/* * (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands. * See the copyright notice in the ACK home directory, in the file "Copyright". */ /* $Id$ */ /* C O D E - G E N E R A T I N G R O U T I N E S */ #include #include #include "lint.h" #include "debug.h" #include "dbsymtab.h" #ifndef LINT #include #else #include "l_em.h" #include "l_lint.h" #endif /* LINT */ #include "botch_free.h" #include #include "dataflow.h" #include "use_tmp.h" #include #include "arith.h" #include "type.h" #include "idf.h" #include "label.h" #include "code.h" #include "stmt.h" #include "def.h" #include "expr.h" #include "sizes.h" #include "stack.h" #include "level.h" #include "decspecs.h" #include "declar.h" #include "Lpars.h" #include "specials.h" #include "atw.h" #include "assert.h" #include "LLlex.h" #include "align.h" #include "blocks.h" #include "code_c.h" #include "conversion.h" #include #ifdef LINT #include "l_lint.h" #endif /* LINT */ #ifdef DBSYMTAB #include #endif /* DBSYMTAB */ label lab_count = 1; label datlab_count = 1; int fp_used; /* global function info */ char *func_name; struct type *func_type; #ifdef LINT int func_notypegiven; #endif #ifdef USE_TMP static int tmp_id; static int pro_id; #endif /* USE_TMP */ extern char options[]; extern char *source; static void def_strings(struct string_cst *sc); static void prc_entry(char *name); static void prc_exit(); #ifndef LINT void init_code(char *dst_file) { /* init_code() initialises the output file on which the compact EM code is written */ C_init(word_size, pointer_size); /* initialise EM module */ if (C_open(dst_file) == 0) fatal("cannot write to %s\n", dst_file); C_magic(); C_ms_emx(word_size, pointer_size); #ifdef DBSYMTAB if (options['g']) { C_ms_std(source, N_SO, 0); stb_typedef(int_type, "int"); stb_typedef(schar_type, "char"); stb_typedef(long_type, "long"); stb_typedef(short_type, "short"); stb_typedef(uchar_type, "unsigned char"); stb_typedef(ushort_type, "unsigned short"); stb_typedef(ulong_type, "unsigned long"); stb_typedef(uint_type, "unsigned int"); stb_typedef(float_type, "float"); stb_typedef(double_type, "double"); stb_typedef(lngdbl_type, "long double"); stb_typedef(void_type, "void"); } #endif /* DBSYMTAB */ #ifdef USE_TMP #ifdef PREPEND_SCOPES C_insertpart(tmp_id = C_getid()); #endif /* PREPEND_SCOPES */ #endif /* USE_TMP */ } #endif /* LINT */ struct string_cst *str_list = 0; label code_string(char *val, int len) { register struct string_cst *sc = new_string_cst(); label dlb = data_label(); C_ina_dlb(dlb); sc->next = str_list; str_list = sc; sc->sc_value = val; sc->sc_len = len; sc->sc_dlb = dlb; return dlb; } static void def_strings(struct string_cst *sc) { while (sc) { struct string_cst *sc1 = sc; C_df_dlb(sc->sc_dlb); str_cst(sc->sc_value, sc->sc_len, 1); /* string in rom */ sc = sc->next; free(sc1->sc_value); free_string_cst(sc1); } } /* flush_strings() is called from program.g after each external definition */ void flush_strings() { if (str_list) { def_strings(str_list); str_list = 0; } } #ifndef LINT void end_code() { /* end_code() performs the actions to be taken when closing the output stream. */ if (fp_used) { /* floating point used */ C_ms_flt(); } C_ms_src((int)(LineNumber - 2), source); C_close(); } #endif /* LINT */ #ifdef PREPEND_SCOPES void prepend_scopes() { /* prepend_scopes() runs down the list of global idf's and generates those exa's, exp's, ina's and inp's that superior hindsight has provided. */ struct stack_entry *se = local_level->sl_entry; #ifdef USE_TMP C_beginpart(tmp_id); #endif /* USE_TMP */ while (se != 0) { struct def *df = se->se_idf->id_def; if (df && (df->df_initialized || df->df_used || df->df_alloc)) { code_scope(se->se_idf->id_text, df); } se = se->next; } #ifdef USE_TMP C_endpart(tmp_id); #endif /* USE_TMP */ } #endif /* PREPEND_SCOPES */ void code_scope(char *text, struct def *def) { /* generates code for one name, text, of the storage class as given by def, if meaningful. */ int fund = def->df_type->tp_fund; switch (def->df_sc) { case EXTERN: case GLOBAL: if (fund == FUNCTION) C_exp(text); else C_exa_dnam(text); break; case STATIC: if (fund == FUNCTION) C_inp(text); else C_ina_dnam(text); break; } } static label return_label, return2_label; static char return_expr_occurred; static arith func_size; static int struct_return; static char *last_fn_given = (char *)0; static label file_name_label; /* to be called when entering a procedure */ void begin_proc(struct decspecs *ds, struct idf *idf) { /* begin_proc() is called at the entrance of a new function and performs the necessary code generation: - a scope indicator (if needed) exp/inp - the procedure entry pro $name - reserves some space if the result of the function does not fit in the return area - a fil pseudo instruction */ char *name = idf->id_text; struct def *def = idf->id_def; /* idf->id_def does not indicate the right def structure * when the function being defined has a parameter of the * same name in an old-style function definition. */ while (def->df_level != L_GLOBAL) def = def->next; /* When we have a new-style function definition, the parameters * are defined first, which means that it may look as if they have * the greatest scope. Correct this. */ if (idf->id_def == def && def->next && def->next->df_level == L_PROTO) { struct def *tmpdef = def->next; def->next = tmpdef->next; tmpdef->next = def; idf->id_def = tmpdef; } #ifndef PREPEND_SCOPES code_scope(name, def); #endif /* PREPEND_SCOPES */ #ifdef DATAFLOW if (options['d']) DfaStartFunction(name); #endif /* DATAFLOW */ /* set global function info */ func_name = name; if (def->df_type->tp_fund != FUNCTION) { error("making function body for non-function"); def->df_type = error_type; } func_type = def->df_type->tp_up; #ifdef LINT func_notypegiven = ds->ds_notypegiven; #endif func_size = ATW(func_type->tp_size); sp_occurred[SP_SETJMP] = 0; #ifndef USE_TMP C_pro_narg(name); #else C_insertpart(pro_id = C_getid()); #endif if (is_struct_or_union(func_type->tp_fund)) { if (func_size <= 0) { error("unknown return type for function %s", name); } else { struct_return = 1; } } else struct_return = 0; /* Special arrangements if the function result doesn't fit in the function return area of the EM machine. The size of the function return area is implementation dependent. */ lab_count = (label) 1; return_label = text_label(); return2_label = text_label(); return_expr_occurred = 0; LocalInit(); prc_entry(name); if (! options['L']) { /* profiling */ if (!last_fn_given || strcmp(last_fn_given, FileName) != 0) { /* previous function came from other file */ C_df_dlb(file_name_label = data_label()); C_con_scon(last_fn_given = FileName, (arith)(strlen(FileName) + 1)); } /* enable debug trace of EM source */ C_fil_dlb(file_name_label, (arith)0); C_lin((arith)LineNumber); } #ifdef DBSYMTAB if (options['g']) { stb_string(def, FUNCTION, name); if (! strcmp(name, "main")) { C_ms_stb_cst(name, N_MAIN, 0, (arith) 0); } } #endif } void end_proc(arith fbytes) { /* end_proc() deals with the code to be generated at the end of a function, as there is: - the EM ret instruction: "ret 0" - loading of the function result in the function result area if there has been a return in the function body (see do_return_expr()) - indication of the use of floating points - indication of the number of bytes used for formal parameters - use of special identifiers such as "__setjmp" - "end" + number of bytes used for local variables */ arith nbytes; char optionsn = options['n']; #ifdef DATAFLOW if (options['d']) DfaEndFunction(); #endif /* DATAFLOW */ C_df_ilb(return2_label); if (return_expr_occurred && struct_return == 0) { C_asp(-func_size); } C_df_ilb(return_label); prc_exit(); if (return_expr_occurred) { if (struct_return != 0) { LoadLocal((arith) 0, pointer_size); C_ret(pointer_size); } else C_ret(func_size); } else C_ret((arith) 0); /* getting the number of "local" bytes is posponed until here, because copying the function result may need temporaries! However, local_level is now L_FORMAL2, because L_LOCAL is already unstacked. Therefore, "unstack_level" must also pass "sl_max_block" to the level above L_LOCAL. */ nbytes = ATW(- local_level->sl_max_block); #ifdef USE_TMP C_beginpart(pro_id); C_pro(func_name, nbytes); #endif if (fbytes > max_int) { error("%s has more than %ld parameter bytes", func_name, (long) max_int); } C_ms_par(fbytes); /* # bytes for formals */ if (sp_occurred[SP_SETJMP]) { /* indicate use of "__setjmp" */ options['n'] = 1; C_ms_gto(); sp_occurred[SP_SETJMP] = 0; } #ifdef USE_TMP C_endpart(pro_id); #endif LocalFinish(); C_end(nbytes); if (nbytes > max_int) { error("%s has more than %ld bytes of local variables", func_name, (long) max_int); } options['n'] = optionsn; } void do_return() { /* do_return handles the case of a return without expression. This version branches to the return label, which is probably smarter than generating a direct return. Return sequences may be expensive. */ #ifdef DBSYMTAB if (options['g']) db_line(dot.tk_file, dot.tk_line); #endif /* DBSYMTAB */ C_bra(return2_label); } void do_return_expr(struct expr *expr) { /* do_return_expr() generates the expression and the jump for a return statement with an expression. */ ch3cast(&expr, RETURN, func_type); code_expr(expr, RVAL, TRUE, NO_LABEL, NO_LABEL); if (struct_return != 0) { LoadLocal((arith) 0, pointer_size); store_block(func_type->tp_size, func_type->tp_align); } C_bra(return_label); return_expr_occurred = 1; } /* struct idf *idf idf to be declared * struct expr *expr initialisation; NULL if absent * int lvl declaration level * int sc storage class, as in the declaration */ void code_declaration(struct idf *idf, struct expr *expr, int lvl, int sc) { /* code_declaration() does the actual declaration of the variable indicated by "idf" on declaration level "lvl". If the variable is initialised, the expression is given in "expr", but for global and static initialisations it is just non-zero, as the expression is not parsed yet. There are some cases to be considered: - filter out typedefs, they don't correspond to code; - global variables, coded only if initialized; - local static variables; - local automatic variables; Since the expression may be modified in the process, code_declaration() frees it after use, as the caller can no longer do so. If there is a storage class indication (EXTERN/STATIC), code_declaration() will generate an exa or ina. The sc is the actual storage class, as given in the declaration. */ struct def *def = idf->id_def; arith size = def->df_type->tp_size; int fund = def->df_type->tp_fund; int def_sc = def->df_sc; if (def_sc == TYPEDEF) { /* no code for typedefs */ #ifdef DBSYMTAB if (options['g']) { stb_typedef(def->df_type, idf->id_text); } #endif /* DBSYMTAB */ return; } if (lvl == L_GLOBAL) { /* global variable */ /* is this an allocating declaration? */ if ( (sc == 0 || sc == STATIC) && fund != FUNCTION ) def->df_alloc = ALLOC_SEEN; if (expr && def_sc == STATIC && sc == EXTERN) { warning("%s has internal linkage", idf->id_text); } if (expr) { /* code only if initialized */ #ifndef PREPEND_SCOPES code_scope(idf->id_text, def); #endif /* PREPEND_SCOPES */ def->df_alloc = ALLOC_DONE; C_df_dnam(idf->id_text); } } else if (lvl >= L_LOCAL) { /* local variable */ /* STATIC, EXTERN, GLOBAL, AUTO or REGISTER */ switch (def_sc) { case STATIC: if (fund == FUNCTION) { /* should produce "inp $function" ??? */ break; } /* they are handled on the spot and get an integer label in EM. */ #ifdef DBSYMTAB if (options['g'] && ! expr) { stb_string(def, sc, idf->id_text); } #endif /* DBSYMTAB */ C_df_dlb((label)def->df_address); if (expr) { /* there is an initialisation */ } else { /* produce blank space */ if (size <= 0) { error("size of %s unknown", idf->id_text); size = (arith)0; } C_bss_cst(ATW(size), (arith)0, 1); } break; case EXTERN: if (expr && !is_anon_idf(idf) && level != L_GLOBAL) error("cannot initialize extern %s in block" , idf->id_text); case GLOBAL: /* we are sure there is no expression */ break; case AUTO: case REGISTER: #ifdef DBSYMTAB if (options['g']) { stb_string(def, sc, idf->id_text); } #endif /* DBSYMTAB */ if (expr) loc_init(expr, idf); else if ((fund == ARRAY) && (def->df_type->tp_size == (arith)-1)) { error("size for local %s unknown" , idf->id_text); } break; default: crash("bad local storage class"); /*NOTREACHED*/ } } } void loc_init(struct expr *expr, struct idf *id) { /* loc_init() generates code for the assignment of expression expr to the local variable described by id. It frees the expression afterwards. */ struct expr *e = expr; struct def *df = id->id_def; struct type *tp = df->df_type; static arith tmpoffset = 0; static arith unknownsize = 0; ASSERT(df->df_sc != STATIC); switch (tp->tp_fund) { case ARRAY: if (tp->tp_size == (arith) -1) unknownsize = 1; case STRUCT: case UNION: if (e != (struct expr *) 0) { break; /* switch */ } else if (!tmpoffset) {/* first time for this variable */ tmpoffset = df->df_address; if (unknownsize) tmpoffset = -1; df->df_address = data_label(); C_df_dlb((label)df->df_address); } else { C_lae_dlb((label)df->df_address, (arith)0); load_block(tp->tp_size, word_align); if (unknownsize) { /* tmpoffset += tp->tp_size; */ unknownsize = 0; tmpoffset = NewLocal(tp->tp_size , tp->tp_align , regtype(tp) , df->df_sc); } C_lal(tmpoffset); store_block(tp->tp_size, tmpoffset % word_align ? 1 : word_align); df->df_address = tmpoffset; tmpoffset = 0; } #ifdef DBSYMTAB if (options['g']) { stb_string(df, AUTO, id->id_text); } #endif /* DBSYMTAB */ return; } if (ISCOMMA(e)) { /* embraced: int i = {12}; */ while (e) { loc_init(e->OP_LEFT, id); e = e->OP_RIGHT; } } else { /* not embraced */ ch3cast(&expr, '=', tp); /* may modify expr */ #ifndef LINT { struct value vl; EVAL(expr, RVAL, TRUE, NO_LABEL, NO_LABEL); vl.vl_class = Name; vl.vl_data.vl_idf = id; vl.vl_value = (arith)0; store_val(&vl, tp); } #else /* LINT */ id->id_def->df_set = 1; #endif /* LINT */ free_expression(expr); } } void bss(struct idf *idf) { /* bss() allocates bss space for the global idf. */ struct def *df = idf->id_def; #ifndef PREPEND_SCOPES code_scope(idf->id_text, df); #endif /* PREPEND_SCOPES */ #ifdef DBSYMTAB if (options['g']) { stb_string(df, df->df_sc, idf->id_text); } #endif /* DBSYMTAB */ if (df->df_type->tp_size <= 0) { if (df->df_sc != STATIC && df->df_type->tp_fund == ARRAY && df->df_type->tp_up && df->df_type->tp_up->tp_size >= 0) { C_df_dnam(idf->id_text); C_bss_cst(ATW(df->df_type->tp_up->tp_size), (arith)0, 1); } else error("size of %s unknown (\"%s\", line %d)" , idf->id_text, df->df_file, df->df_line); } else { C_df_dnam(idf->id_text); C_bss_cst(ATW(df->df_type->tp_size), (arith)0, 1); } } void formal_cvt(int hasproto, struct def *df) { /* formal_cvt() converts a formal