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view lwasm/section.c @ 505:59b8c8b15bd4
Add integer shifts and fix code template errors for mul/div/mod
One needs to remove stuff from the stack after putting it there. Actually do
that in the code output for multiplication, division, and modulus.
Add integer shifting code output which is optimized for constant shift
counts but calls a routine for non-constant shift counts. Shifting by a
negative amount is a no-op. Shifting by more than the size of an integer
results in 0 (for left shifts) or -1 (for right shifts). Both negative shift
counts and shift counts larger than the base type are undefined in the C
standard so this behaviour is allowed.
author | William Astle <lost@l-w.ca> |
---|---|
date | Sat, 26 Oct 2019 22:01:55 -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; } }