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Filter: Store variables and function arguments on stack
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@marenamat
marenamat committed May 21, 2019
1 parent 20c6ea7 commit 96d757c
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Showing 11 changed files with 126 additions and 196 deletions.
3 changes: 2 additions & 1 deletion conf/conf.h
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Original file line number Diff line number Diff line change
Expand Up @@ -116,7 +116,8 @@ struct symbol {
const struct filter *filter; /* For SYM_FILTER */
struct rtable_config *table; /* For SYM_TABLE */
struct f_dynamic_attr *attribute; /* For SYM_ATTRIBUTE */
struct f_val *val; /* For SYM_CONSTANT or SYM_VARIABLE */
struct f_val *val; /* For SYM_CONSTANT */
uint offset; /* For SYM_VARIABLE */
};

char name[0];
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2 changes: 1 addition & 1 deletion conf/confbase.Y
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Original file line number Diff line number Diff line change
Expand Up @@ -70,7 +70,7 @@ CF_DECLS
struct f_dynamic_attr fda;
struct f_static_attr fsa;
struct f_lval flv;
const struct f_line *fl;
struct f_line *fl;
const struct filter *f;
struct f_tree *e;
struct f_trie *trie;
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140 changes: 57 additions & 83 deletions filter/config.Y
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Original file line number Diff line number Diff line change
Expand Up @@ -15,6 +15,8 @@ CF_HDR

CF_DEFINES

static uint decls_count;

static inline u32 pair(u32 a, u32 b) { return (a << 16) | b; }
static inline u32 pair_a(u32 p) { return p >> 16; }
static inline u32 pair_b(u32 p) { return p & 0xFFFF; }
Expand Down Expand Up @@ -398,8 +400,8 @@ assert_assign(struct f_lval *lval, struct f_inst *expr, const char *start, const
struct f_inst *setter, *getter, *checker;
switch (lval->type) {
case F_LVAL_VARIABLE:
setter = f_new_inst(FI_SET, expr, lval->sym);
getter = f_new_inst(FI_VARIABLE, lval->sym);
setter = f_new_inst(FI_VAR_SET, expr, lval->sym);
getter = f_new_inst(FI_VAR_GET, lval->sym);
break;
case F_LVAL_PREFERENCE:
setter = f_new_inst(FI_PREF_SET, expr);
Expand Down Expand Up @@ -446,14 +448,14 @@ CF_KEYWORDS(FUNCTION, PRINT, PRINTN, UNSET, RETURN,
%nonassoc THEN
%nonassoc ELSE

%type <xp> cmds_int function_body declsn function_params
%type <x> term block cmd cmds constant constructor print_one print_list var_list var_listn function_call symbol_value bgp_path_expr bgp_path bgp_path_tail one_decl decls
%type <xp> cmds_int
%type <x> term block cmd cmds constant constructor print_one print_list var_list function_call symbol_value bgp_path_expr bgp_path bgp_path_tail
%type <fda> dynamic_attr
%type <fsa> static_attr
%type <f> filter where_filter
%type <fl> filter_body
%type <fl> filter_body function_body
%type <flv> lvalue
%type <i> type
%type <i> type function_params
%type <ecs> ec_kind
%type <fret> break_command
%type <i32> cnum
Expand Down Expand Up @@ -553,44 +555,25 @@ type:
}
;

one_decl:
type CF_SYM_VOID {
struct f_val * val = cfg_alloc(sizeof(struct f_val));
val->type = T_VOID;
$2 = cf_define_symbol($2, SYM_VARIABLE | $1, val, val);
DBG( "New variable %s type %x\n", $2->name, $1 );
$$ = f_new_inst(FI_SET, NULL, $2);
}
;

/* Decls with ';' at the end. Beware; these are reversed. */
decls: /* EMPTY */ { $$ = NULL; }
| one_decl ';' decls {
$$ = $1;
$$->next = $3;
}
/* Declarations with ';' at the end */
decls:
/* EMPTY */
| declsn ';'
;

/* Declarations that have no ';' at the end. */
declsn: one_decl { $$[0] = $$[1] = $1; }
| one_decl ';' declsn {
$3[1]->next = $1;
$$[1] = $3[1] = $1;
$$[0] = $3[0];
declsn:
type CF_SYM_VOID {
cf_define_symbol($2, SYM_VARIABLE | $1, offset, decls_count++);
}
;

filter_body:
function_body {
if ($1[0]) {
const struct f_inst *inst[2] = { $1[0], $1[1] };
$$ = f_postfixify_concat(inst, 2);
}
else
$$ = f_postfixify($1[1]);
| declsn ';' type CF_SYM_VOID {
if (decls_count >= 0xff) cf_error("Too many declarations, at most 255 allowed");
cf_define_symbol($4, SYM_VARIABLE | $3, offset, decls_count++);
}
;

filter_body: { decls_count = 0; } function_body { $$ = $2; } ;

filter:
CF_SYM_KNOWN {
cf_assert_symbol($1, SYM_FILTER);
Expand All @@ -611,14 +594,14 @@ where_filter:
;

function_params:
'(' declsn ')' { $$[0] = $2[0]; $$[1] = $2[1]; }
| '(' ')' { $$[0] = $$[1] = NULL; }
'(' declsn ')' { $$ = decls_count; }
| '(' ')' { $$ = 0; }
;

function_body:
decls '{' cmds '}' {
$$[0] = $1 ? f_clear_local_vars($1) : NULL;
$$[1] = $3;
$$ = f_postfixify($3);
$$->vars = decls_count;
}
;

