To shorten the porting time and avoid problems which are difficult to isolate, we use the C program in Listing One , which tests each of the system-specific dependencies found in c-tree Plus. By compiling and executing this module (which does not require any of the c-tree API) you can determine, among many other things, if your definition of COUNT really results in 2-byte integers, or whether the memcmp function performs signed or unsigned byte-wise comparisons. When we port to a new environment, executing this test program is one of the first steps we take.
Listing One
/* Copyright (c) 1984 - 1994 FairCom Corporation. ALL RIGHTS RESERVED
* FairCom Corporation, 4006 West Broadway, Columbia, MO 65203.
* 314-445-6833
*/
#include "ctstdr.h"
#include "ctoptn.h"
#define CTF " 1 3 "
#define S377 "'\\377'"
typedef struct {
TEXT mb1;
} MB;
TEXT getbuf[128];
TEXT *align[5] = {
"strange: call FairCom (314) 445-6833",
"byte",
"word (2 bytes)",
"strange: call FairCom (314) 445-6833",
"double word (4 bytes)"
};
#ifdef PROTOTYPE
main ()
#else
main ()
#endif
{
TEXT buffer[8];
TEXT t255,*tp;
COUNT i,done,d[4],afactor;
UCOUNT tu;
TEXT *th,*tl;
MB mb[2];
struct {
ctRECPT pa1;
TEXT pa2;
ctRECPT pp;
ctRECPT pa3;
ctRECPT pa4;
} p;
struct {
ctRECPT ca1;
TEXT ca2;
COUNT cc;
} c;
struct {
ctRECPT aa1;
TEXT aa2;
TEXT aa[3];
} a;
struct {
ctRECPT ta1;
TEXT ta2;
TEXT tt;
} t;
if (SIZEOF(COUNT) != 2 ||
SIZEOF(UCOUNT) != 2 ||
SIZEOF(LONG) !=4 ||
SIZEOF(VRLEN) != 4) {
printf(
"\n\nBefore continuing with CTTEST be sure that the following types are");
printf(
"\ncorrectly sized. Make the necessary changes in CTPORT.H.\n\n");
printf(" COUNT UCOUNT LONG VRLEN\n");
printf(" ------- ------- ------- -------\n");
printf(" Should be: 2 bytes 2 bytes 4 bytes 4 bytes\n");
printf("Actual size: %d %d %d %d\n\n",
SIZEOF(COUNT),SIZEOF(UCOUNT),SIZEOF(LONG),SIZEOF(VRLEN));
exit(0);
} else {
printf("\n\nCOUNT, UCOUNT, LONG & VRLEN are properly sized.");
tu = 40000;
if (!(tu > 0)) {
printf(
"\n\nBefore continuing with CTTEST, be sure that UCOUNT is an");
printf("\nunsigned short integer. See CTPORT.H\n\n");
exit(0);
}
}
t255 = '\377';
printf("\n\nC255 Test for CTCMPL.H:");
printf("\n\tUse the following setup in CTCMPL.H - \t#define C255\t");
if (t255 == -1)
printf("%d",t255);
else
printf(S377);
printf("\n\t\t\t Current setting - \t#define C255\t");
if (C255 == 0x00ff)
printf(S377);
if (C255 == -1)
printf("%d",C255);
i = 0x0201;
tp = (TEXT *) &i;
printf("\n\nLOW HIGH Test for CTOPTN.H:");
printf("\n\tUse the following setup in CTOPTN.H - \t#define ");
if ((*tp & 0x00ff) > (*(tp + 1) & 0x00ff))
printf("HIGH_LOW");
else
printf("LOW_HIGH");
printf("\n\t\t\t Current setting - \t#define ");
#ifdef LOW_HIGH
printf("LOW_HIGH");
#endif
#ifdef HIGH_LOW
printf("HIGH_LOW");
#endif
/* NULL size test */
printf("\nNULL Size Test: ");
if (SIZEOF(NULL) == SIZEOF(tp))
printf("ok (%d bytes)",SIZEOF(NULL));
else
printf("inconsistent (NULL is %d bytes & ptr's are %d bytes)",
SIZEOF(NULL),SIZEOF(tp));
/* test of compar function for byte-wise comparisons */