parameter of type char or short from int to that type. It also converts a formal parameter of type float from a double to a float. */ struct type *tp = df->df_type; if (tp->tp_size != int_size && (tp->tp_fund == CHAR || tp->tp_fund == SHORT) ) { LoadLocal(df->df_address, int_size); /* conversion(int_type, df->df_type); ??? No, you can't do this on the stack! (CJ) */ StoreLocal(df->df_address, tp->tp_size); } else if (tp->tp_size != double_size && tp->tp_fund == FLOAT && !hasproto) { LoadLocal(df->df_address, double_size); #ifndef LINT conversion(double_type, float_type); #endif /* LINT */ StoreLocal(df->df_address, tp->tp_size); } } #ifdef LINT /*ARGSUSED*/ #endif /* LINT */ void code_expr(struct expr *expr, int val, int code, label tlbl, label flbl) { /* code_expr() is the parser's interface to the expression code generator. If line number trace is wanted, it generates a lin instruction. EVAL() is called directly. */ #ifndef LINT if (! options['L']) /* profiling */ C_lin((arith)(expr->ex_line)); #ifdef DBSYMTAB if (options['g']) db_line(expr->ex_file, (unsigned int)expr->ex_line); #endif EVAL(expr, val, code, tlbl, flbl); #else /* LINT */ lint_expr(expr, code ? USED : IGNORED); #endif /* LINT */ } /* The FOR/WHILE/DO/SWITCH stacking mechanism: stack_stmt() has to be called at the entrance of a for, while, do or switch statement to indicate the EM labels where a subsequent break or continue causes the program to jump to. */ static struct stmt_block *stmt_stack; /* top of statement stack */ /* code_break() generates EM code needed at the occurrence of "break": it generates a branch instruction to the break label of the innermost statement in which break has a meaning. As "break" is legal in any of 'while', 'do', 'for' or 'switch', which are the only ones that are stacked, only the top of the stack is interesting. */ void code_break() { struct stmt_block *stmt_block = stmt_stack; #ifdef DBSYMTAB if (options['g']) db_line(dot.tk_file, dot.tk_line); #endif /* DBSYMTAB */ if (stmt_block) C_bra(stmt_block->st_break); else error("break not inside for, while, do or switch"); } /* code_continue() generates EM code needed at the occurrence of "continue": it generates a branch instruction to the continue label of the innermost statement in which continue has a meaning. */ void code_continue() { struct stmt_block *stmt_block = stmt_stack; while (stmt_block) { if (stmt_block->st_continue) { #ifdef DBSYMTAB if (options['g']) db_line(dot.tk_file, dot.tk_line); #endif /* DBSYMTAB */ C_bra(stmt_block->st_continue); return; } stmt_block = stmt_block->next; } error("continue not inside for, while or do"); } void stack_stmt(label break_label, label cont_label) { struct stmt_block *stmt_block = new_stmt_block(); stmt_block->next = stmt_stack; stmt_block->st_break = break_label; stmt_block->st_continue = cont_label; stmt_stack = stmt_block; } void unstack_stmt() { /* unstack_stmt() unstacks the data of a statement which may contain break or continue */ register struct stmt_block *sbp = stmt_stack; stmt_stack = sbp->next; free_stmt_block(sbp); } static label prc_name; static void prc_entry(char *name) { if (options['p']) { C_df_dlb(prc_name = data_label()); C_rom_scon(name, (arith) (strlen(name) + 1)); C_lae_dlb(prc_name, (arith) 0); C_cal("procentry"); C_asp(pointer_size); } } static void prc_exit() { if (options['p']) { C_lae_dlb(prc_name, (arith) 0); C_cal("procexit"); C_asp(pointer_size); } } #ifdef DBSYMTAB void db_line(char *file, unsigned int line) { static unsigned oldline; static char *oldfile; if (file != oldfile || line != oldline) { C_ms_std((char *) 0, N_SLINE, (int) line); oldline = line; oldfile = file; } } #endif /* DBSYMTAB */