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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Ashutosh Sharma <ashu.coek88@gmail.com>
cc: pgsql-interfaces@postgresql.org, Michael Meskes <meskes@postgresql.org>
Subject: Re: ecpg: issue related to preprocessor directives
In-reply-to: <1853327.1596240391@sss.pgh.pa.us>
References: 
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 <1853327.1596240391@sss.pgh.pa.us>
Comments: In-reply-to Tom Lane <tgl@sss.pgh.pa.us>
	message dated "Fri, 31 Jul 2020 20:06:31 -0400"
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I wrote:
> Looking at pgc.l, it seems that 'elif' is treated as though it were
> 'endif' followed by 'ifdef', which of course completely loses the
> expected property that a previous successful branch would keep the
> elif branch from being expanded.
> While this doesn't look terribly hard to fix, I'm a little disturbed
> by the fact that the existing semantics seem to date back to 1999
> (b57b0e044).  We're probably risking breaking existing app code if
> we change it.  I think we *should* change it, of course, but I'm kind
> of inclined not to back-patch.

Here's a proposed patch, which also clarifies the documentation,
which seemed a bit confused/misleading to me.

As stated, I'm not sure it's wise to back-patch this aggressively
... but maybe it'd be okay to squeeze it into v13?

			regards, tom lane


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diff --git a/doc/src/sgml/ecpg.sgml b/doc/src/sgml/ecpg.sgml
index 106ae0984e..ecdc417d0b 100644
--- a/doc/src/sgml/ecpg.sgml
+++ b/doc/src/sgml/ecpg.sgml
@@ -5695,7 +5695,7 @@ EXEC SQL UPDATE Tbl SET col =3D MYNUMBER;
   </sect2>
 =

   <sect2 id=3D"ecpg-ifdef">
-   <title>ifdef, ifndef, else, elif, and endif Directives</title>
+   <title>ifdef, ifndef, elif, else, and endif Directives</title>
    <para>
    You can use the following directives to compile code sections conditio=
nally:
 =

@@ -5705,7 +5705,7 @@ EXEC SQL UPDATE Tbl SET col =3D MYNUMBER;
      <listitem>
      <para>
       Checks a <replaceable>name</replaceable> and processes subsequent l=
ines if
-      <replaceable>name</replaceable> has been created with <literal>EXEC=
 SQL define
+      <replaceable>name</replaceable> has been defined via <literal>EXEC =
SQL define
       <replaceable>name</replaceable></literal>.
      </para>
      </listitem>
@@ -5716,30 +5716,40 @@ EXEC SQL UPDATE Tbl SET col =3D MYNUMBER;
      <listitem>
      <para>
       Checks a <replaceable>name</replaceable> and processes subsequent l=
ines if
-      <replaceable>name</replaceable> has <emphasis>not</emphasis> been c=
reated with
+      <replaceable>name</replaceable> has <emphasis>not</emphasis> been d=
efined via
       <literal>EXEC SQL define <replaceable>name</replaceable></literal>.
      </para>
      </listitem>
     </varlistentry>
 =

     <varlistentry>
-     <term><literal>EXEC SQL else;</literal></term>
+     <term><literal>EXEC SQL elif <replaceable>name</replaceable>;</liter=
al></term>
      <listitem>
      <para>
-      Starts processing an alternative section to a section introduced by
-      either <literal>EXEC SQL ifdef <replaceable>name</replaceable></lit=
eral> or
-      <literal>EXEC SQL ifndef <replaceable>name</replaceable></literal>.
+      Begins an alternative section after an
+      <literal>EXEC SQL ifdef <replaceable>name</replaceable></literal> o=
r
+      <literal>EXEC SQL ifndef <replaceable>name</replaceable></literal>
+      directive.  Any number of <literal>elif</literal> sections can appe=
ar.
+      Lines following an <literal>elif</literal> will be processed
+      if <replaceable>name</replaceable> has been
+      defined <emphasis>and</emphasis> no previous section of the same
+      <literal>ifdef</literal>/<literal>ifndef</literal>...<literal>endif=
</literal>
+      construct has been processed.
      </para>
      </listitem>
     </varlistentry>
 =

