expr.c

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Author : Pierre Le Marre
Date : 2023-09-18 18:17:34
Hash : ef81d04e
Message : Structured log messages with a message registry Currently there is little structure in the log messages, making difficult to use them for the following use cases: - A user looking for help about a log message: the user probably uses a search engine, thus the results will depend on the proper indexing of our documentation and the various forums. It relies only on the wording of the message, which may change with time. - A user wants to filter the logs resulting of the use of one of the components of xkbcommon. A typical example would be testing xkeyboard-config against libxkbcommon. It requires the use of a pattern (simple words detection or regex). The issue is that the pattern may become silently out-of-sync with xkbcommon. A common practice (e.g. in compilers) is to assign unique error codes to reference theses messages, along with an error index for documentation. Thus this commit implements the following features: - Create a message registry (message-registry.yaml) that defines the log messages produced by xkbcommon. This is a simple YAML file that provides, for each message: - A unique numeric code as a short identifier. It is used in the output message and thus can be easily be filtered to spot errors or searched in the internet. It must not change: if the semantics of message changes, it is better to introduce a new message for clarity. - A unique text identifier, meant for two uses: 1. Generate constants dealing with log information in our code base. 2. Generate human-friendly names for the documentation. - A type: currently warning or error. Used to prefix the constants (see hereinabove) and for basic classification in documentation. - A short description, used as concise and mandatory documentation. - An optionnal detailed description. - Optional examples, intended to help the user to fix issues themself. - Version of xkbcommon it was added. For old entries this often unknown, so they will default to 1.0.0. - Version of xkbcommon it was removed (optional) No entry should ever be deleted from this index, even if the message is not used anymore: it ensures we have unique identifiers along the history of xkbcommon, and that users can refer to the documentation even for older versions. - Add the script update-message-registry.py to generate the following files: - messages.h: message code enumeration for the messages currently used in the code base. Currently a private API. - message.registry.md: the error index documentation page. - Modify the logging functions to use structured messages. This is a work in progress.

src/xkbcomp/expr.c

/************************************************************
 * Copyright (c) 1994 by Silicon Graphics Computer Systems, Inc.
 *
 * Permission to use, copy, modify, and distribute this
 * software and its documentation for any purpose and without
 * fee is hereby granted, provided that the above copyright
 * notice appear in all copies and that both that copyright
 * notice and this permission notice appear in supporting
 * documentation, and that the name of Silicon Graphics not be
 * used in advertising or publicity pertaining to distribution
 * of the software without specific prior written permission.
 * Silicon Graphics makes no representation about the suitability
 * of this software for any purpose. It is provided "as is"
 * without any express or implied warranty.
 *
 * SILICON GRAPHICS DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS
 * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL SILICON
 * GRAPHICS BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL
 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION  WITH
 * THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 ********************************************************/

#include "config.h"

#include "xkbcomp-priv.h"
#include "text.h"
#include "expr.h"
#include "keysym.h"

typedef bool (*IdentLookupFunc)(struct xkb_context *ctx, const void *priv,
                                xkb_atom_t field, enum expr_value_type type,
                                unsigned int *val_rtrn);

bool
ExprResolveLhs(struct xkb_context *ctx, const ExprDef *expr,
               const char **elem_rtrn, const char **field_rtrn,
               ExprDef **index_rtrn)
{
    switch (expr->expr.op) {
    case EXPR_IDENT:
        *elem_rtrn = NULL;
        *field_rtrn = xkb_atom_text(ctx, expr->ident.ident);
        *index_rtrn = NULL;
        return (*field_rtrn != NULL);
    case EXPR_FIELD_REF:
        *elem_rtrn = xkb_atom_text(ctx, expr->field_ref.element);
        *field_rtrn = xkb_atom_text(ctx, expr->field_ref.field);
        *index_rtrn = NULL;
        return (*elem_rtrn != NULL && *field_rtrn != NULL);
    case EXPR_ARRAY_REF:
        *elem_rtrn = xkb_atom_text(ctx, expr->array_ref.element);
        *field_rtrn = xkb_atom_text(ctx, expr->array_ref.field);
        *index_rtrn = expr->array_ref.entry;
        if (expr->array_ref.element != XKB_ATOM_NONE && *elem_rtrn == NULL)
            return false;
        if (*field_rtrn == NULL)
            return false;
        return true;
    default:
        break;
    }
    log_wsgo(ctx, "Unexpected operator %d in ResolveLhs\n", expr->expr.op);
    return false;
}