Expand All @@ -627,33 +610,11 @@ function_def:
FUNCTION CF_SYM_VOID { DBG( "Beginning of function %s\n", $2->name );
$2 = cf_define_symbol($2, SYM_FUNCTION, function, NULL);
cf_push_scope($2);
decls_count = 0;
} function_params function_body {
const struct f_inst *catlist[4];
uint count = 0;

/* Argument setters */
if ($4[0])
catlist[count++] = $4[0];

/* Local var clearers */
if ($5[0])
catlist[count++] = $5[0];

/* Return void if no return is needed */
catlist[count++] = f_new_inst(FI_CONSTANT, (struct f_val) { .type = T_VOID });

/* Function body itself */
if ($5[1])
catlist[count++] = $5[1];

struct f_line *fl = f_postfixify_concat(catlist, count);

fl->args = 0;
for (const struct f_inst *arg = $4[0]; arg; arg = arg->next)
fl->args++;

$2->function = fl;

$5->vars -= $4;
$5->args = $4;
$2->function = $5;
cf_pop_scope();
}
;
Expand Down Expand Up @@ -862,18 +823,44 @@ constructor:
;


/* This generates the function_call variable list backwards. */
var_list: /* EMPTY */ { $$ = NULL; }
| term { $$ = $1; }
| var_list ',' term { $$ = $3; $$->next = $1; }

function_call:
CF_SYM_KNOWN '(' var_list ')' {
$$ = f_new_inst(FI_CALL, $1, $3);
if ($1->class != SYM_FUNCTION)
cf_error("You can't call something which is not a function. Really.");

struct f_inst *fc = f_new_inst(FI_CALL, $1);
uint args = 0;
while ($3) {
args++;
struct f_inst *tmp = $3->next;
$3->next = fc;

fc = $3;
$3 = tmp;
}

if (args != $1->function->args)
cf_error("Function call '%s' got %u arguments, need %u arguments.",
$1->name, args, $1->function->args);

$$ = f_new_inst(FI_CONSTANT, (struct f_val) { .type = T_VOID });
$$->next = fc;
}
;

symbol_value: CF_SYM_KNOWN
{
switch ($1->class) {
case SYM_CONSTANT_RANGE:
$$ = f_new_inst(FI_CONSTANT_DEFINED, $1);
break;
case SYM_VARIABLE_RANGE:
$$ = f_new_inst(FI_VARIABLE, $1);
$$ = f_new_inst(FI_VAR_GET, $1);
break;
case SYM_ATTRIBUTE:
$$ = f_new_inst(FI_EA_GET, *$1->attribute);
Expand Down Expand Up @@ -988,19 +975,6 @@ print_list: /* EMPTY */ { $$ = NULL; }
}
;

var_listn: term {
$$ = $1;
}
| term ',' var_listn {
$$ = $1;
$$->next = $3;
}
;

var_list: /* EMPTY */ { $$ = NULL; }
| var_listn { $$ = $1; }
;

cmd:
IF term THEN block {
$$ = f_new_inst(FI_CONDITION, $2, $4, NULL);
Expand All @@ -1011,7 +985,7 @@ cmd:
| CF_SYM_KNOWN '=' term ';' {
switch ($1->class) {
case SYM_VARIABLE_RANGE:
$$ = f_new_inst(FI_SET, $3, $1);
$$ = f_new_inst(FI_VAR_SET, $3, $1);
break;
case SYM_ATTRIBUTE:
$$ = f_new_inst(FI_EA_SET, $3, *$1->attribute);
Expand Down
4 changes: 2 additions & 2 deletions filter/data.h
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Original file line number Diff line number Diff line change
Expand Up @@ -17,8 +17,8 @@

/* Internal types */
enum f_type {
/* Do not use type of zero, that way we'll see errors easier. */
T_VOID = 1,
/* Nothing. Simply nothing. */
T_VOID = 0,

/* User visible types, which fit in int */
T_INT = 0x10,
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3 changes: 2 additions & 1 deletion filter/decl.m4
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Original file line number Diff line number Diff line change
Expand Up @@ -209,6 +209,7 @@ do {
estk.item[estk.cnt].pos = 0;
estk.item[estk.cnt].line = $1;
estk.item[estk.cnt].ventry = vstk.cnt;
estk.item[estk.cnt].vbase = estk.item[estk.cnt-1].vbase;
estk.item[estk.cnt].emask = 0;
estk.cnt++;
} while (0)m4_dnl
Expand Down Expand Up @@ -377,7 +378,7 @@ FID_WR_PUT(4)

/* Filter instruction structure for config */
struct f_inst {
const struct f_inst *next; /* Next instruction */
struct f_inst *next; /* Next instruction */
enum f_instruction_code fi_code; /* Instruction code */
int size; /* How many instructions are underneath */
int lineno; /* Line number */
Expand Down
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