); break; case '\t': be_emit_cstring("\\t"); break; case '\\': be_emit_cstring("\\\\"); break; default : if (isprint(c)) be_emit_char(c); else be_emit_irprintf("\\%03o", c); break; } } static size_t emit_string_initializer(const ir_initializer_t *initializer) { be_emit_cstring("\t.asciz \""); size_t const len = initializer->compound.n_initializers - 1; for (size_t i = 0; i < len; ++i) { const ir_initializer_t *sub_initializer = get_initializer_compound_value(initializer, i); ir_tarval *tv = get_initializer_tarval(sub_initializer); int c = get_tarval_long(tv); emit_string_char(c); } be_emit_cstring("\"\n"); be_emit_write_line(); return initializer->compound.n_initializers; } void be_gas_emit_string_literal(const char *string) { be_emit_char('"'); for (const char *c = string; *c != '\0'; ++c) { emit_string_char(*c); } be_emit_char('"'); } void be_gas_emit_cstring(const char *string) { be_emit_cstring("\t.asciz "); be_gas_emit_string_literal(string); be_emit_char('\n'); be_emit_write_line(); } typedef enum normal_or_bitfield_kind { NORMAL = 0, TARVAL, STRING, BITFIELD } normal_or_bitfield_kind; typedef struct { normal_or_bitfield_kind kind; ir_type *type; union { ir_node *value; ir_tarval *tarval; unsigned char bf_val; const ir_initializer_t *string; } v; } normal_or_bitfield; static size_t get_initializer_size(const ir_initializer_t *initializer, ir_type *type) { switch (get_initializer_kind(initializer)) { case IR_INITIALIZER_TARVAL: assert(get_tarval_mode(get_initializer_tarval_value(initializer)) == get_type_mode(type)); return get_type_size(type); case IR_INITIALIZER_CONST: case IR_INITIALIZER_NULL: return get_type_size(type); case IR_INITIALIZER_COMPOUND: if (is_Array_type(type)) { if (get_array_size(type) == 0) { ir_type *element_type = get_array_element_type(type); unsigned element_size = get_type_size(element_type); unsigned element_align = get_type_alignment(element_type); unsigned misalign = element_size % element_align; size_t n_inits = get_initializer_compound_n_entries(initializer); element_size += element_align - misalign; return n_inits * element_size; } else { return get_type_size(type); } } else { assert(is_compound_type(type)); size_t size = get_type_size(type); /* Last initializer may be an array of flexible size. */ size_t const n = get_initializer_compound_n_entries(initializer); if (n != 0) { ir_entity *const last_ent = get_compound_member(type, n - 1); ir_type *const last_type = get_entity_type(last_ent); if (is_Array_type(last_type) && get_array_size(last_type) == 0) { ir_initializer_t const *const last = get_initializer_compound_value(initializer, n - 1); size += get_initializer_size(last, last_type); } } return size; } } panic("found invalid initializer"); } static unsigned long compute_entity_size(ir_entity const *const entity) { ir_type *const type = get_entity_type(entity); unsigned long size = get_type_size(type); if (is_alias_entity(entity)) return size; /* Note that for variable array/compound types we may have to inspect the * initializer to get the actual size */ ir_initializer_t const *const initializer = get_entity_initializer(entity); if (initializer != NULL) size = get_initializer_size(initializer, type); return size; } #ifndef NDEBUG static normal_or_bitfield *glob_vals; static unsigned long max_vals; #endif static void emit_bitfield(normal_or_bitfield *vals, unsigned offset_bits, unsigned bitfield_size, const ir_initializer_t *initializer, ir_type *type) { static const size_t BITS_PER_BYTE = 8; ir_tarval *tv = NULL; switch (get_initializer_kind(initializer)) { case IR_INITIALIZER_NULL: return; case IR_INITIALIZER_TARVAL: tv = get_initializer_tarval_value(initializer); break; case IR_INITIALIZER_CONST: { ir_node *const node = get_initializer_const_value(initializer); if (!is_Const(node)) panic("bitfield initializer not a Const node"); tv = get_Const_tarval(node); break; } case IR_INITIALIZER_COMPOUND: panic("bitfield initializer is compound"); } if (!tv || tv == tarval_bad) panic("couldn't get numeric value for bitfield initializer"); int value_len = get_type_size(type); size_t bit_offset = 0; size_t end = bitfield_size; bool big_endian = ir_target_big_endian(); while (bit_offset < end) { size_t src_offset = bit_offset / BITS_PER_BYTE; size_t src_offset_bits = bit_offset % BITS_PER_BYTE; size_t dst_offset = (bit_offset + offset_bits) / BITS_PER_BYTE; size_t dst_offset_bits = (bit_offset + offset_bits) % BITS_PER_BYTE; size_t src_bits_len = end - bit_offset; size_t dst_bits_len = BITS_PER_BYTE - dst_offset_bits; src_bits_len = MIN(dst_bits_len, src_bits_len); normal_or_bitfield *const val = big_endian ? &vals[value_len - dst_offset - 1] : &vals[dst_offset]; assert(val - glob_vals < (ptrdiff_t)max_vals); assert(val->kind == BITFIELD || (val->kind == NORMAL && !val->v.value)); val->kind = BITFIELD; unsigned char curr_bits = get_tarval_sub_bits(tv, src_offset); curr_bits = curr_bits >> src_offset_bits; if (src_offset_bits + src_bits_len > 8) { unsigned next_bits = get_tarval_sub_bits(tv, src_offset+1); curr_bits |= next_bits << (8 - src_offset_bits); } curr_bits &= (1 << src_bits_len) - 1; val->v.bf_val |= curr_bits << dst_offset_bits; bit_offset += dst_bits_len; } } static void emit_ir_initializer(normal_or_bitfield *vals, const ir_initializer_t *initializer, ir_type *type) { assert((unsigned long) (vals - glob_vals) <= max_vals); if (initializer_is_string_const(initializer, false)) { assert(vals->kind != BITFIELD); vals->kind = STRING; vals->v.string = initializer; return; } switch (get_initializer_kind(initializer)) { case IR_INITIALIZER_NULL: return; case IR_INITIALIZER_TARVAL: assert(vals->kind != BITFIELD); vals->kind = TARVAL; vals->type = type; vals->v.tarval = get_initializer_tarval_value(initializer); assert(get_type_mode(type) == get_tarval_mode(vals->v.tarval)); for (size_t i = 1; i < get_type_size(type); ++i) { vals[i].kind = NORMAL; vals[i].type = NULL; vals[i].v.value = NULL; } return; case IR_INITIALIZER_CONST: assert(vals->kind != BITFIELD); vals->kind = NORMAL; vals->type = type; vals->v.value = get_initializer_const_value(initializer); for (size_t i = 1; i < get_type_size(type); ++i) { vals[i].kind = NORMAL; vals[i].type = NULL; vals[i].v.value = NULL; } return; case IR_INITIALIZER_COMPOUND: if (is_Array_type(type)) { ir_type *element_type = get_array_element_type(type); size_t skip = get_type_size(element_type); size_t alignment = get_type_alignment(element_type); size_t misalign = skip % alignment; if (misalign != 0) skip += alignment - misalign; for (size_t i = 0, n = get_initializer_compound_n_entries(initializer); i < n; ++i) { ir_initializer_t *sub_initializer = get_initializer_compound_value(initializer, i); emit_ir_initializer(vals, sub_initializer, element_type); vals += skip; } } else { assert(is_compound_type(type)); for (size_t i = 0, n_members = get_compound_n_members(type); i < n_members; ++i) { ir_entity *member = get_compound_member(type, i); size_t offset = get_entity_offset(member); assert(i < get_initializer_compound_n_entries(initializer)); ir_initializer_t *sub_initializer = get_initializer_compound_value(initializer, i); ir_type *subtype = get_entity_type(member); unsigned bitfield_size = get_entity_bitfield_size(member); if (bitfield_size > 0) { unsigned offset_bits = get_entity_bitfield_offset(member); emit_bitfield(&vals[offset], offset_bits, bitfield_size, sub_initializer, subtype); continue; } emit_ir_initializer(&vals[offset], sub_initializer, subtype); } } return; } panic("invalid ir_initializer kind found"); } static void emit_tarval_data(ir_type *type, ir_tarval *tv) { size_t size = get_type_size(type); if (size > 8) { assert(size % 4 == 0); if (ir_target_big_endian()) { for (unsigned i = size; i != 0;) { emit_size_type(4); emit_tv(tv, i -= 4, 4); be_emit_char('\n'); } } else { /* Beware: Mixed endian