static bool
SimpleLookup(struct xkb_context *ctx, const void *priv, xkb_atom_t field,
             enum expr_value_type type, unsigned int *val_rtrn)
{
    const LookupEntry *entry;
    const char *str;

    if (!priv || field == XKB_ATOM_NONE || type != EXPR_TYPE_INT)
        return false;

    str = xkb_atom_text(ctx, field);
    for (entry = priv; entry && entry->name; entry++) {
        if (istreq(str, entry->name)) {
            *val_rtrn = entry->value;
            return true;
        }
    }

    return false;
}

/* Data passed in the *priv argument for LookupModMask. */
typedef struct {
    const struct xkb_mod_set *mods;
    enum mod_type mod_type;
} LookupModMaskPriv;

static bool
LookupModMask(struct xkb_context *ctx, const void *priv, xkb_atom_t field,
              enum expr_value_type type, xkb_mod_mask_t *val_rtrn)
{
    const char *str;
    xkb_mod_index_t ndx;
    const LookupModMaskPriv *arg = priv;
    const struct xkb_mod_set *mods = arg->mods;
    enum mod_type mod_type = arg->mod_type;

    if (type != EXPR_TYPE_INT)
        return false;

    str = xkb_atom_text(ctx, field);
    if (!str)
        return false;

    if (istreq(str, "all")) {
        *val_rtrn  = MOD_REAL_MASK_ALL;
        return true;
    }

    if (istreq(str, "none")) {
        *val_rtrn = 0;
        return true;
    }

    ndx = XkbModNameToIndex(mods, field, mod_type);
    if (ndx == XKB_MOD_INVALID)
        return false;

    *val_rtrn = (1u << ndx);
    return true;
}

bool
ExprResolveBoolean(struct xkb_context *ctx, const ExprDef *expr,
                   bool *set_rtrn)
{
    bool ok = false;
    const char *ident;

    switch (expr->expr.op) {
    case EXPR_VALUE:
        if (expr->expr.value_type != EXPR_TYPE_BOOLEAN) {
            log_err(ctx,
                    "Found constant of type %s where boolean was expected\n",
                    expr_value_type_to_string(expr->expr.value_type));
            return false;
        }
        *set_rtrn = expr->boolean.set;
        return true;

    case EXPR_IDENT:
        ident = xkb_atom_text(ctx, expr->ident.ident);
        if (ident) {
            if (istreq(ident, "true") ||
                istreq(ident, "yes") ||
                istreq(ident, "on")) {
                *set_rtrn = true;
                return true;
            }
            else if (istreq(ident, "false") ||
                     istreq(ident, "no") ||
                     istreq(ident, "off")) {
                *set_rtrn = false;
                return true;
            }
        }
        log_err(ctx, "Identifier \"%s\" of type boolean is unknown\n", ident);
        return false;

    case EXPR_FIELD_REF:
        log_err(ctx, "Default \"%s.%s\" of type boolean is unknown\n",
                xkb_atom_text(ctx, expr->field_ref.element),
                xkb_atom_text(ctx, expr->field_ref.field));
        return false;

    case EXPR_INVERT:
    case EXPR_NOT:
        ok = ExprResolveBoolean(ctx, expr->unary.child, set_rtrn);
        if (ok)
            *set_rtrn = !*set_rtrn;
        return ok;
    case EXPR_ADD:
    case EXPR_SUBTRACT:
    case EXPR_MULTIPLY:
    case EXPR_DIVIDE:
    case EXPR_ASSIGN:
    case EXPR_NEGATE:
    case EXPR_UNARY_PLUS:
    case EXPR_ACTION_DECL:
    case EXPR_ACTION_LIST:
    case EXPR_KEYSYM_LIST:
        log_err(ctx, "%s of boolean values not permitted\n",
                expr_op_type_to_string(expr->expr.op));
        break;

