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view lwasm/section.c @ 473:8181ddd707f1
Add "nooutput" pragma
Add the "nooutput" pragma which causes assembly to proceed as normal for
code with the exception that no output is generated for any instructions
under this pragma. The current address is increased as usual and the symbol
table is still constructed. However, no actual output is generated for lines
operating under this pragma.
author | William Astle <lost@l-w.ca> |
---|---|
date | Thu, 01 Nov 2018 23:07:03 -0600 |
parents | ed7b8f74087d |
children |
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/* section.c Copyright © 2010 William Astle This file is part of LWTOOLS. LWTOOLS is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>. */ #include <string.h> #include <ctype.h> #include <lw_string.h> #include <lw_alloc.h> #include "lwasm.h" #include "instab.h" PARSEFUNC(pseudo_parse_section) { char *p2; char *sn; char *opts = NULL; sectiontab_t *s; if (as -> output_format != OUTPUT_OBJ && as -> output_format != OUTPUT_LWMOD) { lwasm_register_error(as, l, E_SECTION_TARGET); return; } if (!**p) { lwasm_register_error(as, l, E_SECTION_NAME); return; } l -> len = 0; if (as -> csect) { lw_expr_destroy(as -> csect -> offset); as -> csect -> offset = lw_expr_copy(l -> addr); as -> csect = NULL; } for (p2 = *p; *p2 && *p2 != ',' && !isspace(*p2); p2++) /* do nothing */ ; sn = lw_strndup(*p, p2 - *p); *p = p2; if (**p == ',' && as -> output_format != OUTPUT_LWMOD) { // have opts (*p)++; for (p2 = *p; *p2 && !isspace(*p2); p2++) /* do nothing */ ; opts = lw_strndup(*p, p2 - *p); *p = p2; } if (as -> output_format == OUTPUT_LWMOD) { for (p2 = sn; *p2; p2++) *p2 = tolower(*p2); if (strcmp(sn, "bss") && strcmp(sn, "main") && strcmp(sn, "init") && strcmp(sn, "calls") && strcmp(sn, "modname")) { lwasm_register_error(as, l, E_SECTION_NAME); lw_free(sn); lw_free(opts); return; } } for (s = as -> sections; s; s = s -> next) { if (!strcmp(s -> name, sn)) break; } if (s && opts) { lwasm_register_error(as, l, W_DUPLICATE_SECTION); } if (!s) { // create section data structure s = lw_alloc(sizeof(sectiontab_t)); s -> oblen = 0; s -> obsize = 0; s -> obytes = NULL; s -> tbase = -1; s -> name = lw_strdup(sn); s -> offset = lw_expr_build(lw_expr_type_special, lwasm_expr_secbase, s); s -> flags = section_flag_none; s -> reloctab = NULL; if (!strcasecmp(sn, "bss") || !strcasecmp(sn, ".bss")) { s -> flags |= section_flag_bss; } if (!strcasecmp(sn, "_constant") || !strcasecmp(sn, "_constants")) { s -> flags |= section_flag_constant; } // parse options if (opts) { // only one option ("bss" or "!bss") if (!strcasecmp(opts, "bss")) { s -> flags |= section_flag_bss; } else if (!strcasecmp(opts, "!bss")) { s -> flags &= ~section_flag_bss; } else if (!strcasecmp(opts, "constant")) { s -> flags |= section_flag_constant; } else if (!strcasecmp(opts, "!constant")) { s -> flags |= section_flag_constant; } else { lwasm_register_error(as, l, E_SECTION_FLAG); lw_free(sn); lw_free(opts); lw_free(s -> name); lw_expr_destroy(s -> offset); lw_free(s); return; } } s -> next = as -> sections; as -> sections = s; } // cause all instances of "constant" sections to start at 0 if (s -> flags & section_flag_constant) s -> offset = lw_expr_build(lw_expr_type_int, 0); lw_expr_destroy(l -> addr); l -> addr = lw_expr_copy(s -> offset); lw_expr_destroy(l -> daddr); l -> daddr = lw_expr_copy(s -> offset); as -> csect = s; as -> context = lwasm_next_context(as); l -> len = 0; lw_free(opts); lw_free(sn); } PARSEFUNC(pseudo_parse_endsection) { if (as -> output_format != OUTPUT_OBJ && as -> output_format != OUTPUT_LWMOD) { lwasm_register_error(as, l, E_SECTION_TARGET); return; } l -> len = 0; if (!