struct token_config config;
char *file_name;
int parse_error;
- struct exec *prog;
## parse context
};
int fd;
int len;
char *file;
- struct section *s, *ss;
+ struct section *s = NULL, *ss;
char *section = NULL;
struct parse_context context = {
.config = {
if (!ss) {
fprintf(stderr, "oceani: cannot find section %s\n",
section);
- exit(1);
+ goto cleanup;
}
} else
ss = s; // NOTEST
+ if (!ss->code) {
+ fprintf(stderr, "oceani: no code found in requested section\n"); // NOTEST
+ goto cleanup; // NOTEST
+ }
+
parse_oceani(ss->code, &context.config, dotrace ? stderr : NULL);
- if (!context.prog) {
- fprintf(stderr, "oceani: no main function found.\n");
+ if (!context.parse_error && !analyse_funcs(&context)) {
+ fprintf(stderr, "oceani: type error in program - not running.\n");
context.parse_error = 1;
}
- if (context.prog && doprint) {
+
+ if (doprint) {
## print const decls
## print type decls
- print_exec(context.prog, 0, brackets);
- }
- if (context.prog && doexec && !context.parse_error) {
- if (!analyse_prog(context.prog, &context)) {
- fprintf(stderr, "oceani: type error in program - not running.\n");
- exit(1);
- }
- interp_prog(&context, context.prog, argc - optind, argv+optind);
+ ## print func decls
}
- free_exec(context.prog);
-
+ if (doexec && !context.parse_error)
+ interp_main(&context, argc - optind, argv + optind);
+ cleanup:
while (s) {
struct section *t = s->next;
code_free(s->code);
free(s);
s = t;
}
- ## free context vars
+ // FIXME parser should pop scope even on error
+ while (context.scope_depth > 0)
+ scope_pop(&context);
+ ## free global vars
## free context types
## free context storage
exit(context.parse_error ? 1 : 0);
###### forward decls
static void fput_loc(struct exec *loc, FILE *f);
+ static void type_err(struct parse_context *c,
+ char *fmt, struct exec *loc,
+ struct type *t1, int rules, struct type *t2);
###### core functions
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)
}
}
- static void _dup_value(struct type *type,
+ static void _dup_value(struct type *type,
struct value *vold, struct value *vnew)
{
switch (type->vtype) {
## 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 -
in which declared variables must not be in scope, and subsequent
branches, whether they may already be conditionally scoped.
+We need a total ordering of scopes so we can easily compare to variables
+to see if they are concurrently in scope. To achieve this we record a
+`scope_count` which is actually a count of both beginnings and endings
+of scopes. Then each variable has a record of the scope count where it
+enters scope, and where it leaves.
+
To push a new frame *before* any code in the frame is parsed, we need a
grammar reduction. This is most easily achieved with a grammar
element which derives the empty string, and creates the new scope when
###### parse context
int scope_depth;
+ int scope_count;
struct scope *scope_stack;
+###### variable fields
+ int scope_start, scope_end;
+
###### ast functions
static void scope_pop(struct parse_context *c)
{
c->scope_stack = s->parent;
free(s);
c->scope_depth -= 1;
+ c->scope_count += 1;
}
static void scope_push(struct parse_context *c)
s->parent = c->scope_stack;
c->scope_stack = s;
c->scope_depth += 1;
+ c->scope_count += 1;
}
###### Grammar
$void
OpenScope -> ${ scope_push(c); }$
- ClosePara -> ${ var_block_close(c, CloseParallel); }$
Each variable records a scope depth and is in one of four states:
enclosed the declaration, and that has closed.
- "conditionally in scope". The "in scope" block and all parallel
- scopes have closed, and no further mention of the name has been
- seen. This state includes a secondary nest depth which records the
- outermost scope seen since the variable became conditionally in
- scope. If a use of the name is found, the variable becomes "in
- scope" and that secondary depth becomes the recorded scope depth.
- If the name is declared as a new variable, the old variable becomes
- "out of scope" and the recorded scope depth stays unchanged.
+ scopes have closed, and no further mention of the name has been seen.
+ This state includes a secondary nest depth (`min_depth`) which records
+ the outermost scope seen since the variable became conditionally in
+ scope. If a use of the name is found, the variable becomes "in scope"
+ and that secondary depth becomes the recorded scope depth. If the
+ name is declared as a new variable, the old variable becomes "out of
+ scope" and the recorded scope depth stays unchanged.
- "out of scope". The variable is neither in scope nor conditionally
in scope. It is permanently out of scope now and can be removed from
- the "in scope" stack.
+ the "in scope" stack. When a variable becomes out-of-scope it is
+ moved to a separate list (`out_scope`) of variables which have fully
+ known scope. This will be used at the end of each function to assign
+ each variable a place in the stack frame.
###### variable fields
int depth, min_depth;
###### parse context
struct variable *in_scope;
+ struct variable *out_scope;
All variables with the same name are linked together using the
'previous' link. Those variable that have been affirmatively merged all
The storage of the value of a variable will be described later. For now
we just need to know that when a variable goes out of scope, it might
-need to be freed. For this we need to be able to find it, so assume that
+need to be freed. For this we need to be able to find it, so assume that
`var_value()` will provide that.
###### variable fields
{
struct variable *v;
- if (primary->merged)
- // shouldn't happen
- primary = primary->merged; // NOTEST
+ primary = primary->merged;
for (v = primary->previous; v; v=v->previous)
if (v == secondary || v == secondary->merged ||
v->merged == secondary ||
- (v->merged && v->merged == secondary->merged)) {
+ v->merged == secondary->merged) {
v->scope = OutScope;
v->merged = primary;
+ if (v->scope_start < primary->scope_start)
+ primary->scope_start = v->scope_start;
+ if (v->scope_end > primary->scope_end)
+ primary->scope_end = v->scope_end; // NOTEST
+ 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;
context.varlist = b->next;
free(b);
while (v) {
- 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);
- free(t);
+ struct variable *next = v->previous;
+
+ if (v->global) {
+ free_value(v->type, var_value(&context, v));
+ if (v->depth == 0)
+ // This is a global constant
+ free_exec(v->where_decl);
+ }
+ free(v);
+ v = next;
}
}
#### Manipulating Bindings
-When a name is conditionally visible, a new declaration discards the
-old binding - the condition lapses. Conversely a usage of the name
-affirms the visibility and extends it to the end of the containing
-block - i.e. the block that contains both the original declaration and
-the latest usage. This is determined from `min_depth`. When a
-conditionally visible variable gets affirmed like this, it is also
-merged with other conditionally visible variables with the same name.
+When a name is conditionally visible, a new declaration discards the old
+binding - the condition lapses. Similarly when we reach the end of a
+function (outermost non-global scope) any conditional scope must lapse.
+Conversely a usage of the name affirms the visibility and extends it to
+the end of the containing block - i.e. the block that contains both the
+original declaration and the latest usage. This is determined from
+`min_depth`. When a conditionally visible variable gets affirmed like
+this, it is also merged with other conditionally visible variables with
+the same name.
When we parse a variable declaration we either report an error if the
name is currently bound, or create a new variable at the current nest
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
all pending-scope variables become conditionally scoped.
