diff --git a/bugs.md b/bugs.md index ad3506e86..2a98c56c7 100644 --- a/bugs.md +++ b/bugs.md @@ -522,13 +522,13 @@ If you join the lines you end up with: If you look at column 25 which is the end of the word 'mh111' and you go down to the next row you'll see a 0 and if you go one row down another 0. This is the -buffer size, 100, for `u`. The column to the left is the same for the `t` +buffer size, 100, for `u`! The column to the left is the same for the `t` variable. Thus it seems that in order to get the generated output correct one needs to provide the correct input in comments or possibly by rearranging some of the -code (this was required to make the generated code compile at all when changing -the buffer size). +code (this was actually required to make the generated code compile at all when +changing the buffer size, see below). ### Important points: @@ -550,6 +550,103 @@ can cause a compilation error! Make sure that the output of: can be compiled and the output of that new program when fed itself can also be compiled! +## [1994/shapiro](1994/shapiro/shapiro.c) ([README.md](1994/shapiro/README.md)) +## STATUS: missing file - please provide it + +[Cody Boone Ferguson](/winners.html#Cody_Boone_Ferguson) noted that the +README.md file refers to an alternative version of the code that is not +obfuscated but it is missing from the entry directory and the archive. Do you +have this file? + +We would be grateful if you could provide it to us. If you can provide this +file you might consider removing this entry from this file as well but if not +we'll take care of it. + +### Important reminder to fix the `-1` value check for `getc()`: + +Cody wants to remind you that he fixed the code to not use `-1` for the return +value of `getc()`; this is important because `EOF` is **NOT** guaranteed to be +`-1` but rather any negative value. On systems where `EOF != -1` the program +would enter an infinite loop until the program crashed, by chance reads a `-1` +or was killed. See the README.md for more details. If you don't feel comfortable +changing it to `EOF` Cody will happily do it for you but otherwise go right +ahead. We'll credit you in the README.md file regardless. + + +## STATUS: doesn't work with some platforms - please help us fix + +[Cody Boone Ferguson](/winners.html#Cody_Boone_Ferguson) pointed out a potential +bug in [1994/shapiro](1994/shapiro/shapiro.c) on systems where `EOF != -1` as +the code assumes that `EOF` will always be `-1`. As the standard says (see `7.21 +Input/output` subsection 1) it only has to be a negative int, not +necessarily `-1`. The problem is that the source file's last character is a +newline (10 in decimal) and so on systems where `EOF != -1` the `getc()` +functions would not terminate the loop (but see below). This would cause a +breakage in the entry. + +However due to clever encoding of the code it is not a simple matter of applying +the following patch: + +```diff +diff --git i/1994/shapiro/shapiro.c w/1994/shapiro/shapiro.c +index d2da120c7bc4e251b7624859e48f47f188d398e9..e054a1ceb067b82bf37c07e5ce75e82be7a03b85 100644 +--- i/1994/shapiro/shapiro.c ++++ w/1994/shapiro/shapiro.c +@@ -9,11 +9,11 @@ + /*PPPPVPOQMQRPR*/=0;FILE/*TPSLUMWQT*/ * + J/*MPRPKPLQ*/; J= fopen(__FILE__ + /*T*/,"r");for (;( L/*KPUOWOWMUQ + LLOLMPULWLWL WLW LWLWLWLWLWLW + LWLWLULVOXP LLV LLLOLMPULOL +- MMNP*/=getc (J) )!= -1;L/* ++ MMNP*/=getc (J) )!=EOF;L/* + OLWLRMMQUL VOX PLLVLLLMQO + PMPYPXPNP MQL LVLLLWPSP + XPOQNQOPMQ LLV LTj*/>='J' + &&L/*LRPYP OQL QMQLLVLLL + OLMQVOXPL LVL LLVOe*/<= + +``` + +as doing so will cause `warning: illegal character encoding in string +literal` and the error `error: source file is not valid UTF-8`. Looking at the +file you'll see on line 4 of `shapiro_t2.c`: + + +``` +char *a[]={"%c+------------+\n","%c+%3dPRÒ<82>3·Âå&Â"2W6öæF6'Â"Ò<96>æVGW6'¢ <82>öV'7'Â"R2Çå&Â"Â^E33sÃ^E33³UB¶cS³<83>T2Ç^E33<83>#Ò·£<90>æF^G"¶ÕÕ³^GÃ^BÃ^RsÃ^RCÃ^R^SÃ^BÓ·£Ð^V<96>æ<86>bÇ2<96><92>æF^Gb·3<86>^V&^G¢¢^B2¶£°7<86>^V&^GB¶E^CÓÅ¢RÆbÖc³£@<97>ÖVöE^Gr¶£`<94>ÄT^D¢<82>Æ¢<92>¶£p<87><96>ÆV^F<82>ÒÒb^Fbb^B^R^B<97>^FW<86>B<96>^Bbb^B^Rbö&·<86><92><92>²£<80>ÖcFö^FWæ<86>bÓbÆÃ^SÃ"^R&<92>²<93>ÖcFö^FWæ<86><82>bÓbÆÃ^S<93>²^RÃ""'<92>²£`ö&<87>²³<93>²<97>f<86>b<96>²gvVF7<87>BÆB^CÃ<92><96>²C¶5G'ÇVæ<86>B<96>Ò^RÓÕsÂ^Es²£<90>f<86>¢BÖÓs^Bs²b<96>²7^G'<97>æFg<86>¢2Æ"R2Çå&ÂB¶^R<93>²ó<86>2GGöVGÇbÃbÓbÆB¶^RÃ^B<93>Ò§<90>f<86>¢Bæs^Bs²b<96>ò<86><82>ÆRÃBÆ^BÃ^B<93>ÒWÆ6W¶G<97>ÖV<86>br<96>²SÖ^S67F<97>ÖV<86>Âö6^VÆF<97>ÖV<86>br<96><92>²£`ö&<87>b×^S³cÇc³c·²<92>ò<86><82>Æb^WÒ^Scbb^WÒcÓ^RÃb·r^BsÂ^RF÷<96><86>R¶"¶e×<95>Âb<97>2ÇVV^F<87>^R<93>²Ó×ק  +``` + +when it should be something entirely different. For what it should be try +running `make clobber all ; cat shapiro_t2.c` or else look at the second program +in the spoilers file [shapiro.md](1994/shapiro/shapiro.md]). + +Cody is working will be working on this here and there but if you have a fix or +any suggestions you're welcome to provide it or them. + +Cody points you to the README.md file for what should happen when the entry is +successfully compiled (including no compilation errors when running `make +clobber all`). + +Another problem is that in the [shapiro.md](shapiro.md) file the first program +does not work. + +### Tips on this entry: + +Cody provides some tips on this entry: + +First: the comments are the important part of this entry. Remove them and the +program breaks. + +Second and perhaps part of the problem with changing the code to `EOF` instead +of `-1` is the `for` loop particularly to do with the bitwise operations, +perhaps also made worse by the seemingly gibberish comments. + +Another important point is that the Makefile compiles the program as +`shapiro_t1` so that the source code that corresponds with it is actually +[shapiro.c](1994/shapiro/shapiro.c). But notice how running `shapiro_t1` results +in different functionality than `shapiro` itself? The source code that +`shapiro_t1` generates, `shapiro_t2.c`, is what is compiled into `shapiro`. # 1995