Deal with compiler changes on Windows giving different bitfield padding

Author: ibmmqmet

CHANGES.md

@@ -95,3 +95,6 @@ Jul 2019 (v5.1.2)
 
 Aug 2019 (v5.1.3)
 * Print QJST SLPTU as number not timestamp
+
+Aug 2019 (v5.1.4)
+* Newer compilers have changed bitfield structure padding layouts

bin/aix/convH

@@ -4,12 +4,12 @@ plat=`uname`
 
 if [ "$plat" = "AIX" ]
 then
-  flags="-q32 -qmaxmem=-1 $CCEXTRAFLAGS"
+  flags="-q32 -qmaxmem=-1 $CCEXTRAFLAGS -D PLATFORM_AIX"
   cc="xlc"
   targdir="../bin/aix"
   optim="-O3"
 else
-  flags="-m32 $CCEXTRAFLAGS"
+  flags="-m32 $CCEXTRAFLAGS -D PLATFORM_LINUX"
   cc="gcc"
   targdir="../bin/linux"
   optim="-O3"

bin/aix/mqsmfcsv

@@ -1,6 +1,6 @@
 
 CC=i686-w64-mingw32-gcc
-CFLAGS= -I. -m32 -O2
+CFLAGS= -I. -m32 -fpack-struct=1 -DPLATFORM_WINDOWS
 PLATFLAGS=
 VERS=913
 SRC = mqsmf.c \
@@ -9,6 +9,7 @@ SRC = mqsmf.c \
       smfConv.c \
       smfJson.c \
       smfPrint.c \
+      checkSize.c \
       printDEBUG.c \
       printQ5ST.c    \
       printQCST.c    \
@@ -38,6 +39,11 @@ SRC = mqsmf.c \
 HDR = mqsmfstruc.h \
       mqsmf.h
 
+checkSize: mqsmfcsv.exe
+	./mqsmfcsv.exe -v > sizes.tmp
+	diff -b sizes.tmp sizes.master
+
+
 mqsmfcsv.exe: $(SRC) $(HDR) Makefile.gcc.win dummy
 	-rm -f $@
 	$(CC) $(PLATFLAGS) -o $@ $(SRC) $(CFLAGS) -DCSQDSMF_VERSION=$(VERS)
@@ -48,7 +54,7 @@ mqsmfstruc.h: csqdsmfc-$(VERS).h convH.exe dummy
 	./convH.exe < csqdsmfc-$(VERS).h > $@
 
 convH.exe: convH.c
-	$(CC) -o $@ convH.c
+	$(CC) $(CFLAGS) -o $@ convH.c
 	cp $@ ../bin/win
 
 

bin/linux/convH

@@ -8,6 +8,7 @@ SRC = \
       smfDate.c \
       smfConv.c \
       smfJson.c \
+      checkSize.c \
       printDEBUG.c \
       printQ5ST.c    \
       printQCST.c    \
@@ -38,6 +39,10 @@ SRC = \
 HDR = mqsmfstruc.h \
       mqsmf.h
 
+checkSize: mqsmfcsv
+	./mqsmfcsv -v > sizes.tmp
+	diff -b sizes.tmp sizes.master
+
 mqsmfcsv: $(SRC) $(HDR) Makefile.unix dummy
 	$(CC) $(PLATFLAGS) -o $@ $(SRC) $(CFLAGS) -DCSQDSMF_VERSION=$(VERS)
 

bin/linux/mqsmfcsv

@@ -1,11 +1,12 @@
-CFLAGS=-nologo /D_CRT_SECURE_NO_WARNINGS /Zp1 /J /O2
+CFLAGS=-nologo /D_CRT_SECURE_NO_WARNINGS /Zp1 /J /O2 /DPLATFORM_WINDOWS
 VERS=913
 SRC = mqsmf.c \
       smfDDL.c \
       smfDate.c \
       smfConv.c \
       smfJson.c \
       smfPrint.c \
+      checkSize.c \
       printDEBUG.c \
       printQ5ST.c    \
       printQCST.c    \
@@ -35,6 +36,10 @@ SRC = mqsmf.c \
 HDR = mqsmfstruc.h \
       mqsmf.h
 
