Re: ecpg: issue related to preprocessor directives - Mailing list pgsql-interfaces

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

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 = MYNUMBER;
   </sect2>

   <sect2 id="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 conditionally:

@@ -5705,7 +5705,7 @@ EXEC SQL UPDATE Tbl SET col = MYNUMBER;
      <listitem>
      <para>
       Checks a <replaceable>name</replaceable> and processes subsequent lines 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 = MYNUMBER;
      <listitem>
      <para>
       Checks a <replaceable>name</replaceable> and processes subsequent lines if
-      <replaceable>name</replaceable> has <emphasis>not</emphasis> been created with
+      <replaceable>name</replaceable> has <emphasis>not</emphasis> been defined 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>;</literal></term>
      <listitem>
      <para>
-      Starts processing an alternative section to a section introduced by
-      either <literal>EXEC SQL ifdef <replaceable>name</replaceable></literal> or
-      <literal>EXEC SQL ifndef <replaceable>name</replaceable></literal>.
+      Begins an alternative section after an
+      <literal>EXEC SQL ifdef <replaceable>name</replaceable></literal> or
+      <literal>EXEC SQL ifndef <replaceable>name</replaceable></literal>
+      directive.  Any number of <literal>elif</literal> sections can appear.
+      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>;</literal></term>
+     <term><literal>EXEC SQL else;</literal></term>
      <listitem>
      <para>
-      Checks <replaceable>name</replaceable> and starts an alternative section 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> or
+      <literal>EXEC SQL ifndef <replaceable>name</replaceable></literal>
+      directive.  Subsequent lines will be processed if no previous section
+      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 = 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 = 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/preproc/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 current
+ * 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 expanded).
+ * 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 another
+ * '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}|{ifndef}|{import})((\/\*[^*/]*\*+
                           return S_ANYTHING;
                       }
                     }
-<C,xskip>{exec_sql}{ifdef}{space}*    { ifcond = true; BEGIN(xcond); }
+<C,xskip>{exec_sql}{ifdef}{space}* {
+                      if (preproc_tos >= MAX_NESTED_IF-1)
+                          mmfatal(PARSE_ERROR, "too many nested EXEC SQL IFDEF conditions");
+                      preproc_tos++;
+                      stacked_if_value[preproc_tos].active = false;
+                      stacked_if_value[preproc_tos].saw_active = false;
+                      stacked_if_value[preproc_tos].else_branch = false;
+                      ifcond = true;
+                      BEGIN(xcond);
+                    }
 <C,xskip>{informix_special}{ifdef}{space}* {
                       /* are we simulating Informix? */
                       if (INFORMIX_MODE)
                       {
+                          if (preproc_tos >= MAX_NESTED_IF-1)
+                              mmfatal(PARSE_ERROR, "too many nested EXEC SQL IFDEF conditions");
+                          preproc_tos++;
+                          stacked_if_value[preproc_tos].active = false;
+                          stacked_if_value[preproc_tos].saw_active = false;
+                          stacked_if_value[preproc_tos].else_branch = false;
                           ifcond = true;
                           BEGIN(xcond);
                       }
@@ -1179,11 +1208,26 @@ cppline            {space}*#([^i][A-Za-z]*|{if}|{ifdef}|{ifndef}|{import})((\/\*[^*/]*\*+
                           return S_ANYTHING;
                       }
                     }
-<C,xskip>{exec_sql}{ifndef}{space}* { ifcond = false; BEGIN(xcond); }
+<C,xskip>{exec_sql}{ifndef}{space}* {
+                      if (preproc_tos >= MAX_NESTED_IF-1)
+                          mmfatal(PARSE_ERROR, "too many nested EXEC SQL IFDEF conditions");
+                      preproc_tos++;
+                      stacked_if_value[preproc_tos].active = false;
+                      stacked_if_value[preproc_tos].saw_active = false;
+                      stacked_if_value[preproc_tos].else_branch = false;
+                      ifcond = false;
+                      BEGIN(xcond);
+                    }
 <C,xskip>{informix_special}{ifndef}{space}* {
                       /* are we simulating Informix? */
                       if (INFORMIX_MODE)
                       {
+                          if (preproc_tos >= MAX_NESTED_IF-1)
+                              mmfatal(PARSE_ERROR, "too many nested EXEC SQL IFDEF conditions");
+                          preproc_tos++;
+                          stacked_if_value[preproc_tos].active = false;
+                          stacked_if_value[preproc_tos].saw_active = false;
+                          stacked_if_value[preproc_tos].else_branch = false;
                           ifcond = false;
                           BEGIN(xcond);
                       }
@@ -1193,16 +1237,13 @@ cppline            {space}*#([^i][A-Za-z]*|{if}|{ifdef}|{ifndef}|{import})((\/\*[^*/]*\*+
                           return S_ANYTHING;
                       }
                     }
-<C,xskip>{exec_sql}{elif}{space}*    {    /* pop stack */
-                        if ( preproc_tos == 0 ) {
+<C,xskip>{exec_sql}{elif}{space}*    {
+                        if (preproc_tos == 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 = true; BEGIN(xcond);
+                        ifcond = 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}|{ifndef}|{import})((\/\*[^*/]*\*+
                     {
                         if (preproc_tos == 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 = true;
                         BEGIN(xcond);
                     }
@@ -1226,16 +1264,19 @@ cppline            {space}*#([^i][A-Za-z]*|{if}|{ifdef}|{ifndef}|{import})((\/\*[^*/]*\*+
                 }