    default:
        log_wsgo(ctx, "Unknown operator %d in ResolveBoolean\n",
                 expr->expr.op);
        break;
    }

    return false;
}

bool
ExprResolveKeyCode(struct xkb_context *ctx, const ExprDef *expr,
                   xkb_keycode_t *kc)
{
    xkb_keycode_t leftRtrn, rightRtrn;

    switch (expr->expr.op) {
    case EXPR_VALUE:
        if (expr->expr.value_type != EXPR_TYPE_INT) {
            log_err(ctx,
                    "Found constant of type %s where an int was expected\n",
                    expr_value_type_to_string(expr->expr.value_type));
            return false;
        }

        *kc = (xkb_keycode_t) expr->integer.ival;
        return true;

    case EXPR_ADD:
    case EXPR_SUBTRACT:
    case EXPR_MULTIPLY:
    case EXPR_DIVIDE:
        if (!ExprResolveKeyCode(ctx, expr->binary.left, &leftRtrn) ||
            !ExprResolveKeyCode(ctx, expr->binary.right, &rightRtrn))
            return false;

        switch (expr->expr.op) {
        case EXPR_ADD:
            *kc = leftRtrn + rightRtrn;
            break;
        case EXPR_SUBTRACT:
            *kc = leftRtrn - rightRtrn;
            break;
        case EXPR_MULTIPLY:
            *kc = leftRtrn * rightRtrn;
            break;
        case EXPR_DIVIDE:
            if (rightRtrn == 0) {
                log_err(ctx, "Cannot divide by zero: %d / %d\n",
                        leftRtrn, rightRtrn);
                return false;
            }

            *kc = leftRtrn / rightRtrn;
            break;
        default:
            break;
        }

        return true;

    case EXPR_NEGATE:
        if (!ExprResolveKeyCode(ctx, expr->unary.child, &leftRtrn))
            return false;

        *kc = ~leftRtrn;
        return true;

    case EXPR_UNARY_PLUS:
        return ExprResolveKeyCode(ctx, expr->unary.child, kc);

    default:
        log_wsgo(ctx, "Unknown operator %d in ResolveKeyCode\n",
                 expr->expr.op);
        break;
    }

    return false;
}

/**
 * This function returns ... something.  It's a bit of a guess, really.
 *
 * If an integer is given in value ctx, it will be returned in ival.
 * If an ident or field reference is given, the lookup function (if given)
 * will be called.  At the moment, only SimpleLookup use this, and they both
 * return the results in uval.  And don't support field references.
 *
 * Cool.
 */
static bool
ExprResolveIntegerLookup(struct xkb_context *ctx, const ExprDef *expr,
                         int *val_rtrn, IdentLookupFunc lookup,
                         const void *lookupPriv)
{
    bool ok = false;
    int l, r;
    unsigned u;
    ExprDef *left, *right;

    switch (expr->expr.op) {
    case EXPR_VALUE:
        if (expr->expr.value_type != EXPR_TYPE_INT) {
            log_err(ctx,
                    "Found constant of type %s where an int was expected\n",
                    expr_value_type_to_string(expr->expr.value_type));
            return false;
        }

        *val_rtrn = expr->integer.ival;
        return true;

    case EXPR_IDENT:
        if (lookup)
            ok = lookup(ctx, lookupPriv, expr->ident.ident, EXPR_TYPE_INT, &u);

        if (!ok)
            log_err(ctx, "Identifier \"%s\" of type int is unknown\n",
                    xkb_atom_text(ctx, expr->ident.ident));
        else
            *val_rtrn = (int) u;

        return ok;

    case EXPR_FIELD_REF:
        log_err(ctx, "Default \"%s.%s\" of type int is unknown\n",
                xkb_atom_text(ctx, expr->field_ref.element),
                xkb_atom_text(ctx, expr->field_ref.field));
        return false;

    case EXPR_ADD:
    case EXPR_SUBTRACT:
    case EXPR_MULTIPLY:
    case EXPR_DIVIDE:
        left = expr->binary.left;
        right = expr->binary.right;
        if (!ExprResolveIntegerLookup(ctx, left, &l, lookup, lookupPriv) ||
            !ExprResolveIntegerLookup(ctx, right, &r, lookup, lookupPriv))
            return false;

