On 18/03/14 20:15, Pavel Stehule wrote:
2014-03-18 20:14 GMT+01:00 Simon Riggs <si...@2ndquadrant.com
<mailto:si...@2ndquadrant.com>>:
On 18 March 2014 19:04, Pavel Stehule <pavel.steh...@gmail.com
<mailto:pavel.steh...@gmail.com>> wrote:
> I don't think so only "shadow" is good name for some check. Maybe
> "shadow-variables-check"
"shadowed-variables" would be a better name.
+1
Attached V4 uses "shadowed-variables" instead of "shadow".
--
Petr Jelinek http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services
diff --git a/doc/src/sgml/plpgsql.sgml b/doc/src/sgml/plpgsql.sgml
index bddd458..d6709fd 100644
--- a/doc/src/sgml/plpgsql.sgml
+++ b/doc/src/sgml/plpgsql.sgml
@@ -4711,6 +4711,51 @@ a_output := a_output || $$ if v_$$ || referrer_keys.kind || $$ like '$$
</variablelist>
</sect2>
+ <sect2 id="plpgsql-extra-checks">
+ <title>Additional compile-time checks</title>
+
+ <para>
+ To aid the user in finding instances of simple but common problems before
+ they cause harm, <application>PL/PgSQL</> provides a number of additional
+ <replaceable>checks</>. When enabled, depending on the configuration, they
+ can be used to emit either a <literal>WARNING</> or an <literal>ERROR</>
+ during the compilation of a function.
+ </para>
+
+ <para>
+ These additional checks are enabled through the configuration variables
+ <varname>plpgsql.extra_warnings</> for warnings and
+ <varname>plpgsql.extra_errors</> for errors. Both can be set either to
+ a comma-separated list of checks, <literal>"none"</> or <literal>"all"</>.
+ The default is <literal>"none"</>. Currently the list of available checks
+ includes only one:
+ <variablelist>
+ <varlistentry>
+ <term><varname>shadowed-variables</varname></term>
+ <listitem>
+ <para>
+ Checks if a declaration shadows a previously defined variable. For
+ example (with <varname>plpgsql.extra_warnings</> set to
+ <varname>shadowed-variables</varname>):
+<programlisting>
+CREATE FUNCTION foo(f1 int) RETURNS int AS $$
+DECLARE
+f1 int;
+BEGIN
+RETURN f1;
+END
+$$ LANGUAGE plpgsql;
+WARNING: variable "f1" shadows a previously defined variable
+LINE 3: f1 int;
+ ^
+CREATE FUNCTION
+</programlisting>
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </para>
+ </sect2>
</sect1>
<!-- **** Porting from Oracle PL/SQL **** -->
diff --git a/src/pl/plpgsql/src/pl_comp.c b/src/pl/plpgsql/src/pl_comp.c
index 5afc2e5..8732efc 100644
--- a/src/pl/plpgsql/src/pl_comp.c
+++ b/src/pl/plpgsql/src/pl_comp.c
@@ -352,6 +352,9 @@ do_compile(FunctionCallInfo fcinfo,
function->out_param_varno = -1; /* set up for no OUT param */
function->resolve_option = plpgsql_variable_conflict;
function->print_strict_params = plpgsql_print_strict_params;
+ /* only promote extra warnings and errors at CREATE FUNCTION time */
+ function->extra_warnings = plpgsql_extra_warnings && forValidator;
+ function->extra_errors = plpgsql_extra_errors && forValidator;
if (is_dml_trigger)
function->fn_is_trigger = PLPGSQL_DML_TRIGGER;
@@ -849,6 +852,9 @@ plpgsql_compile_inline(char *proc_source)
function->out_param_varno = -1; /* set up for no OUT param */
function->resolve_option = plpgsql_variable_conflict;
function->print_strict_params = plpgsql_print_strict_params;
+ /* don't do extra validation for inline code as we don't want to add spam at runtime */
+ function->extra_warnings = false;
+ function->extra_errors = false;
plpgsql_ns_init();
plpgsql_ns_push(func_name);
diff --git a/src/pl/plpgsql/src/pl_gram.y b/src/pl/plpgsql/src/pl_gram.y
index c0cb585..98f7ddd 100644
--- a/src/pl/plpgsql/src/pl_gram.y
+++ b/src/pl/plpgsql/src/pl_gram.y
@@ -727,6 +727,20 @@ decl_varname : T_WORD
$1.ident, NULL, NULL,
NULL) != NULL)
yyerror("duplicate declaration");
+
+ if (plpgsql_curr_compile->extra_warnings || plpgsql_curr_compile->extra_errors)
+ {
+ PLpgSQL_nsitem *nsi;
+ nsi = plpgsql_ns_lookup(plpgsql_ns_top(), false,
+ $1.ident, NULL, NULL, NULL);
+ if (nsi != NULL)
