]> ocean-lang.org Git - ocean/blobdiff - csrc/oceani.mdc
oceani: improve reporting of variables being freed at end of block.
[ocean] / csrc / oceani.mdc
index 215a9a709bca6b4ebe568a0b6a1e3ca2e5e252d5..76c8c9b4efd96414511685e620c4d7b7e849acbd 100644 (file)
@@ -236,6 +236,11 @@ structures can be used.
                        }
                } else
                        ss = s;                         // NOTEST
+               if (!ss->code) {
+                       fprintf(stderr, "oceani: no code found in requested section\n");        // NOTEST
+                       exit(1);                        // NOTEST
+               }
+
                parse_oceani(ss->code, &context.config, dotrace ? stderr : NULL);
 
                if (!context.prog) {
@@ -263,7 +268,7 @@ structures can be used.
                        free(s);
                        s = t;
                }
-               ## free context vars
+               ## free global vars
                ## free context types
                ## free context storage
                exit(context.parse_error ? 1 : 0);
@@ -498,8 +503,10 @@ Named type are stored in a simple linked list.  Objects of each type are
 
        static void free_value(struct type *type, struct value *v)
        {
-               if (type && v)
+               if (type && v) {
                        type->free(type, v);
+                       memset(v, 0x5a, type->size);
+               }
        }
 
        static void type_print(struct type *type, FILE *f)
@@ -846,6 +853,42 @@ cannot nest, so a declaration while a name is in-scope is an error.
                ## variable fields
        };
 
+When a scope closes, the values of the variables might need to be freed.
+This happens in the context of some `struct exec` and each `exec` will
+need to know which variables need to be freed when it completes.
+
+####### exec fields
+       struct variable *to_free;
+
+####### variable fields
+       struct exec *cleanup_exec;
+       struct variable *next_free;
+
+####### interp exec cleanup
+       {
+               struct variable *v;
+               for (v = e->to_free; v; v = v->next_free) {
+                       struct value *val = var_value(c, v);
+                       free_value(v->type, val);
+               }
+       }
+
+###### ast functions
+       static void variable_unlink_exec(struct variable *v)
+       {
+               struct variable **vp;
+               if (!v->cleanup_exec)
+                       return;
+               for (vp = &v->cleanup_exec->to_free;
+                   *vp; vp = &(*vp)->next_free) {
+                       if (*vp != v)
+                               continue;
+                       *vp = v->next_free;
+                       v->cleanup_exec = NULL;
+                       break;
+               }
+       }
+
 While the naming seems strange, we include local constants in the
 definition of variables.  A name declared `var := value` can
 subsequently be changed, but a name declared `var ::= value` cannot -
@@ -1010,13 +1053,14 @@ need to be freed.  For this we need to be able to find it, so assume that
                            v->merged == secondary->merged) {
                                v->scope = OutScope;
                                v->merged = primary;
+                               variable_unlink_exec(v);
                        }
        }
 
 ###### forward decls
        static struct value *var_value(struct parse_context *c, struct variable *v);
 
-###### free context vars
+###### free global vars
 
        while (context.varlist) {
                struct binding *b = context.varlist;
@@ -1027,10 +1071,11 @@ need to be freed.  For this we need to be able to find it, so assume that
                        struct variable *t = v;
 
                        v = t->previous;
-                       free_value(t->type, var_value(&context, t));
-                       if (t->depth == 0)
-                               // This is a global constant
-                               free_exec(t->where_decl);
+                       if (t->global) {
+                               free_value(t->type, var_value(&context, t));
+                               if (t->depth == 0)
+                                       free_exec(t->where_decl);
+                       }
                        free(t);
                }
        }
@@ -1065,7 +1110,7 @@ switch.  Other scopes are "sequential".
 
