preprocessor: submodule update

doc/manual/source/the-model-file.rst

@@ -10313,7 +10313,7 @@ directives are:
     * ``@#includepath``, paths to search for files that are to be included,
     * ``@#include``, for file inclusion,
     * ``@#define``, for defining a macro processor variable,
-    * ``@#if, @#ifdef, @#ifndef, @#else, @#endif`` for conditional statements,
+    * ``@#if, @#ifdef, @#ifndef, @#elseif, @#else, @#endif`` for conditional statements,
     * ``@#for, @#endfor`` for constructing loops.
 
 The macro processor maintains its own list of variables (distinct from model
@@ -10629,20 +10629,29 @@ Macro directives
 .. macrodir:: @#if MACRO_EXPRESSION
               @#ifdef MACRO_VARIABLE
               @#ifndef MACRO_VARIABLE
+              @#elseif MACRO_EXPRESSION
               @#else
               @#endif
 
     |br| Conditional inclusion of some part of the ``.mod`` file. The lines
-    between ``@#if``, ``@#ifdef``, or ``@#ifndef`` and the next ``@#else`` or
-    ``@#endif`` is executed only if the condition evaluates to ``true``. The
-    ``@#else`` branch is optional and, if present, is only evaluated if the
-    condition evaluates to ``false``.
+    between ``@#if``, ``@#ifdef``, or ``@#ifndef`` and the next ``@#elseif``,
+    ``@#else`` or ``@#endif`` is executed only if the condition evaluates to
+    ``true``. Following the ``@#if`` body, you can zero or more ``@#elseif``
+    branches. An ``@#elseif`` condition is only evaluated if the preceding
+    ``@#if`` or ``@#elseif`` condition evaluated to ``false``. The ``@#else``
+    branch is optional and is only evaluated if all ``@#if`` and ``@#elseif``
+    statements evaluate to false.
 
     Note that when using ``@#ifdef``, the condition will evaluate to ``true``
     if the MACRO_VARIABLE has been previously defined, regardless of its
     value. Conversely, ``@#ifndef`` will evaluate to true if the MACRO_VARIABLE
     has not yet been defined.
 
+    Note that when using ``@#elseif`` you can check whether or not a variable
+    has been defined by using the ``defined`` operator. Hence, to enter the
+    body of an ``@#elseif`` branch if the variable ``X`` has not been defined,
+    you would write: ``@#elseif !defined(X)``.
+
     Note that if a real appears as the result of the MACRO_EXPRESSION, it
     will be interpreted as a boolean; a value of ``0`` is interpreted as ``false``,
     otherwise it is interpreted as ``true``. Further note that because of the

preprocessor @ 588896b5

-Subproject commit 75b000a0b5f36893e2d32d97abcfe17bc1a3f71b
+Subproject commit 588896b5091ddee650a9548088a2df164df5c22b

tests/example1_macro.mod

@@ -95,9 +95,9 @@ e = 0;
 u = 0;
 end;
 
-@#define DEFINED=0
+@#define DEFINEDvar=0
 
-@#ifndef DEFINED
+@#ifndef DEFINEDvar
 @#error "IFNDEF PROBLEM"
 @#else
 shocks;
@@ -107,12 +107,24 @@ var e, u = phi*0.009*0.009;
 end;
 @#endif
 
-@#ifdef DEFINED
+@#ifdef DEFINEDvar
 stoch_simul;
+@#elseif true
+@#error "ELSEIF PROBLEM"
 @#else
 @#error "IFDEF PROBLEM"
 @#endif
 
+@#if false
+@#error "IF ERROR"
+@#elseif false
+@#error "ELSEIF ERROR"
+@#elseif defined(DEFINEDvar)
+@#echo "Good"
+@#else
+@#error "ELSE ERROR"
+@#endif
+
 @#define a = 1
 @#define f(x) = x + a
 @#define a = 2