Add Oracle like handling of char arrays.

In some cases Oracle Pro*C handles char array differently than ECPG. This patch
adds a Oracle compatibility mode to make ECPG behave like Pro*C.

Patch by David Rader <davidr@openscg.com>

Author: Michael Meskes

src/interfaces/ecpg/ecpglib/data.c

@@ -464,7 +464,45 @@ ecpg_get_data(const PGresult *results, int act_tuple, int act_field, int lineno,
 
 						if (varcharsize == 0 || varcharsize > size)
 						{
-							strncpy(str, pval, size + 1);
+							/* compatibility mode, blank pad and null terminate char array */
+							if (ORACLE_MODE(compat) && (type == ECPGt_char || type == ECPGt_unsigned_char))
+							{
+								memset(str, ' ', varcharsize);
+								memcpy(str, pval, size);
+								str[varcharsize-1] = '\0';
+
+								/* compatiblity mode empty string gets -1 indicator but no warning */
+								if (size == 0) {
+									/* truncation */
+									switch (ind_type)
+									{
+										case ECPGt_short:
+										case ECPGt_unsigned_short:
+											*((short *) (ind + ind_offset * act_tuple)) = -1;
+											break;
+										case ECPGt_int:
+										case ECPGt_unsigned_int:
+											*((int *) (ind + ind_offset * act_tuple)) = -1;
+											break;
+										case ECPGt_long:
+										case ECPGt_unsigned_long:
+											*((long *) (ind + ind_offset * act_tuple)) = -1;
+											break;
+	#ifdef HAVE_LONG_LONG_INT
+										case ECPGt_long_long:
+										case ECPGt_unsigned_long_long:
+											*((long long int *) (ind + ind_offset * act_tuple)) = -1;
+											break;
+	#endif							/* HAVE_LONG_LONG_INT */
+										default:
+											break;
+									}
+								}
+							}
+							else
+							{
+								strncpy(str, pval, size + 1);
+							}
 							/* do the rtrim() */
 							if (type == ECPGt_string)
 							{
@@ -481,7 +519,14 @@ ecpg_get_data(const PGresult *results, int act_tuple, int act_field, int lineno,
 						{
 							strncpy(str, pval, varcharsize);
 
-							if (varcharsize < size)
+							/* compatibility mode, null terminate char array */
+							if (ORACLE_MODE(compat) && (varcharsize - 1) < size)
+							{
+								if (type == ECPGt_char || type == ECPGt_unsigned_char)
+									str[varcharsize-1] = '\0';
+							}
+
+							if (varcharsize < size || (ORACLE_MODE(compat) && (varcharsize - 1) < size))
 							{
 								/* truncation */
 								switch (ind_type)

src/interfaces/ecpg/ecpglib/extern.h

@@ -15,12 +15,13 @@
 
 enum COMPAT_MODE
 {
-	ECPG_COMPAT_PGSQL = 0, ECPG_COMPAT_INFORMIX, ECPG_COMPAT_INFORMIX_SE
+	ECPG_COMPAT_PGSQL = 0, ECPG_COMPAT_INFORMIX, ECPG_COMPAT_INFORMIX_SE, ECPG_COMPAT_ORACLE
 };
 
 extern bool ecpg_internal_regression_mode;
 
 #define INFORMIX_MODE(X) ((X) == ECPG_COMPAT_INFORMIX || (X) == ECPG_COMPAT_INFORMIX_SE)
+#define ORACLE_MODE(X) ((X) == ECPG_COMPAT_ORACLE)
 
 enum ARRAY_TYPE
 {

src/interfaces/ecpg/preproc/ecpg.c

@@ -41,7 +41,7 @@ help(const char *progname)
 	printf(_("  -c             automatically generate C code from embedded SQL code;\n"
 			 "                 this affects EXEC SQL TYPE\n"));
 	printf(_("  -C MODE        set compatibility mode; MODE can be one of\n"
-			 "                 \"INFORMIX\", \"INFORMIX_SE\"\n"));
+			 "                 \"INFORMIX\", \"INFORMIX_SE\", \"ORACLE\"\n"));
 #ifdef YYDEBUG
 	printf(_("  -d             generate parser debug output\n"));
 #endif
@@ -208,6 +208,10 @@ main(int argc, char *const argv[])
 					snprintf(informix_path, MAXPGPATH, "%s/informix/esql", pkginclude_path);
 					add_include_path(informix_path);
 				}
+				else if (strncmp(optarg, "ORACLE", strlen("ORACLE")) == 0)
+				{
+					compat = ECPG_COMPAT_ORACLE;
+				}
 				else
 				{
 					fprintf(stderr, _("Try \"%s --help\" for more information.\n"), argv[0]);

src/interfaces/ecpg/preproc/extern.h

@@ -122,10 +122,12 @@ extern int	filtered_base_yylex(void);
 
 enum COMPAT_MODE
 {
-	ECPG_COMPAT_PGSQL = 0, ECPG_COMPAT_INFORMIX, ECPG_COMPAT_INFORMIX_SE
+	ECPG_COMPAT_PGSQL = 0, ECPG_COMPAT_INFORMIX, ECPG_COMPAT_INFORMIX_SE, ECPG_COMPAT_ORACLE
 };
 extern enum COMPAT_MODE compat;
 