     <varlistentry>
-     <term><literal>EXEC SQL elif <replaceable>name</replaceable>;</liter=
al></term>
+     <term><literal>EXEC SQL else;</literal></term>
      <listitem>
      <para>
-      Checks <replaceable>name</replaceable> and starts an alternative se=
ction if
-      <replaceable>name</replaceable> has been created with <literal>EXEC=
 SQL define
-      <replaceable>name</replaceable></literal>.
+      Begins an optional, final alternative section after an
+      <literal>EXEC SQL ifdef <replaceable>name</replaceable></literal> o=
r
+      <literal>EXEC SQL ifndef <replaceable>name</replaceable></literal>
+      directive.  Subsequent lines will be processed if no previous secti=
on
+      of the same
+      <literal>ifdef</literal>/<literal>ifndef</literal>...<literal>endif=
</literal>
+      construct has been processed.
      </para>
      </listitem>
     </varlistentry>
@@ -5748,7 +5758,9 @@ EXEC SQL UPDATE Tbl SET col =3D MYNUMBER;
      <term><literal>EXEC SQL endif;</literal></term>
      <listitem>
      <para>
-      Ends an alternative section.
+      Ends an
+      <literal>ifdef</literal>/<literal>ifndef</literal>...<literal>endif=
</literal>
+      construct.  Subsequent lines are processed normally.
      </para>
      </listitem>
     </varlistentry>
@@ -5756,14 +5768,20 @@ EXEC SQL UPDATE Tbl SET col =3D MYNUMBER;
    </para>
 =

    <para>
-    Example:
+    <literal>ifdef</literal>/<literal>ifndef</literal>...<literal>endif</=
literal>
+    constructs can be nested, up to 127 levels deep.
+   </para>
+
+   <para>
+    This example will compile exactly one of the three <literal>SET
+    TIMEZONE</literal> commands:
 <programlisting>
-EXEC SQL ifndef TZVAR;
-EXEC SQL SET TIMEZONE TO 'GMT';
+EXEC SQL ifdef TZVAR;
+EXEC SQL SET TIMEZONE TO TZVAR;
 EXEC SQL elif TZNAME;
 EXEC SQL SET TIMEZONE TO TZNAME;
 EXEC SQL else;
-EXEC SQL SET TIMEZONE TO TZVAR;
+EXEC SQL SET TIMEZONE TO 'GMT';
 EXEC SQL endif;
 </programlisting>
    </para>
diff --git a/src/interfaces/ecpg/preproc/pgc.l b/src/interfaces/ecpg/prepr=
oc/pgc.l
index f6052798fd..514ea27a80 100644
--- a/src/interfaces/ecpg/preproc/pgc.l
+++ b/src/interfaces/ecpg/preproc/pgc.l
@@ -79,13 +79,27 @@ struct _yy_buffer
 =

 static char *old;
 =

+/*
+ * Vars for handling ifdef/elif/endif constructs.  preproc_tos is the cur=
rent
+ * nesting depth of such constructs, and stacked_if_value[preproc_tos] is=
 the
+ * state for the innermost level.  (For convenience, stacked_if_value[0] =
is
+ * initialized as though we are in the active branch of some outermost if=
.)
+ * The active field is true if the current branch is active (being expand=
ed).
+ * The saw_active field is true if we have found any successful branch,
+ * so that all subsequent branches of this level should be skipped.
+ * The else_branch field is true if we've found an 'else' (so that anothe=
r
+ * 'else' or 'elif' at this level is an error.)
+ * ifcond is valid only while evaluating an if-condition; it's true if we
+ * are doing ifdef, false if ifndef.
+ */
 #define MAX_NESTED_IF 128
 static short preproc_tos;
-static short ifcond;
+static bool ifcond;
 static struct _if_value
 {
-	short condition;
-	short else_branch;
+	bool active;
+	bool saw_active;
+	bool else_branch;
 } stacked_if_value[MAX_NESTED_IF];
 =