+ ereport(plpgsql_curr_compile->extra_errors ? ERROR : WARNING,
+ (errcode(ERRCODE_DUPLICATE_ALIAS),
+ errmsg("variable \"%s\" shadows a previously defined variable",
+ $1.ident),
+ parser_errposition(@1)));
+ }
+
}
| unreserved_keyword
{
@@ -740,6 +754,20 @@ decl_varname : T_WORD
$1, NULL, NULL,
NULL) != NULL)
yyerror("duplicate declaration");
+
+ if (plpgsql_curr_compile->extra_warnings || plpgsql_curr_compile->extra_errors)
+ {
+ PLpgSQL_nsitem *nsi;
+ nsi = plpgsql_ns_lookup(plpgsql_ns_top(), false,
+ $1, NULL, NULL, NULL);
+ if (nsi != NULL)
+ ereport(plpgsql_curr_compile->extra_errors ? ERROR : WARNING,
+ (errcode(ERRCODE_DUPLICATE_ALIAS),
+ errmsg("variable \"%s\" shadows a previously defined variable",
+ $1),
+ parser_errposition(@1)));
+ }
+
}
;
diff --git a/src/pl/plpgsql/src/pl_handler.c b/src/pl/plpgsql/src/pl_handler.c
index f21393a..a8e9210 100644
--- a/src/pl/plpgsql/src/pl_handler.c
+++ b/src/pl/plpgsql/src/pl_handler.c
@@ -25,6 +25,11 @@
#include "utils/lsyscache.h"
#include "utils/syscache.h"
+
+static bool plpgsql_extra_checks_check_hook(char **newvalue, void **extra, GucSource source);
+static void plpgsql_extra_warnings_assign_hook(const char *newvalue, void *extra);
+static void plpgsql_extra_errors_assign_hook(const char *newvalue, void *extra);
+
PG_MODULE_MAGIC;
/* Custom GUC variable */
@@ -39,10 +44,45 @@ int plpgsql_variable_conflict = PLPGSQL_RESOLVE_ERROR;
bool plpgsql_print_strict_params = false;
+char *plpgsql_extra_warnings_list = NULL;
+char *plpgsql_extra_errors_list = NULL;
+bool plpgsql_extra_warnings;
+bool plpgsql_extra_errors;
+
/* Hook for plugins */
PLpgSQL_plugin **plugin_ptr = NULL;
+static bool
+plpgsql_extra_checks_check_hook(char **newvalue, void **extra, GucSource source)
+{
+ if (strcmp(*newvalue, "all") == 0 ||
+ strcmp(*newvalue, "shadowed-variables") == 0 ||
+ strcmp(*newvalue, "none") == 0)
+ return true;
+ return false;
+}
+
+static void
+plpgsql_extra_warnings_assign_hook(const char *newvalue, void *extra)
+{
+ if (strcmp(newvalue, "all") == 0 ||
+ strcmp(newvalue, "shadowed-variables") == 0)
+ plpgsql_extra_warnings = true;
+ else
+ plpgsql_extra_warnings = false;
+}
+
+static void
+plpgsql_extra_errors_assign_hook(const char *newvalue, void *extra)
+{
+ if (strcmp(newvalue, "all") == 0 ||
+ strcmp(newvalue, "shadowed-variables") == 0)
+ plpgsql_extra_errors = true;
+ else
+ plpgsql_extra_errors = false;
+}
+
/*
* _PG_init() - library load-time initialization
*
@@ -76,6 +116,26 @@ _PG_init(void)
PGC_USERSET, 0,
NULL, NULL, NULL);
+ DefineCustomStringVariable("plpgsql.extra_warnings",
+ gettext_noop("List of programming constructs which should produce a warning."),
+ NULL,
+ &plpgsql_extra_warnings_list,
+ "none",
+ PGC_USERSET, 0,
+ plpgsql_extra_checks_check_hook,
+ plpgsql_extra_warnings_assign_hook,
+ NULL);
+
+ DefineCustomStringVariable("plpgsql.extra_errors",
+ gettext_noop("List of programming constructs which should produce an error."),
+ NULL,
+ &plpgsql_extra_errors_list,
+ "none",
+ PGC_USERSET, 0,
+ plpgsql_extra_checks_check_hook,
+ plpgsql_extra_errors_assign_hook,
+ NULL);
+
EmitWarningsOnPlaceholders("plpgsql");
plpgsql_HashTableInit();
diff --git a/src/pl/plpgsql/src/plpgsql.h b/src/pl/plpgsql/src/plpgsql.h
index f3d1283..93956fd 100644
--- a/src/pl/plpgsql/src/plpgsql.h
+++ b/src/pl/plpgsql/src/plpgsql.h
@@ -739,6 +739,10 @@ typedef struct PLpgSQL_function
bool print_strict_params;
+ /* extra checks */
+ bool extra_warnings;
+ bool extra_errors;
+
int ndatums;
PLpgSQL_datum **datums;
PLpgSQL_stmt_block *action;
@@ -881,6 +885,9 @@ extern int plpgsql_variable_conflict;
extern bool plpgsql_print_strict_params;
+extern bool plpgsql_extra_warnings;
+extern bool plpgsql_extra_errors;
+
extern bool plpgsql_check_syntax;
extern bool plpgsql_DumpExecTree;
diff --git a/src/test/regress/expected/plpgsql.out b/src/test/regress/expected/plpgsql.out
index 0405ef4..4eb01eb 100644