 When exiting a parallel scope we check if there are any variables that
 were previously pending and are still visible. If there are, then
-there weren't redeclared in the most recent scope, so they cannot be
+they weren't redeclared in the most recent scope, so they cannot be
 merged and must become out-of-scope.  If it is not the first of
 parallel scopes (based on `child_count`), we check that there was a
 previous binding that is still pending-scope.  If there isn't, the new
@@ -1108,6 +1153,7 @@ all pending-scope variables become conditionally scoped.
                v->scope = InScope;
                v->in_scope = c->in_scope;
                c->in_scope = v;
+               ## variable init
                return v;
        }
 
@@ -1139,7 +1185,8 @@ all pending-scope variables become conditionally scoped.
                return v;
        }
 
-       static void var_block_close(struct parse_context *c, enum closetype ct)
+       static void var_block_close(struct parse_context *c, enum closetype ct,
+                                   struct exec *e)
        {
                /* Close off all variables that are in_scope.
                 * Some variables in c->scope may already be not-in-scope,
@@ -1163,6 +1210,14 @@ all pending-scope variables become conditionally scoped.
                                 * closed the scope.
                                 */
                                continue;
+                       v->min_depth = c->scope_depth;
+                       if (v->scope == InScope) {
+                               /* This variable gets cleaned up when 'e' finishes */
+                               variable_unlink_exec(v);
+                               v->cleanup_exec = e;
+                               v->next_free = e->to_free;
+                               e->to_free = v;
+                       }
                        switch (ct) {
                        case CloseElse:
                        case CloseParallel: /* handle PendingScope */
@@ -1195,7 +1250,7 @@ all pending-scope variables become conditionally scoped.
                                         * parallel scope to be nested immediately
                                         * in a parallel scope, and that never
                                         * happens.
-                                        */
+                                        */                     // NOTEST
                                case OutScope:
                                        /* Not possible as we already tested for
                                         * OutScope
@@ -1219,9 +1274,9 @@ all pending-scope variables become conditionally scoped.
                                        for (v2 = v;
                                             v2 && v2->scope == PendingScope;
                                             v2 = v2->previous)
-                                               if (v2->type == Tlabel) {
+                                               if (v2->type == Tlabel)
                                                        v2->scope = CondScope;
-                                               else
+                                               else
                                                        v2->scope = OutScope;
                                        break;
                                case CondScope:
@@ -1245,9 +1300,15 @@ the frame needs to be reallocated as it grows so it can store those
 values.  The local frame doesn't get values until the interpreted phase
 is started, so there is no need to allocate until the size is known.
 
+We initialize the `frame_pos` to an impossible value, so that we can
+tell if it was set or not later.
+
 ###### variable fields
-               short frame_pos;
-               short global;
+       short frame_pos;
+       short global;
+
+###### variable init
+       v->frame_pos = -1;
 
 ###### parse context
 
@@ -1261,7 +1322,7 @@ is started, so there is no need to allocate until the size is known.
        {
                if (!v->global) {
                        if (!c->local || !v->type)
-                               return NULL;
+                               return NULL;                    // NOTEST
                        if (v->frame_pos + v->type->size > c->local_size) {
                                printf("INVALID frame_pos\n");  // NOTEST
                                exit(2);                        // NOTEST
@@ -1377,6 +1438,7 @@ from the `exec_types` enum.
        struct exec {
                enum exec_types type;
                int line, column;
+               ## exec fields
        };
        struct binode {
                struct exec;
@@ -1474,12 +1536,23 @@ also want to know what sort of bracketing to use.
        static void print_exec(struct exec *e, int indent, int bracket)
        {
                if (!e)
-                       return;         // NOTEST
+                       return;
                switch (e->type) {
                case Xbinode:
                        print_binode(cast(binode, e), indent, bracket); break;
                ## print exec cases
                }
+               if (e->to_free) {
+                       struct variable *v;
+                       do_indent(indent, "/* FREE");
+                       for (v = e->to_free; v; v = v->next_free) {
+                               printf(" %.*s", v->name->name.len, v->name->name.txt);
+                               if (v->frame_pos >= 0)
+                                       printf("(%d+%d)", v->frame_pos,
+                                              v->type ? v->type->size:0);
+                       }
+                       printf(" */\n");
+               }
        }
 
 ###### forward decls
@@ -1625,6 +1698,7 @@ in `rval`.
                ret.lval = lrv;
                ret.rval = rv;
                ret.type = rvtype;
+               ## interp exec cleanup
                return ret;
        }
 
@@ -2283,6 +2357,9 @@ or as an indented list of one parameter per line
        do
                code block
 