###### ast
- enum closetype { CloseSequential, CloseParallel, CloseElse };
+ enum closetype { CloseSequential, CloseFunction, CloseParallel, CloseElse };
###### ast functions
v->previous = b->var;
b->var = v;
v->name = b;
+ v->merged = v;
v->min_depth = v->depth = c->scope_depth;
v->scope = InScope;
v->in_scope = c->in_scope;
+ v->scope_start = c->scope_count;
c->in_scope = v;
+ ## variable init
return v;
}
return v;
}
- static void var_block_close(struct parse_context *c, enum closetype ct)
+ static int var_refile(struct parse_context *c, struct variable *v)
+ {
+ /* Variable just went out of scope. Add it to the out_scope
+ * list, sorted by ->scope_start
+ */
+ struct variable **vp = &c->out_scope;
+ while ((*vp) && (*vp)->scope_start < v->scope_start)
+ vp = &(*vp)->in_scope;
+ v->in_scope = *vp;
+ *vp = v;
+ return 0;
+ }
+
+ static void var_block_close(struct parse_context *c, enum closetype ct,
+ struct exec *e)
{
- /* Close off all variables that are in_scope */
+ /* Close off all variables that are in_scope.
+ * Some variables in c->scope may already be not-in-scope,
+ * such as when a PendingScope variable is hidden by a new
+ * variable with the same name.
+ * So we check for v->name->var != v and drop them.
+ * If we choose to make a variable OutScope, we drop it
+ * immediately too.
+ */
struct variable *v, **vp, *v2;
scope_pop(c);
for (vp = &c->in_scope;
- v = *vp, v && v->depth > c->scope_depth && v->min_depth > c->scope_depth;
- ) {
- if (v->name->var == v) switch (ct) {
+ (v = *vp) && v->min_depth > c->scope_depth;
+ (v->scope == OutScope || v->name->var != v)
+ ? (*vp = v->in_scope, var_refile(c, v))
+ : ( vp = &v->in_scope, 0)) {
+ v->min_depth = c->scope_depth;
+ if (v->name->var != v)
+ /* This is still in scope, but we haven't just
+ * closed the scope.
+ */
+ continue;
+ v->min_depth = c->scope_depth;
+ if (v->scope == InScope)
+ v->scope_end = c->scope_count;
+ if (v->scope == InScope && e && !v->global) {
+ /* 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 */
switch(v->scope) {
case InScope:
case CondScope:
if (c->scope_stack->child_count == 1)
+ /* first among parallel branches */
v->scope = PendingScope;
else if (v->previous &&
v->previous->scope == PendingScope)
+ /* all previous branches used name */
v->scope = PendingScope;
else if (v->type == Tlabel)
- v->scope = PendingScope;
- else if (v->name->var == v)
+ /* Labels remain pending even when not used */
+ v->scope = PendingScope; // UNTESTED
+ else
v->scope = OutScope;
if (ct == CloseElse) {
/* All Pending variables with this name
}
break;
case PendingScope:
- for (v2 = v;
- v2 && v2->scope == PendingScope;
- v2 = v2->previous)
- if (v2->type != Tlabel)
- v2->scope = OutScope;
- break;
- case OutScope: break;
+ /* Not possible as it would require
+ * 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
+ */
+ abort(); // NOTEST
}
break;
+ case CloseFunction:
+ if (v->scope == CondScope)
+ /* Condition cannot continue past end of function */
+ v->scope = InScope;
+ /* fallthrough */
case CloseSequential:
if (v->type == Tlabel)
v->scope = PendingScope;
for (v2 = v;
v2 && v2->scope == PendingScope;
v2 = v2->previous)
- if (v2->type == Tlabel) {
+ if (v2->type == Tlabel)
v2->scope = CondScope;
- v2->min_depth = c->scope_depth;
- } else
+ else
v2->scope = OutScope;
break;
case CondScope:
}
break;
}
- if (v->scope == OutScope || v->name->var != v)
- *vp = v->in_scope;
- else
- vp = &v->in_scope;
}
}
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
{
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
As global values are found -- struct field initializers, labels etc --
`global_alloc()` is called to record the value in the global frame.
-When the program is fully parsed, we need to walk the list of variables
-to find any that weren't merged away and that aren't global, and to
-calculate the frame size and assign a frame position for each variable.
-For this we have `scope_finalize()`.
+When the program is fully parsed, each function is analysed, we need to
+walk the list of variables local to that function and assign them an
+offset in the stack frame. For this we have `scope_finalize()`.
+
+We keep the stack from dense by re-using space for between variables
+that are not in scope at the same time. The `out_scope` list is sorted
+by `scope_start` and as we process a varible, we move it to an FIFO
+stack. For each variable we consider, we first discard any from the
+stack anything that went out of scope before the new variable came in.
+Then we place the new variable just after the one at the top of the
+stack.
###### ast functions
- static void scope_finalize(struct parse_context *c)
+ static void scope_finalize(struct parse_context *c, struct type *ft)
{
- struct binding *b;
-
- for (b = c->varlist; b; b = b->next) {
- struct variable *v;
- for (v = b->var; v; v = v->previous) {
- struct type *t = v->type;
- if (v->merged && v->merged != v)
- continue;
- if (v->global)
- continue;
- if (c->local_size & (t->align - 1))
- c->local_size = (c->local_size + t->align) & ~(t->align-1);
- v->frame_pos = c->local_size;
- c->local_size += v->type->size;
- }
+ int size = 0;
+ struct variable *next = ft->function.scope;
+ struct variable *done = NULL;
+ while (next) {
+ struct variable *v = next;
+ struct type *t = v->type;
+ int pos;
+ next = v->in_scope;
+ if (v->merged != v)
+ continue;
+ if (!t)
+ continue;
+ while (done && done->scope_end < v->scope_start)
+ done = done->in_scope;
+ if (done)
+ pos = done->frame_pos + done->type->size;
+ else
+ pos = 0;
+ if (pos & (t->align - 1))
+ pos = (pos + t->align) & ~(t->align-1);
+ v->frame_pos = pos;
+ if (size < pos + v->type->size)
+ size = pos + v->type->size;
+ v->in_scope = done;
+ done = v;
}
- c->local = calloc(1, c->local_size);
+ c->out_scope = NULL;
+ ft->function.local_size = size;
}
###### free context storage
free(context.global);
- free(context.local);
### Executables
struct exec {
enum exec_types type;
int line, column;
+ ## exec fields
};
struct binode {
struct exec;
if (loc->type == Xbinode)
return __fput_loc(cast(binode,loc)->left, f) ||
__fput_loc(cast(binode,loc)->right, f); // NOTEST
- return 0; // NOTEST
+ return 0;
}
static void fput_loc(struct exec *loc, FILE *f)
{
if (!__fput_loc(loc, f))
- fprintf(f, "??:??: "); // NOTEST
+ fprintf(f, "??:??: ");
}
Each different type of `exec` node needs a number of functions defined,
static void do_indent(int i, char *str)
{
- while (i--)
+ while (i-- > 0)
printf(" ");
printf("%s", str);
}
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);
+ printf("[%d,%d]", v->scope_start, v->scope_end);
+ if (v->frame_pos >= 0)
+ printf("(%d+%d)", v->frame_pos,
+ v->type ? v->type->size:0);
+ }
+ printf(" */\n");
+ }
}
###### forward decls
###### ast
- enum val_rules {Rnolabel = 1<<0, Rboolok = 1<<1, Rnoconstant = 2<<1};
+ enum val_rules {Rnolabel = 1<<0, Rboolok = 1<<1, Rnoconstant = 1<<2};
###### format cases
case 'r':
fputs(" (labels not permitted)", stderr);
break;
-###### core functions
-
+###### forward decls
static struct type *propagate_types(struct exec *prog, struct parse_context *c, int *ok,
struct type *type, int rules);
+###### core functions
+
static struct type *__propagate_types(struct exec *prog, struct parse_context *c, int *ok,
struct type *type, int rules)
{
struct value rval, *lval;
};
- static struct lrval _interp_exec(struct parse_context *c, struct exec *e);
+ /* If dest is passed, dtype must give the expected type, and
+ * result can go there, in which case type is returned as NULL.