 %}
@@ -1165,11 +1179,26 @@ cppline			{space}*#([^i][A-Za-z]*|{if}|{ifdef}|{if=
ndef}|{import})((\/\*[^*/]*\*+
 						  return S_ANYTHING;
 					  }
 					}
-<C,xskip>{exec_sql}{ifdef}{space}*	{ ifcond =3D true; BEGIN(xcond); }
+<C,xskip>{exec_sql}{ifdef}{space}* {
+					  if (preproc_tos >=3D MAX_NESTED_IF-1)
+						  mmfatal(PARSE_ERROR, "too many nested EXEC SQL IFDEF conditions")=
;
+					  preproc_tos++;
+					  stacked_if_value[preproc_tos].active =3D false;
+					  stacked_if_value[preproc_tos].saw_active =3D false;
+					  stacked_if_value[preproc_tos].else_branch =3D false;
+					  ifcond =3D true;
+					  BEGIN(xcond);
+					}
 <C,xskip>{informix_special}{ifdef}{space}* {
 					  /* are we simulating Informix? */
 					  if (INFORMIX_MODE)
 					  {
+						  if (preproc_tos >=3D MAX_NESTED_IF-1)
+							  mmfatal(PARSE_ERROR, "too many nested EXEC SQL IFDEF conditions"=
);
+						  preproc_tos++;
+						  stacked_if_value[preproc_tos].active =3D false;
+						  stacked_if_value[preproc_tos].saw_active =3D false;
+						  stacked_if_value[preproc_tos].else_branch =3D false;
 						  ifcond =3D true;
 						  BEGIN(xcond);
 					  }
@@ -1179,11 +1208,26 @@ cppline			{space}*#([^i][A-Za-z]*|{if}|{ifdef}|{if=
ndef}|{import})((\/\*[^*/]*\*+
 						  return S_ANYTHING;
 					  }
 					}
-<C,xskip>{exec_sql}{ifndef}{space}* { ifcond =3D false; BEGIN(xcond); }
+<C,xskip>{exec_sql}{ifndef}{space}* {
+					  if (preproc_tos >=3D MAX_NESTED_IF-1)
+						  mmfatal(PARSE_ERROR, "too many nested EXEC SQL IFDEF conditions")=
;
+					  preproc_tos++;
+					  stacked_if_value[preproc_tos].active =3D false;
+					  stacked_if_value[preproc_tos].saw_active =3D false;
+					  stacked_if_value[preproc_tos].else_branch =3D false;
+					  ifcond =3D false;
+					  BEGIN(xcond);
+					}
 <C,xskip>{informix_special}{ifndef}{space}* {
 					  /* are we simulating Informix? */
 					  if (INFORMIX_MODE)
 					  {
+						  if (preproc_tos >=3D MAX_NESTED_IF-1)
+							  mmfatal(PARSE_ERROR, "too many nested EXEC SQL IFDEF conditions"=
);
+						  preproc_tos++;
+						  stacked_if_value[preproc_tos].active =3D false;
+						  stacked_if_value[preproc_tos].saw_active =3D false;
+						  stacked_if_value[preproc_tos].else_branch =3D false;
 						  ifcond =3D false;
 						  BEGIN(xcond);
 					  }
@@ -1193,16 +1237,13 @@ cppline			{space}*#([^i][A-Za-z]*|{if}|{ifdef}|{if=
ndef}|{import})((\/\*[^*/]*\*+
 						  return S_ANYTHING;
 					  }
 					}
-<C,xskip>{exec_sql}{elif}{space}*	{	/* pop stack */
-						if ( preproc_tos =3D=3D 0 ) {
+<C,xskip>{exec_sql}{elif}{space}*	{
+						if (preproc_tos =3D=3D 0)
 							mmfatal(PARSE_ERROR, "missing matching \"EXEC SQL IFDEF\" / \"EXEC=
 SQL IFNDEF\"");
-						}
-						else if ( stacked_if_value[preproc_tos].else_branch )
+						if (stacked_if_value[preproc_tos].else_branch)
 							mmfatal(PARSE_ERROR, "missing \"EXEC SQL ENDIF;\"");
-						else
-							preproc_tos--;
-
-						ifcond =3D true; BEGIN(xcond);
+						ifcond =3D true;
+						BEGIN(xcond);
 					}
 <C,xskip>{informix_special}{elif}{space}* {
 					/* are we simulating Informix? */
@@ -1210,11 +1251,8 @@ cppline			{space}*#([^i][A-Za-z]*|{if}|{ifdef}|{ifn=
def}|{import})((\/\*[^*/]*\*+
 					{
 						if (preproc_tos =3D=3D 0)
 							mmfatal(PARSE_ERROR, "missing matching \"EXEC SQL IFDEF\" / \"EXEC=
 SQL IFNDEF\"");
-						else if (stacked_if_value[preproc_tos].else_branch)
+						if (stacked_if_value[preproc_tos].else_branch)
 							mmfatal(PARSE_ERROR, "missing \"EXEC SQL ENDIF;\"");
-						else
-							preproc_tos--;
-
 						ifcond =3D true;
 						BEGIN(xcond);
 					}
@@ -1226,16 +1264,19 @@ cppline			{space}*#([^i][A-Za-z]*|{if}|{ifdef}|{if=
ndef}|{import})((\/\*[^*/]*\*+
 				}
 =

