root/scripts/dtc/dtc-parser.y
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * (C) Copyright David Gibson <dwg@au1.ibm.com>, IBM Corporation.  2005.
 */
%locations

%{
#include <stdio.h>
#include <inttypes.h>

#include "dtc.h"
#include "srcpos.h"

extern int yylex(void);
extern void yyerror(char const *s);
#define ERROR(loc, ...) \
        do { \
                srcpos_error((loc), "Error", __VA_ARGS__); \
                treesource_error = true; \
        } while (0)

#define YYERROR_CALL(msg) yyerror(msg)

extern struct dt_info *parser_output;
extern bool treesource_error;

static bool is_ref_relative(const char *ref)
{
        return ref[0] != '/' && strchr(&ref[1], '/');
}

%}

%union {
        char *propnodename;
        char *labelref;
        uint8_t byte;
        struct data data;

        struct {
                struct data     data;
                int             bits;
        } array;

        struct property *prop;
        struct property *proplist;
        struct node *node;
        struct node *nodelist;
        struct reserve_info *re;
        uint64_t integer;
        unsigned int flags;
}

%token DT_V1
%token DT_PLUGIN
%token DT_MEMRESERVE
%token DT_LSHIFT DT_RSHIFT DT_LE DT_GE DT_EQ DT_NE DT_AND DT_OR
%token DT_BITS
%token DT_DEL_PROP
%token DT_DEL_NODE
%token DT_OMIT_NO_REF
%token <propnodename> DT_PROPNODENAME
%token <integer> DT_LITERAL
%token <integer> DT_CHAR_LITERAL
%token <byte> DT_BYTE
%token <data> DT_STRING
%token <labelref> DT_LABEL
%token <labelref> DT_LABEL_REF
%token <labelref> DT_PATH_REF
%token DT_INCBIN

%type <data> propdata
%type <data> propdataprefix
%type <flags> header
%type <flags> headers
%type <re> memreserve
%type <re> memreserves
%type <array> arrayprefix
%type <data> bytestring
%type <prop> propdef
%type <proplist> proplist
%type <labelref> dt_ref

%type <node> devicetree
%type <node> nodedef
%type <node> subnode
%type <nodelist> subnodes

%type <integer> integer_prim
%type <integer> integer_unary
%type <integer> integer_mul
%type <integer> integer_add
%type <integer> integer_shift
%type <integer> integer_rela
%type <integer> integer_eq
%type <integer> integer_bitand
%type <integer> integer_bitxor
%type <integer> integer_bitor
%type <integer> integer_and
%type <integer> integer_or
%type <integer> integer_trinary
%type <integer> integer_expr

%%

sourcefile:
          headers memreserves devicetree
                {
                        parser_output = build_dt_info($1, $2, $3,
                                                      guess_boot_cpuid($3));
                }
        ;

header:
          DT_V1 ';'
                {
                        $$ = DTSF_V1;
                }
        | DT_V1 ';' DT_PLUGIN ';'
                {
                        $$ = DTSF_V1 | DTSF_PLUGIN;
                }
        ;

headers:
          header
        | header headers
                {
                        if ($2 != $1)
                                ERROR(&@2, "Header flags don't match earlier ones");
                        $$ = $1;
                }
        ;

memreserves:
          /* empty */
                {
                        $$ = NULL;
                }
        | memreserve memreserves
                {
                        $$ = chain_reserve_entry($1, $2);
                }
        ;

memreserve:
          DT_MEMRESERVE integer_prim integer_prim ';'
                {
                        $$ = build_reserve_entry($2, $3);
                }
        | DT_LABEL memreserve
                {
                        add_label(&$2->labels, $1);
                        $$ = $2;
                }
        ;

dt_ref: DT_LABEL_REF | DT_PATH_REF;