        switch (expr->expr.op) {
        case EXPR_ADD:
            *val_rtrn = l + r;
            break;
        case EXPR_SUBTRACT:
            *val_rtrn = l - r;
            break;
        case EXPR_MULTIPLY:
            *val_rtrn = l * r;
            break;
        case EXPR_DIVIDE:
            if (r == 0) {
                log_err(ctx, "Cannot divide by zero: %d / %d\n", l, r);
                return false;
            }
            *val_rtrn = l / r;
            break;
        default:
            log_err(ctx, "%s of integers not permitted\n",
                    expr_op_type_to_string(expr->expr.op));
            return false;
        }

        return true;

    case EXPR_ASSIGN:
        log_wsgo(ctx, "Assignment operator not implemented yet\n");
        break;

    case EXPR_NOT:
        log_err(ctx, "The ! operator cannot be applied to an integer\n");
        return false;

    case EXPR_INVERT:
    case EXPR_NEGATE:
        left = expr->unary.child;
        if (!ExprResolveIntegerLookup(ctx, left, &l, lookup, lookupPriv))
            return false;

        *val_rtrn = (expr->expr.op == EXPR_NEGATE ? -l : ~l);
        return true;

    case EXPR_UNARY_PLUS:
        left = expr->unary.child;
        return ExprResolveIntegerLookup(ctx, left, val_rtrn, lookup,
                                        lookupPriv);

    default:
        log_wsgo(ctx, "Unknown operator %d in ResolveInteger\n",
                 expr->expr.op);
        break;
    }

    return false;
}

bool
ExprResolveInteger(struct xkb_context *ctx, const ExprDef *expr,
                   int *val_rtrn)
{
    return ExprResolveIntegerLookup(ctx, expr, val_rtrn, NULL, NULL);
}

bool
ExprResolveGroup(struct xkb_context *ctx, const ExprDef *expr,
                 xkb_layout_index_t *group_rtrn)
{
    bool ok;
    int result;

    ok = ExprResolveIntegerLookup(ctx, expr, &result, SimpleLookup,
                                  groupNames);
    if (!ok)
        return false;

    if (result <= 0 || result > XKB_MAX_GROUPS) {
        log_err_with_code(ctx, XKB_ERROR_UNSUPPORTED_GROUP_INDEX,
                          "Group index %u is out of range (1..%d)\n",
                          result, XKB_MAX_GROUPS);
        return false;
    }

    *group_rtrn = (xkb_layout_index_t) result;
    return true;
}

bool
ExprResolveLevel(struct xkb_context *ctx, const ExprDef *expr,
                 xkb_level_index_t *level_rtrn)
{
    bool ok;
    int result;

    ok = ExprResolveIntegerLookup(ctx, expr, &result, SimpleLookup,
                                  levelNames);
    if (!ok)
        return false;

    if (result < 1) {
        log_err_with_code(ctx, XKB_ERROR_UNSUPPORTED_SHIFT_LEVEL,
                          "Shift level %d is out of range\n", result);
        return false;
    }

    /* Level is zero-indexed from now on. */
    *level_rtrn = (unsigned int) (result - 1);
    return true;
}

bool
ExprResolveButton(struct xkb_context *ctx, const ExprDef *expr, int *btn_rtrn)
{
    return ExprResolveIntegerLookup(ctx, expr, btn_rtrn, SimpleLookup,
                                    buttonNames);
}

bool
ExprResolveString(struct xkb_context *ctx, const ExprDef *expr,
                  xkb_atom_t *val_rtrn)
{
    switch (expr->expr.op) {
    case EXPR_VALUE:
        if (expr->expr.value_type != EXPR_TYPE_STRING) {
            log_err(ctx, "Found constant of type %s, expected a string\n",
                    expr_value_type_to_string(expr->expr.value_type));
            return false;
        }