--- a/src/test/regress/expected/plpgsql.out
+++ b/src/test/regress/expected/plpgsql.out
@@ -3208,6 +3208,79 @@ select footest();
ERROR: query returned more than one row
DETAIL: parameters: p1 = '2', p3 = 'foo'
CONTEXT: PL/pgSQL function footest() line 10 at SQL statement
+-- test warnings when shadowing a variable
+set plpgsql.extra_warnings to 'shadowed-variables';
+-- simple shadowing of input and output parameters
+create or replace function shadowtest(in1 int)
+ returns table (out1 int) as $$
+declare
+in1 int;
+out1 int;
+begin
+end
+$$ language plpgsql;
+WARNING: variable "in1" shadows a previously defined variable
+LINE 4: in1 int;
+ ^
+WARNING: variable "out1" shadows a previously defined variable
+LINE 5: out1 int;
+ ^
+drop function shadowtest(int);
+-- shadowing in a second DECLARE block
+create or replace function shadowtest()
+ returns void as $$
+declare
+f1 int;
+begin
+ declare
+ f1 int;
+ begin
+ end;
+end$$ language plpgsql;
+WARNING: variable "f1" shadows a previously defined variable
+LINE 7: f1 int;
+ ^
+drop function shadowtest();
+-- several levels of shadowing
+create or replace function shadowtest(in1 int)
+ returns void as $$
+declare
+in1 int;
+begin
+ declare
+ in1 int;
+ begin
+ end;
+end$$ language plpgsql;
+WARNING: variable "in1" shadows a previously defined variable
+LINE 4: in1 int;
+ ^
+WARNING: variable "in1" shadows a previously defined variable
+LINE 7: in1 int;
+ ^
+drop function shadowtest(int);
+-- shadowing in cursor definitions
+create or replace function shadowtest()
+ returns void as $$
+declare
+f1 int;
+c1 cursor (f1 int) for select 1;
+begin
+end$$ language plpgsql;
+WARNING: variable "f1" shadows a previously defined variable
+LINE 5: c1 cursor (f1 int) for select 1;
+ ^
+drop function shadowtest();
+-- test errors when shadowing a variable
+set plpgsql.extra_errors to 'shadowed-variables';
+create or replace function shadowtest(f1 int)
+ returns void as $$
+declare f1 int; begin end $$ language plpgsql;
+ERROR: variable "f1" shadows a previously defined variable
+LINE 3: declare f1 int; begin end $$ language plpgsql;
+ ^
+reset plpgsql.extra_errors;
+reset plpgsql.extra_warnings;
-- test scrollable cursor support
create function sc_test() returns setof integer as $$
declare
diff --git a/src/test/regress/sql/plpgsql.sql b/src/test/regress/sql/plpgsql.sql
index d01011a..2f0fa9c 100644
--- a/src/test/regress/sql/plpgsql.sql
+++ b/src/test/regress/sql/plpgsql.sql
@@ -2689,6 +2689,68 @@ end$$ language plpgsql;
select footest();
+-- test warnings when shadowing a variable
+
+set plpgsql.extra_warnings to 'shadowed-variables';
+
+-- simple shadowing of input and output parameters
+create or replace function shadowtest(in1 int)
+ returns table (out1 int) as $$
+declare
+in1 int;
+out1 int;
+begin
+end
+$$ language plpgsql;
+drop function shadowtest(int);
+
+-- shadowing in a second DECLARE block
+create or replace function shadowtest()
+ returns void as $$
+declare
+f1 int;
+begin
+ declare
+ f1 int;
+ begin
+ end;
+end$$ language plpgsql;
+drop function shadowtest();
+
+-- several levels of shadowing
+create or replace function shadowtest(in1 int)
+ returns void as $$
+declare
+in1 int;
+begin
+ declare
+ in1 int;
+ begin
+ end;
+end$$ language plpgsql;
+drop function shadowtest(int);
+
+-- shadowing in cursor definitions
+create or replace function shadowtest()
+ returns void as $$
+declare
+f1 int;
+c1 cursor (f1 int) for select 1;
+begin
+end$$ language plpgsql;
+drop function shadowtest();
+
+-- test errors when shadowing a variable
+
+set plpgsql.extra_errors to 'shadowed-variables';
+
+create or replace function shadowtest(f1 int)
+ returns void as $$
+declare f1 int; begin end $$ language plpgsql;
+
+reset plpgsql.extra_errors;
+reset plpgsql.extra_warnings;
+
-- test scrollable cursor support
create function sc_test() returns setof integer as $$
--
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