output! One little endian number emitted as * longs. Each long initializer is written in big endian. */ for (unsigned i = 0; i != size; i += 4) { emit_size_type(4); emit_tv(tv, i, 4); be_emit_char('\n'); } } } else { /* default case */ emit_size_type(size); emit_tv(tv, 0, size); be_emit_char('\n'); } be_emit_write_line(); } /** * Emit an atomic value. * * @param init a node representing the atomic value (on the const code irg) */ static void emit_node_data(ir_node *const init, ir_type *const type) { size_t const size = get_type_size(type); if (size == 12 || size == 16) { if (!is_Const(init)) panic("12/16byte initializers only support Const nodes yet"); ir_tarval *const tv = get_Const_tarval(init); emit_tarval_data(type, tv); return; } emit_size_type(size); emit_init_expression(init); be_emit_char('\n'); be_emit_write_line(); } static void emit_initializer(ir_entity const *const entity, unsigned long const size) { ir_initializer_t const *const initializer = get_entity_initializer(entity); if (initializer_is_string_const(initializer, false)) { emit_string_initializer(initializer); return; } assert(size > 0); /* In the worst case, every initializer allocates one byte. * Moreover, initializer might be big, do not allocate on stack. */ normal_or_bitfield *const vals = XMALLOCNZ(normal_or_bitfield, size); #ifndef NDEBUG glob_vals = vals; max_vals = size; #endif ir_type *const type = get_entity_type(entity); emit_ir_initializer(vals, initializer, type); /* now write values sorted */ for (size_t k = 0; k < size;) { int elem_size; switch (vals[k].kind) { case NORMAL: if (vals[k].v.value != NULL) { emit_node_data(vals[k].v.value, vals[k].type); elem_size = get_type_size(vals[k].type); } else { elem_size = 0; } break; case TARVAL: emit_tarval_data(vals[k].type, vals[k].v.tarval); elem_size = get_type_size(vals[k].type); break; case STRING: elem_size = emit_string_initializer(vals[k].v.string); break; case BITFIELD: be_emit_irprintf("\t.byte\t%d\n", vals[k].v.bf_val); be_emit_write_line(); elem_size = 1; break; default: panic("internal compiler error (invalid normal_or_bitfield_kind"); } k += elem_size; int space = 0; while (k < size && vals[k].kind == NORMAL && vals[k].v.value == NULL) { ++space; ++k; } /* a gap */ if (space > 0) { be_emit_irprintf("\t.space\t%d, 0\n", space); be_emit_write_line(); } } free(vals); } static void emit_align(unsigned p2alignment) { be_emit_irprintf("\t.p2align\t%u\n", log2_floor(p2alignment)); be_emit_write_line(); } static unsigned get_effective_entity_alignment(const ir_entity *entity) { unsigned alignment = get_entity_alignment(entity); if (alignment == 0) { ir_type *type = get_entity_type(entity); alignment = get_type_alignment(type); } return alignment; } static void emit_common(const ir_entity *entity, unsigned long size, bool is_local) { unsigned const alignment = get_effective_entity_alignment(entity); switch (ir_platform.object_format) { case OBJECT_FORMAT_MACH_O: assert(!is_local); be_emit_cstring("\t.comm "); be_gas_emit_entity(entity); be_emit_irprintf(",%lu,%u\n", size, log2_floor(alignment)); be_emit_write_line(); return; case OBJECT_FORMAT_ELF: if (is_local) emit_symbol_directive(".local", entity); be_emit_cstring("\t.comm "); be_gas_emit_entity(entity); be_emit_irprintf(",%lu,%u\n", size, alignment); be_emit_write_line(); return; case OBJECT_FORMAT_PE_COFF: be_emit_string(is_local ? "\t.lcomm " : "\t.comm "); be_gas_emit_entity(entity); be_emit_irprintf(",%lu # %u\n", size, alignment); be_emit_write_line(); return; } panic("invalid object file format"); } static void emit_zerofill(const ir_entity *entity, const char *section_segment, unsigned long const size) { be_emit_cstring("\t.zerofill\t"); be_emit_string(section_segment); be_emit_char(','); be_gas_emit_entity(entity); unsigned const alignment = get_effective_entity_alignment(entity); be_emit_irprintf(",%lu,%u\n", size, log2_floor(alignment)); be_emit_write_line(); } static