 <C,xskip>{exec_sql}{else}{space}*";" {	/* only exec sql endif pops the st=
ack, so take care of duplicated 'else' */
-					if (stacked_if_value[preproc_tos].else_branch)
+					if ( preproc_tos =3D=3D 0 )
+						mmfatal(PARSE_ERROR, "missing matching \"EXEC SQL IFDEF\" / \"EXEC =
SQL IFNDEF\"");
+					else if (stacked_if_value[preproc_tos].else_branch)
 						mmfatal(PARSE_ERROR, "more than one EXEC SQL ELSE");
 					else
 					{
 						stacked_if_value[preproc_tos].else_branch =3D true;
-						stacked_if_value[preproc_tos].condition =3D
-							(stacked_if_value[preproc_tos-1].condition &&
-							 !stacked_if_value[preproc_tos].condition);
+						stacked_if_value[preproc_tos].active =3D
+							(stacked_if_value[preproc_tos-1].active &&
+							 !stacked_if_value[preproc_tos].saw_active);
+						stacked_if_value[preproc_tos].saw_active =3D true;
 =

-						if (stacked_if_value[preproc_tos].condition)
+						if (stacked_if_value[preproc_tos].active)
 							BEGIN(C);
 						else
 							BEGIN(xskip);
@@ -1245,16 +1286,19 @@ cppline			{space}*#([^i][A-Za-z]*|{if}|{ifdef}|{if=
ndef}|{import})((\/\*[^*/]*\*+
 					/* are we simulating Informix? */
 					if (INFORMIX_MODE)
 					{
-						if (stacked_if_value[preproc_tos].else_branch)
+						if ( preproc_tos =3D=3D 0 )
+							mmfatal(PARSE_ERROR, "missing matching \"EXEC SQL IFDEF\" / \"EXEC=
 SQL IFNDEF\"");
+						else if (stacked_if_value[preproc_tos].else_branch)
 							mmfatal(PARSE_ERROR, "more than one EXEC SQL ELSE");
 						else
 						{
 							stacked_if_value[preproc_tos].else_branch =3D true;
-							stacked_if_value[preproc_tos].condition =3D
-							(stacked_if_value[preproc_tos-1].condition &&
-							 !stacked_if_value[preproc_tos].condition);
+							stacked_if_value[preproc_tos].active =3D
+								(stacked_if_value[preproc_tos-1].active &&
+								 !stacked_if_value[preproc_tos].saw_active);
+							stacked_if_value[preproc_tos].saw_active =3D true;
 =

-							if (stacked_if_value[preproc_tos].condition)
+							if (stacked_if_value[preproc_tos].active)
 								BEGIN(C);
 							else
 								BEGIN(xskip);
@@ -1272,7 +1316,7 @@ cppline			{space}*#([^i][A-Za-z]*|{if}|{ifdef}|{ifnd=
ef}|{import})((\/\*[^*/]*\*+
 					else
 						preproc_tos--;
 =

-					if (stacked_if_value[preproc_tos].condition)
+					if (stacked_if_value[preproc_tos].active)
 					   BEGIN(C);
 					else
 					   BEGIN(xskip);
@@ -1286,7 +1330,7 @@ cppline			{space}*#([^i][A-Za-z]*|{if}|{ifdef}|{ifnd=
ef}|{import})((\/\*[^*/]*\*+
 						else
 							preproc_tos--;
 =

-						if (stacked_if_value[preproc_tos].condition)
+						if (stacked_if_value[preproc_tos].active)
 							BEGIN(C);
 						else
 							BEGIN(xskip);
@@ -1301,12 +1345,10 @@ cppline			{space}*#([^i][A-Za-z]*|{if}|{ifdef}|{if=
ndef}|{import})((\/\*[^*/]*\*+
 <xskip>{other}		{ /* ignore */ }
 =

