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

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

extern FILE *yyin;
extern int yyparse(void);
extern YYLTYPE yylloc;

struct dt_info *parser_output;
bool treesource_error;

struct dt_info *dt_from_source(const char *fname)
{
        parser_output = NULL;
        treesource_error = false;

        srcfile_push(fname);
        yyin = current_srcfile->f;
        yylloc.file = current_srcfile;

        if (yyparse() != 0)
                die("Unable to parse input tree\n");

        if (treesource_error)
                die("Syntax error parsing input tree\n");

        return parser_output;
}

static void write_prefix(FILE *f, int level)
{
        int i;

        for (i = 0; i < level; i++)
                fputc('\t', f);
}

static bool isstring(char c)
{
        return (isprint((unsigned char)c)
                || (c == '\0')
                || strchr("\a\b\t\n\v\f\r", c));
}

static void write_propval_string(FILE *f, const char *s, size_t len)
{
        const char *end = s + len - 1;

        if (!len)
                return;

        assert(*end == '\0');

        fprintf(f, "\"");
        while (s < end) {
                char c = *s++;
                switch (c) {
                case '\a':
                        fprintf(f, "\\a");
                        break;
                case '\b':
                        fprintf(f, "\\b");
                        break;
                case '\t':
                        fprintf(f, "\\t");
                        break;
                case '\n':
                        fprintf(f, "\\n");
                        break;
                case '\v':
                        fprintf(f, "\\v");
                        break;
                case '\f':
                        fprintf(f, "\\f");
                        break;
                case '\r':
                        fprintf(f, "\\r");
                        break;
                case '\\':
                        fprintf(f, "\\\\");
                        break;
                case '\"':
                        fprintf(f, "\\\"");
                        break;
                case '\0':
                        fprintf(f, "\\0");
                        break;
                default:
                        if (isprint((unsigned char)c))
                                fprintf(f, "%c", c);
                        else
                                fprintf(f, "\\x%02"PRIx8, c);
                }
        }
        fprintf(f, "\"");
}

static void write_propval_int(FILE *f, const char *p, size_t len, size_t width)
{
        const char *end = p + len;
        assert(len % width == 0);

        for (; p < end; p += width) {
                switch (width) {
                case 1:
                        fprintf(f, "%02"PRIx8, *(const uint8_t*)p);
                        break;
                case 2:
                        fprintf(f, "0x%02"PRIx16, dtb_ld16(p));
                        break;
                case 4:
                        fprintf(f, "0x%02"PRIx32, dtb_ld32(p));
                        break;
                case 8:
                        fprintf(f, "0x%02"PRIx64, dtb_ld64(p));
                        break;
                }
                if (p + width < end)
                        fputc(' ', f);
        }
}

static const char *delim_start[] = {
        [TYPE_UINT8] = "[",
        [TYPE_UINT16] = "/bits/ 16 <",
        [TYPE_UINT32] = "<",
        [TYPE_UINT64] = "/bits/ 64 <",
        [TYPE_STRING] = "",
};
static const char *delim_end[] = {
        [TYPE_UINT8] = "]",
        [TYPE_UINT16] = ">",
        [TYPE_UINT32] = ">",
        [TYPE_UINT64] = ">",
        [TYPE_STRING] = "",
};

/*
 * The invariants in the marker list are:
 *  - offsets are non-strictly monotonically increasing
 *  - for a single offset there is at most one type marker
 *  - for a single offset that has both a type marker and non-type markers, the
 *    type marker appears before the others.
 */
static struct marker **add_marker(struct marker **mi,
                                  enum markertype type, unsigned int offset, char *ref)
{
        struct marker *nm;

        while (*mi && (*mi)->offset < offset)
                mi = &(*mi)->next;

        if (*mi && (*mi)->offset == offset && is_type_marker((*mi)->type)) {
                if (is_type_marker(type))
                        return mi;
                mi = &(*mi)->next;
        }

        if (*mi && (*mi)->offset == offset && type == (*mi)->type)
                return mi;

