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 d4ca2711d71a472b5d272d6d597124b9fd1bbfd4..260f9f6e42a7071e4b285929a51c6a20d652dcc2 100644 (file)
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -6961,6 +6961,8 @@ is_newvalue_equal(struct config_generic * record, const char *newvalue)
  *
  *     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
@@ -6997,8 +6999,7 @@ 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;
 
@@ -7022,7 +7023,12 @@ 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
@@ -7125,8 +7131,10 @@ read_nondefault_variables(void)
 {
    FILE       *fp;
    char       *varname,
-              *varvalue;
-   int         varsource;
+              *varvalue,
+              *varsourcefile;
+   int         varsourceline;
+   GucSource   varsource;
 
    /*
     * Open file
@@ -7151,16 +7159,26 @@ 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);