[Doxygen-develop] Patch: Preprocessing DOT input files

[Michael M. <Mic...@tt...>]

Hi there,

There was a post on the doxygen-users list a few days ago asking if it is
possible to do something like the following:

/** blah blah 
\dot
graph G {
  a -- b
#if defined(ENABLE_C)
  b -- c
  c -- a
#endif
}
\enddot

*/

Basically this allows showing or hiding of nodes based on the pre-processor
defines.  As far as I've been able to workout, this cannot be done without
invoking an external pre-processor as part of a build step or script.

This feature is something I very much want, as I have a large diagram with a
few small parts which are optional depending on compile switches.  DOT
itself seems to like the idea of pre-processing as it ignores any lines that
start with a # character, so is safe to ignore and '#line' output, were the
pre-processor to make any.

There follows a patch that adds an option "PREPROCESS_DOT_FILES" to allow
DOT input files to be preprocessed.  I would be very grateful to know if
this patch can be included in a future version or Doxygen, or whether it
needs any changes to be acceptable.  

The patch can be applied in the following way:

$ tar -xzf doxygen-1.4.3.src.tar.gz
$ cd doxygen-1.4.3
$ patch -p1 < patchfile

Here is the patch:

diff -Naurw doxygen-1.4.3.orig/addon/doxywizard/config.l
doxygen-1.4.3/addon/doxywizard/config.l
--- doxygen-1.4.3.orig/addon/doxywizard/config.l	2005-05-16
20:38:16.000000000 +0100
+++ doxygen-1.4.3/addon/doxywizard/config.l	2005-05-24
22:57:11.358347200 +0100
@@ -2491,6 +2491,16 @@
                     TRUE
                  );
   cb->addDependency("ENABLE_PREPROCESSING");
+  cb = addBool(
+                    "PREPROCESS_DOT_FILES",
+                    "If the PREPROCESS_DOT_FILES tag is set to YES then
doxygen's preprocessor \n"
+                    "will be called on all files that are about to be
passed to DOT.  This \n"
+                    "allows pre-processor protections to be added around
nodes such that build \n"
+                    "defines can add or hide graph nodes.  The default
option is NO such that \n"
+                    "compatibility with older versions of Doxygen is
maintained. \n",
+                    FALSE
+                 );
+  cb->addDependency("ENABLE_PREPROCESSING");
 
//--------------------------------------------------------------------------
---------------------
   addInfo(  "External","Configuration::additions related to external
references   ");
 
//--------------------------------------------------------------------------
---------------------
diff -Naurw doxygen-1.4.3.orig/src/config.l doxygen-1.4.3/src/config.l
--- doxygen-1.4.3.orig/src/config.l	2005-05-12 20:19:42.000000000 +0100
+++ doxygen-1.4.3/src/config.l	2005-05-24 22:56:52.050584000 +0100
@@ -2491,6 +2491,16 @@
                     TRUE
                  );
   cb->addDependency("ENABLE_PREPROCESSING");
+  cb = addBool(
+                    "PREPROCESS_DOT_FILES",
+                    "If the PREPROCESS_DOT_FILES tag is set to YES then
doxygen's preprocessor \n"
+                    "will be called on all files that are about to be
passed to DOT.  This \n"
+                    "allows pre-processor protections to be added around
nodes such that build \n"
+                    "defines can add or hide graph nodes.  The default
option is NO such that \n"
+                    "compatibility with older versions of Doxygen is
maintained. \n",
+                    FALSE
+                 );
+  cb->addDependency("ENABLE_PREPROCESSING");
 
//--------------------------------------------------------------------------
---------------------
   addInfo(  "External","Configuration::additions related to external
references   ");
 
//--------------------------------------------------------------------------
---------------------
diff -Naurw doxygen-1.4.3.orig/src/dot.cpp doxygen-1.4.3/src/dot.cpp
--- doxygen-1.4.3.orig/src/dot.cpp	2005-04-17 17:55:56.000000000 +0100
+++ doxygen-1.4.3/src/dot.cpp	2005-05-24 23:44:22.929947200 +0100
@@ -29,6 +29,8 @@
 #include "docparser.h"
 #include "debug.h"
 #include "pagedef.h"
+#include "pre.h"
+#include "bufstr.h"
 
 #include <qdir.h>
 #include <qfile.h>
@@ -2714,6 +2716,24 @@
 #endif
   absOutFile+=outFile;
 
+  // Preprocess the file if needed */
+  if(Config_getBool("PREPROCESS_DOT_FILES"))
+  {
+    BufStr ppBuf(512);
+
+    preprocessFile(inFile, ppBuf);
+
+    // Rewrite the buffer to the input file
+    QFile file(inFile);
+    if (!file.open(IO_WriteOnly))
+    {
+      err("Could not open file %s for writing\n",inFile);
+    }
+    file.writeBlock( ppBuf.data(), ppBuf.curPos() );
+    file.close();
+  }
+
+
   // chdir to the output dir, so dot can find the font file.
   QCString oldDir = convertToQCString(QDir::currentDirPath());
   // go to the html output directory (i.e. path)



Cheers,

Mike