 <xcond>{identifier}{space}*";" {
-					if (preproc_tos >=3D MAX_NESTED_IF-1)
-						mmfatal(PARSE_ERROR, "too many nested EXEC SQL IFDEF conditions");
-					else
 					{
 						struct _defines *defptr;
 						unsigned int i;
+						bool this_active;
 =

 						/*
 						 *	Skip the ";" and trailing whitespace. Note that yytext
@@ -1324,13 +1366,15 @@ cppline			{space}*#([^i][A-Za-z]*|{if}|{ifdef}|{if=
ndef}|{import})((\/\*[^*/]*\*+
 							 defptr =3D defptr->next)
 							/* skip */ ;
 =

-						preproc_tos++;
-						stacked_if_value[preproc_tos].else_branch =3D false;
-						stacked_if_value[preproc_tos].condition =3D
-						(defptr ? ifcond : !ifcond) && stacked_if_value[preproc_tos-1].cond=
ition;
+						this_active =3D (defptr ? ifcond : !ifcond);
+						stacked_if_value[preproc_tos].active =3D
+							(stacked_if_value[preproc_tos-1].active &&
+							 !stacked_if_value[preproc_tos].saw_active &&
+							 this_active);
+						stacked_if_value[preproc_tos].saw_active |=3D this_active;
 					}
 =

-					if (stacked_if_value[preproc_tos].condition)
+					if (stacked_if_value[preproc_tos].active)
 						BEGIN(C);
 					else
 						BEGIN(xskip);
@@ -1442,10 +1486,12 @@ lex_init(void)
 	parenths_open =3D 0;
 	current_function =3D NULL;
 =

-	preproc_tos =3D 0;
 	yylineno =3D 1;
-	ifcond =3D true;
-	stacked_if_value[preproc_tos].condition =3D ifcond;
+
+	/* initialize state for if/else/endif */
+	preproc_tos =3D 0;
+	stacked_if_value[preproc_tos].active =3D true;
+	stacked_if_value[preproc_tos].saw_active =3D true;
 	stacked_if_value[preproc_tos].else_branch =3D false;
 =

 	/* initialize literal buffer to a reasonable but expansible size */
diff --git a/src/interfaces/ecpg/test/expected/preproc-define.c b/src/inte=
rfaces/ecpg/test/expected/preproc-define.c
index bde15b74a0..0256609b1f 100644
--- a/src/interfaces/ecpg/test/expected/preproc-define.c
+++ b/src/interfaces/ecpg/test/expected/preproc-define.c
@@ -40,73 +40,90 @@ main(void)
 {
 /* exec sql begin declare section */
 =

+
 	   typedef char  string [ 8 ];
 =

-#line 21 "define.pgc"
+#line 22 "define.pgc"
 =

 	 =

 	   =

-	  	 =

 =

-#line 22 "define.pgc"
+	   =

+
+	    =

+
+
+
+	   =

+
+  =

+	   =

+  =

+	  	   =

+
+	   =

+
+
+
+#line 23 "define.pgc"
  intarray amount ;
  =

-#line 23 "define.pgc"
+#line 24 "define.pgc"
  char name [ 6 ] [ 8 ] ;
  =

-#line 24 "define.pgc"
+#line 37 "define.pgc"
  char letter [ 6 ] [ 1 ] ;
  =

 #if 0
  =

-#line 26 "define.pgc"
+#line 39 "define.pgc"
  int not_used ;
  =

 #endif
 /* exec sql end declare section */
-#line 29 "define.pgc"
+#line 46 "define.pgc"
 =

 	int i,j;
 =

 	ECPGdebug(1, stderr);
 =

 	{ ECPGconnect(__LINE__, 0, "ecpg1_regression" , NULL, NULL , NULL, 0); =

-#line 34 "define.pgc"
+#line 51 "define.pgc"
 =

 if (sqlca.sqlcode < 0) sqlprint();}
-#line 34 "define.pgc"
+#line 51 "define.pgc"
 =

 =

 	{ ECPGdo(__LINE__, 0, 1, NULL, 0, ECPGst_normal, "create table test ( na=
me char ( 8 ) , amount int , letter char ( 1 ) )", ECPGt_EOIT, ECPGt_EORT)=
;
-#line 36 "define.pgc"
+#line 53 "define.pgc"
 =

 if (sqlca.sqlcode < 0) sqlprint();}
-#line 36 "define.pgc"
+#line 53 "define.pgc"
 =