        *val_rtrn = expr->string.str;
        return true;

    case EXPR_IDENT:
        log_err(ctx, "Identifier \"%s\" of type string not found\n",
                xkb_atom_text(ctx, expr->ident.ident));
        return false;

    case EXPR_FIELD_REF:
        log_err(ctx, "Default \"%s.%s\" of type string not found\n",
                xkb_atom_text(ctx, expr->field_ref.element),
                xkb_atom_text(ctx, expr->field_ref.field));
        return false;

    case EXPR_ADD:
    case EXPR_SUBTRACT:
    case EXPR_MULTIPLY:
    case EXPR_DIVIDE:
    case EXPR_ASSIGN:
    case EXPR_NEGATE:
    case EXPR_INVERT:
    case EXPR_NOT:
    case EXPR_UNARY_PLUS:
    case EXPR_ACTION_DECL:
    case EXPR_ACTION_LIST:
    case EXPR_KEYSYM_LIST:
        log_err(ctx, "%s of strings not permitted\n",
                expr_op_type_to_string(expr->expr.op));
        return false;

    default:
        log_wsgo(ctx, "Unknown operator %d in ResolveString\n",
                 expr->expr.op);
        break;
    }
    return false;
}

bool
ExprResolveEnum(struct xkb_context *ctx, const ExprDef *expr,
                unsigned int *val_rtrn, const LookupEntry *values)
{
    if (expr->expr.op != EXPR_IDENT) {
        log_err(ctx, "Found a %s where an enumerated value was expected\n",
                expr_op_type_to_string(expr->expr.op));
        return false;
    }

    if (!SimpleLookup(ctx, values, expr->ident.ident, EXPR_TYPE_INT,
                      val_rtrn)) {
        log_err(ctx, "Illegal identifier %s; expected one of:\n",
                xkb_atom_text(ctx, expr->ident.ident));
        while (values && values->name)
        {
            log_err(ctx, "\t%s\n", values->name);
            values++;
        }
        return false;
    }

    return true;
}

static bool
ExprResolveMaskLookup(struct xkb_context *ctx, const ExprDef *expr,
                      unsigned int *val_rtrn, IdentLookupFunc lookup,
                      const void *lookupPriv)
{
    bool ok = false;
    unsigned int l = 0, r = 0;
    int v;
    ExprDef *left, *right;
    const char *bogus = NULL;

    switch (expr->expr.op) {
    case EXPR_VALUE:
        if (expr->expr.value_type != EXPR_TYPE_INT) {
            log_err(ctx,
                    "Found constant of type %s where a mask was expected\n",
                    expr_value_type_to_string(expr->expr.value_type));
            return false;
        }
        *val_rtrn = (unsigned int) expr->integer.ival;
        return true;

    case EXPR_IDENT:
        ok = lookup(ctx, lookupPriv, expr->ident.ident, EXPR_TYPE_INT,
                    val_rtrn);
        if (!ok)
            log_err(ctx, "Identifier \"%s\" of type int is unknown\n",
                    xkb_atom_text(ctx, expr->ident.ident));
        return ok;

    case EXPR_FIELD_REF:
        log_err(ctx, "Default \"%s.%s\" of type int is unknown\n",
                xkb_atom_text(ctx, expr->field_ref.element),
                xkb_atom_text(ctx, expr->field_ref.field));
        return false;

    case EXPR_ARRAY_REF:
        bogus = "array reference";
        /* fallthrough */
    case EXPR_ACTION_DECL:
        if (bogus == NULL)
            bogus = "function use";
        log_err(ctx,
                "Unexpected %s in mask expression; Expression Ignored\n",
                bogus);
        return false;

    case EXPR_ADD:
    case EXPR_SUBTRACT:
    case EXPR_MULTIPLY:
    case EXPR_DIVIDE:
        left = expr->binary.left;
        right = expr->binary.right;
        if (!ExprResolveMaskLookup(ctx, left, &l, lookup, lookupPriv) ||
            !ExprResolveMaskLookup(ctx, right, &r, lookup, lookupPriv))
            return false;

        switch (expr->expr.op) {
        case EXPR_ADD:
            *val_rtrn = l | r;
            break;
        case EXPR_SUBTRACT:
            *val_rtrn = l & (~r);
            break;
        case EXPR_MULTIPLY:
        case EXPR_DIVIDE:
            log_err(ctx, "Cannot %s masks; Illegal operation ignored\n",
                    (expr->expr.op == EXPR_DIVIDE ? "divide" : "multiply"));
            return false;
        default:
            break;
        }

        return true;

    case EXPR_ASSIGN:
        log_wsgo(ctx, "Assignment operator not implemented yet\n");
        break;

    case EXPR_INVERT:
        left = expr->unary.child;
        if (!ExprResolveIntegerLookup(ctx, left, &v, lookup, lookupPriv))
            return false;

