GitLab

Bugzilla Link	333
Created on	Dec 05, 2006 15:13
Resolution	FIXED
Resolved on	Dec 07, 2006 11:04
Version	svn
OS	Linux
Architecture	Other

Extended Description

I observed a strange compile error (actually a linker error) when separating 
some of my own sac functions (in this example: double2GrayLevels) from the file 
containing the main function. I created a new module (in the following examples 
"MyModule") in which I placed double2GrayLevels. When trying to "use" MyModule 
in the main file, I get several similar error messages of the form 
 
: In function `SACwf_String__tos__b_S': 
: undefined reference to `SACbtos' 
 
Using an include file instead of the module will cause these error messages to 
vanish, which seems rather strange to me. 
 
Additionally, when exchanging some statements in function main, the error will 
also vanish. I added some special comments on those lines in the source code. 
 
compiler flags: -O3 -nophm -E/opt/local/lib 
 
Files: MyModule.sac, MyModule_incl.sac, module_xmpl.sac 
 
 
------------------------------------------------------------------------ 
MyModule.sac: 
 
module MyModule; 
 
use Structures: all; 
 
/* export all; */ 
provide {double2GrayLevels}; 
 
 
/* Converts an array of double values to an array of 
 * graylevel colors ranging from 0 to 255 */ 
 
color[*] double2GrayLevels(double[*] image) { 
  /* determine minimum and maximum values */ 
  min = minval(image); 
  max = maxval(image); 
 
  /* normalize double values */ 
  image = (image - min)*(255.0/(max-min)); 
 
  /* convert image to array of color values */ 
 
  image_gray =  
    with { 
      ( . <= iv <= . ): newColor(genarray([3],toi(image[iv]))); 
      } : genarray(shape(image),black()); 
   
  return(image_gray); 
 
} 
 
 
/* Converts an array of doubles to an array of 
 * graylevels unsing a Hounsfield window. Values below  
 * winMin will be set to zero, values above winMax will 
 * be set to 255. All intermediate values will be scaled 
 * between 0 and 255. */ 
 
color[*] double2GrayLevels(double[*] image, double winMin, double winMax) { 
 
  /* Scale double values */ 
  image = (image - winMin)*(255.0/(winMax-winMin)); 
 
  /* convert image to array of color values */ 
  image_gray =  
    with { 
      ( . <= iv <= . ) { color = toi(image[iv]); 
			 if (color < 0) color=0;  
			 if (color > 255) color=255; 
      }: newColor(genarray([3],color)); 
    }: genarray(shape(image),black()); 
 
  return(image_gray); 
 
} 
 
 
------------------------------------------------------------------------ 
MyModule_incl.sac: 
 
/*module MyModule; 
 
use Structures: all;*/ 
 
/* export all; */ 
/*provide {double2GrayLevels}; */ 
 
 
/* Converts an array of double values to an array of 
 * graylevel colors ranging from 0 to 255 */ 
 
color[*] double2GrayLevels(double[*] image) { 
  /* determine minimum and maximum values */ 
  min = minval(image); 
  max = maxval(image); 
 
  /* normalize double values */ 
  image = (image - min)*(255.0/(max-min)); 
 
  /* convert image to array of color values */ 
 
  image_gray =  
    with { 
      ( . <= iv <= . ): newColor(genarray([3],toi(image[iv]))); 
      } : genarray(shape(image),black()); 
   
  return(image_gray); 
 
} 
 
 
/* Converts an array of doubles to an array of 
 * graylevels unsing a Hounsfield window. Values below  
 * winMin will be set to zero, values above winMax will 
 * be set to 255. All intermediate values will be scaled 
 * between 0 and 255. */ 
 
color[*] double2GrayLevels(double[*] image, double winMin, double winMax) { 
 
  /* Scale double values */ 
  image = (image - winMin)*(255.0/(winMax-winMin)); 
 
  /* convert image to array of color values */ 
  image_gray =  
    with { 
      ( . <= iv <= . ) { color = toi(image[iv]); 
			 if (color < 0) color=0;  
			 if (color > 255) color=255; 
      }: newColor(genarray([3],color)); 
    }: genarray(shape(image),black()); 
 
  return(image_gray); 
 
} 
 
------------------------------------------------------------------------ 
module_xmpl.sac: 
 
use StdIO: all; 
import Array: all; 
import Structures: all; 
use SDLdisplay: all; 
 
 
/* compile error arises if we use the module MyModule. If we use 
 * the include file instead, the error vanishes */ 
 
use MyModule: all; 
/* #include "MyModule_incl.sac" */ 
 
double[*] foo(int[.] shp) { 
  return(genarray(shp,0d)); 
} 
 
void foo2(color[*] arr) { 
  /* do not do anything interesting */ 
  a = 1; 
} 
 
int main() { 
  shp = [64,64]; 
   
  /* open file */ 
  errcode, fd = binfopen("/any/file/you/like", 
			 O_RDONLY()); 
 
  /* read 2D image as an array of doubles */ 
  image_2D = binfReadDoubleArray(fd,shape(shp)[[0]],shp); 
 
  /* uncomment one of the following lines and 
   * the compiler error will vanish */ 
 
/*   image_2D = foo(shp); */ 
/*   image_2D = genarray(shp,1d); */ 
 
  /* initialize display */ 
  disp = initDisplay(take([2],shp)); 
 
  gl = double2GrayLevels(image_2D); 
   
  /* unsing foo2 here instead of drawArray will cause the 
   * compile error to vanish */ 
 
/*   foo2(gl); */ 
  drawArray(disp,gl); 
 
  destroyDisplay(disp); 
 
  return(0); 
}