void emit_indirect_symbol(const ir_entity *entity, be_gas_section_t section) { if (!is_macho()) panic("indirect_symbol entities only supported for ELF"); be_gas_emit_entity(entity); be_emit_cstring(":\n"); be_emit_write_line(); be_emit_irprintf("\t.indirect_symbol %I\n", get_entity_ident(entity)); be_emit_write_line(); if (section == GAS_SECTION_PIC_TRAMPOLINES) { be_emit_cstring("\thlt ; hlt ; hlt ; hlt ; hlt\n"); be_emit_write_line(); } else { assert(section == GAS_SECTION_PIC_SYMBOLS); be_emit_cstring("\t.long 0\n"); be_emit_write_line(); } } static void emit_alias(const ir_entity *entity) { if (ir_platform.object_format != OBJECT_FORMAT_ELF) panic("alias entities only supported for ELF"); be_emit_cstring("\t.set "); be_gas_emit_entity(entity); be_emit_char(','); be_gas_emit_entity(get_entity_alias(entity)); be_emit_char('\n'); be_emit_write_line(); } char const *be_gas_get_private_prefix(void) { return is_macho() ? "L" : ".L"; } static bool check_needs_quotes(char const *const s) { if (is_macho()) { for (char const *i = s; *i != '\0'; ++i) { if ((unsigned char)*i >= 128) return true; } } return false; } void be_gas_emit_entity(const ir_entity *entity) { if (entity->kind == IR_ENTITY_LABEL) { ir_label_t label = get_entity_label(entity); be_emit_irprintf("%s_%lu", be_gas_get_private_prefix(), label); return; } char const *const name = get_entity_ld_name(entity); bool const needs_quotes = check_needs_quotes(name); if (needs_quotes) be_emit_char('"'); if (get_entity_visibility(entity) == ir_visibility_private) be_emit_string(be_gas_get_private_prefix()); be_emit_string(name); if (needs_quotes) be_emit_char('"'); } void be_gas_emit_block_name(const ir_node *block) { ir_entity *entity = get_Block_entity(block); if (entity != NULL) { be_gas_emit_entity(entity); } else { void *nr_val = pmap_get(void, block_numbers, block); int nr; if (nr_val == NULL) { nr = next_block_nr++; pmap_insert(block_numbers, block, INT_TO_PTR(nr + 1)); } else { nr = PTR_TO_INT(nr_val) - 1; } be_emit_irprintf("%s%d", be_gas_get_private_prefix(), nr); } } static bool block_needs_label(ir_node const *const block) { if (get_Block_entity(block)) return true; int const n_cfgpreds = get_Block_n_cfgpreds(block); if (n_cfgpreds == 0) { return false; } else if (n_cfgpreds == 1) { ir_node *const cfgpred = get_Block_cfgpred(block, 0); ir_node *const cfgpred_block = get_nodes_block(cfgpred); if (be_emit_get_prev_block(block) != cfgpred_block) return true; if (is_x_regular_Proj(cfgpred)) return false; ir_node const *const pred = skip_Proj(cfgpred); return !(arch_get_irn_flags(pred) & arch_irn_flag_fallthrough); } else { return true; } } void be_gas_begin_block(ir_node const *const block) { if (block_needs_label(block)) { be_gas_emit_block_name(block); be_emit_char(':'); } else { if (!be_options.verbose_asm) return; be_emit_cstring("/*"); be_gas_emit_block_name(block); be_emit_cstring(":*/"); } if (be_options.verbose_asm) { be_emit_pad_comment(); be_emit_irprintf("/* %+F preds:", block); int arity = get_irn_arity(block); if (arity == 0) { be_emit_cstring(" none"); } else { for (int i = 0; i < arity; ++i) { ir_node *predblock = get_Block_cfgpred_block(block, i); if (predblock == NULL) continue; be_emit_char(' '); be_gas_emit_block_name(predblock); } } be_emit_irprintf(", freq: %.3f */", get_block_execfreq(block)); } be_emit_char('\n'); be_emit_write_line(); } /** * Dump a global entity. */ static void emit_global(be_main_env_t const *const main_env, ir_entity const *const entity) { ir_entity_kind kind = get_entity_kind(entity); /* Block labels are already emitted in the code. */ if (kind == IR_ENTITY_LABEL) return; /* we already emitted all functions with graphs in other functions like * be_gas_emit_function_prolog(). All others don't need to be emitted. */ be_gas_section_t const section = determine_section(main_env, entity); if (kind == IR_ENTITY_METHOD && section != GAS_SECTION_PIC_TRAMPOLINES) return; if (section == GAS_SECTION_PIC_TRAMPOLINES || section == GAS_SECTION_PIC_SYMBOLS) { emit_section(section, entity); emit_indirect_symbol(entity, section); return; } be_dwarf_variable(entity); ir_visibility const visibility = get_entity_visibility(entity); ir_linkage const linkage = get_entity_linkage(entity); bool const zero_initializer = entity_is_zero_initialized(entity); unsigned long size = compute_entity_size(entity); /* We need to output at least 1 byte, otherwise macho will merge * the label with the next thing */ if (size == 0) size = 1; if ((linkage & IR_LINKAGE_MERGE || zero_initializer) && !(section & GAS_SECTION_FLAG_TLS)) { switch (visibility) { case ir_visibility_external: case ir_visibility_external_private: case ir_visibility_external_protected: if (linkage & IR_LINKAGE_MERGE) { emit_visibility(entity, true); emit_common(entity, size, false); return; } else if (is_macho() && !(linkage & IR_LINKAGE_CONSTANT)) { emit_visibility(entity, false); emit_zerofill(entity, "__DATA,__common", size); return; } break; case ir_visibility_local: case ir_visibility_private: if (!(linkage & IR_LINKAGE_CONSTANT)) { switch (ir_platform.object_format) { case OBJECT_FORMAT_ELF: case OBJECT_FORMAT_PE_COFF: emit_visibility(entity, true); emit_common(entity, size, true); return; case OBJECT_FORMAT_MACH_O: emit_visibility(entity, false); emit_zerofill(entity, "__DATA,__bss", size); return; } } break; } } /* nothing left to do without an initializer */ if (!entity_has_definition(entity)) return; emit_section(section, entity); emit_visibility(entity, false); if (kind == IR_ENTITY_ALIAS) { emit_alias(entity); return; } /* alignment */ unsigned alignment = get_effective_entity_alignment(entity); if (!is_po2_or_zero(alignment)) panic("alignment not a power of 2"); if (alignment > 1) emit_align(alignment); if (ir_platform.object_format == OBJECT_FORMAT_ELF && be_gas_emit_types && visibility != ir_visibility_private) { be_emit_cstring("\t.type\t"); be_gas_emit_entity(entity); be_emit_irprintf(", %cobject\n\t.size\t", be_gas_elf_type_char); be_gas_emit_entity(entity); ir_type *const type = get_entity_type(entity); be_emit_irprintf(", %u\n", get_type_size(type)); } ident *ld_ident = get_entity_ld_ident(entity); if (get_id_str(ld_ident)[0] != '\0') { be_gas_emit_entity(entity); be_emit_cstring(":\n"); be_emit_write_line(); } if (!zero_initializer) { emit_initializer(entity, size); } else if (size > 0) { /* use .space for stuff in the bss segment */ be_emit_irprintf("\t.space %u, 0\n", size); be_emit_write_line(); } } /** * Dumps declarations of global variables and the initialization code. * * @param gt a global like type, either the global or the TLS one */ static void be_gas_emit_globals(ir_type *const gt, be_main_env_t const *const main_env) { for (size_t i = 0, n = get_compound_n_members(gt); i < n; i++) { ir_entity *const ent = get_compound_member(gt, i); if (!(get_entity_linkage(ent) & IR_LINKAGE_NO_CODEGEN)) emit_global(main_env, ent); } } /* Generate all entities. */ static void emit_global_decls(be_main_env_t const *const main_env) { be_gas_emit_globals(get_glob_type(), main_env); be_gas_emit_globals(get_tls_type(), main_env); be_gas_emit_globals(get_segment_type(IR_SEGMENT_CONSTRUCTORS), main_env); be_gas_emit_globals(get_segment_type(IR_SEGMENT_DESTRUCTORS), main_env); be_gas_emit_globals(get_segment_type(IR_SEGMENT_JCR), main_env); be_gas_emit_globals(main_env->pic_symbols_type, main_env); be_gas_emit_globals(main_env->pic_trampolines_type, main_env); /** * ".subsections_via_symbols marks object files which are OK to divide * their section contents into individual blocks". * From my understanding this means no label points in the middle of an * object which we want to address as a whole. Firm code should be fine * with this. */ if (is_macho()) { be_emit_cstring("\t.subsections_via_symbols\n"); be_emit_write_line(); } } void