        *val_rtrn = ~v;
        return true;

    case EXPR_UNARY_PLUS:
    case EXPR_NEGATE:
    case EXPR_NOT:
        left = expr->unary.child;
        if (!ExprResolveIntegerLookup(ctx, left, &v, lookup, lookupPriv))
            log_err(ctx, "The %s operator cannot be used with a mask\n",
                    (expr->expr.op == EXPR_NEGATE ? "-" : "!"));
        return false;

    default:
        log_wsgo(ctx, "Unknown operator %d in ResolveMask\n",
                 expr->expr.op);
        break;
    }

    return false;
}

bool
ExprResolveMask(struct xkb_context *ctx, const ExprDef *expr,
                unsigned int *mask_rtrn, const LookupEntry *values)
{
    return ExprResolveMaskLookup(ctx, expr, mask_rtrn, SimpleLookup, values);
}

bool
ExprResolveModMask(struct xkb_context *ctx, const ExprDef *expr,
                   enum mod_type mod_type, const struct xkb_mod_set *mods,
                   xkb_mod_mask_t *mask_rtrn)
{
    LookupModMaskPriv priv = { .mods = mods, .mod_type = mod_type };
    return ExprResolveMaskLookup(ctx, expr, mask_rtrn, LookupModMask, &priv);
}

bool
ExprResolveKeySym(struct xkb_context *ctx, const ExprDef *expr,
                  xkb_keysym_t *sym_rtrn)
{
    int val;

    if (expr->expr.op == EXPR_IDENT) {
        const char *str = xkb_atom_text(ctx, expr->ident.ident);
        *sym_rtrn = xkb_keysym_from_name(str, 0);
        if (*sym_rtrn != XKB_KEY_NoSymbol)
            return true;
    }

    if (!ExprResolveInteger(ctx, expr, &val))
        return false;

    if (val < XKB_KEYSYM_MIN) {
        log_warn_with_code(ctx, XKB_WARNING_UNRECOGNIZED_KEYSYM,
                           "unrecognized keysym \"-0x%x\" (%d)\n",
                           (unsigned int) -val, val);
        return false;
    }

    /* Special case for digits 0..9 */
    if (val < 10) {
        *sym_rtrn = XKB_KEY_0 + (xkb_keysym_t) val;
        return true;
    }

    if (val <= XKB_KEYSYM_MAX) {
        *sym_rtrn = (xkb_keysym_t) val;
        return true;
    }

    log_warn_with_code(ctx, XKB_WARNING_UNRECOGNIZED_KEYSYM,
                       "unrecognized keysym \"0x%x\" (%d)\n",
                       (unsigned int) val, val);
    return false;

}

bool
ExprResolveMod(struct xkb_context *ctx, const ExprDef *def,
               enum mod_type mod_type, const struct xkb_mod_set *mods,
               xkb_mod_index_t *ndx_rtrn)
{
    xkb_mod_index_t ndx;
    xkb_atom_t name;

    if (def->expr.op != EXPR_IDENT) {
        log_err(ctx,
                "Cannot resolve virtual modifier: "
                "found %s where a virtual modifier name was expected\n",
                expr_op_type_to_string(def->expr.op));
        return false;
    }

    name = def->ident.ident;
    ndx = XkbModNameToIndex(mods, name, mod_type);
    if (ndx == XKB_MOD_INVALID) {
        log_err(ctx,
                "Cannot resolve virtual modifier: "
                "\"%s\" was not previously declared\n",
                xkb_atom_text(ctx, name));
        return false;
    }

    *ndx_rtrn = ndx;
    return true;
}

kc3-lang/libxkbcommon/src/xkbcomp/expr.c

Commit

kc3-lang/libxkbcommon /src/xkbcomp/expr.c