[Vm-dev] VM Maker: ImageFormat-dtl.29.mcz

[Eliot Miranda]

Hi David, Subbu,

    forgive me...

> On Apr 11, 2018, at 4:54 AM, commits at source.squeak.org wrote:
> 
> 
> David T. Lewis uploaded a new version of ImageFormat to project VM Maker:
> http://source.squeak.org/VMMaker/ImageFormat-dtl.29.mcz
> 
> ==================== Summary ====================
> 
> Name: ImageFormat-dtl.29
> Author: dtl
> Time: 11 April 2018, 8:54:16.07 am
> UUID: ea0c2ff3-c413-4917-a6fb-8177e5a2ebec
> Ancestors: ImageFormat-dtl.28
> 
> Fix by K K Subbu: Use memcmp instead of strncmp in ckformat to compare byte arrays.
> 
> =============== Diff against ImageFormat-dtl.28 ===============
> 
> Item was changed:
>  ----- Method: ImageFormat class>>generateCkFormatProgram:on: (in category 'ckformat') -----
>  generateCkFormatProgram: programName on: stream
>      "Generate source code for an image format version reader. The program
>      is intended for testing image file format from a unix shell script such that
>      the shell script can decide what VM to run based on image requirements."
> 
>      | formatNumber |
>      stream nextPutAll: '/* ', programName, ': Print the image format number on standard output */'; cr;
>              nextPutAll: '/* for use in a shell script to test image format requirements. */'; cr;
>              nextPutAll: '/* A non-zero return status code indicates failure. */'; cr; cr;
>              nextPutAll: '/* Usage: ', programName, ' imageFileName */'; cr; cr;
>              nextPutAll: '/* --- DO NOT EDIT THIS FILE --- */'; cr;
>              nextPutAll: '/* --- Automatically generated from class ', self name, ' ', DateAndTime now asString, '--- */'; cr;
>              nextPutAll: '/* --- Source code is in package ImageFormat in the VMMaker repository --- */'; cr;
>              nextPutAll: '/* --- DO NOT EDIT THIS FILE --- */'; cr; cr;
>              nextPutAll: '#include <stdio.h>'; cr;
>              nextPutAll: '#include <stdlib.h>'; cr;
>              nextPutAll: '#include <string.h>'; cr; cr;
>              nextPutAll: 'main(int argc, char **argv) {'; cr;
>              tab; nextPutAll: 'FILE *f;'; cr;
>              tab; nextPutAll: 'unsigned char buf[8];'; cr;        
>              tab; nextPutAll: 'int formatNumber;'; cr;        
>              tab; nextPutAll: 'unsigned char c;'; cr;        
>              tab; nextPutAll: 'int match;'; cr;        
>              tab; nextPutAll: 'if (argc !!= 2) {'; cr;
>              tab; tab; nextPutAll: 'printf("usage: ', programName,  ' imageFileName\n");'; cr;
>              tab; tab; nextPutAll: 'exit(1);'; cr;
>              tab; nextPutAll: '}'; cr;
>              tab; nextPutAll: 'f = fopen(argv[1], "r");'; cr;
>              tab; nextPutAll: 'if (f == NULL) {'; cr;
>              tab; tab; nextPutAll: 'perror(argv[1]);'; cr;
>              tab; tab; nextPutAll: 'exit(2);'; cr;
>              tab; nextPutAll: '}'; cr.
>      { 0. 512 } do: [:offset |
>          stream
>              tab; nextPutAll: 'if(fseek(f, '; nextPutAll: offset asString; nextPutAll: 'L, SEEK_SET) !!= 0) {';cr;
>              tab; tab; nextPutAll: 'fprintf(stderr, "cannot go to pos %d in %s\n", '; nextPutAll: offset asString; nextPutAll: ', argv[1]);'; cr;
>              tab; tab; nextPutAll: 'exit(3);'; cr;
>              tab; nextPutAll: '}'; cr;
>              tab; nextPutAll: 'if (fread(buf, 1, 8, f) < 8) {'; cr;
>              tab; tab; nextPutAll: 'fprintf(stderr, "cannot read %s\n", argv[1]);'; cr;
>              tab; tab; nextPutAll: 'exit(3);'; cr;
>              tab; nextPutAll: '}'; cr.
>          self versionNumberByteArrays withIndexDo: [ :v :tag | | b |
>              formatNumber := (self fromBytes: v) asInteger.
>              b := 'b_', formatNumber asString, '_', tag asString.
>              stream tab; nextPutAll: '{'; cr; tab; nextPutAll: 'unsigned char ', b, '[', v size asString, ']= { '.
>              v inject: true into: [:first : elem |
>                  first ifFalse: [stream nextPutAll: ', '].
>                  stream nextPutAll: elem asString.
>                  false].
>              stream nextPutAll: '};'; cr;
> +                    tab; nextPutAll: 'if (memcmp(buf, ', b, ', ', v size asString, ') == 0) {'; cr;
> -                    tab; nextPutAll: 'if (strncmp(buf, ', b, ', ', v size asString, ') == 0) {'; cr;
>                      tab; tab; nextPutAll: 'printf("%d\n", ', formatNumber, ');'; cr;
>                      tab; tab; nextPutAll: 'exit(0);'; cr;
>                      tab; nextPutAll: '}'; cr; tab; nextPutAll: '}'; cr]].
>      stream tab; nextPutAll: 'printf("0\n"); /* print an invalid format number */';cr;
>              tab; nextPutAll: 'exit (-1); /* not found, exit with error code */'; cr;
>              nextPutAll: '}'; cr
>  !

This is unreadable.  Either express it as a string or as a Slang program; anything but this horrid mashup of nextPutAll:s and C fragments :-(