Add sourcefile/sourceline data to EXEC_BACKEND GUC transmission files.

This oversight meant that on Windows, the pg_settings view would not
display source file or line number information for values coming from
postgresql.conf, unless the backend had received a SIGHUP since starting.

In passing, also make the error detection in read_nondefault_variables a
tad more thorough, and fix it to not lose precision on float GUCs (these
changes are already in HEAD as of my previous commit).

diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 6507ad62bf2cbae6b65e74f902e113704004078a..5cc90fbe51f73affdf7ecd63b1ffe7ae4515b2c8 100644 (file)
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -7337,6 +7337,8 @@ _ShowOption(struct config_generic * record, bool use_units)
  *
  *             variable name, string, null terminated
  *             variable value, string, null terminated
+ *             variable sourcefile, string, null terminated (empty if none)
+ *             variable sourceline, integer
  *             variable source, integer
  */
 static void
@@ -7373,8 +7375,7 @@ write_one_nondefault_variable(FILE *fp, struct config_generic * gconf)
                        {
                                struct config_real *conf = (struct config_real *) gconf;
 
-                               /* Could lose precision here? */
-                               fprintf(fp, "%f", *conf->variable);
+                               fprintf(fp, "%.17g", *conf->variable);
                        }
                        break;
 
@@ -7398,7 +7399,12 @@ write_one_nondefault_variable(FILE *fp, struct config_generic * gconf)
 
        fputc(0, fp);
 
-       fwrite(&gconf->source, sizeof(gconf->source), 1, fp);
+       if (gconf->sourcefile)
+               fprintf(fp, "%s", gconf->sourcefile);
+       fputc(0, fp);
+
+       fwrite(&gconf->sourceline, 1, sizeof(gconf->sourceline), fp);
+       fwrite(&gconf->source, 1, sizeof(gconf->source), fp);
 }
 
 void
@@ -7501,8 +7507,10 @@ read_nondefault_variables(void)
 {
        FILE       *fp;
        char       *varname,
-                          *varvalue;
-       int                     varsource;
+                          *varvalue,
+                          *varsourcefile;
+       int                     varsourceline;
+       GucSource       varsource;
 
        /*
         * Open file
@@ -7527,16 +7535,26 @@ read_nondefault_variables(void)
                        break;
 
                if ((record = find_option(varname, true, FATAL)) == NULL)
-                       elog(FATAL, "failed to locate variable %s in exec config params file", varname);
+                       elog(FATAL, "failed to locate variable \"%s\" in exec config params file", varname);
+
                if ((varvalue = read_string_with_null(fp)) == NULL)
                        elog(FATAL, "invalid format of exec config params file");
-               if (fread(&varsource, sizeof(varsource), 1, fp) == 0)
+               if ((varsourcefile = read_string_with_null(fp)) == NULL)
                        elog(FATAL, "invalid format of exec config params file");
+               if (fread(&varsourceline, 1, sizeof(varsourceline), fp) != sizeof(varsourceline))
+                       elog(FATAL, "invalid format of exec config params file");
+               if (fread(&varsource, 1, sizeof(varsource), fp) != sizeof(varsource))
+                       elog(FATAL, "invalid format of exec config params file");
+
+               (void) set_config_option(varname, varvalue,
+                                                                record->context, varsource,
+                                                                GUC_ACTION_SET, true);
+               if (varsourcefile[0])
+                       set_config_sourcefile(varname, varsourcefile, varsourceline);
 
-               (void) set_config_option(varname, varvalue, record->context,
-                                                                varsource, GUC_ACTION_SET, true);
                free(varname);
                free(varvalue);
+               free(varsourcefile);
        }
 
        FreeFile(fp);