comptut
changeset 5:bebbe71ba949 tutor5
mostly completed tutor5.txt, without the hundred different looping constructs, which I don't care about
| author | John Tsiombikas <nuclear@member.fsf.org> |
|---|---|
| date | Mon, 16 Mar 2015 01:06:49 +0200 |
| parents | ae1c30fa39f3 |
| children | 098d02ac0319 |
| files | src/main.c |
| diffstat | 1 files changed, 23 insertions(+), 9 deletions(-) [+] |
line diff
1.1 --- a/src/main.c Mon Mar 16 00:13:54 2015 +0200 1.2 +++ b/src/main.c Mon Mar 16 01:06:49 2015 +0200 1.3 @@ -13,9 +13,10 @@ 1.4 1.5 void init(void); 1.6 void program(void); 1.7 -void block(void); 1.8 -void doif(void); 1.9 +void block(int brklb); 1.10 +void doif(int brklb); 1.11 void dowhile(void); 1.12 +void dobreak(int brklb); 1.13 void condition(void); 1.14 void expression(void); 1.15 void assignment(void); 1.16 @@ -94,7 +95,7 @@ 1.17 1.18 void program(void) 1.19 { 1.20 - block(); 1.21 + block(-1); 1.22 if(look != 'e') { 1.23 expected("End"); 1.24 } 1.25 @@ -106,18 +107,22 @@ 1.26 emitln("%c", get_name()); 1.27 } 1.28 1.29 -void block(void) 1.30 +void block(int brklb) 1.31 { 1.32 while(look != 'e' && look != 'l') { 1.33 switch(look) { 1.34 case 'i': 1.35 - doif(); 1.36 + doif(brklb); 1.37 break; 1.38 1.39 case 'w': 1.40 dowhile(); 1.41 break; 1.42 1.43 + case 'b': 1.44 + dobreak(brklb); 1.45 + break; 1.46 + 1.47 default: 1.48 other(); 1.49 break; 1.50 @@ -125,7 +130,7 @@ 1.51 } 1.52 } 1.53 1.54 -void doif(void) 1.55 +void doif(int brklb) 1.56 { 1.57 int lb1, lb2; 1.58 1.59 @@ -136,14 +141,14 @@ 1.60 lb2 = lb1; 1.61 1.62 emitln("jz %s", labelstr(lb1)); 1.63 - block(); 1.64 + block(brklb); 1.65 1.66 if(look == 'l') { 1.67 match('l'); 1.68 lb2 = newlabel(); 1.69 emitln("jmp %s", labelstr(lb2)); 1.70 postlabel(lb1); 1.71 - block(); 1.72 + block(brklb); 1.73 } 1.74 match('e'); 1.75 postlabel(lb2); 1.76 @@ -159,12 +164,21 @@ 1.77 postlabel(lbtop); 1.78 condition(); 1.79 emitln("jz %s", labelstr(lbend)); 1.80 - block(); 1.81 + block(lbend); 1.82 match('e'); 1.83 emitln("jmp %s", labelstr(lbtop)); 1.84 postlabel(lbend); 1.85 } 1.86 1.87 +void dobreak(int brklb) 1.88 +{ 1.89 + match('b'); 1.90 + if(brklb == -1) { 1.91 + stop("invalid break, not in loop"); 1.92 + } 1.93 + emitln("jmp %s", labelstr(brklb)); 1.94 +} 1.95 + 1.96 void condition(void) 1.97 { 1.98 emitln("<condition>");