+For constructing these lists we use a `List` binode, which will be
+further detailed when Expression Lists are introduced.
+
 ###### Binode types
        Func, List,
 
@@ -2296,7 +2373,7 @@ or as an indented list of one parameter per line
                        $0->op = Func;
                        $0->left = reorder_bilist($<Ar);
                        $0->right = $<Bl;
-                       var_block_close(c, CloseSequential);
+                       var_block_close(c, CloseSequential, $0);
                        if (c->scope_stack && !c->parse_error) abort();
                }$
                | func main IN OpenScope OptNL Args OUT OptNL do Block Newlines ${
@@ -2304,7 +2381,7 @@ or as an indented list of one parameter per line
                        $0->op = Func;
                        $0->left = reorder_bilist($<Ar);
                        $0->right = $<Bl;
-                       var_block_close(c, CloseSequential);
+                       var_block_close(c, CloseSequential, $0);
                        if (c->scope_stack && !c->parse_error) abort();
                }$
                | func main NEWLINE OpenScope OptNL do Block Newlines ${
@@ -2312,7 +2389,7 @@ or as an indented list of one parameter per line
                        $0->op = Func;
                        $0->left = NULL;
                        $0->right = $<Bl;
-                       var_block_close(c, CloseSequential);
+                       var_block_close(c, CloseSequential, $0);
                        if (c->scope_stack && !c->parse_error) abort();
                }$
 
@@ -2746,6 +2823,57 @@ there.
                }
                break;
 
+### Expression list
+
+We take a brief detour, now that we have expressions, to describe lists
+of expressions.  These will be needed for function parameters and
+possibly other situations.  They seem generic enough to introduce here
+to be used elsewhere.
+
+And ExpressionList will use the `List` type of `binode`, building up at
+the end.  And place where they are used will probably call
+`reorder_bilist()` to get a more normal first/next arrangement.
+
+###### declare terminals
+       $TERM ,
+
+`List` execs have no implicit semantics, so they are never propagated or
+interpreted.  The can be printed as a comma separate list, which is how
+they are parsed.  Note they are also used for function formal parameter
+lists.  In that case a separate function is used to print them.
+
+###### print binode cases
+       case List:
+               while (b) {
+                       printf(" ");
+                       print_exec(b->left, -1, bracket);
+                       if (b->right)
+                               printf(",");
+                       b = cast(binode, b->right);
+               }
+               break;
+
+###### propagate binode cases
+       case List: abort(); // NOTEST
+###### interp binode cases
+       case List: abort(); // NOTEST
+
+###### Grammar
+
+       $*binode
+       ExpressionList -> ExpressionList , Expression ${
+                       $0 = new(binode);
+                       $0->op = List;
+                       $0->left = $<1;
+                       $0->right = $<3;
+               }$
+               | Expression ${
+                       $0 = new(binode);
+                       $0->op = List;
+                       $0->left = NULL;
+                       $0->right = $<1;
+               }$
+
 ### Expressions: Boolean
 
 The next class of expressions to use the `binode` will be Boolean
@@ -3443,62 +3571,47 @@ is in-place.
 expressions and prints the values separated by spaces and terminated
 by a newline.  No control of formatting is possible.
 
-`print` faces the same list-ordering issue as blocks, and uses the
-same solution.
+`print` uses `ExpressionList` to collect the expressions and stores them
+on the left side of a `Print` binode unlessthere is a trailing comma
+when the list is stored on the `right` side and no trailing newline is
+printed.
 
 ###### Binode types
        Print,
 
 ##### expr precedence
-       $TERM print ,
+       $TERM print
 
 ###### SimpleStatement Grammar
 
        | print ExpressionList ${
-               $0 = reorder_bilist($<2);
-       }$
-       | print ExpressionList , ${
                $0 = new(binode);
                $0->op = Print;
                $0->right = NULL;
-               $0->left = $<2;
-               $0 = reorder_bilist($0);
+               $0->left = reorder_bilist($<EL);
        }$
+       | print ExpressionList , ${ {
+               $0 = new(binode);
+               $0->op = Print;
+               $0->right = reorder_bilist($<EL);
+               $0->left = NULL;
+       } }$
        | print ${
                $0 = new(binode);
                $0->op = Print;
+               $0->left = NULL;
                $0->right = NULL;
        }$
 