+ */
+ static struct lrval _interp_exec(struct parse_context *c, struct exec *e,
+ struct value *dest, struct type *dtype);
static struct value interp_exec(struct parse_context *c, struct exec *e,
struct type **typeret)
{
- struct lrval ret = _interp_exec(c, e);
+ struct lrval ret = _interp_exec(c, e, NULL, NULL);
if (!ret.type) abort();
if (typeret)
static struct value *linterp_exec(struct parse_context *c, struct exec *e,
struct type **typeret)
{
- struct lrval ret = _interp_exec(c, e);
+ struct lrval ret = _interp_exec(c, e, NULL, NULL);
+ if (!ret.type) abort();
if (ret.lval)
*typeret = ret.type;
else
return ret.lval;
}
- static struct lrval _interp_exec(struct parse_context *c, struct exec *e)
+ /* dinterp_exec is used when the destination type is certain and
+ * the value has a place to go.
+ */
+ static void dinterp_exec(struct parse_context *c, struct exec *e,
+ struct value *dest, struct type *dtype,
+ int need_free)
{
+ struct lrval ret = _interp_exec(c, e, dest, dtype);
+ if (!ret.type)
+ return; // NOTEST
+ if (need_free)
+ free_value(dtype, dest);
+ if (ret.lval)
+ dup_value(dtype, ret.lval, dest);
+ else
+ memcpy(dest, &ret.rval, dtype->size);
+ }
+
+ static struct lrval _interp_exec(struct parse_context *c, struct exec *e,
+ struct value *dest, struct type *dtype)
+ {
+ /* If the result is copied to dest, ret.type is set to NULL */
struct lrval ret;
struct value rv = {}, *lrv = NULL;
struct type *rvtype;
}
## interp exec cases
}
- ret.lval = lrv;
- ret.rval = rv;
- ret.type = rvtype;
+ if (rvtype) {
+ ret.lval = lrv;
+ ret.rval = rv;
+ ret.type = rvtype;
+ }
+ ## interp exec cleanup
return ret;
}
return 0;
if (have->array.unspec && require->array.unspec) {
if (have->array.vsize && require->array.vsize &&
- have->array.vsize != require->array.vsize)
+ have->array.vsize != require->array.vsize) // UNTESTED
/* sizes might not be the same */
- return 0;
+ return 0; // UNTESTED
return 1;
}
if (have->array.unspec || require->array.unspec)
- return 1;
+ return 1; // UNTESTED
if (require->array.vsize == NULL && have->array.vsize == NULL)
return require->array.size == have->array.size;
- return require->array.vsize == have->array.vsize;
+ return require->array.vsize == have->array.vsize; // UNTESTED
}
static void array_print_type(struct type *type, FILE *f)
t->array.vsize = NULL;
if (number_parse(num, tail, $2.txt) == 0)
tok_err(c, "error: unrecognised number", &$2);
- else if (tail[0])
+ else if (tail[0]) {
tok_err(c, "error: unsupported number suffix", &$2);
- else {
+ mpq_clear(num);
+ } else {
t->array.size = mpz_get_ui(mpq_numref(num));
if (mpz_cmp_ui(mpq_denref(num), 1) != 0) {
tok_err(c, "error: array size must be an integer",
if (i >= 0 && i < ltype->array.size)
lrv = ptr + i * rvtype->size;
else
- val_init(ltype->array.member, &rv);
+ val_init(ltype->array.member, &rv); // UNSAFE
ltype = NULL;
break;
}
struct value *v;
v = (void*) val->ptr + type->structure.fields[i].offset;
if (type->structure.fields[i].init)
- dup_value(type->structure.fields[i].type,
+ dup_value(type->structure.fields[i].type,
type->structure.fields[i].init,
v);
else
struct type *st = propagate_types(f->left, c, ok, NULL, 0);
if (!st)
- type_err(c, "error: unknown type for field access", f->left,
+ type_err(c, "error: unknown type for field access", f->left, // UNTESTED
NULL, 0, NULL);
else if (st->init != structure_init)
type_err(c, "error: field reference attempted on %1, not a struct",
return;
free_fieldlist(f->prev);
if (f->f.init) {
- free_value(f->f.type, f->f.init);
- free(f->f.init);
+ free_value(f->f.type, f->f.init); // UNTESTED
+ free(f->f.init); // UNTESTED
}
free(f);
}
| ERROR ${ tok_err(c, "Syntax error in struct field", &$1); }$
Field -> IDENTIFIER : Type = Expression ${ {
- int ok;
+ int ok; // UNTESTED
$0 = calloc(1, sizeof(struct fieldlist));
$0->f.name = $1.txt;
propagate_types($<5, c, &ok, $3, 0);
} while (ok == 2);
if (!ok)
- c->parse_error = 1;
+ c->parse_error = 1; // UNTESTED
else {
struct value vl = interp_exec(c, $5, NULL);
$0->f.init = global_alloc(c, $0->f.type, NULL, &vl);
static void structure_print_type(struct type *t, FILE *f);
###### value functions
- static void structure_print_type(struct type *t, FILE *f)
- {
- int i;
+ static void structure_print_type(struct type *t, FILE *f) // UNTESTED
+ { // UNTESTED
+ int i; // UNTESTED
fprintf(f, "struct %.*s\n", t->name.len, t->name.txt);
if (fl->type->print && fl->init) {
fprintf(f, " = ");
if (fl->type == Tstr)
- fprintf(f, "\"");
+ fprintf(f, "\""); // UNTESTED
print_value(fl->type, fl->init);
if (fl->type == Tstr)
- fprintf(f, "\"");
+ fprintf(f, "\""); // UNTESTED
}
printf("\n");
}
}
###### print type decls
- {
- struct type *t;
+ { // UNTESTED
+ struct type *t; // UNTESTED
int target = -1;
while (target != 0) {
int i = 0;
for (t = context.typelist; t ; t=t->next)
- if (t->print_type_decl) {
+ if (t->print_type_decl && !t->check_args) {
i += 1;
if (i == target)
break;
}
}
-### Functions
-
-A function is a named chunk of code which can be passed parameters and
-can return results. Each function has an implicit type which includes
-the set of parameters and the return value. As yet these types cannot
-be declared separate from the function itself.
+#### Functions
-In fact, only one function is currently possible - `main`. `main` is
-passed an array of strings together with the size of the array, and
-doesn't return anything. The strings are command line arguments.
+A function is a chunk of code which can be passed parameters and can
+return results. Each function has a type which includes the set of
+parameters and the return value. As yet these types cannot be declared
+separately from the function itself.
-The parameters can be specified either in parentheses as a list, such as
+The parameters can be specified either in parentheses as a ';' separated
+list, such as
##### Example: function 1
- func main(av:[ac::number]string)
+ func main(av:[ac::number]string; env:[envc::number]string)
code block
-or as an indented list of one parameter per line
+or as an indented list of one parameter per line (though each line can
+be a ';' separated list)
##### Example: function 2
func main
argv:[argc::number]string
+ env:[envc::number]string
+ do
+ code block
+
+In the first case a return type can follow the paentheses after a colon,
+in the second it is given on a line starting with the word `return`.
+
+##### Example: functions that return
+
+ func add(a:number; b:number): number
+ code block
+
+ func catenate
+ a: string
+ b: string
+ return string
do
code block
+
+For constructing these lists we use a `List` binode, which will be
+further detailed when Expression Lists are introduced.
