1756Speter /* Copyright (c) 1979 Regents of the University of California */ 2756Speter 3*826Speter static char sccsid[] = "@(#)lab.c 1.2 08/31/80"; 4756Speter 5756Speter #include "whoami.h" 6756Speter #include "0.h" 7756Speter #include "tree.h" 8756Speter #include "opcode.h" 9756Speter #include "objfmt.h" 10756Speter #ifdef PC 11756Speter # include "pc.h" 12756Speter # include "pcops.h" 13756Speter #endif PC 14756Speter 15756Speter /* 16756Speter * Label enters the definitions 17756Speter * of the label declaration part 18756Speter * into the namelist. 19756Speter */ 20756Speter label(r, l) 21756Speter int *r, l; 22756Speter { 23756Speter #ifndef PI0 24756Speter register *ll; 25756Speter register struct nl *p, *lp; 26756Speter 27756Speter lp = NIL; 28756Speter #else 29756Speter send(REVLAB, r); 30756Speter #endif 31756Speter if ( ! progseen ) { 32756Speter level1(); 33756Speter } 34756Speter line = l; 35756Speter #ifndef PI1 36756Speter #ifdef PC 37756Speter if (opt('s')) { 38756Speter if (parts & (CPRT|TPRT|VPRT)){ 39756Speter standard(); 40756Speter error("Label declarations must precede const, type and var declarations"); 41756Speter } 42756Speter if (parts & LPRT) { 43756Speter standard(); 44756Speter error("All labels must be declared in one label part"); 45756Speter } 46756Speter } 47756Speter #endif PC 48756Speter #ifdef OBJ 49756Speter if (parts & (CPRT|TPRT|VPRT)) 50756Speter error("Label declarations must precede const, type and var declarations"); 51756Speter if (parts & LPRT) 52756Speter error("All labels must be declared in one label part"); 53756Speter #endif OBJ 54756Speter parts |= LPRT; 55756Speter #endif 56756Speter #ifndef PI0 57756Speter for (ll = r; ll != NIL; ll = ll[2]) { 58756Speter l = getlab(); 59756Speter p = enter(defnl(ll[1], LABEL, 0, l)); 60756Speter /* 61756Speter * Get the label for the eventual target 62756Speter */ 63756Speter p->value[1] = getlab(); 64756Speter p->chain = lp; 65756Speter p->nl_flags |= (NFORWD|NMOD); 66756Speter p->value[NL_GOLEV] = NOTYET; 67756Speter p->entloc = l; 68756Speter lp = p; 69756Speter # ifdef OBJ 70756Speter /* 71756Speter * This operator is between 72756Speter * the bodies of two procedures 73756Speter * and provides a target for 74756Speter * gotos for this label via TRA. 75756Speter */ 76756Speter putlab(l); 77756Speter put2(O_GOTO | cbn<<8+INDX, p->value[1]); 78756Speter # endif OBJ 79756Speter # ifdef PC 80756Speter /* 81756Speter * labels have to be .globl otherwise /lib/c2 may 82756Speter * throw them away if they aren't used in the function 83756Speter * which defines them. 84756Speter */ 85756Speter if (cbn == 1) { 86756Speter /* 87756Speter * stab the label for separate compilation. 88756Speter * make label number = label name. 89756Speter */ 90*826Speter stabglab( p -> symbol , line ); 91756Speter p -> value[1] = atol( p -> symbol ); 92756Speter putprintf( " .globl " , 1 ); 93756Speter putprintf( PREFIXFORMAT , 0 , PLABELPREFIX 94756Speter , p -> value[1] ); 95756Speter } else { 96756Speter putprintf( " .globl " , 1 ); 97756Speter putprintf( PREFIXFORMAT , 0 , GLABELPREFIX 98756Speter , p -> value[1] ); 99756Speter } 100756Speter # endif PC 101756Speter } 102756Speter gotos[cbn] = lp; 103756Speter # ifdef PTREE 104756Speter { 105756Speter pPointer Labels = LabelDCopy( r ); 106756Speter 107756Speter pDEF( PorFHeader[ nesting ] ).PorFLabels = Labels; 108756Speter } 109756Speter # endif PTREE 110756Speter #endif 111756Speter } 112756Speter 113756Speter #ifndef PI0 114756Speter /* 115756Speter * Gotoop is called when 116756Speter * we get a statement "goto label" 117756Speter * and generates the needed tra. 118756Speter */ 119756Speter gotoop(s) 120756Speter char *s; 121756Speter { 122756Speter register struct nl *p; 123756Speter 124756Speter gocnt++; 125756Speter p = lookup(s); 126756Speter if (p == NIL) 127756Speter return (NIL); 128756Speter # ifdef OBJ 129756Speter put2(O_TRA4, p->entloc); 130756Speter # endif OBJ 131756Speter # ifdef PC 132756Speter if ( cbn != bn ) { 133756Speter /* 134756Speter * call goto to unwind the stack to the destination level 135756Speter */ 136756Speter putleaf( P2ICON , 0 , 0 , ADDTYPE( P2FTN | P2INT , P2PTR ) 137756Speter , "_GOTO" ); 138756Speter putLV( DISPLAYNAME , 0 , bn * sizeof( struct dispsave ) 139756Speter , P2PTR | P2INT ); 140756Speter putop( P2CALL , P2INT ); 141756Speter putdot( filename , line ); 142756Speter } 143756Speter if ( bn <= 1 ) { 144756Speter printjbr( PLABELPREFIX , p -> value[1] ); 145756Speter } else { 146756Speter printjbr( GLABELPREFIX , p -> value[1] ); 147756Speter } 148756Speter # endif PC 149756Speter if (bn == cbn) 150756Speter if (p->nl_flags & NFORWD) { 151756Speter if (p->value[NL_GOLEV] == NOTYET) { 152756Speter p->value[NL_GOLEV] = level; 153756Speter p->value[NL_GOLINE] = line; 154756Speter } 155756Speter } else 156756Speter if (p->value[NL_GOLEV] == DEAD) { 157756Speter recovered(); 158756Speter error("Goto %s is into a structured statement", p->symbol); 159756Speter } 160756Speter } 161756Speter 162756Speter /* 163756Speter * Labeled is called when a label 164756Speter * definition is encountered, and 165756Speter * marks that it has been found and 166756Speter * patches the associated GOTO generated 167756Speter * by gotoop. 168756Speter */ 169756Speter labeled(s) 170756Speter char *s; 171756Speter { 172756Speter register struct nl *p; 173756Speter 174756Speter p = lookup(s); 175756Speter if (p == NIL) 176756Speter return (NIL); 177756Speter if (bn != cbn) { 178756Speter error("Label %s not defined in correct block", s); 179756Speter return; 180756Speter } 181756Speter if ((p->nl_flags & NFORWD) == 0) { 182756Speter error("Label %s redefined", s); 183756Speter return; 184756Speter } 185756Speter p->nl_flags &= ~NFORWD; 186756Speter # ifdef OBJ 187756Speter patch4(p->entloc); 188756Speter # endif OBJ 189756Speter # ifdef PC 190756Speter if ( bn <= 1 ) { 191756Speter putprintf( PREFIXFORMAT , 1 , PLABELPREFIX , p -> value[1] ); 192756Speter } else { 193756Speter putprintf( PREFIXFORMAT , 1 , GLABELPREFIX , p -> value[1] ); 194756Speter } 195756Speter putprintf( ":" , 0 ); 196756Speter # endif PC 197756Speter if (p->value[NL_GOLEV] != NOTYET) 198756Speter if (p->value[NL_GOLEV] < level) { 199756Speter recovered(); 200756Speter error("Goto %s from line %d is into a structured statement", s, p->value[NL_GOLINE]); 201756Speter } 202756Speter p->value[NL_GOLEV] = level; 203756Speter } 204756Speter #endif 205