+checkSize: mqsmfcsv.exe
+	mqsmfcsv.exe -v > sizes.tmp
+	diff -b sizes.master sizes.tmp
+
 mqsmfcsv.exe: $(SRC) $(HDR) Makefile.win
 	rm -f $@
 	$(CC) $(SRC) -I. /Fe$@ $(CFLAGS) -DCSQDSMF_VERSION=$(VERS)
@@ -45,7 +50,7 @@ mqsmfstruc.h: csqdsmfc-$(VERS).h convH.exe dummy
 	convH < csqdsmfc-$(VERS).h > $@
 
 convH.exe: convH.c
-	$(CC) /Fe$@ convH.c
+	$(CC) $(CFLAGS) /Fe$@ convH.c
 	copy $@ ..\bin\win
 
 

bin/win/convH.exe

@@ -0,0 +1,45 @@
+#include "stdio.h"
+#include "stddef.h"
+#include "../src/mqsmfstruc.h"
+
+void checkStructureSizes(FILE *fp) {
+
+fprintf(fp,"%s : %d\n","q5st",sizeof(q5st));
+fprintf(fp,"%s : %d\n","qcct",sizeof(qcct));
+fprintf(fp,"%s : %d\n","qct_dsp",sizeof(qct_dsp));
+fprintf(fp,"%s : %d\n","qct_adp",sizeof(qct_adp));
+fprintf(fp,"%s : %d\n","qct_ssl",sizeof(qct_ssl));
+fprintf(fp,"%s : %d\n","qct_dns",sizeof(qct_dns));
+fprintf(fp,"%s : %d\n","qcst",sizeof(qcst));
+fprintf(fp,"%s : %d\n","qest",sizeof(qest));
+fprintf(fp,"%s : %d\n","qesd",sizeof(qesd));
+fprintf(fp,"%s : %d\n","qist",sizeof(qist));
+fprintf(fp,"%s : %d\n","qis1",sizeof(qis1));
+fprintf(fp,"%s : %d\n","qjst",sizeof(qjst));
+fprintf(fp,"%s : %d\n","qlst",sizeof(qlst));
+fprintf(fp,"%s : %d\n","qmac",sizeof(qmac));
+fprintf(fp,"%s : %d\n","qmst",sizeof(qmst));
+fprintf(fp,"%s : %d\n","qpst",sizeof(qpst));
+fprintf(fp,"%s : %d\n","qsgm",sizeof(qsgm));
+fprintf(fp,"%s : %d\n","qsph",sizeof(qsph));
+fprintf(fp,"%s : %d\n","qsrs",sizeof(qsrs));
+fprintf(fp,"%s : %d\n","qsst",sizeof(qsst));
+fprintf(fp,"%s : %d\n","qtst",sizeof(qtst));
+fprintf(fp,"%s : %d\n","qwac",sizeof(qwac));
+fprintf(fp,"%s : %d\n","qwhc",sizeof(qwhc));
+fprintf(fp,"%s : %d\n","qwhs",sizeof(qwhs));
+fprintf(fp,"%s : %d\n","wtas",sizeof(wtas));
+fprintf(fp,"%s : %d\n","wtid",sizeof(wtid));
+fprintf(fp,"%s : %d\n","qwst",sizeof(qwst));
+fprintf(fp,"%s : %d\n","qws0",sizeof(qws0));
+fprintf(fp,"%s : %d\n","qws1",sizeof(qws1));
+fprintf(fp,"%s : %d\n","qws5",sizeof(qws5));
+fprintf(fp,"%s : %d\n","qws8",sizeof(qws8));
+fprintf(fp,"%s : %d\n","qws9",sizeof(qws9));
+fprintf(fp,"%s : %d\n","qwsx",sizeof(qwsx));
+fprintf(fp,"%s : %d\n","qwas",sizeof(qwas));
+fprintf(fp,"%s : %d\n","qwa0",sizeof(qwa0));
+fprintf(fp,"%s : %d\n","wq  ",sizeof(wq));
+fprintf(fp,"wq->maxqdpth: %d\n",offsetof(wq,maxqdpth));
+fprintf(fp,"wq->z__001  : %d\n",offsetof(wq,z__001  ));
+}