+
+###### type union fields
+
+ struct {
+ struct binode *params;
+ struct type *return_type;
+ struct variable *scope;
+ int local_size;
+ } function;
+
+###### value union fields
+ struct exec *function;
+
+###### type functions
+ void (*check_args)(struct parse_context *c, int *ok,
+ struct type *require, struct exec *args);
+
+###### value functions
+
+ static void function_free(struct type *type, struct value *val)
+ {
+ free_exec(val->function);
+ val->function = NULL;
+ }
+
+ static int function_compat(struct type *require, struct type *have)
+ {
+ // FIXME can I do anything here yet?
+ return 0;
+ }
+
+ static void function_check_args(struct parse_context *c, int *ok,
+ struct type *require, struct exec *args)
+ {
+ /* This should be 'compat', but we don't have a 'tuple' type to
+ * hold the type of 'args'
+ */
+ struct binode *arg = cast(binode, args);
+ struct binode *param = require->function.params;
+
+ while (param) {
+ struct var *pv = cast(var, param->left);
+ if (!arg) {
+ type_err(c, "error: insufficient arguments to function.",
+ args, NULL, 0, NULL);
+ break;
+ }
+ *ok = 1;
+ propagate_types(arg->left, c, ok, pv->var->type, 0);
+ param = cast(binode, param->right);
+ arg = cast(binode, arg->right);
+ }
+ if (arg)
+ type_err(c, "error: too many arguments to function.",
+ args, NULL, 0, NULL);
+ }
+
+ static void function_print(struct type *type, struct value *val)
+ {
+ print_exec(val->function, 1, 0);
+ }
+
+ static void function_print_type_decl(struct type *type, FILE *f)
+ {
+ struct binode *b;
+ fprintf(f, "(");
+ for (b = type->function.params; b; b = cast(binode, b->right)) {
+ struct variable *v = cast(var, b->left)->var;
+ fprintf(f, "%.*s%s", v->name->name.len, v->name->name.txt,
+ v->constant ? "::" : ":");
+ type_print(v->type, f);
+ if (b->right)
+ fprintf(f, "; ");
+ }
+ fprintf(f, ")");
+ if (type->function.return_type != Tnone) {
+ fprintf(f, ":");
+ type_print(type->function.return_type, f);
+ }
+ fprintf(f, "\n");
+ }
+
+ static void function_free_type(struct type *t)
+ {
+ free_exec(t->function.params);
+ }
+
+ static struct type function_prototype = {
+ .size = sizeof(void*),
+ .align = sizeof(void*),
+ .free = function_free,
+ .compat = function_compat,
+ .check_args = function_check_args,
+ .print = function_print,
+ .print_type_decl = function_print_type_decl,
+ .free_type = function_free_type,
+ };
+
+###### declare terminals
+
+ $TERM func
+
###### Binode types
- Func, List,
+ List,
###### Grammar
- $TERM func main
+ $*variable
+ FuncName -> IDENTIFIER ${ {
+ struct variable *v = var_decl(c, $1.txt);
+ struct var *e = new_pos(var, $1);
+ e->var = v;
+ if (v) {
+ v->where_decl = e;
+ $0 = v;
+ } else {
+ v = var_ref(c, $1.txt);
+ e->var = v;
+ type_err(c, "error: function '%v' redeclared",
+ e, NULL, 0, NULL);
+ type_err(c, "info: this is where '%v' was first declared",
+ v->where_decl, NULL, 0, NULL);
+ free_exec(e);
+ }
+ } }$
$*binode
- MainFunction -> func main ( OpenScope Args ) Block Newlines ${
- $0 = new(binode);
- $0->op = Func;
- $0->left = reorder_bilist($<Ar);
- $0->right = $<Bl;
- var_block_close(c, CloseSequential);
- if (c->scope_stack && !c->parse_error) abort();
- }$
- | func main IN OpenScope OptNL Args OUT OptNL do Block Newlines ${
- $0 = new(binode);
- $0->op = Func;
- $0->left = reorder_bilist($<Ar);
- $0->right = $<Bl;
- var_block_close(c, CloseSequential);
- if (c->scope_stack && !c->parse_error) abort();
- }$
- | func main NEWLINE OpenScope OptNL do Block Newlines ${
- $0 = new(binode);
- $0->op = Func;
- $0->left = NULL;
- $0->right = $<Bl;
- var_block_close(c, CloseSequential);
- if (c->scope_stack && !c->parse_error) abort();
- }$
+ Args -> ArgsLine NEWLINE ${ $0 = $<AL; }$
+ | Args ArgsLine NEWLINE ${ {
+ struct binode *b = $<AL;
+ struct binode **bp = &b;
+ while (*bp)
+ bp = (struct binode **)&(*bp)->left;
+ *bp = $<A;
+ $0 = b;
+ } }$
- Args -> ${ $0 = NULL; }$
+ ArgsLine -> ${ $0 = NULL; }$
| Varlist ${ $0 = $<1; }$
| Varlist ; ${ $0 = $<1; }$
- | Varlist NEWLINE ${ $0 = $<1; }$
Varlist -> Varlist ; ArgDecl ${
$0 = new(binode);
{
char tail[3];
if (number_parse($0->val.num, tail, $1.txt) == 0)
- mpq_init($0->val.num);
+ mpq_init($0->val.num); // UNTESTED
if (tail[0])
tok_err(c, "error: unsupported number suffix",
&$1);
} else
fputs("???", stderr); // NOTEST
} else
- fputs("NOTVAR", stderr); // NOTEST
+ fputs("NOTVAR", stderr);
break;
###### propagate exec cases
type_err(c, "%d:BUG: no variable!!", prog, NULL, 0, NULL); // NOTEST
return Tnone; // NOTEST
}
- if (v->merged)
- v = v->merged;
+ v = v->merged;
if (v->constant && (rules & Rnoconstant)) {
type_err(c, "error: Cannot assign to a constant: %v",
prog, NULL, 0, NULL);
struct var *var = cast(var, e);
struct variable *v = var->var;
- if (v->merged)
- v = v->merged;
+ v = v->merged;
lrv = var_value(c, v);
rvtype = v->type;
break;
struct binode *b2 = cast(binode, b->right);
left = interp_exec(c, b->left, <ype);
if (left.bool)
- rv = interp_exec(c, b2->left, &rvtype);
+ rv = interp_exec(c, b2->left, &rvtype); // UNTESTED
else
rv = interp_exec(c, b2->right, &rvtype);
}
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
if (t)
propagate_types(b->right, c, ok, t, 0);
else {
- t = propagate_types(b->right, c, ok, NULL, Rnolabel);
- if (t)
- t = propagate_types(b->left, c, ok, t, 0);
+ t = propagate_types(b->right, c, ok, NULL, Rnolabel); // UNTESTED
+ if (t) // UNTESTED
+ t = propagate_types(b->left, c, ok, t, 0); // UNTESTED
}
if (!type_compat(type, Tbool, 0))
type_err(c, "error: Comparison returns %1 but %2 expected", prog,
break;
}
-### Expressions: The rest
+### Expressions: Arithmetic etc.