 #define INFORMIX_MODE	(compat == ECPG_COMPAT_INFORMIX || compat == ECPG_COMPAT_INFORMIX_SE)
+#define ORACLE_MODE (compat == ECPG_COMPAT_ORACLE)
+
 
 #endif							/* _ECPG_PREPROC_EXTERN_H */

src/interfaces/ecpg/test/Makefile

@@ -30,6 +30,7 @@ all install installdirs uninstall distprep:
 	$(MAKE) -C pgtypeslib $@
 	$(MAKE) -C preproc $@
 	$(MAKE) -C compat_informix $@
+	$(MAKE) -C compat_oracle $@
 	$(MAKE) -C thread $@
 
 clean distclean maintainer-clean:
@@ -38,6 +39,7 @@ clean distclean maintainer-clean:
 	$(MAKE) -C pgtypeslib $@
 	$(MAKE) -C preproc $@
 	$(MAKE) -C compat_informix $@
+	$(MAKE) -C compat_oracle $@
 	$(MAKE) -C thread $@
 	rm -rf tmp_check results log
 	rm -f pg_regress regression.diffs regression.out pg_regress_ecpg.o $(WIN32RES)

src/interfaces/ecpg/test/compat_oracle/.gitignore

@@ -0,0 +1,2 @@
+/char_array
+/char_array.c

src/interfaces/ecpg/test/compat_oracle/Makefile

@@ -0,0 +1,11 @@
+subdir = src/interfaces/ecpg/test/compat_oracle
+top_builddir = ../../../../..
+include $(top_builddir)/src/Makefile.global
+include $(top_srcdir)/$(subdir)/../Makefile.regress
+
+# Use special oracle compatibility switch for all tests in this directory
+ECPG += -C ORACLE
+
+TESTS = char_array char_array.c
+
+all: $(TESTS)

src/interfaces/ecpg/test/compat_oracle/char_array.pgc

@@ -0,0 +1,66 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+EXEC SQL INCLUDE ../regression;
+
+static void warn();
+
+/* Compatible handling of char array to retrieve varchar field to char array
+   should be fixed-length, blank-padded, then null-terminated.
+   Conforms to the ANSI Fixed Character type. */
+
+int main() {
+
+  ECPGdebug(1, stderr);
+  EXEC SQL CONNECT TO REGRESSDB1;
+
+  EXEC SQL WHENEVER SQLWARNING do warn();
+  EXEC SQL WHENEVER SQLERROR SQLPRINT;
+
+  const char *ppppp = "XXXXX";
+
+  EXEC SQL BEGIN DECLARE SECTION;
+  char shortstr[5];
+  char bigstr[11];
+  short shstr_ind = 0;
+  short bigstr_ind = 0;
+  EXEC SQL END DECLARE SECTION;
+
+  EXEC SQL CREATE TABLE strdbase (strval varchar(10));
+  EXEC SQL INSERT INTO strdbase values ('');
+  EXEC SQL INSERT INTO strdbase values ('AB');
+  EXEC SQL INSERT INTO strdbase values ('ABCD');
+  EXEC SQL INSERT INTO strdbase values ('ABCDE');
+  EXEC SQL INSERT INTO strdbase values ('ABCDEF');
+  EXEC SQL INSERT INTO strdbase values ('ABCDEFGHIJ');
+
+  EXEC SQL declare C cursor for select strval, strval from strdbase;
+  EXEC SQL OPEN C;
+
+  EXEC SQL WHENEVER NOT FOUND DO BREAK;
+
+  printf("Full Str.  :  Short  Ind.\n");
+  while(1) {
+    strncpy(shortstr, ppppp, sizeof shortstr);
+    memset(bigstr, 0, sizeof bigstr);
+    EXEC SQL FETCH C into :bigstr :bigstr_ind, :shortstr :shstr_ind;
+    printf("\"%s\": \"%s\"  %d\n", bigstr, shortstr, shstr_ind);
+  }
+
+  EXEC SQL close cstr;
+  EXEC SQL DROP TABLE strdbase;
+
+  printf("\nGOOD-BYE!!\n\n");
+
+  EXEC SQL COMMIT WORK;
+
+  EXEC SQL DISCONNECT ALL;
+
+  return 0;
+}
+
+static void warn(void)
+{
+  fprintf(stderr, "Warning: At least one column was truncated\n");
+}

src/interfaces/ecpg/test/ecpg_schedule

@@ -7,6 +7,7 @@ test: compat_informix/sqlda
 test: compat_informix/describe
 test: compat_informix/test_informix
 test: compat_informix/test_informix2
+test: compat_oracle/char_array
 test: connect/test2
 test: connect/test3
 test: connect/test4