devicetree:
          '/' nodedef
                {
                        $$ = name_node($2, "");
                }
        | devicetree '/' nodedef
                {
                        $$ = merge_nodes($1, $3);
                }
        | dt_ref nodedef
                {
                        /*
                         * We rely on the rule being always:
                         *   versioninfo plugindecl memreserves devicetree
                         * so $-1 is what we want (plugindecl)
                         */
                        if (!($<flags>-1 & DTSF_PLUGIN))
                                ERROR(&@2, "Label or path %s not found", $1);
                        else if (is_ref_relative($1))
                                ERROR(&@2, "Label-relative reference %s not supported in plugin", $1);
                        $$ = add_orphan_node(
                                        name_node(build_node(NULL, NULL, NULL),
                                                  ""),
                                        $2, $1);
                }
        | devicetree DT_LABEL dt_ref nodedef
                {
                        struct node *target = get_node_by_ref($1, $3);

                        if (($<flags>-1 & DTSF_PLUGIN) && is_ref_relative($3))
                                ERROR(&@2, "Label-relative reference %s not supported in plugin", $3);

                        if (target) {
                                add_label(&target->labels, $2);
                                merge_nodes(target, $4);
                        } else
                                ERROR(&@3, "Label or path %s not found", $3);
                        $$ = $1;
                }
        | devicetree DT_PATH_REF nodedef
                {
                        /*
                         * We rely on the rule being always:
                         *   versioninfo plugindecl memreserves devicetree
                         * so $-1 is what we want (plugindecl)
                         */
                        if ($<flags>-1 & DTSF_PLUGIN) {
                                if (is_ref_relative($2))
                                        ERROR(&@2, "Label-relative reference %s not supported in plugin", $2);
                                add_orphan_node($1, $3, $2);
                        } else {
                                struct node *target = get_node_by_ref($1, $2);

                                if (target)
                                        merge_nodes(target, $3);
                                else
                                        ERROR(&@2, "Label or path %s not found", $2);
                        }
                        $$ = $1;
                }
        | devicetree DT_LABEL_REF nodedef
                {
                        struct node *target = get_node_by_ref($1, $2);

                        if (target) {
                                merge_nodes(target, $3);
                        } else {
                                /*
                                 * We rely on the rule being always:
                                 *   versioninfo plugindecl memreserves devicetree
                                 * so $-1 is what we want (plugindecl)
                                 */
                                if ($<flags>-1 & DTSF_PLUGIN)
                                        add_orphan_node($1, $3, $2);
                                else
                                        ERROR(&@2, "Label or path %s not found", $2);
                        }
                        $$ = $1;
                }
        | devicetree DT_DEL_NODE dt_ref ';'
                {
                        struct node *target = get_node_by_ref($1, $3);

                        if (target)
                                delete_node(target);
                        else
                                ERROR(&@3, "Label or path %s not found", $3);


                        $$ = $1;
                }
        | devicetree DT_OMIT_NO_REF dt_ref ';'
                {
                        struct node *target = get_node_by_ref($1, $3);

                        if (target)
                                omit_node_if_unused(target);
                        else
                                ERROR(&@3, "Label or path %s not found", $3);


                        $$ = $1;
                }
        ;

nodedef:
          '{' proplist subnodes '}' ';'
                {
                        $$ = build_node($2, $3, &@$);
                }
        ;

proplist:
          /* empty */
                {
                        $$ = NULL;
                }
        | proplist propdef
                {
                        $$ = chain_property($2, $1);
                }
        ;

propdef:
          DT_PROPNODENAME '=' propdata ';'
                {
                        $$ = build_property($1, $3, &@$);
                        free($1);
                }
        | DT_PROPNODENAME ';'
                {
                        $$ = build_property($1, empty_data, &@$);
                        free($1);
                }
        | DT_DEL_PROP DT_PROPNODENAME ';'
                {
                        $$ = build_property_delete($2);
                        free($2);
                }
        | DT_LABEL propdef
                {
                        add_label(&$2->labels, $1);
                        $$ = $2;
                }
        ;

propdata:
          propdataprefix DT_STRING
                {
                        $$ = data_merge($1, $2);
                }
        | propdataprefix arrayprefix '>'
                {
                        $$ = data_merge($1, $2.data);
                }
        | propdataprefix '[' bytestring ']'
                {
                        $$ = data_merge($1, $3);
                }
        | propdataprefix dt_ref
                {
                        $1 = data_add_marker($1, TYPE_STRING, $2);
                        $$ = data_add_marker($1, REF_PATH, $2);
                }
        | propdataprefix DT_INCBIN '(' DT_STRING ',' integer_prim ',' integer_prim ')'
                {
                        FILE *f = srcfile_relative_open($4.val, NULL);
                        struct data d;

