From 167c708e6923556af991ca74e8b7a14aea9afc97 Mon Sep 17 00:00:00 2001
From: Holger Vogt <holger.vogt@uni-due.de>
Date: Fri, 27 Jan 2023 10:08:16 +0100
Subject: [PATCH] Add searchpath for *.osdi relative to ngspice executable

---
 src/include/ngspice/ngspice.h |  1 +
 src/misc/ivars.c              | 19 +++++++++++++-
 src/osdi/osdiregistry.c       | 48 ++++++++++++++++++++++++++++-------
 3 files changed, 58 insertions(+), 10 deletions(-)

diff --git a/src/include/ngspice/ngspice.h b/src/include/ngspice/ngspice.h
index 74535553e..0937f597d 100644
--- a/src/include/ngspice/ngspice.h
+++ b/src/include/ngspice/ngspice.h
@@ -279,6 +279,7 @@ extern char *Help_Path;
 extern char *Lib_Path;
 extern char *Inp_Path;
 extern char *Infile_Path;
+extern char *Spice_Exec_Path;
 
 #ifdef TCL_MODULE
 
diff --git a/src/misc/ivars.c b/src/misc/ivars.c
index 5c8afcaa9..5bbeea7e9 100644
--- a/src/misc/ivars.c
+++ b/src/misc/ivars.c
@@ -11,6 +11,7 @@ char *News_File;
 char *Help_Path;
 char *Lib_Path;
 char *Inp_Path;
+char *Spice_Exec_Path;
 
 
 static void
@@ -102,7 +103,22 @@ ivars(char *argv0)
     env_overr(&temp, "SPICE_ASCIIRAWFILE");
     if(temp)
        AsciiRawFile = atoi(temp);
-    
+
+    /* path of the ngspice executable */
+    Spice_Exec_Path = copy(argv0);
+    /* find the last occurence of "ngspice" in Spice_Exec_Path */
+    char* path_end = strstr(Spice_Exec_Path, "ngspice");
+    if (path_end) {
+        char* exec_only = strstr(path_end + 7, "ngspice");
+        while (exec_only) {
+            path_end = strstr(Spice_Exec_Path, "ngspice");
+            if (path_end)
+                exec_only = strstr(path_end + 7, "ngspice");
+        }
+        if (path_end)
+            *path_end = '\0';
+        fprintf(stdout, "ngspice path %s\n", Spice_Exec_Path);
+    }
 }
 
 void
@@ -113,4 +129,5 @@ destroy_ivars(void)
     tfree(Lib_Path);
     tfree(Spice_Path);
     tfree(Inp_Path);
+    tfree(Spice_Exec_Path);
 }
diff --git a/src/osdi/osdiregistry.c b/src/osdi/osdiregistry.c
index 164ed741e..6da846451 100644
--- a/src/osdi/osdiregistry.c
+++ b/src/osdi/osdiregistry.c
@@ -121,7 +121,8 @@ static char *resolve_input_path(const char *name) {
 
   /*
    * If called from a script inputdir != NULL so try relativ to that dir
-   * Otherwise try relativ to the current workdir
+   * Otherwise try relativ to the current workdir and relativ to the
+   * executables path
    */
 
   if (inputdir) {
@@ -152,18 +153,47 @@ static char *resolve_input_path(const char *name) {
       if (r)
           return r;
   }
+
+  if (Spice_Exec_Path && *Spice_Exec_Path) {
+      DS_CREATE(ds, 100);
+      int rc_ds = 0;
+      rc_ds |= ds_cat_str(&ds, Spice_Exec_Path);  /* copy the dir name */
+      const size_t n = ds_get_length(&ds); /* end of copied dir name */
+
+      /* Append a directory separator if not present already */
+      const char ch_last = n > 0 ? Spice_Exec_Path[n - 1] : '\0';
+      if (ch_last != DIR_TERM
+#ifdef _WIN32
+          && ch_last != DIR_TERM_LINUX
+#endif
+          ) {
+          rc_ds |= ds_cat_char(&ds, DIR_TERM);
+      }
+      rc_ds |= ds_cat_str(&ds, name); /* append the file name */
+
+      if (rc_ds != 0) {
+          (void)fprintf(cp_err, "Unable to build \"dir\" path name "
+              "in inp_pathresolve_at");
+          controlled_exit(EXIT_FAILURE);
+      }
+
+      char* const r = resolve_path(ds_get_buf(&ds));
+      ds_free(&ds);
+      if (r)
+          return r;
+  }
   /* no inputdir, or not found relative to inputdir:
-     search relative to current working directory */
+   search relative to current working directory */
   DS_CREATE(ds, 100);
   if (ds_cat_printf(&ds, ".%c%s", DIR_TERM, name) != 0) {
-    (void)fprintf(cp_err,
-                    "Unable to build \".\" path name in inp_pathresolve_at");
-    controlled_exit(EXIT_FAILURE);
+      (void)fprintf(cp_err,
+          "Unable to build \".\" path name in inp_pathresolve_at");
+      controlled_exit(EXIT_FAILURE);
   }
-  char *const r = resolve_path(ds_get_buf(&ds));
+  char* const r = resolve_path(ds_get_buf(&ds));
   ds_free(&ds);
-  if (r != (char *)NULL) {
-    return r;
+  if (r != (char*)NULL) {
+      return r;
   }
 
   return NULL;
@@ -194,7 +224,7 @@ static size_t calc_osdi_instance_data_off(const OsdiDescriptor *descr) {
 
 #define ERR_AND_RET                                                            \
   error = dlerror();                                                           \
-  printf("Error opening osdi lib \"%s\": %s\n", path, error);                  \
+  fprintf(stderr, "Error opening osdi lib \"%s\": %s\n", path, error);                  \
   FREE_DLERR_MSG(error);                                                       \
   return INVALID_OBJECT;