 	{ ECPGtrans(__LINE__, NULL, "commit");
-#line 37 "define.pgc"
+#line 54 "define.pgc"
 =

 if (sqlca.sqlcode < 0) sqlprint();}
-#line 37 "define.pgc"
+#line 54 "define.pgc"
 =

 =

 	{ ECPGdo(__LINE__, 0, 1, NULL, 0, ECPGst_normal, "insert into Test ( nam=
e , amount , letter ) values ( 'false' , 1 , 'f' )", ECPGt_EOIT, ECPGt_EOR=
T);
-#line 39 "define.pgc"
+#line 56 "define.pgc"
 =

 if (sqlca.sqlcode < 0) sqlprint();}
-#line 39 "define.pgc"
+#line 56 "define.pgc"
 =

 	{ ECPGdo(__LINE__, 0, 1, NULL, 0, ECPGst_normal, "insert into test ( nam=
e , amount , letter ) values ( 'true' , 2 , 't' )", ECPGt_EOIT, ECPGt_EORT=
);
-#line 40 "define.pgc"
+#line 57 "define.pgc"
 =

 if (sqlca.sqlcode < 0) sqlprint();}
-#line 40 "define.pgc"
+#line 57 "define.pgc"
 =

 	{ ECPGtrans(__LINE__, NULL, "commit");
-#line 41 "define.pgc"
+#line 58 "define.pgc"
 =

 if (sqlca.sqlcode < 0) sqlprint();}
-#line 41 "define.pgc"
+#line 58 "define.pgc"
 =

 =

 	{ ECPGdo(__LINE__, 0, 1, NULL, 0, ECPGst_normal, "select * from test", E=
CPGt_EOIT, =

@@ -116,10 +133,10 @@ if (sqlca.sqlcode < 0) sqlprint();}
 	ECPGt_NO_INDICATOR, NULL , 0L, 0L, 0L, =

 	ECPGt_char,(letter),(long)1,(long)6,(1)*sizeof(char), =

 	ECPGt_NO_INDICATOR, NULL , 0L, 0L, 0L, ECPGt_EORT);
-#line 43 "define.pgc"
+#line 60 "define.pgc"
 =

 if (sqlca.sqlcode < 0) sqlprint();}
-#line 43 "define.pgc"
+#line 60 "define.pgc"
 =

 =

 	for (i=3D0, j=3Dsqlca.sqlerrd[2]; i<j; i++)
@@ -129,16 +146,16 @@ if (sqlca.sqlcode < 0) sqlprint();}
 		   =

 		   =

 		=

-#line 48 "define.pgc"
+#line 65 "define.pgc"
  string n ;
  =

-#line 49 "define.pgc"
+#line 66 "define.pgc"
  char l =3D letter [ i ] [ 0 ] ;
  =

-#line 50 "define.pgc"
+#line 67 "define.pgc"
  int a =3D amount [ i ] ;
 /* exec sql end declare section */
-#line 51 "define.pgc"
+#line 68 "define.pgc"
 =

 =

 		strncpy(n, name[i],  8);
@@ -146,22 +163,22 @@ if (sqlca.sqlcode < 0) sqlprint();}
 	}
 =

 	{ ECPGdo(__LINE__, 0, 1, NULL, 0, ECPGst_normal, "drop table test", ECPG=
t_EOIT, ECPGt_EORT);
-#line 57 "define.pgc"
+#line 74 "define.pgc"
 =

 if (sqlca.sqlcode < 0) sqlprint();}
-#line 57 "define.pgc"
+#line 74 "define.pgc"
 =

 	{ ECPGtrans(__LINE__, NULL, "commit");
-#line 58 "define.pgc"
+#line 75 "define.pgc"
 =

 if (sqlca.sqlcode < 0) sqlprint();}
-#line 58 "define.pgc"
+#line 75 "define.pgc"
 =

 	{ ECPGdisconnect(__LINE__, "CURRENT");
-#line 59 "define.pgc"
+#line 76 "define.pgc"
 =

 if (sqlca.sqlcode < 0) sqlprint();}
-#line 59 "define.pgc"
+#line 76 "define.pgc"
 =