                        if ($6 != 0)
                                if (fseek(f, $6, SEEK_SET) != 0)
                                        die("Couldn't seek to offset %llu in \"%s\": %s",
                                            (unsigned long long)$6, $4.val,
                                            strerror(errno));

                        d = data_copy_file(f, $8);

                        $$ = data_merge($1, d);
                        fclose(f);
                }
        | propdataprefix DT_INCBIN '(' DT_STRING ')'
                {
                        FILE *f = srcfile_relative_open($4.val, NULL);
                        struct data d = empty_data;

                        d = data_copy_file(f, -1);

                        $$ = data_merge($1, d);
                        fclose(f);
                }
        | propdata DT_LABEL
                {
                        $$ = data_add_marker($1, LABEL, $2);
                }
        ;

propdataprefix:
          /* empty */
                {
                        $$ = empty_data;
                }
        | propdata ','
                {
                        $$ = $1;
                }
        | propdataprefix DT_LABEL
                {
                        $$ = data_add_marker($1, LABEL, $2);
                }
        ;

arrayprefix:
        DT_BITS DT_LITERAL '<'
                {
                        unsigned long long bits;
                        enum markertype type = TYPE_UINT32;

                        bits = $2;

                        switch (bits) {
                        case 8: type = TYPE_UINT8; break;
                        case 16: type = TYPE_UINT16; break;
                        case 32: type = TYPE_UINT32; break;
                        case 64: type = TYPE_UINT64; break;
                        default:
                                ERROR(&@2, "Array elements must be"
                                      " 8, 16, 32 or 64-bits");
                                bits = 32;
                        }

                        $$.data = data_add_marker(empty_data, type, NULL);
                        $$.bits = bits;
                }
        | '<'
                {
                        $$.data = data_add_marker(empty_data, TYPE_UINT32, NULL);
                        $$.bits = 32;
                }
        | arrayprefix integer_prim
                {
                        if ($1.bits < 64) {
                                uint64_t mask = (1ULL << $1.bits) - 1;
                                /*
                                 * Bits above mask must either be all zero
                                 * (positive within range of mask) or all one
                                 * (negative and sign-extended). The second
                                 * condition is true if when we set all bits
                                 * within the mask to one (i.e. | in the
                                 * mask), all bits are one.
                                 */
                                if (($2 > mask) && (($2 | mask) != -1ULL)) {
                                        char *loc = srcpos_string(&@2);
                                        fprintf(stderr,
                                                "WARNING: %s: Value 0x%016" PRIx64
                                                " truncated to 0x%0*" PRIx64 "\n",
                                                loc, $2, $1.bits / 4, ($2 & mask));
                                        free(loc);
                                }
                        }

                        $$.data = data_append_integer($1.data, $2, $1.bits);
                }
        | arrayprefix dt_ref
                {
                        uint64_t val = ~0ULL >> (64 - $1.bits);

                        if ($1.bits == 32)
                                $1.data = data_add_marker($1.data,
                                                          REF_PHANDLE,
                                                          $2);
                        else
                                ERROR(&@2, "References are only allowed in "
                                            "arrays with 32-bit elements.");