be_emit_jump_table(ir_node const *const node, be_switch_attr_t const *const swtch, ir_mode *const entry_mode, emit_target_func const emit_target) { /* go over all proj's and collect their jump targets */ unsigned n_outs = arch_get_irn_n_outs(node); const ir_node **targets = XMALLOCNZ(const ir_node*, n_outs); foreach_out_edge(node, edge) { ir_node *proj = get_edge_src_irn(edge); unsigned pn = get_Proj_num(proj); targets[pn] = proj; } ir_switch_table const *const table = swtch->table; /* go over table to determine max value (note that we normalized the * ranges so that the minimum is 0) */ size_t n_entries = ir_switch_table_get_n_entries(table); unsigned long length = 0; for (size_t e = 0; e < n_entries; ++e) { const ir_switch_table_entry *entry = ir_switch_table_get_entry_const(table, e); ir_tarval *max = entry->max; if (entry->pn == 0) continue; if (!tarval_is_long(max)) panic("switch case overflow (%+F)", node); unsigned long const val = (unsigned long)get_tarval_long(max); length = MAX(length, val); } /* the 16000 isn't a real limit of the architecture. But should protect us * from seamingly endless compiler runs */ if (length > 16000) { /* switch lowerer should have broken this monster to pieces... */ panic("too large switch encountered (%+F)", node); } ++length; const ir_node **labels = XMALLOCNZ(const ir_node*, length); for (size_t e = 0; e < n_entries; ++e) { const ir_switch_table_entry *entry = ir_switch_table_get_entry_const(table, e); ir_tarval *min = entry->min; ir_tarval *max = entry->max; const ir_node *target = targets[entry->pn]; assert(entry->pn < n_outs); if (min == max) { unsigned long val = (unsigned long)get_tarval_long(max); labels[val] = target; } else { if (!tarval_is_long(min)) panic("switch case overflow (%+F)", node); unsigned long const min_val = (unsigned long)get_tarval_long(min); unsigned long const max_val = (unsigned long)get_tarval_long(max); assert(min_val <= max_val); for (unsigned long i = min_val; i <= max_val; ++i) { labels[i] = target; } } } /* emit table */ unsigned const pointer_size = get_mode_size_bytes(entry_mode); ir_entity const *const entity = swtch->table_entity; if (entity) { if (!is_macho()) be_gas_emit_switch_section(GAS_SECTION_RODATA); be_emit_irprintf("\t.align %u\n", pointer_size); be_gas_emit_entity(entity); be_emit_cstring(":\n"); } for (unsigned long i = 0; i < length; ++i) { ir_node const *target = labels[i]; if (target == NULL) target = targets[0]; emit_size_type(pointer_size); emit_target(entity, target); be_emit_char('\n'); be_emit_write_line(); } if (entity && !is_macho()) be_gas_emit_switch_section(GAS_SECTION_TEXT); free(labels); free(targets); } static void emit_global_asms(void) { be_gas_emit_switch_section(GAS_SECTION_TEXT); for (size_t i = 0, n = get_irp_n_asms(); i < n; ++i) { ident *asmtext = get_irp_asm(i); be_emit_cstring("#APP\n"); be_emit_write_line(); be_emit_irprintf("%I\n", asmtext); be_emit_write_line(); be_emit_cstring("#NO_APP\n"); be_emit_write_line(); } } bool be_gas_produces_dwarf_line_info(void) { return ir_platform.object_format == OBJECT_FORMAT_ELF; } void be_gas_begin_compilation_unit(const be_main_env_t *env) { be_dwarf_open(); be_dwarf_unit_begin(env->cup_name); block_numbers = pmap_create(); next_block_nr = 0; emit_global_asms(); } void be_gas_end_compilation_unit(const be_main_env_t *env) { emit_global_decls(env); pmap_destroy(block_numbers); be_dwarf_unit_end(); be_dwarf_close(); } void be_emit_finish_line_gas(const ir_node *node) { if (node && be_options.verbose_asm) { be_emit_pad_comment(); dbg_info *const dbg = get_irn_dbg_info(node); src_loc_t const loc = ir_retrieve_dbg_info(dbg); char const *const fmt = !loc.file ? "/* %+F */\n" : loc.line == 0 ? "/* %+F %s */\n" : loc.column == 0 ? "/* %+F %s:%u */\n" : /* */ "/* %+F %s:%u:%u */\n"; be_emit_irprintf(fmt, node, loc.file, loc.line, loc.column); } else { be_emit_char('\n'); } be_emit_write_line(); }