-###### Grammar
-
-       $*binode
-       ExpressionList -> ExpressionList , Expression ${
-               $0 = new(binode);
-               $0->op = Print;
-               $0->left = $<1;
-               $0->right = $<3;
-               }$
-               | Expression ${
-                       $0 = new(binode);
-                       $0->op = Print;
-                       $0->left = NULL;
-                       $0->right = $<1;
-               }$
-
 ###### print binode cases
 
        case Print:
                do_indent(indent, "print");
-               while (b) {
-                       if (b->left) {
-                               printf(" ");
-                               print_exec(b->left, -1, bracket);
-                               if (b->right)
-                                       printf(",");
-                       }
-                       b = cast(binode, b->right);
-               }
+               if (b->right) {
+                       print_exec(b->right, -1, bracket);
+                       printf(",");
+               } else
+                       print_exec(b->left, -1, bracket);
                if (indent >= 0)
                        printf("\n");
                break;
@@ -3507,30 +3620,33 @@ same solution.
 
        case Print:
                /* don't care but all must be consistent */
-               propagate_types(b->left, c, ok, NULL, Rnolabel);
-               propagate_types(b->right, c, ok, NULL, Rnolabel);
+               if (b->left)
+                       b = cast(binode, b->left);
+               else
+                       b = cast(binode, b->right);
+               while (b) {
+                       propagate_types(b->left, c, ok, NULL, Rnolabel);
+                       b = cast(binode, b->right);
+               }
                break;
 
 ###### interp binode cases
 
        case Print:
        {
-               char sep = 0;
-               int eol = 1;
-               for ( ; b; b = cast(binode, b->right))
-                       if (b->left) {
-                               if (sep)
-                                       putchar(sep);
-                               left = interp_exec(c, b->left, &ltype);
-                               print_value(ltype, &left);
-                               free_value(ltype, &left);
-                               if (b->right)
-                                       sep = ' ';
-                       } else if (sep)
-                               eol = 0;
-               ltype = Tnone;
-               if (eol)
+               struct binode *b2 = cast(binode, b->left);
+               if (!b2)
+                       b2 = cast(binode, b->right);
+               for (; b2; b2 = cast(binode, b2->right)) {
+                       left = interp_exec(c, b2->left, &ltype);
+                       print_value(ltype, &left);
+                       free_value(ltype, &left);
+                       if (b2->right)
+                               putchar(' ');
+               }
+               if (b->right == NULL)
                        printf("\n");
+               ltype = Tnone;
                break;
        }
 
@@ -3665,7 +3781,6 @@ it is declared, and error will be raised as the name is created as
                struct value *val;
                v = v->merged;
                val = var_value(c, v);
-               free_value(v->type, val);
                if (v->type->prepare_type)
                        v->type->prepare_type(c, v->type, 0);
                if (b->right) {
@@ -3872,13 +3987,13 @@ casepart` to track a list of case parts.
                        $0->forpart = $<FP;
                        $0->thenpart = $<TP;
                        $0->looppart = $<WP;
-                       var_block_close(c, CloseSequential);
+                       var_block_close(c, CloseSequential, $0);
                        }$
                | ForPart OptNL WhilePart CondSuffix ${
                        $0 = $<CS;
                        $0->forpart = $<FP;
                        $0->looppart = $<WP;
-                       var_block_close(c, CloseSequential);
+                       var_block_close(c, CloseSequential, $0);
                        }$
                | WhilePart CondSuffix ${
                        $0 = $<CS;
@@ -3889,21 +4004,21 @@ casepart` to track a list of case parts.
                        $0->condpart = $<SP;
                        $CP->next = $0->casepart;
                        $0->casepart = $<CP;
-                       var_block_close(c, CloseSequential);
+                       var_block_close(c, CloseSequential, $0);
                        }$
                | SwitchPart : IN OptNL CasePart CondSuffix OUT Newlines ${
                        $0 = $<CS;
                        $0->condpart = $<SP;
                        $CP->next = $0->casepart;
                        $0->casepart = $<CP;
-                       var_block_close(c, CloseSequential);
+                       var_block_close(c, CloseSequential, $0);
                        }$
                | IfPart IfSuffix ${
                        $0 = $<IS;
                        $0->condpart = $IP.condpart; $IP.condpart = NULL;
                        $0->thenpart = $IP.thenpart; $IP.thenpart = NULL;
                        // This is where we close an "if" statement
-                       var_block_close(c, CloseSequential);
+                       var_block_close(c, CloseSequential, $0);
                        }$
 