The remaining expressions with the highest precedence are arithmetic,
string concatenation, and string conversion. String concatenation
| Value ${ $0 = $<1; }$
| Variable ${ $0 = $<1; }$
+###### Grammar
+
$eop
Eop -> + ${ $0.op = Plus; }$
| - ${ $0.op = Minus; }$
/* op must be string, result is number */
propagate_types(b->left, c, ok, Tstr, 0);
if (!type_compat(type, Tnum, 0))
- type_err(c,
+ type_err(c, // UNTESTED
"error: Can only convert string to number, not %1",
prog, type, 0, NULL);
return Tnum;
char tail[3];
int neg = 0;
if (tx.txt[0] == '-') {
- neg = 1;
- tx.txt++;
- tx.len--;
+ neg = 1; // UNTESTED
+ tx.txt++; // UNTESTED
+ tx.len--; // UNTESTED
}
if (number_parse(rv.num, tail, tx) == 0)
- mpq_init(rv.num);
+ mpq_init(rv.num); // UNTESTED
else if (neg)
- mpq_neg(rv.num, rv.num);
+ mpq_neg(rv.num, rv.num); // UNTESTED
if (tail[0])
- printf("Unsupported suffix: %.*s\n", tx.len, tx.txt);
+ printf("Unsupported suffix: %.*s\n", tx.len, tx.txt); // UNTESTED
break;
return rv;
}
+### Function calls
+
+A function call can appear either as an expression or as a statement.
+As functions cannot yet return values, only the statement version will work.
+We use a new 'Funcall' binode type to link the function with a list of
+arguments, form with the 'List' nodes.
+
+###### Binode types
+ Funcall,
+
+###### expression grammar
+ | Variable ( ExpressionList ) ${ {
+ struct binode *b = new(binode);
+ b->op = Funcall;
+ b->left = $<V;
+ b->right = reorder_bilist($<EL);
+ $0 = b;
+ } }$
+ | Variable ( ) ${ {
+ struct binode *b = new(binode);
+ b->op = Funcall;
+ b->left = $<V;
+ b->right = NULL;
+ $0 = b;
+ } }$
+
+###### SimpleStatement Grammar
+
+ | Variable ( ExpressionList ) ${ {
+ struct binode *b = new(binode);
+ b->op = Funcall;
+ b->left = $<V;
+ b->right = reorder_bilist($<EL);
+ $0 = b;
+ } }$
+
+###### print binode cases
+
+ case Funcall:
+ do_indent(indent, "");
+ print_exec(b->left, -1, bracket);
+ printf("(");
+ for (b = cast(binode, b->right); b; b = cast(binode, b->right)) {
+ if (b->left) {
+ printf(" ");
+ print_exec(b->left, -1, bracket);
+ if (b->right)
+ printf(",");
+ }
+ }
+ printf(")");
+ if (indent >= 0)
+ printf("\n");
+ break;
+
+###### propagate binode cases
+
+ case Funcall: {
+ /* Every arg must match formal parameter, and result
+ * is return type of function
+ */
+ struct binode *args = cast(binode, b->right);
+ struct var *v = cast(var, b->left);
+
+ if (!v->var->type || v->var->type->check_args == NULL) {
+ type_err(c, "error: attempt to call a non-function.",
+ prog, NULL, 0, NULL);
+ return NULL;
+ }
+ v->var->type->check_args(c, ok, v->var->type, args);
+ return v->var->type->function.return_type;
+ }
+
+###### interp binode cases
+
+ case Funcall: {
+ struct var *v = cast(var, b->left);
+ struct type *t = v->var->type;
+ void *oldlocal = c->local;
+ int old_size = c->local_size;
+ void *local = calloc(1, t->function.local_size);
+ struct value *fbody = var_value(c, v->var);
+ struct binode *arg = cast(binode, b->right);
+ struct binode *param = t->function.params;
+
+ while (param) {
+ struct var *pv = cast(var, param->left);
+ struct type *vtype = NULL;
+ struct value val = interp_exec(c, arg->left, &vtype);
+ struct value *lval;
+ c->local = local; c->local_size = t->function.local_size;
+ lval = var_value(c, pv->var);
+ c->local = oldlocal; c->local_size = old_size;
+ memcpy(lval, &val, vtype->size);
+ param = cast(binode, param->right);
+ arg = cast(binode, arg->right);
+ }
+ c->local = local; c->local_size = t->function.local_size;
+ rv = interp_exec(c, fbody->function, &rvtype);
+ c->local = oldlocal; c->local_size = old_size;
+ free(local);
+ break;
+ }
+
### Blocks, Statements, and Statement lists.
Now that we have expressions out of the way we need to turn to
case Block:
if (indent < 0) {
// simple statement
- if (b->left == NULL)
- printf("pass");
+ if (b->left == NULL) // UNTESTED
+ printf("pass"); // UNTESTED
else
- print_exec(b->left, indent, bracket);
- if (b->right) {
- printf("; ");
- print_exec(b->right, indent, bracket);
+ print_exec(b->left, indent, bracket); // UNTESTED
+ if (b->right) { // UNTESTED
+ printf("; "); // UNTESTED
+ print_exec(b->right, indent, bracket); // UNTESTED
}
} else {
// block, one per line
for (e = b; e; e = cast(binode, e->right)) {
t = propagate_types(e->left, c, ok, NULL, rules);
- if ((rules & Rboolok) && t == Tbool)
+ if ((rules & Rboolok) && (t == Tbool || t == Tnone))
t = NULL;
- if (t && t != Tnone && t != Tbool) {
+ if (t == Tnone && e->right)
+ /* Only the final statement *must* return a value
+ * when not Rboolok
+ */
+ t = NULL;
+ if (t) {
if (!type)
type = t;
else if (t != type)
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;
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, <ype);
- 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, <ype);
+ print_value(ltype, &left);
+ free_value(ltype, &left);
+ if (b2->right)
+ putchar(' ');
+ }
+ if (b->right == NULL)
printf("\n");
+ ltype = Tnone;
break;
}
type_err(c,
"Variable declared with no type or value: %v",
$1, NULL, 0, NULL);
+ free_var($1);
} else {
$0 = new(binode);
$0->op = Declare;
do_indent(indent, "");
print_exec(b->left, indent, bracket);
if (cast(var, b->left)->var->constant) {
+ printf("::");
if (v->where_decl == v->where_set) {
- printf("::");
type_print(v->type, stdout);
printf(" ");
- } else
- printf(" ::");
+ }
} else {
+ printf(":");
if (v->where_decl == v->where_set) {
- printf(":");
type_print(v->type, stdout);
printf(" ");
- } else
- printf(" :");
+ }
}
if (b->right) {
printf("= ");
case Assign:
lleft = linterp_exec(c, b->left, <ype);
- right = interp_exec(c, b->right, &rtype);
- if (lleft) {
- free_value(ltype, lleft);
- dup_value(ltype, &right, lleft);
- ltype = NULL;
- }
+ if (lleft)
+ dinterp_exec(c, b->right, lleft, ltype, 1);
+ ltype = Tnone;
break;
case Declare:
{
struct variable *v = cast(var, b->left)->var;
struct value *val;
- if (v->merged)
- v = v->merged;
+ 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) {
- right = interp_exec(c, b->right, &rtype);
- memcpy(val, &right, rtype->size);
- rtype = Tnone;
- } else {
+ if (b->right)
+ dinterp_exec(c, b->right, val, v->type, 0);
+ else
val_init(v->type, val);
- }
break;
}
### The `use` statement
-The `use` statement is the last "simple" statement. It is needed when
-the condition in a conditional statement is a block. `use` works much
-like `return` in C, but only completes the `condition`, not the whole
-function.
+The `use` statement is the last "simple" statement. It is needed when a
+statement block can return a value. This includes the body of a
+function which has a return type, and the "condition" code blocks in
+`if`, `while`, and `switch` statements.