for (i = 0; i < 4; i++) {
buffer[i] = 'A';
buffer[i+4] = '\377';
}
tp = buffer;
#ifndef FASTCOMP
#ifdef ctDS
done = ((COUNT) *tp & 0x00ff) - ((COUNT) *(tp + 4) & 0x00ff);
#else
done = (*tp & 0x00ff) - (*(tp + 4) & 0x00ff);
#endif
if (done >= 0) {
printf(
"\n\n\nBefore continuing with CTTEST, call FairCom (314) 445-6833 concerning");
printf(
"\nthe critical compar function in CTCOMP.C. Please report the following");
printf(
"\nthree numbers to FairCom: %d %d %d\n",(*tp & 0x00ff),(*(tp + 4) & 0x00ff),
done);
exit(0);
} else
#endif /* ~FASTCOMP */
printf("\n\ncompar function (CTCOMP.C) test is successful.");
#ifndef ctNOMEMCMP
done = ctrt_memcmp(tp,tp + 4,1);
if (done >= 0) {
printf(
"\n\n\nBefore continuing with CTTEST, add '#define ctNOMEMCMP' to ctcmpl.h.");
printf(
"\nThis indicates that your memcmp function cannot be used in our high speed");
printf(
"\nkey loading routine since its treats bytes as signed quantities.\n");
exit(0);
}
#endif
/* PAUSE IN OUTPUT */
printf("\n\nHit RETURN (or ENTER) to continue...");
gets(getbuf);
printf("\n\nAlignment test for help in computing key segment offsets.");
th = (TEXT *) &p.pa4;
tl = (TEXT *) &p.pa3;
i = th - tl;
if (i == 1) {
printf(
"\n\n*** This machine addresses 32 bit words (not bytes). Call ***");
printf(
"\n*** FairCom at (314) 445-6833. STATUS & HDRSIZ must be changed. ***");
afactor = 4;
} else if (i == 2) {
printf(
"\n\n*** This machine addresses words (not bytes). Add 2 to STATUS in ***");
printf(
"\n*** CTOPTN.H and add 4 to HDRSIZ in CTOPTN.H. Also each member ***");
printf(
"\n*** of a structure will be at least word aligned. In particular,");
afactor = 2;
} else
afactor = 1;
printf(" Members of\nstructures will be aligned as follows:\n\n");
printf("\tMember Type Alignment\n");
printf("\t----------- -----------------\n");
th = (TEXT *) &p.pp;
tl = &p.pa2;
i = (th - tl) * afactor;
if (i > 4) i = 0;
printf("\t4 byte int %s\n",align[i]);
th = (TEXT *) &c.cc;
tl = &c.ca2;
i = (th - tl) * afactor;
if (i > 4) i = 0;
printf("\t2 byte int %s\n",align[i]);
if (i > 2)
printf(
"\nCall FairCom (314) 445-6833 concerning 2 byte integer alignment.\n");
th = (TEXT *) a.aa;
tl = &a.aa2;
i = (th - tl) * afactor;
if (i > 4) i = 0;
printf("\tchar array %s\n",align[i]);
th = &t.tt;
tl = &t.ta2;
i = (th - tl) * afactor;
if (i > 4) i = 0;
printf("\tchar %s\n",align[i]);
printf("\n\nStructure 'SIZEOF' Test: ");
i = SIZEOF(MB);
th = &mb[1].mb1;
tl = &mb[0].mb1;
if (i == (th - tl))
printf(" OK");
else
printf(
"\nCall FairCom at (314) 445-6833 to report these two numbers: %d %d\n",
i, (th - tl));
printf("\n\nShort Integer Input Test for CTOPTN.H:");
done = NO;
d[1] = d[3] = 5;
if (sscanf(CTF,"%h %h",d,d+2) == 2 &&
d[0] == 1 && d[2] == 3 && d[1] == 5 && d[3] == 5) {
printf(
"\n\tUse the PERC_H option in CTOPTN.H.\n");
done = YES;
}
if (!done) {
d[1] = d[3] = 5;
if (sscanf(CTF,"%d %d",d,d+2) == 2 &&
d[0] == 1 && d[2] == 3 && d[1] == 5 && d[3] == 5) {
printf(
"\n\tUse the PERC_D option in CTOPTN.H.\n");
done = YES;
}
}