 =

 	return 0;
diff --git a/src/interfaces/ecpg/test/expected/preproc-define.stderr b/src=
/interfaces/ecpg/test/expected/preproc-define.stderr
index 722cdc7572..869dc46b0d 100644
--- a/src/interfaces/ecpg/test/expected/preproc-define.stderr
+++ b/src/interfaces/ecpg/test/expected/preproc-define.stderr
@@ -2,53 +2,53 @@
 [NO_PID]: sqlca: code: 0, state: 00000
 [NO_PID]: ECPGconnect: opening database ecpg1_regression on <DEFAULT> por=
t <DEFAULT>  =

 [NO_PID]: sqlca: code: 0, state: 00000
-[NO_PID]: ecpg_execute on line 36: query: create table test ( name char (=
 8 ) , amount int , letter char ( 1 ) ); with 0 parameter(s) on connection=
 ecpg1_regression
+[NO_PID]: ecpg_execute on line 53: query: create table test ( name char (=
 8 ) , amount int , letter char ( 1 ) ); with 0 parameter(s) on connection=
 ecpg1_regression
 [NO_PID]: sqlca: code: 0, state: 00000
-[NO_PID]: ecpg_execute on line 36: using PQexec
+[NO_PID]: ecpg_execute on line 53: using PQexec
 [NO_PID]: sqlca: code: 0, state: 00000
-[NO_PID]: ecpg_process_output on line 36: OK: CREATE TABLE
+[NO_PID]: ecpg_process_output on line 53: OK: CREATE TABLE
 [NO_PID]: sqlca: code: 0, state: 00000
-[NO_PID]: ECPGtrans on line 37: action "commit"; connection "ecpg1_regres=
sion"
+[NO_PID]: ECPGtrans on line 54: action "commit"; connection "ecpg1_regres=
sion"
 [NO_PID]: sqlca: code: 0, state: 00000
-[NO_PID]: ecpg_execute on line 39: query: insert into Test ( name , amoun=
t , letter ) values ( 'false' , 1 , 'f' ); with 0 parameter(s) on connecti=
on ecpg1_regression
+[NO_PID]: ecpg_execute on line 56: query: insert into Test ( name , amoun=
t , letter ) values ( 'false' , 1 , 'f' ); with 0 parameter(s) on connecti=
on ecpg1_regression
 [NO_PID]: sqlca: code: 0, state: 00000
-[NO_PID]: ecpg_execute on line 39: using PQexec
+[NO_PID]: ecpg_execute on line 56: using PQexec
 [NO_PID]: sqlca: code: 0, state: 00000
-[NO_PID]: ecpg_process_output on line 39: OK: INSERT 0 1
+[NO_PID]: ecpg_process_output on line 56: OK: INSERT 0 1
 [NO_PID]: sqlca: code: 0, state: 00000
-[NO_PID]: ecpg_execute on line 40: query: insert into test ( name , amoun=
t , letter ) values ( 'true' , 2 , 't' ); with 0 parameter(s) on connectio=
n ecpg1_regression
+[NO_PID]: ecpg_execute on line 57: query: insert into test ( name , amoun=
t , letter ) values ( 'true' , 2 , 't' ); with 0 parameter(s) on connectio=
n ecpg1_regression
 [NO_PID]: sqlca: code: 0, state: 00000
-[NO_PID]: ecpg_execute on line 40: using PQexec
+[NO_PID]: ecpg_execute on line 57: using PQexec
 [NO_PID]: sqlca: code: 0, state: 00000
-[NO_PID]: ecpg_process_output on line 40: OK: INSERT 0 1
+[NO_PID]: ecpg_process_output on line 57: OK: INSERT 0 1
 [NO_PID]: sqlca: code: 0, state: 00000
-[NO_PID]: ECPGtrans on line 41: action "commit"; connection "ecpg1_regres=
sion"
+[NO_PID]: ECPGtrans on line 58: action "commit"; connection "ecpg1_regres=
sion"
 [NO_PID]: sqlca: code: 0, state: 00000
-[NO_PID]: ecpg_execute on line 43: query: select * from test; with 0 para=
meter(s) on connection ecpg1_regression
+[NO_PID]: ecpg_execute on line 60: query: select * from test; with 0 para=
meter(s) on connection ecpg1_regression
 [NO_PID]: sqlca: code: 0, state: 00000