###### Binode types
Use,
###### expr precedence
- $TERM use
+ $TERM use
###### SimpleStatement Grammar
| use Expression ${
`Rboolok` flag which is passed to `propagate_types()`.
The `cond_statement` cannot fit into a `binode` so a new `exec` is
-defined.
+defined. As there are two scopes which cover multiple parts - one for
+the whole statement and one for "while" and "do" - and as we will use
+the 'struct exec' to track scopes, we actually need two new types of
+exec. One is a `binode` for the looping part, the rest is the
+`cond_statement`. The `cond_statement` will use an auxilliary `struct
+casepart` to track a list of case parts.
+
+###### Binode types
+ Loop
###### exec type
Xcond_statement,
};
struct cond_statement {
struct exec;
- struct exec *forpart, *condpart, *dopart, *thenpart, *elsepart;
+ struct exec *forpart, *condpart, *thenpart, *elsepart;
+ struct binode *looppart;
struct casepart *casepart;
};
return;
free_exec(s->forpart);
free_exec(s->condpart);
- free_exec(s->dopart);
+ free_exec(s->looppart);
free_exec(s->thenpart);
free_exec(s->elsepart);
free_casepart(s->casepart);
// may or may not end with EOL
// WhilePart and IfPart include an appropriate Suffix
- // Both ForPart and Whilepart open scopes, and CondSuffix only
- // closes one - so in the first branch here we have another to close.
+ // ForPart, SwitchPart, and IfPart open scopes, o we have to close
+ // them. WhilePart opens and closes its own scope.
CondStatement -> ForPart OptNL ThenPart OptNL WhilePart CondSuffix ${
$0 = $<CS;
$0->forpart = $<FP;
$0->thenpart = $<TP;
- $0->condpart = $WP.condpart; $WP.condpart = NULL;
- $0->dopart = $WP.dopart; $WP.dopart = NULL;
- var_block_close(c, CloseSequential);
+ $0->looppart = $<WP;
+ var_block_close(c, CloseSequential, $0);
}$
| ForPart OptNL WhilePart CondSuffix ${
$0 = $<CS;
$0->forpart = $<FP;
- $0->condpart = $WP.condpart; $WP.condpart = NULL;
- $0->dopart = $WP.dopart; $WP.dopart = NULL;
- var_block_close(c, CloseSequential);
+ $0->looppart = $<WP;
+ var_block_close(c, CloseSequential, $0);
}$
| WhilePart CondSuffix ${
$0 = $<CS;
- $0->condpart = $WP.condpart; $WP.condpart = NULL;
- $0->dopart = $WP.dopart; $WP.dopart = NULL;
+ $0->looppart = $<WP;
}$
| SwitchPart OptNL CasePart CondSuffix ${
$0 = $<CS;
$0->condpart = $<SP;
$CP->next = $0->casepart;
$0->casepart = $<CP;
+ 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, $0);
}$
| 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 ${
$0 = $<1;
- // This is where we close scope of the whole
- // "for" or "while" statement
- var_block_close(c, CloseSequential);
}$
| Newlines CasePart CondSuffix ${
$0 = $<CS;
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
$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
- // These scopes are closed in CondSuffix
+ // These scopes are closed in CondStatement
ForPart -> for OpenBlock ${
$0 = $<Bl;
}$
ThenPart -> then OpenBlock ${
$0 = $<OB;
- var_block_close(c, CloseSequential);
+ var_block_close(c, CloseSequential, $0);
}$
- $cond_statement
- // This scope is closed in CondSuffix
- WhilePart -> while UseBlock OptNL do Block ${
- $0.condpart = $<UB;
- $0.dopart = $<Bl;
+ $*binode
+ // This scope is closed in CondStatement
+ WhilePart -> while UseBlock OptNL do OpenBlock ${
+ $0 = new(binode);
+ $0->op = Loop;
+ $0->left = $<UB;
+ $0->right = $<OB;
+ var_block_close(c, CloseSequential, $0->right);
+ var_block_close(c, CloseSequential, $0);
}$
- | while OpenScope Expression ColonBlock ${
- $0.condpart = $<Exp;
- $0.dopart = $<Bl;
+ | while OpenScope Expression OpenScope ColonBlock ${
+ $0 = new(binode);
+ $0->op = Loop;
+ $0->left = $<Exp;
+ $0->right = $<CB;
+ var_block_close(c, CloseSequential, $0->right);
+ var_block_close(c, CloseSequential, $0);
}$
- IfPart -> if UseBlock OptNL then OpenBlock ClosePara ${
+ $cond_statement
+ IfPart -> if UseBlock OptNL then OpenBlock ${
$0.condpart = $<UB;
- $0.thenpart = $<Bl;
+ $0.thenpart = $<OB;
+ var_block_close(c, CloseParallel, $0.thenpart);
}$
- | if OpenScope Expression OpenScope ColonBlock ClosePara ${
+ | if OpenScope Expression OpenScope ColonBlock ${
$0.condpart = $<Ex;
- $0.thenpart = $<Bl;
+ $0.thenpart = $<CB;
+ var_block_close(c, CloseParallel, $0.thenpart);
}$
- | if OpenScope Expression OpenScope OptNL then Block ClosePara ${
+ | if OpenScope Expression OpenScope OptNL then Block ${
$0.condpart = $<Ex;
$0.thenpart = $<Bl;
+ var_block_close(c, CloseParallel, $0.thenpart);
}$
$*exec
- // This scope is closed in CondSuffix
+ // This scope is closed in CondStatement
SwitchPart -> switch OpenScope Expression ${
$0 = $<Ex;
}$
$0 = $<Bl;
}$
+###### print binode cases
+ case Loop:
+ if (b->left && b->left->type == Xbinode &&
+ cast(binode, b->left)->op == Block) {
+ if (bracket)
+ do_indent(indent, "while {\n");
+ else
+ do_indent(indent, "while\n");
+ print_exec(b->left, indent+1, bracket);
+ if (bracket)
+ do_indent(indent, "} do {\n");
+ else
+ do_indent(indent, "do\n");
+ print_exec(b->right, indent+1, bracket);
+ if (bracket)
+ do_indent(indent, "}\n");
+ } else {
+ do_indent(indent, "while ");
+ print_exec(b->left, 0, bracket);
+ if (bracket)
+ printf(" {\n");
+ else
+ printf(":\n");
+ print_exec(b->right, indent+1, bracket);
+ if (bracket)
+ do_indent(indent, "}\n");
+ }
+ break;
+
###### print exec cases
case Xcond_statement:
}
if (bracket) do_indent(indent, "}\n");
}
- if (cs->dopart) {
- // a loop
- if (cs->condpart && cs->condpart->type == Xbinode &&
- cast(binode, cs->condpart)->op == Block) {
- if (bracket)
- do_indent(indent, "while {\n");
- else
- do_indent(indent, "while\n");
- print_exec(cs->condpart, indent+1, bracket);
- if (bracket)
- do_indent(indent, "} do {\n");
- else
- do_indent(indent, "do\n");
- print_exec(cs->dopart, indent+1, bracket);
- if (bracket)
- do_indent(indent, "}\n");
- } else {
- do_indent(indent, "while ");
- print_exec(cs->condpart, 0, bracket);
- if (bracket)
- printf(" {\n");
- else
- printf(":\n");
- print_exec(cs->dopart, indent+1, bracket);
- if (bracket)
- do_indent(indent, "}\n");
- }
+ if (cs->looppart) {
+ print_exec(cs->looppart, indent, bracket);
} else {
// a condition
if (cs->casepart)
if (bracket)
printf(" {\n");
else
- printf(":\n");
+ printf("\n");
print_exec(cs->condpart, indent+1, bracket);
if (bracket)
do_indent(indent, "}\n");
if (cs->thenpart) {
- do_indent(indent, "then:\n");
+ do_indent(indent, "then\n");
print_exec(cs->thenpart, indent+1, bracket);
}
} else {
break;
}
+###### propagate binode cases
+ case Loop:
+ t = propagate_types(b->right, c, ok, Tnone, 0);
+ if (!type_compat(Tnone, t, 0))
+ *ok = 0; // UNTESTED
+ return propagate_types(b->left, c, ok, type, rules);
+
###### propagate exec cases
case Xcond_statement:
{
- // forpart and dopart must return Tnone
- // thenpart must return Tnone if there is a dopart,
+ // forpart and looppart->right must return Tnone
+ // thenpart must return Tnone if there is a loopart,
// otherwise it is like elsepart.