        CondSuffix -> IfSuffix ${
@@ -3927,12 +4042,12 @@ casepart` to track a list of case parts.
        ElsePart -> else OpenBlock Newlines ${
                        $0 = new(cond_statement);
                        $0->elsepart = $<OB;
-                       var_block_close(c, CloseElse);
+                       var_block_close(c, CloseElse, $0->elsepart);
                }$
                | else OpenScope CondStatement ${
                        $0 = new(cond_statement);
                        $0->elsepart = $<CS;
-                       var_block_close(c, CloseElse);
+                       var_block_close(c, CloseElse, $0->elsepart);
                }$
 
        $*casepart
@@ -3940,7 +4055,7 @@ casepart` to track a list of case parts.
                        $0 = calloc(1,sizeof(struct casepart));
                        $0->value = $<Ex;
                        $0->action = $<Bl;
-                       var_block_close(c, CloseParallel);
+                       var_block_close(c, CloseParallel, $0->action);
                }$
 
        $*exec
@@ -3951,7 +4066,7 @@ casepart` to track a list of case parts.
 
        ThenPart -> then OpenBlock ${
                        $0 = $<OB;
-                       var_block_close(c, CloseSequential);
+                       var_block_close(c, CloseSequential, $0);
                }$
 
        $*binode
@@ -3961,33 +4076,33 @@ casepart` to track a list of case parts.
                        $0->op = Loop;
                        $0->left = $<UB;
                        $0->right = $<OB;
-                       var_block_close(c, CloseSequential);
-                       var_block_close(c, CloseSequential);
+                       var_block_close(c, CloseSequential, $0->right);
+                       var_block_close(c, CloseSequential, $0);
                }$
                | while OpenScope Expression OpenScope ColonBlock ${
                        $0 = new(binode);
                        $0->op = Loop;
                        $0->left = $<Exp;
                        $0->right = $<CB;
-                       var_block_close(c, CloseSequential);
-                       var_block_close(c, CloseSequential);
+                       var_block_close(c, CloseSequential, $0->right);
+                       var_block_close(c, CloseSequential, $0);
                }$
 
        $cond_statement
        IfPart -> if UseBlock OptNL then OpenBlock ${
                        $0.condpart = $<UB;
                        $0.thenpart = $<OB;
-                       var_block_close(c, CloseParallel);
+                       var_block_close(c, CloseParallel, $0.thenpart);
                }$
                | if OpenScope Expression OpenScope ColonBlock ${
                        $0.condpart = $<Ex;
                        $0.thenpart = $<CB;
-                       var_block_close(c, CloseParallel);
+                       var_block_close(c, CloseParallel, $0.thenpart);
                }$
                | if OpenScope Expression OpenScope OptNL then Block ${
                        $0.condpart = $<Ex;
                        $0.thenpart = $<Bl;
-                       var_block_close(c, CloseParallel);
+                       var_block_close(c, CloseParallel, $0.thenpart);
                }$
 
        $*exec
@@ -4407,7 +4522,6 @@ analysis is a bit more interesting at this level.
 
 ###### print binode cases
        case Func:
-       case List:
                do_indent(indent, "func main(");
                for (b2 = cast(binode, b->left); b2; b2 = cast(binode, b2->right)) {
                        struct variable *v = cast(var, b2->left)->var;
@@ -4426,7 +4540,6 @@ analysis is a bit more interesting at this level.
                break;
 
 ###### propagate binode cases
-       case List:
        case Func: abort();             // NOTEST
 
 ###### core functions
@@ -4519,8 +4632,6 @@ analysis is a bit more interesting at this level.
        }
 
 ###### interp binode cases
-       case List: abort();     // NOTEST
-
        case Func:
                rv = interp_exec(c, b->right, &rvtype);
                break;