if (!done) {
d[1] = d[3] = 5;
if (sscanf(CTF,"%hd %hd",d,d+2) == 2 &&
d[0] == 1 && d[2] == 3 && d[1] == 5 && d[3] == 5) {
printf(
"\n\tUse the PERC_HD option in CTOPTN.H.\n");
done = YES;
}
}
if (!done)
printf(
"\n\n*** COMPILER DOES NOT CONFORM TO KNOWN CONVENTIONS ***\n");
printf("\tCurrent setting - ");
#ifdef PERC_H
printf("PERC_H");
#endif
#ifdef PERC_D
printf("PERC_D");
#endif
#ifdef PERC_HD
printf("PERC_HD");
#endif
/* PAUSE IN OUTPUT */
printf("\n\nHit RETURN (or ENTER) to continue...");
gets(getbuf);
printf("\n\nCTOPTN.H SUMMARY -\n");
#ifdef FPUTFGET
printf("\nFPUTFGET:\tnon-server, multi-user application");
#endif
#ifdef NOTFORCE
printf("\nNOTFORCE:\tsingle-user or server based application");
#endif
#ifdef RESOURCE
printf("\nRESOURCE:\tresources are supported");
#else
printf("\nNO_RESOURCE:\tresources are NOT supported");
#endif
#ifdef CTBATCH
printf("\nCTBATCH:\tbatch retrieval is supported");
#else
printf("\nNO_BATCH:\tbatch retrieval is NOT supported");
#endif
#ifdef CTSUPER
printf("\nCTSUPER:\tsuperfiles are supported");
#else
printf("\nNO_SUPER:\tsuperfiles are NOT supported");
#endif
#ifdef LOW_HIGH
printf("\nLOW_HIGH:\tLSB to MSB ordering (ala Intel 8086 family)");
#endif
#ifdef HIGH_LOW
printf("\nHIGH_LOW:\tMSB to LSB ordering (ala Motorola 68000 family)");
#endif
#ifdef VARLDATA
printf("\nVARLDATA:\tvariable length data records are supported");
#else
printf("\nNO_VARLD:\tvariable length data records are NOT supported");
#endif
#ifdef PERC_H
printf("\nPERC_H:\t\t%%h");
#endif
#ifdef PERC_D
printf("\nPERC_D:\t\t%%d");
#endif
#ifdef PERC_HD
printf("\nPERC_HD:\t%%hd");
#endif
printf(" short integer format specification");
#ifdef VARLKEYS
printf("\nVARLKEYS:\tkey compression supported");
#else
printf("\nNO_VARLK:\tkey compression is NOT supported");
#endif
#ifdef PARMFILE
printf("\nPARMFILE:\tISAM parameter files are supported");
#else
printf("\nNO_PARMF:\tISAM parameter files are NOT supported");
#endif
#ifdef RTREE
printf("\nRTREE:\t\tr-tree supported");
#else
printf("\nNO_RTREE:\tr-tree is NOT supported");
#endif
#ifdef CTS_ISAM
printf("\nCTS_ISAM:\tISAM functionality supported");
#else
printf("\nNO_ISAM:\tISAM functionality is NOT supported");
#endif
#ifdef CTBOUND
printf("\nCTBOUND:\tnon-server mode of operation");
#else
printf("\nNO_BOUND:\tserver mode of operation");
#endif
#ifdef PROTOTYPE
printf("\nPROTOTYPE:\tfunction prototypes are supported");
#else
printf("\nNO_PROTOTYPE:\tfunction prototypes are NOT supported");
#endif
printf("\n\nEnd Of CTTEST\n");
exit(0);
}
C lends itself to run-time library support. Many developers turn to third-party libraries to assist with database I/O, report generation, and other application necessities. When examining a third-party library, it is important to investigate its portability. If the library is developed and used properly, it can be a tremendous timesaver to the development and port of the application. Of course, if the library is not portable or available on different platforms, it may prove detrimental.