 <C,xskip>{exec_sql}{else}{space}*";" {    /* only exec sql endif pops the stack, so take care of duplicated 'else' */
-                    if (stacked_if_value[preproc_tos].else_branch)
+                    if ( preproc_tos == 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 = true;
-                        stacked_if_value[preproc_tos].condition =
-                            (stacked_if_value[preproc_tos-1].condition &&
-                             !stacked_if_value[preproc_tos].condition);
+                        stacked_if_value[preproc_tos].active =
+                            (stacked_if_value[preproc_tos-1].active &&
+                             !stacked_if_value[preproc_tos].saw_active);
+                        stacked_if_value[preproc_tos].saw_active = 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}|{ifndef}|{import})((\/\*[^*/]*\*+
                     /* are we simulating Informix? */
                     if (INFORMIX_MODE)
                     {
-                        if (stacked_if_value[preproc_tos].else_branch)
+                        if ( preproc_tos == 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 = true;
-                            stacked_if_value[preproc_tos].condition =
-                            (stacked_if_value[preproc_tos-1].condition &&
-                             !stacked_if_value[preproc_tos].condition);
+                            stacked_if_value[preproc_tos].active =
+                                (stacked_if_value[preproc_tos-1].active &&
+                                 !stacked_if_value[preproc_tos].saw_active);
+                            stacked_if_value[preproc_tos].saw_active = 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}|{ifndef}|{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}|{ifndef}|{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}|{ifndef}|{import})((\/\*[^*/]*\*+
 <xskip>{other}        { /* ignore */ }

 <xcond>{identifier}{space}*";" {
-                    if (preproc_tos >= 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}|{ifndef}|{import})((\/\*[^*/]*\*+
                              defptr = defptr->next)
                             /* skip */ ;

-                        preproc_tos++;
-                        stacked_if_value[preproc_tos].else_branch = false;
-                        stacked_if_value[preproc_tos].condition =
-                        (defptr ? ifcond : !ifcond) && stacked_if_value[preproc_tos-1].condition;
+                        this_active = (defptr ? ifcond : !ifcond);
+                        stacked_if_value[preproc_tos].active =
+                            (stacked_if_value[preproc_tos-1].active &&
+                             !stacked_if_value[preproc_tos].saw_active &&
+                             this_active);
+                        stacked_if_value[preproc_tos].saw_active |= 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 = 0;
     current_function = NULL;

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

     /* initialize literal buffer to a reasonable but expansible size */
diff --git a/src/interfaces/ecpg/test/expected/preproc-define.c b/src/interfaces/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 ( name 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 ( name , amount , letter ) values ( 'false' , 1
,'f' )", ECPGt_EOIT, ECPGt_EORT); 
-#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 ( name , 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", ECPGt_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=0, j=sqlca.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 = letter [ i ] [ 0 ] ;

-#line 50 "define.pgc"
+#line 67 "define.pgc"
  int a = 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", ECPGt_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> port <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
0parameter(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
0parameter(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_regression"
+[NO_PID]: ECPGtrans on line 54: action "commit"; connection "ecpg1_regression"
 [NO_PID]: sqlca: code: 0, state: 00000
-[NO_PID]: ecpg_execute on line 39: query: insert into Test ( name , amount , letter ) values ( 'false' , 1 , 'f' );
with0 parameter(s) on connection ecpg1_regression 
+[NO_PID]: ecpg_execute on line 56: query: insert into Test ( name , amount , letter ) values ( 'false' , 1 , 'f' );
with0 parameter(s) on connection 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 , amount , letter ) values ( 'true' , 2 , 't' );
with0 parameter(s) on connection ecpg1_regression 
+[NO_PID]: ecpg_execute on line 57: query: insert into test ( name , amount , letter ) values ( 'true' , 2 , 't' );
with0 parameter(s) on connection 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_regression"
+[NO_PID]: ECPGtrans on line 58: action "commit"; connection "ecpg1_regression"
 [NO_PID]: sqlca: code: 0, state: 00000
-[NO_PID]: ecpg_execute on line 43: query: select * from test; with 0 parameter(s) on connection ecpg1_regression
+[NO_PID]: ecpg_execute on line 60: query: select * from test; with 0 parameter(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 fields
+[NO_PID]: ecpg_process_output on line 60: correctly got 2 tuples with 3 fields
 [NO_PID]: sqlca: code: 0, state: 00000
-[NO_PID]: ecpg_get_data on line 43: RESULT: false    offset: -1; array: no
+[NO_PID]: ecpg_get_data on line 60: RESULT: false    offset: -1; array: no
 [NO_PID]: sqlca: code: 0, state: 00000
-[NO_PID]: ecpg_get_data on line 43: RESULT: true     offset: -1; array: no
+[NO_PID]: ecpg_get_data on line 60: RESULT: true     offset: -1; array: no
 [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 parameter(s) on connection ecpg1_regression
+[NO_PID]: ecpg_execute on line 74: query: drop table test; with 0 parameter(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_regression"
+[NO_PID]: ECPGtrans on line 75: action "commit"; connection "ecpg1_regression"
 [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;