(as -> csect)) { lwasm_register_error(as, l, E_SECTION_END); return; } // save offset in case another instance of the section appears lw_expr_destroy(as -> csect -> offset); as -> csect -> offset = l -> addr; // reset address to 0 l -> addr = lw_expr_build(lw_expr_type_int, 0); as -> csect = NULL; // end of section is a context break as -> context = lwasm_next_context(as); skip_operand(p); } PARSEFUNC(pseudo_parse_export) { int after = 0; char *sym = NULL; exportlist_t *e; if (as -> output_format != OUTPUT_OBJ) { lwasm_register_error2(as, l, E_OBJTARGET_ONLY, "(%s)", "EXPORT"); return; } l -> len = 0; if (l -> sym) { sym = lw_strdup(l -> sym); l -> symset = 1; } if (l -> sym) { skip_operand(p); } again: if (after || !sym) { char *p2; after = 1; for (p2 = *p; *p2 && *p2 != ',' && !isspace(*p2); p2++) /* do nothing */ ; sym = lw_strndup(*p, p2 - *p); *p = p2; } if (!sym) { lwasm_register_error2(as, l, E_SYMBOL_MISSING, "for %s", "EXPORT"); return; } // add the symbol to the "export" list (which will be resolved // after the parse pass is complete e = lw_alloc(sizeof(exportlist_t)); e -> next = as -> exportlist; e -> symbol = lw_strdup(sym); e -> line = l; e -> se = NULL; as -> exportlist = e; lw_free(sym); if (after && **p == ',') { (*p)++; for (; **p && isspace(**p); (*p)++) /* do nothing */ ; goto again; } } PARSEFUNC(pseudo_parse_extern) { int after = 0; char *sym = NULL; importlist_t *e; if (as -> output_format != OUTPUT_OBJ) { lwasm_register_error2(as, l, E_OBJTARGET_ONLY, "(%s)", "IMPORT"); return; } l -> len = 0; if (l -> sym) { sym = lw_strdup(l -> sym); l -> symset = 1; } if (l -> sym) { skip_operand(p); } again: if (after || !sym) { char *p2; after = 1; for (p2 = *p; *p2 && *p2 != ',' && !isspace(*p2); p2++) /* do nothing */ ; sym = lw_strndup(*p, p2 - *p); *p = p2; } if (!sym) { lwasm_register_error2(as, l, E_SYMBOL_MISSING, "for %s", "IMPORT"); return; } // add the symbol to the "export" list (which will be resolved // after the parse pass is complete e = lw_alloc(sizeof(importlist_t)); e -> next = as -> importlist; e -> symbol = lw_strdup(sym); as -> importlist = e; lw_free(sym); if (after && **p == ',') { (*p)++; for (; **p && isspace(**p); (*p)++) /* do nothing */ ; goto again; } } PARSEFUNC(pseudo_parse_extdep) { int after = 0; char *sym = NULL; // importlist_t *e; if (as -> output_format != OUTPUT_OBJ) { lwasm_register_error2(as, l, E_OBJTARGET_ONLY, "(%s)", "EXTDEP"); return; } if (!as -> csect) { lwasm_register_error(as, l, E_SECTION_EXTDEP); return; } l -> len = 0; if (l -> sym) sym = lw_strdup(l -> sym); if (l -> sym) { skip_operand(p); } again: if (after || !sym) { char *p2; after = 1; for (p2 = *p; *p2 && *p2 != ',' && !isspace(*p2); p2++) /* do nothing */ ; sym = lw_strndup(*p, p2 - *p); } if (!sym) { lwasm_register_error2(as, l, E_SYMBOL_MISSING, "for %s", "EXTDEP"); return; } // create a zero-width dependency { lw_expr_t e; e = lw_expr_build(lw_expr_type_int, 0); lwasm_emitexpr(l, e, 0); lw_expr_destroy(e); } if (after && **p == ',') { (*p)++; for (; **p && isspace(**p); (*p)++) /* do nothing */ ; goto again; } }