// condpart must:
// be bool if there is no casepart
t = propagate_types(cs->forpart, c, ok, Tnone, 0);
if (!type_compat(Tnone, t, 0))
- *ok = 0;
- t = propagate_types(cs->dopart, c, ok, Tnone, 0);
- if (!type_compat(Tnone, t, 0))
- *ok = 0;
- if (cs->dopart) {
+ *ok = 0; // UNTESTED
+
+ if (cs->looppart) {
t = propagate_types(cs->thenpart, c, ok, Tnone, 0);
if (!type_compat(Tnone, t, 0))
- *ok = 0;
+ *ok = 0; // UNTESTED
}
- if (cs->casepart == NULL)
+ if (cs->casepart == NULL) {
propagate_types(cs->condpart, c, ok, Tbool, 0);
- else {
+ propagate_types(cs->looppart, c, ok, Tbool, 0);
+ } else {
/* Condpart must match case values, with bool permitted */
t = NULL;
for (cp = cs->casepart;
cp && !t; cp = cp->next)
t = propagate_types(cp->value, c, ok, NULL, 0);
if (!t && cs->condpart)
- t = propagate_types(cs->condpart, c, ok, NULL, Rboolok);
+ t = propagate_types(cs->condpart, c, ok, NULL, Rboolok); // UNTESTED
+ if (!t && cs->looppart)
+ t = propagate_types(cs->looppart, c, ok, NULL, Rboolok); // UNTESTED
// Now we have a type (I hope) push it down
if (t) {
for (cp = cs->casepart; cp; cp = cp->next)
propagate_types(cp->value, c, ok, t, 0);
propagate_types(cs->condpart, c, ok, t, Rboolok);
+ propagate_types(cs->looppart, c, ok, t, Rboolok);
}
}
// (if)then, else, and case parts must return expected type.
- if (!cs->dopart && !type)
+ if (!cs->looppart && !type)
type = propagate_types(cs->thenpart, c, ok, NULL, rules);
if (!type)
type = propagate_types(cs->elsepart, c, ok, NULL, rules);
for (cp = cs->casepart;
cp && !type;
- cp = cp->next)
- type = propagate_types(cp->action, c, ok, NULL, rules);
+ cp = cp->next) // UNTESTED
+ type = propagate_types(cp->action, c, ok, NULL, rules); // UNTESTED
if (type) {
- if (!cs->dopart)
+ if (!cs->looppart)
propagate_types(cs->thenpart, c, ok, type, rules);
propagate_types(cs->elsepart, c, ok, type, rules);
for (cp = cs->casepart; cp ; cp = cp->next)
return NULL;
}
+###### interp binode cases
+ case Loop:
+ // This just performs one iterration of the loop
+ rv = interp_exec(c, b->left, &rvtype);
+ if (rvtype == Tnone ||
+ (rvtype == Tbool && rv.bool != 0))
+ // rvtype is Tnone or Tbool, doesn't need to be freed
+ interp_exec(c, b->right, NULL);
+ break;
+
###### interp exec cases
case Xcond_statement:
{
if (cs->forpart)
interp_exec(c, cs->forpart, NULL);
- do {
- if (cs->condpart)
- cnd = interp_exec(c, cs->condpart, &cndtype);
- else
- cndtype = Tnone;
- if (!(cndtype == Tnone ||
- (cndtype == Tbool && cnd.bool != 0)))
- break;
- // cnd is Tnone or Tbool, doesn't need to be freed
- if (cs->dopart)
- interp_exec(c, cs->dopart, NULL);
-
- if (cs->thenpart) {
+ if (cs->looppart) {
+ while ((cnd = interp_exec(c, cs->looppart, &cndtype)),
+ cndtype == Tnone || (cndtype == Tbool && cnd.bool != 0))
+ interp_exec(c, cs->thenpart, NULL);
+ } else {
+ cnd = interp_exec(c, cs->condpart, &cndtype);
+ if ((cndtype == Tnone ||
+ (cndtype == Tbool && cnd.bool != 0))) {
+ // cnd is Tnone or Tbool, doesn't need to be freed
rv = interp_exec(c, cs->thenpart, &rvtype);
- if (rvtype != Tnone || !cs->dopart)
- goto Xcond_done;
- free_value(rvtype, &rv);
- rvtype = Tnone;
+ // skip else (and cases)
+ goto Xcond_done;
}
- } while (cs->dopart);
-
+ }
for (cp = cs->casepart; cp; cp = cp->next) {
v = interp_exec(c, cp->value, &vtype);
if (value_cmp(cndtype, vtype, &v, &cnd) == 0) {
| DeclarationList Declaration
Declaration -> ERROR Newlines ${
- tok_err(c,
+ tok_err(c, // UNTESTED
"error: unhandled parse error", &$1);
}$
| DeclareConstant
v->where_set = var;
var->var = v;
v->constant = 1;
+ v->global = 1;
} else {
- v = var_ref(c, $1.txt);
+ struct variable *vorig = var_ref(c, $1.txt);
tok_err(c, "error: name already declared", &$1);
type_err(c, "info: this is where '%v' was first declared",
- v->where_decl, NULL, 0, NULL);
+ vorig->where_decl, NULL, 0, NULL);
}
do {
ok = 1;
while (target != 0) {
int i = 0;
for (v = context.in_scope; v; v=v->in_scope)
- if (v->depth == 0) {
+ if (v->depth == 0 && v->constant) {
i += 1;
if (i == target)
break;
}
}
-### Finally the whole `main` function.
+### Function declarations
-An Ocean program can currently have only one function - `main` - and
-that must exist. It expects an array of strings with a provided size.
-Following this is a `block` which is the code to execute.
+The code in an Ocean program is all stored in function declarations.
+One of the functions must be named `main` and it must accept an array of
+strings as a parameter - the command line arguments.
-As this is the top level, several things are handled a bit
-differently.
-The function is not interpreted by `interp_exec` as that isn't
-passed the argument list which the program requires. Similarly type
-analysis is a bit more interesting at this level.
+As this is the top level, several things are handled a bit differently.
+The function is not interpreted by `interp_exec` as that isn't passed
+the argument list which the program requires. Similarly type analysis
+is a bit more interesting at this level.