        nm = xmalloc(sizeof(*nm));
        nm->type = type;
        nm->offset = offset;
        nm->ref = ref;
        nm->next = *mi;
        *mi = nm;

        return &nm->next;
}

void property_add_marker(struct property *prop,
                         enum markertype type, unsigned int offset, char *ref)
{
        add_marker(&prop->val.markers, type, offset, ref);
}

static void add_string_markers(struct property *prop, unsigned int offset, int len)
{
        int l;
        const char *p = prop->val.val + offset;
        struct marker **mi = &prop->val.markers;

        for (l = strlen(p) + 1; l < len; l += strlen(p + l) + 1)
                mi = add_marker(mi, TYPE_STRING, offset + l, NULL);
}

void add_phandle_marker(struct dt_info *dti, struct property *prop, unsigned int offset)
{
        cell_t phandle;
        struct node *refn;
        char *ref;

        if (prop->val.len < offset + 4) {
                if (quiet < 1)
                        fprintf(stderr,
                                "Warning: property %s too short to contain a phandle at offset %u\n",
                                prop->name, offset);
                return;
        }

        phandle = dtb_ld32(prop->val.val + offset);
        refn = get_node_by_phandle(dti->dt, phandle);

        if (!refn) {
                if (quiet < 1)
                        fprintf(stderr,
                                "Warning: node referenced by phandle 0x%x in property %s not found\n",
                                phandle, prop->name);
                return;
        }

        if (refn->labels)
                ref = refn->labels->label;
        else
                ref = refn->fullpath;

        add_marker(&prop->val.markers, REF_PHANDLE, offset, ref);
}

static enum markertype guess_value_type(struct property *prop, unsigned int offset, int len)
{
        const char *p = prop->val.val + offset;
        int nnotstring = 0, nnul = 0;
        int i;

        for (i = 0; i < len; i++) {
                if (! isstring(p[i]))
                        nnotstring++;
                if (p[i] == '\0')
                        nnul++;
        }

        if ((p[len-1] == '\0') && (nnotstring == 0) && (nnul <= len - nnul)) {
                if (nnul > 1)
                        add_string_markers(prop, offset, len);
                return TYPE_STRING;
        } else if ((len % sizeof(cell_t)) == 0) {
                return TYPE_UINT32;
        }

        return TYPE_UINT8;
}

static void guess_type_markers(struct property *prop)
{
        struct marker **m = &prop->val.markers;
        unsigned int offset = 0;

        for (m = &prop->val.markers; *m; m = &((*m)->next)) {
                if (is_type_marker((*m)->type))
                        /* assume the whole property is already marked */
                        return;

                if ((*m)->offset > offset) {
                        m = add_marker(m, guess_value_type(prop, offset, (*m)->offset - offset),
                                       offset, NULL);

                        offset = (*m)->offset;
                }

                if ((*m)->type == REF_PHANDLE) {
                        m = add_marker(m, TYPE_UINT32, offset, NULL);
                        offset += 4;
                }
        }

        if (offset < prop->val.len)
                add_marker(m, guess_value_type(prop, offset, prop->val.len - offset),
                           offset, NULL);
}

static void write_propval(FILE *f, struct property *prop)
{
        size_t len = prop->val.len;
        struct marker *m;
        enum markertype emit_type = TYPE_NONE;
        char *srcstr;

        if (len == 0) {
                fprintf(f, ";");
                if (annotate) {
                        srcstr = srcpos_string_first(prop->srcpos, annotate);
                        if (srcstr) {
                                fprintf(f, " /* %s */", srcstr);
                                free(srcstr);
                        }
                }
                fprintf(f, "\n");
                return;
        }

        fprintf(f, " =");

        guess_type_markers(prop);
        m = prop->val.markers;

        for_each_marker(m) {
                size_t chunk_len = (m->next ? m->next->offset : len) - m->offset;
                size_t data_len = type_marker_length(m) ? : len - m->offset;
                const char *p = &prop->val.val[m->offset];
                struct marker *m_phandle;

