diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/pl/plpgsql/src/pl_comp.c | 12 | ||||
| -rw-r--r-- | src/pl/plpgsql/src/pl_funcs.c | 88 | ||||
| -rw-r--r-- | src/pl/plpgsql/src/pl_gram.y | 15 | ||||
| -rw-r--r-- | src/pl/plpgsql/src/plpgsql.h | 7 |
4 files changed, 121 insertions, 1 deletions
diff --git a/src/pl/plpgsql/src/pl_comp.c b/src/pl/plpgsql/src/pl_comp.c index a2de0880fb7..f36a244140e 100644 --- a/src/pl/plpgsql/src/pl_comp.c +++ b/src/pl/plpgsql/src/pl_comp.c @@ -371,6 +371,7 @@ do_compile(FunctionCallInfo fcinfo, function->nstatements = 0; function->requires_procedure_resowner = false; + function->has_exception_block = false; /* * Initialize the compiler, particularly the namespace stack. The @@ -811,6 +812,9 @@ do_compile(FunctionCallInfo fcinfo, plpgsql_finish_datums(function); + if (function->has_exception_block) + plpgsql_mark_local_assignment_targets(function); + /* Debug dump for completed functions */ if (plpgsql_DumpExecTree) plpgsql_dumptree(function); @@ -906,6 +910,7 @@ plpgsql_compile_inline(char *proc_source) function->nstatements = 0; function->requires_procedure_resowner = false; + function->has_exception_block = false; plpgsql_ns_init(); plpgsql_ns_push(func_name, PLPGSQL_LABEL_BLOCK); @@ -962,6 +967,13 @@ plpgsql_compile_inline(char *proc_source) plpgsql_finish_datums(function); + if (function->has_exception_block) + plpgsql_mark_local_assignment_targets(function); + + /* Debug dump for completed functions */ + if (plpgsql_DumpExecTree) + plpgsql_dumptree(function); + /* * Pop the error context stack */ diff --git a/src/pl/plpgsql/src/pl_funcs.c b/src/pl/plpgsql/src/pl_funcs.c index 88e25b54bcd..6b5394fc5fa 100644 --- a/src/pl/plpgsql/src/pl_funcs.c +++ b/src/pl/plpgsql/src/pl_funcs.c @@ -599,6 +599,91 @@ plpgsql_statement_tree_walker_impl(PLpgSQL_stmt *stmt, /********************************************************************** + * Mark assignment source expressions that have local target variables, + * that is, the target variable is declared within the exception block + * most closely containing the assignment itself. (Such target variables + * need not be preserved if the assignment's source expression raises an + * error, since the variable will no longer be accessible afterwards. + * Detecting this allows better optimization.) + * + * This code need not be called if the plpgsql function contains no exception + * blocks, because mark_expr_as_assignment_source will have set all the flags + * to true already. Also, we need not reconsider default-value expressions + * for variables, because variable declarations are necessarily within the + * nearest exception block. (In DECLARE ... BEGIN ... EXCEPTION ... END, the + * variable initializations are done before entering the exception scope.) + * + * Within the recursion, local_dnos is a Bitmapset of dnos of variables + * known to be declared within the current exception level. + **********************************************************************/ +static void mark_stmt(PLpgSQL_stmt *stmt, Bitmapset *local_dnos); +static void mark_expr(PLpgSQL_expr *expr, Bitmapset *local_dnos); + +static void +mark_stmt(PLpgSQL_stmt *stmt, Bitmapset *local_dnos) +{ + if (stmt == NULL) + return; + if (stmt->cmd_type == PLPGSQL_STMT_BLOCK) + { + PLpgSQL_stmt_block *block = (PLpgSQL_stmt_block *) stmt; + + if (block->exceptions) + { + /* + * The block creates a new exception scope, so variables declared + * at outer levels are nonlocal. For that matter, so are any + * variables declared in the block's DECLARE section. Hence, we + * must pass down empty local_dnos. + */ + plpgsql_statement_tree_walker(stmt, mark_stmt, mark_expr, NULL); + } + else + { + /* + * Otherwise, the block does not create a new exception scope, and + * any variables it declares can also be considered local within + * it. Note that only initializable datum types (VAR, REC) are + * included in initvarnos; but that's sufficient for our purposes. + */ + local_dnos = bms_copy(local_dnos); + for (int i = 0; i < block->n_initvars; i++) + local_dnos = bms_add_member(local_dnos, block->initvarnos[i]); + plpgsql_statement_tree_walker(stmt, mark_stmt, mark_expr, + local_dnos); + bms_free(local_dnos); + } + } + else + plpgsql_statement_tree_walker(stmt, mark_stmt, mark_expr, local_dnos); +} + +static void +mark_expr(PLpgSQL_expr *expr, Bitmapset *local_dnos) +{ + /* + * If this expression has an assignment target, check whether the target + * is local, and mark the expression accordingly. + */ + if (expr && expr->target_param >= 0) + expr->target_is_local = bms_is_member(expr->target_param, local_dnos); +} + +void +plpgsql_mark_local_assignment_targets(PLpgSQL_function *func) +{ + Bitmapset *local_dnos; + + /* Function parameters can be treated as local targets at outer level */ + local_dnos = NULL; + for (int i = 0; i < func->fn_nargs; i++) + local_dnos = bms_add_member(local_dnos, func->fn_argvarnos[i]); + mark_stmt((PLpgSQL_stmt *) func->action, local_dnos); + bms_free(local_dnos); +} + + +/********************************************************************** * Release memory when a PL/pgSQL function is no longer needed * * This code only needs to deal with cleaning up PLpgSQL_expr nodes, @@ -1500,6 +1585,9 @@ static void dump_expr(PLpgSQL_expr *expr) { printf("'%s'", expr->query); + if (expr->target_param >= 0) + printf(" target %d%s", expr->target_param, + expr->target_is_local ? " (local)" : ""); } void diff --git a/src/pl/plpgsql/src/pl_gram.y b/src/pl/plpgsql/src/pl_gram.y index f55aefb1008..8048e040f81 100644 --- a/src/pl/plpgsql/src/pl_gram.y +++ b/src/pl/plpgsql/src/pl_gram.y @@ -2328,6 +2328,8 @@ exception_sect : PLpgSQL_exception_block *new = palloc(sizeof(PLpgSQL_exception_block)); PLpgSQL_variable *var; + plpgsql_curr_compile->has_exception_block = true; + var = plpgsql_build_variable("sqlstate", lineno, plpgsql_build_datatype(TEXTOID, -1, @@ -2673,6 +2675,7 @@ make_plpgsql_expr(const char *query, expr->ns = plpgsql_ns_top(); /* might get changed later during parsing: */ expr->target_param = -1; + expr->target_is_local = false; /* other fields are left as zeroes until first execution */ return expr; } @@ -2687,9 +2690,21 @@ mark_expr_as_assignment_source(PLpgSQL_expr *expr, PLpgSQL_datum *target) * other DTYPEs, so no need to mark in other cases. */ if (target->dtype == PLPGSQL_DTYPE_VAR) + { expr->target_param = target->dno; + + /* + * For now, assume the target is local to the nearest enclosing + * exception block. That's correct if the function contains no + * exception blocks; otherwise we'll update this later. + */ + expr->target_is_local = true; + } else + { expr->target_param = -1; /* should be that already */ + expr->target_is_local = false; /* ditto */ + } } /* Convenience routine to read an expression with one possible terminator */ diff --git a/src/pl/plpgsql/src/plpgsql.h b/src/pl/plpgsql/src/plpgsql.h index b0052167eef..2fa6d73cabc 100644 --- a/src/pl/plpgsql/src/plpgsql.h +++ b/src/pl/plpgsql/src/plpgsql.h @@ -225,9 +225,12 @@ typedef struct PLpgSQL_expr /* * These fields are used to help optimize assignments to expanded-datum * variables. If this expression is the source of an assignment to a - * simple variable, target_param holds that variable's dno (else it's -1). + * simple variable, target_param holds that variable's dno (else it's -1), + * and target_is_local indicates whether the target is declared inside the + * closest exception block containing the assignment. */ int target_param; /* dno of assign target, or -1 if none */ + bool target_is_local; /* is it within nearest exception block? */ /* * Fields above are set during plpgsql parsing. Remaining fields are left @@ -1014,6 +1017,7 @@ typedef struct PLpgSQL_function /* data derived while parsing body */ unsigned int nstatements; /* counter for assigning stmtids */ bool requires_procedure_resowner; /* contains CALL or DO? */ + bool has_exception_block; /* contains BEGIN...EXCEPTION? */ /* these fields change when the function is used */ struct PLpgSQL_execstate *cur_estate; @@ -1312,6 +1316,7 @@ extern PLpgSQL_nsitem *plpgsql_ns_find_nearest_loop(PLpgSQL_nsitem *ns_cur); */ extern PGDLLEXPORT const char *plpgsql_stmt_typename(PLpgSQL_stmt *stmt); extern const char *plpgsql_getdiag_kindname(PLpgSQL_getdiag_kind kind); +extern void plpgsql_mark_local_assignment_targets(PLpgSQL_function *func); extern void plpgsql_free_function_memory(PLpgSQL_function *func); extern void plpgsql_dumptree(PLpgSQL_function *func); |