added tpx file tag string

The tpx file now contains a tag, such that feature branches can increase
the tpx version without the risk of later having tpx files with the same
version number but different format which can not be distinguised on read.

Change-Id: I07e804133bb1e55de6f25fd355bd79a7cb2fe141

diff --git a/src/gmxlib/tpxio.c b/src/gmxlib/tpxio.c
index 1d4ff24e49399e226c1a9cc5cf631a0c1ad135dc..b6c782c5875cc253db32c7dd19e1e129f4c8dd4e 100644 (file)
--- a/src/gmxlib/tpxio.c
+++ b/src/gmxlib/tpxio.c
@@ -63,8 +63,17 @@
 #include "vec.h"
 #include "mtop_util.h"
 
+#define TPX_TAG_RELEASE  "release"
+
+/* This is the tag string which is stored in the tpx file.
+ * Change this if you want to change the tpx format in a feature branch.
+ * This ensures that there will not be different tpx formats around which
+ * can not be distinguished.
+ */
+static const char *tpx_tag = TPX_TAG_RELEASE;
+
 /* This number should be increased whenever the file format changes! */
-static const int tpx_version = 76;
+static const int tpx_version = 77;
 
 /* This number should only be increased when you edit the TOPOLOGY section
  * of the tpx format. This way we can maintain forward compatibility too
@@ -305,7 +314,7 @@ static void do_inputrec(t_fileio *fio, t_inputrec *ir,gmx_bool bRead,
     if (file_version != tpx_version)
     {
         /* Give a warning about features that are not accessible */
-        fprintf(stderr,"Note: tpx file_version %d, software version %d\n",
+        fprintf(stderr,"Note: file tpx version %d, software tpx version %d\n",
                 file_version,tpx_version);
     }
 
@@ -2048,7 +2057,8 @@ static void do_tpxheader(t_fileio *fio,gmx_bool bRead,t_tpxheader *tpx,
                          gmx_bool TopOnlyOK, int *file_version, 
                          int *file_generation)
 {
-  char  buf[STRLEN];
+    char  buf[STRLEN];
+    char  file_tag[STRLEN];
   gmx_bool  bDouble;
   int   precision;
   int   fver,fgen;
@@ -2083,21 +2093,59 @@ static void do_tpxheader(t_fileio *fio,gmx_bool bRead,t_tpxheader *tpx,
     gmx_fio_setprecision(fio,bDouble);
     gmx_fio_do_int(fio,precision);
     fver = tpx_version;
+    sprintf(file_tag,"%s",tpx_tag);
     fgen = tpx_generation;
   }
   
-  /* Check versions! */
-  gmx_fio_do_int(fio,fver);
+    /* Check versions! */
+    gmx_fio_do_int(fio,fver);
   
-  if(fver>=26)
-    gmx_fio_do_int(fio,fgen);
-  else
-    fgen=0;
+    if (fver >= 77)
+    {
+        gmx_fio_do_string(fio,file_tag);
+    }
+    if (bRead)
+    {
+        if (fver < 77)
+        {
+            /* Versions before 77 don't have the tag, set it to release */
+            sprintf(file_tag,"%s",TPX_TAG_RELEASE);
+        }
+
+        if (strcmp(file_tag,tpx_tag) != 0)
+        {
+            fprintf(stderr,"Note: file tpx tag '%s', software tpx tag '%s'\n",
+                    file_tag,tpx_tag);
+
+            /* We only support reading tpx files with the same tag as the code
+             * or tpx files with the release tag and with lower version number.
+             */
+            if (!(strcmp(file_tag,TPX_TAG_RELEASE) == 0 && fver < tpx_version))
+            {
+                gmx_fatal(FARGS,"tpx tag/version mismatch: reading tpx file (%s) version %d, tag '%s' with program for tpx version %d, tag '%s'",
+                          gmx_fio_getname(fio),fver,file_tag,
+                          tpx_version,tpx_tag);
+            }
+        }
+    }
+
+    if (fver >= 26)
+    {
+        gmx_fio_do_int(fio,fgen);
+    }
+    else
+    {
+        fgen=0;
+    }
  
-  if(file_version!=NULL)
-    *file_version = fver;
-  if(file_generation!=NULL)
-    *file_generation = fgen;
+    if (file_version != NULL)
+    {
+        *file_version = fver;
+    }
+    if (file_generation != NULL)
+    {
+        *file_generation = fgen;
+    }
    
   
   if ((fver <= tpx_incompatible_version) ||