bin/win/mqsmfcsv.exe

@@ -13,20 +13,37 @@
 #include <stdio.h>
 #include <string.h>
 
+#if defined(PLATFORM_WINDOWS)
+#define BITFIELDREPRINTNEEDED (1)
+#else
+#define BITFIELDREPRINTNEEDED (0)
+#endif
+
+int inBitfieldReplace = 0;
+void bitfieldReprint(int c);
+
 /*
  * This is a very simple filter to take the product-provided
  * header file from z/OS and strip a few things that are
  * problematic on other platform compilers.
  *
  * It means we don't need to keep a variant copy
- * of the header in sync when new versions come out.
+ * of the header in sync [Awhen new versions come out.
  *
  * In particular, get rid of the z/OS format for
  * the pragmas, and also the trigraph at the top
  * of the file.
  *
  * If the contents of the header file change, this
  * filter may need to be updated to match.
+ *
+ * Newer compiler versions on some platforms have also
+ * affected how bitfields are laid out. This program now
+ * rewrites bitfield structures that have been found to be a problem.
+ * The changes have to be explicitly for each issue, but the build process
+ * does now check if the structure sizes are unexpectedly different.
+ * The AIX compiler seems to give the same sizes as z/OS so that's the master
+ * we will drive the comparison from.
  */
 int main(int argc, char **argv)
 {
@@ -57,13 +74,51 @@ int main(int argc, char **argv)
          continue;
        else
        {
-          printf("%s",line);
-          if (line[strlen(line)-1] != '\n')
-            printf("\n");
+          if (BITFIELDREPRINTNEEDED) {
+            if (strstr(line,"fNoAcctg")) {
+              bitfieldReprint(1);
+            }
+            if (strstr(line,"qwhssmfc")) {
+              bitfieldReprint(2);
+            }
+          }
+
+          if (inBitfieldReplace) {
+            /* Have we reached the end of the bitfield structure */
+            if (strstr(line,"}"))
+              inBitfieldReplace = 0;
+          }
+
+          if (!inBitfieldReplace) {
+            printf("%s",line);
+            if (line[strlen(line)-1] != '\n')
+              printf("\n");
+          }
+
        }
      }
   } while (c);
 
   fflush(stdout);
   return 0;
 }
+
+void bitfieldReprint(int c) {
+  inBitfieldReplace = 1;
+  switch (c) {
+  case 1:
+    printf("  unsigned char fNoAcctg : 1;\n");
+    printf("  unsigned char fTopic   : 1;\n");
+    printf("  unsigned char fAcctqC  : 1;\n");
+    printf("  unsigned char spare    : 5;\n");
+    printf("  unsigned char spare2   : 8;\n");
+    break;
+  case 2:
+    printf("  unsigned char qwhssmfc : 1;\n");
+    printf("  unsigned char qwhspad1 : 7;\n");
+    break;
+  default:
+    break;
+  }
+}
+

src/M

@@ -239,14 +239,14 @@ int main( int argc, char *argv[] )
     exit(1);
   }
 
+
   infoStream=stdout;
 
-  /*fprintf(infoStream,"Sizeof qwhs = %d\n",sizeof(qwhs));*/
 
   /******************************************************************/
   /* Parse command-line parameters                                  */
   /******************************************************************/
-  while((c = mqgetopt(argc, argv, "ab:cd:e:f:h:i:m:o:p:rst:")) != EOF)
+  while((c = mqgetopt(argc, argv, "ab:cd:e:f:h:i:m:o:p:rst:v")) != EOF)
   {
     switch(c)
     {
@@ -327,6 +327,9 @@ int main( int argc, char *argv[] )
       case 't':
         ticker     = atoi(mqoptarg);
         break;
+      case 'v':
+         checkStructureSizes(infoStream);
+         exit(0);
       default:
         error = TRUE;
         break;

src/Makefile.gcc.win

@@ -280,6 +280,7 @@ extern void  smfPrintStop(FILE *,BOOL, BOOL *,columnHeader_t **);
 extern void  smfAddHead(BOOL first,BOOL,char *h,int type,int len);
 extern void  smfAddData(int datatype,char *fmt,...);
 extern void  smfAddString(int, char *);
+extern void checkStructureSizes(FILE *);
 
 #define SMFPRINTGLOB \
   static BOOL first = TRUE;\

src/Makefile.unix

@@ -0,0 +1,38 @@
+q5st : 672
+qcct : 48
+qct_dsp : 36
+qct_adp : 32
+qct_ssl : 48
+qct_dns : 48
+qcst : 324
+qest : 4104
+qesd : 328
+qist : 80
+qis1 : 104
+qjst : 592
+qlst : 32
+qmac : 48
+qmst : 104
+qpst : 104
+qsgm : 48
+qsph : 88
+qsrs : 232
+qsst : 72
+qtst : 96
+qwac : 176
+qwhc : 92
+qwhs : 52
+wtas : 2344
+wtid : 208
+qwst : 28
+qws0 : 96
+qws1 : 72
+qws5 : 16
+qws8 : 16
+qws9 : 16
+qwsx : 48
+qwas : 28
+qwa0 : 56
+wq   : 2788
+wq->maxqdpth: 588
+wq->z__001  : 594