                if (is_type_marker(m->type)) {
                        emit_type = m->type;
                        fprintf(f, " %s", delim_start[emit_type]);
                } else if (m->type == LABEL)
                        fprintf(f, " %s:", m->ref);

                if (emit_type == TYPE_NONE || chunk_len == 0)
                        continue;

                switch(emit_type) {
                case TYPE_UINT16:
                        write_propval_int(f, p, chunk_len, 2);
                        break;
                case TYPE_UINT32:
                        m_phandle = prop->val.markers;
                        for_each_marker_of_type(m_phandle, REF_PHANDLE)
                                if (m->offset == m_phandle->offset)
                                        break;

                        if (m_phandle) {
                                if (m_phandle->ref[0] == '/')
                                        fprintf(f, "&{%s}", m_phandle->ref);
                                else
                                        fprintf(f, "&%s", m_phandle->ref);
                                if (chunk_len > 4) {
                                        fputc(' ', f);
                                        write_propval_int(f, p + 4, chunk_len - 4, 4);
                                }
                        } else {
                                write_propval_int(f, p, chunk_len, 4);
                        }
                        if (data_len > chunk_len)
                                fputc(' ', f);
                        break;
                case TYPE_UINT64:
                        write_propval_int(f, p, chunk_len, 8);
                        break;
                case TYPE_STRING:
                        write_propval_string(f, p, chunk_len);
                        break;
                default:
                        write_propval_int(f, p, chunk_len, 1);
                }

                if (chunk_len == data_len) {
                        size_t pos = m->offset + chunk_len;
                        fprintf(f, pos == len ? "%s" : "%s,",
                                delim_end[emit_type] ? : "");
                        emit_type = TYPE_NONE;
                }
        }
        fprintf(f, ";");
        if (annotate) {
                srcstr = srcpos_string_first(prop->srcpos, annotate);
                if (srcstr) {
                        fprintf(f, " /* %s */", srcstr);
                        free(srcstr);
                }
        }
        fprintf(f, "\n");
}

static void write_tree_source_node(FILE *f, struct node *tree, int level)
{
        struct property *prop;
        struct node *child;
        struct label *l;
        char *srcstr;

        write_prefix(f, level);
        for_each_label(tree->labels, l)
                fprintf(f, "%s: ", l->label);
        if (tree->name && (*tree->name))
                fprintf(f, "%s {", tree->name);
        else
                fprintf(f, "/ {");

        if (annotate) {
                srcstr = srcpos_string_first(tree->srcpos, annotate);
                if (srcstr) {
                        fprintf(f, " /* %s */", srcstr);
                        free(srcstr);
                }
        }
        fprintf(f, "\n");

        for_each_property(tree, prop) {
                write_prefix(f, level+1);
                for_each_label(prop->labels, l)
                        fprintf(f, "%s: ", l->label);
                fprintf(f, "%s", prop->name);
                write_propval(f, prop);
        }
        for_each_child(tree, child) {
                fprintf(f, "\n");
                write_tree_source_node(f, child, level+1);
        }
        write_prefix(f, level);
        fprintf(f, "};");
        if (annotate) {
                srcstr = srcpos_string_last(tree->srcpos, annotate);
                if (srcstr) {
                        fprintf(f, " /* %s */", srcstr);
                        free(srcstr);
                }
        }
        fprintf(f, "\n");
}

void dt_to_source(FILE *f, struct dt_info *dti)
{
        struct reserve_info *re;

        fprintf(f, "/dts-v1/;\n");
        if (dti->dtsflags & DTSF_PLUGIN)
                fprintf(f, "/plugin/;\n");
        fprintf(f, "\n");

        for (re = dti->reservelist; re; re = re->next) {
                struct label *l;

                for_each_label(re->labels, l)
                        fprintf(f, "%s: ", l->label);
                fprintf(f, "/memreserve/\t0x%016llx 0x%016llx;\n",
                        (unsigned long long)re->address,
                        (unsigned long long)re->size);
        }

        write_tree_source_node(f, dti->dt, 0);
}