-[NO_PID]: ecpg_execute on line 43: using PQexec
+[NO_PID]: ecpg_execute on line 60: using PQexec
 [NO_PID]: sqlca: code: 0, state: 00000
-[NO_PID]: ecpg_process_output on line 43: correctly got 2 tuples with 3 f=
ields
+[NO_PID]: ecpg_process_output on line 60: correctly got 2 tuples with 3 f=
ields
 [NO_PID]: sqlca: code: 0, state: 00000
-[NO_PID]: ecpg_get_data on line 43: RESULT: false    offset: -1; array: n=
o
+[NO_PID]: ecpg_get_data on line 60: RESULT: false    offset: -1; array: n=
o
 [NO_PID]: sqlca: code: 0, state: 00000
-[NO_PID]: ecpg_get_data on line 43: RESULT: true     offset: -1; array: n=
o
+[NO_PID]: ecpg_get_data on line 60: RESULT: true     offset: -1; array: n=
o
 [NO_PID]: sqlca: code: 0, state: 00000
-[NO_PID]: ecpg_get_data on line 43: RESULT: 1 offset: -1; array: no
+[NO_PID]: ecpg_get_data on line 60: RESULT: 1 offset: -1; array: no
 [NO_PID]: sqlca: code: 0, state: 00000
-[NO_PID]: ecpg_get_data on line 43: RESULT: 2 offset: -1; array: no
+[NO_PID]: ecpg_get_data on line 60: RESULT: 2 offset: -1; array: no
 [NO_PID]: sqlca: code: 0, state: 00000
-[NO_PID]: ecpg_get_data on line 43: RESULT: f offset: -1; array: no
+[NO_PID]: ecpg_get_data on line 60: RESULT: f offset: -1; array: no
 [NO_PID]: sqlca: code: 0, state: 00000
-[NO_PID]: ecpg_get_data on line 43: RESULT: t offset: -1; array: no
+[NO_PID]: ecpg_get_data on line 60: RESULT: t offset: -1; array: no
 [NO_PID]: sqlca: code: 0, state: 00000
-[NO_PID]: ecpg_execute on line 57: query: drop table test; with 0 paramet=
er(s) on connection ecpg1_regression
+[NO_PID]: ecpg_execute on line 74: query: drop table test; with 0 paramet=
er(s) on connection ecpg1_regression
 [NO_PID]: sqlca: code: 0, state: 00000
-[NO_PID]: ecpg_execute on line 57: using PQexec
+[NO_PID]: ecpg_execute on line 74: using PQexec
 [NO_PID]: sqlca: code: 0, state: 00000
-[NO_PID]: ecpg_process_output on line 57: OK: DROP TABLE
+[NO_PID]: ecpg_process_output on line 74: OK: DROP TABLE
 [NO_PID]: sqlca: code: 0, state: 00000
-[NO_PID]: ECPGtrans on line 58: action "commit"; connection "ecpg1_regres=
sion"
+[NO_PID]: ECPGtrans on line 75: action "commit"; connection "ecpg1_regres=
sion"
 [NO_PID]: sqlca: code: 0, state: 00000
 [NO_PID]: ecpg_finish: connection ecpg1_regression closed
 [NO_PID]: sqlca: code: 0, state: 00000
diff --git a/src/interfaces/ecpg/test/preproc/define.pgc b/src/interfaces/=
ecpg/test/preproc/define.pgc
index 0d07ebfe63..d360da7ece 100644
--- a/src/interfaces/ecpg/test/preproc/define.pgc
+++ b/src/interfaces/ecpg/test/preproc/define.pgc
@@ -17,15 +17,32 @@ int
 main(void)
 {
 exec sql begin declare section;
+
 exec sql ifdef NAMELEN;
 	typedef char string[NAMELEN];
 	intarray amount;
 	char name[AMOUNT][NAMELEN];
+exec sql elif AMOUNT;
+	should not get here;
+exec sql else;
+	should not get here either;
+exec sql endif;
+
+exec sql ifndef NAMELEN;
+	should not get here;
+exec sql elif AMOUNT;
+  exec sql ifdef NOSUCHNAME;
+	should not get here;
+  exec sql else;
 	char letter[AMOUNT][1];
 #if 0
 	int not_used;
 #endif
+  exec sql endif;
+exec sql elif AMOUNT;
+	should not get here;
 exec sql endif;
+
 exec sql end declare section;
 	int i,j;
 =


------- =_aaaaaaaaaa0--