                        $$.data = data_append_integer($1.data, val, $1.bits);
                }
        | arrayprefix DT_LABEL
                {
                        $$.data = data_add_marker($1.data, LABEL, $2);
                }
        ;

integer_prim:
          DT_LITERAL
        | DT_CHAR_LITERAL
        | '(' integer_expr ')'
                {
                        $$ = $2;
                }
        ;

integer_expr:
        integer_trinary
        ;

integer_trinary:
          integer_or
        | integer_or '?' integer_expr ':' integer_trinary { $$ = $1 ? $3 : $5; }
        ;

integer_or:
          integer_and
        | integer_or DT_OR integer_and { $$ = $1 || $3; }
        ;

integer_and:
          integer_bitor
        | integer_and DT_AND integer_bitor { $$ = $1 && $3; }
        ;

integer_bitor:
          integer_bitxor
        | integer_bitor '|' integer_bitxor { $$ = $1 | $3; }
        ;

integer_bitxor:
          integer_bitand
        | integer_bitxor '^' integer_bitand { $$ = $1 ^ $3; }
        ;

integer_bitand:
          integer_eq
        | integer_bitand '&' integer_eq { $$ = $1 & $3; }
        ;

integer_eq:
          integer_rela
        | integer_eq DT_EQ integer_rela { $$ = $1 == $3; }
        | integer_eq DT_NE integer_rela { $$ = $1 != $3; }
        ;

integer_rela:
          integer_shift
        | integer_rela '<' integer_shift { $$ = $1 < $3; }
        | integer_rela '>' integer_shift { $$ = $1 > $3; }
        | integer_rela DT_LE integer_shift { $$ = $1 <= $3; }
        | integer_rela DT_GE integer_shift { $$ = $1 >= $3; }
        ;

integer_shift:
          integer_shift DT_LSHIFT integer_add { $$ = ($3 < 64) ? ($1 << $3) : 0; }
        | integer_shift DT_RSHIFT integer_add { $$ = ($3 < 64) ? ($1 >> $3) : 0; }
        | integer_add
        ;

integer_add:
          integer_add '+' integer_mul { $$ = $1 + $3; }
        | integer_add '-' integer_mul { $$ = $1 - $3; }
        | integer_mul
        ;

integer_mul:
          integer_mul '*' integer_unary { $$ = $1 * $3; }
        | integer_mul '/' integer_unary
                {
                        if ($3 != 0) {
                                $$ = $1 / $3;
                        } else {
                                ERROR(&@$, "Division by zero");
                                $$ = 0;
                        }
                }
        | integer_mul '%' integer_unary
                {
                        if ($3 != 0) {
                                $$ = $1 % $3;
                        } else {
                                ERROR(&@$, "Division by zero");
                                $$ = 0;
                        }
                }
        | integer_unary
        ;

integer_unary:
          integer_prim
        | '-' integer_unary { $$ = -$2; }
        | '~' integer_unary { $$ = ~$2; }
        | '!' integer_unary { $$ = !$2; }
        ;

bytestring:
          /* empty */
                {
                        $$ = data_add_marker(empty_data, TYPE_UINT8, NULL);
                }
        | bytestring DT_BYTE
                {
                        $$ = data_append_byte($1, $2);
                }
        | bytestring DT_LABEL
                {
                        $$ = data_add_marker($1, LABEL, $2);
                }
        ;

subnodes:
          /* empty */
                {
                        $$ = NULL;
                }
        | subnode subnodes
                {
                        $$ = chain_node($1, $2);
                }
        | subnode propdef
                {
                        ERROR(&@2, "Properties must precede subnodes");
                        YYERROR;
                }
        ;

subnode:
          DT_PROPNODENAME nodedef
                {
                        $$ = name_node($2, $1);
                        free($1);
                }
        | DT_DEL_NODE DT_PROPNODENAME ';'
                {
                        $$ = name_node(build_node_delete(&@$), $2);
                        free($2);
                }
        | DT_OMIT_NO_REF subnode
                {
                        $$ = omit_node_if_unused($2);
                }
        | DT_LABEL subnode
                {
                        add_label(&$2->labels, $1);
                        $$ = $2;
                }
        ;

%%

void yyerror(char const *s)
{
        ERROR(&yylloc, "%s", s);
}