+
+###### ast functions
+
+ static struct variable *declare_function(struct parse_context *c,
+ struct variable *name,
+ struct binode *args,
+ struct type *ret,
+ struct exec *code)
+ {
+ struct text funcname = {" func", 5};
+ if (name) {
+ struct value fn = {.function = code};
+ name->type = add_type(c, funcname, &function_prototype);
+ name->type->function.params = reorder_bilist(args);
+ name->type->function.return_type = ret;
+ global_alloc(c, name->type, name, &fn);
+ var_block_close(c, CloseFunction, code);
+ name->type->function.scope = c->out_scope;
+ } else {
+ free_binode(args);
+ free_type(ret);
+ free_exec(code);
+ var_block_close(c, CloseFunction, NULL);
+ }
+ c->out_scope = NULL;
+ return name;
+ }
+
+###### declare terminals
+ $TERM return
###### top level grammar
- DeclareFunction -> MainFunction ${ {
- if (c->prog)
- type_err(c, "\"main\" defined a second time",
- $1, NULL, 0, NULL);
- else
- c->prog = $<1;
- } }$
+ $*variable
+ DeclareFunction -> func FuncName ( OpenScope ArgsLine ) Block Newlines ${
+ $0 = declare_function(c, $<FN, $<Ar, Tnone, $<Bl);
+ }$
+ | func FuncName IN OpenScope Args OUT OptNL do Block Newlines ${
+ $0 = declare_function(c, $<FN, $<Ar, Tnone, $<Bl);
+ }$
+ | func FuncName NEWLINE OpenScope OptNL do Block Newlines ${
+ $0 = declare_function(c, $<FN, NULL, Tnone, $<Bl);
+ }$
+ | func FuncName ( OpenScope ArgsLine ) : Type Block Newlines ${
+ $0 = declare_function(c, $<FN, $<Ar, $<Ty, $<Bl);
+ }$
+ | func FuncName IN OpenScope Args OUT OptNL return Type Newlines do Block Newlines ${
+ $0 = declare_function(c, $<FN, $<Ar, $<Ty, $<Bl);
+ }$
+ | func FuncName NEWLINE OpenScope return Type Newlines do Block Newlines ${
+ $0 = declare_function(c, $<FN, NULL, $<Ty, $<Bl);
+ }$
-###### 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;
- printf(" ");
- print_exec(b2->left, 0, 0);
- printf(":");
- type_print(v->type, stdout);
- }
- if (bracket)
- printf(") {\n");
- else
- printf(")\n");
- print_exec(b->right, indent+1, bracket);
- if (bracket)
- do_indent(indent, "}\n");
- break;
+###### print func decls
+ {
+ struct variable *v;
+ int target = -1;
-###### propagate binode cases
- case List:
- case Func: abort(); // NOTEST
+ while (target != 0) {
+ int i = 0;
+ for (v = context.in_scope; v; v=v->in_scope)
+ if (v->depth == 0 && v->type && v->type->check_args) {
+ i += 1;
+ if (i == target)
+ break;
+ }
+
+ if (target == -1) {
+ target = i;
+ } else {
+ struct value *val = var_value(&context, v);
+ printf("func %.*s", v->name->name.len, v->name->name.txt);
+ v->type->print_type_decl(v->type, stdout);
+ if (brackets)
+ print_exec(val->function, 0, brackets);
+ else
+ print_value(v->type, val);
+ printf("/* frame size %d */\n", v->type->function.local_size);
+ target -= 1;
+ }
+ }
+ }
###### core functions
- static int analyse_prog(struct exec *prog, struct parse_context *c)
+ static int analyse_funcs(struct parse_context *c)
{
- struct binode *bp = cast(binode, prog);
+ struct variable *v;
+ int all_ok = 1;
+ for (v = c->in_scope; v; v = v->in_scope) {
+ struct value *val;
+ int ok = 1;
+ if (v->depth != 0 || !v->type || !v->type->check_args)
+ continue;
+ val = var_value(c, v);
+ do {
+ ok = 1;
+ propagate_types(val->function, c, &ok,
+ v->type->function.return_type, 0);
+ } while (ok == 2);
+ if (ok)
+ /* Make sure everything is still consistent */
+ propagate_types(val->function, c, &ok,
+ v->type->function.return_type, 0);
+ if (!ok)
+ all_ok = 0;
+ if (!v->type->function.return_type->dup) {
+ type_err(c, "error: function cannot return value of type %1",
+ v->where_decl, v->type->function.return_type, 0, NULL);
+ }
+
+ scope_finalize(c, v->type);
+ }
+ return all_ok;
+ }
+
+ static int analyse_main(struct type *type, struct parse_context *c)
+ {
+ struct binode *bp = type->function.params;
struct binode *b;
int ok = 1;
int arg = 0;
struct type *argv_type;
struct text argv_type_name = { " argv", 5 };
- if (!bp)
- return 0; // NOTEST
-
argv_type = add_type(c, argv_type_name, &array_prototype);
argv_type->array.member = Tstr;
argv_type->array.unspec = 1;
- for (b = cast(binode, bp->left); b; b = cast(binode, b->right)) {
+ for (b = bp; b; b = cast(binode, b->right)) {
ok = 1;
switch (arg++) {
case 0: /* argv */
default: /* invalid */ // NOTEST
propagate_types(b->left, c, &ok, Tnone, 0); // NOTEST
}
+ if (!ok)
+ c->parse_error = 1;
}
- do {
- ok = 1;
- propagate_types(bp->right, c, &ok, Tnone, 0);
- } while (ok == 2);
- if (!ok)
- return 0;
-
- /* Make sure everything is still consistent */
- propagate_types(bp->right, c, &ok, Tnone, 0);
- if (!ok)
- return 0;
- scope_finalize(c);
- return 1;
+ return !c->parse_error;
}
- static void interp_prog(struct parse_context *c, struct exec *prog,
- int argc, char **argv)
+ static void interp_main(struct parse_context *c, int argc, char **argv)
{
- struct binode *p = cast(binode, prog);
+ struct value *progp = NULL;
+ struct text main_name = { "main", 4 };
+ struct variable *mainv;
struct binode *al;
int anum = 0;
struct value v;
struct type *vtype;
- if (!prog)
- return; // NOTEST
- al = cast(binode, p->left);
+ mainv = var_ref(c, main_name);
+ if (mainv)
+ progp = var_value(c, mainv);
+ if (!progp || !progp->function) {
+ fprintf(stderr, "oceani: no main function found.\n");
+ c->parse_error = 1;
+ return;
+ }
+ if (!analyse_main(mainv->type, c)) {
+ fprintf(stderr, "oceani: main has wrong type.\n");
+ c->parse_error = 1;
+ return;
+ }
+ al = mainv->type->function.params;
+
+ c->local_size = mainv->type->function.local_size;
+ c->local = calloc(1, c->local_size);
while (al) {
struct var *v = cast(var, al->left);
struct value *vl = var_value(c, v->var);
array_init(v->var->type, vl);
for (i = 0; i < argc; i++) {
struct value *vl2 = vl->array + i * v->var->type->array.member->size;
-
arg.str.txt = argv[i];
arg.str.len = strlen(argv[i]);
}
al = cast(binode, al->right);
}
- v = interp_exec(c, p->right, &vtype);
+ v = interp_exec(c, progp->function, &vtype);
free_value(vtype, &v);
+ free(c->local);
+ c->local = NULL;
}
-###### interp binode cases
- case List:
- case Func: abort(); // NOTEST
+###### ast functions
+ void free_variable(struct variable *v)
+ {
+ }
## And now to test it out.
name:string
alive:Boolean
- func main
- argv:[argc::]string
- do
+ func main(argv:[argc::]string)
print "Hello World, what lovely oceans you have!"
print "Are there", five, "?"
print pi, pie, "but", cake
else
hi = mid
if hi - lo < 1:
+ lo = mid
use GiveUp
use True
do pass
case Found:
print "Yay, I found", target
case GiveUp:
- print "Closest I found was", mid
+ print "Closest I found was", lo
size::= 10
list:[size]number
code / ocean / blobdiff