libidav/davqlparser.c@020a5b5aa510
libidav/davqlparser.c
Wed, 13 May 2015 21:12:41 +0200
- author
- Mike Becker <universe@uap-core.de>
- date
- Wed, 13 May 2015 21:12:41 +0200
- changeset 109
- 020a5b5aa510
- parent 108
- 0199f13c7fe2
- child 111
- 39f4c5fcaa60
- permissions
- -rw-r--r--
added syntax tree display to debugger + expression parser saves source text in every node
/* * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER. * * Copyright 2015 Olaf Wintermann. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #include "davqlparser.h" #include <ucx/utils.h> #include <string.h> #include <stdio.h> #include <ctype.h> #define sfmtarg(s) ((int)(s).length), (s).ptr // ------------------------------------------------------------------------ // D E B U G E R // ------------------------------------------------------------------------ static const char* _map_querytype(davqltype_t type) { switch(type) { case DAVQL_ERROR: return "ERROR"; case DAVQL_GET: return "GET"; case DAVQL_SET: return "SET"; default: return "unknown"; } } static const char* _map_exprtype(davqlexprtype_t type) { switch(type) { case DAVQL_UNDEFINED_TYPE: return "undefined"; case DAVQL_NUMBER: return "NUMBER"; case DAVQL_STRING: return "STRING"; case DAVQL_TIMESTAMP: return "TIMESTAMP"; case DAVQL_IDENTIFIER: return "IDENTIFIER"; case DAVQL_UNARY: return "UNARY"; case DAVQL_BINARY: return "BINARY"; case DAVQL_LOGICAL: return "LOGICAL"; case DAVQL_FUNCCALL: return "FUNCCALL"; default: return "unknown"; } } static const char* _map_specialfield(int info) { switch(info) { case 0: return ""; case 1: return "with wildcard"; case 2: return "(resource data only)"; default: return "with mysterious identifier"; } } static const char* _map_operator(davqloperator_t op) { // don't use string array, because enum values may change switch(op) { case DAVQL_NOOP: return "no operator"; case DAVQL_ADD: return "+"; case DAVQL_SUB: return "-"; case DAVQL_MUL: return "*"; case DAVQL_DIV: return "/"; case DAVQL_AND: return "&"; case DAVQL_OR: return "|"; case DAVQL_XOR: return "^"; case DAVQL_NEG: return "~"; case DAVQL_NOT: return "NOT"; case DAVQL_LAND: return "AND"; case DAVQL_LOR: return "OR"; case DAVQL_LXOR: return "XOR"; case DAVQL_EQ: return "="; case DAVQL_NEQ: return "!="; case DAVQL_LT: return "<"; case DAVQL_GT: return ">"; case DAVQL_LE: return "<="; case DAVQL_GE: return ">="; case DAVQL_LIKE: return "LIKE"; case DAVQL_UNLIKE: return "UNLIKE"; default: return "unknown"; } } static void dav_debug_ql_fnames_print(DavQLStatement *stmt) { if (stmt->fields) { printf("Field names: "); UCX_FOREACH(field, stmt->fields) { DavQLField *f = field->data; printf("%.*s, ", sfmtarg(f->name)); } printf("\b\b \b\b\n"); } } static void dav_debug_ql_stmt_print(DavQLStatement *stmt) { // Basic information size_t fieldcount = ucx_list_size(stmt->fields); int specialfield = 0; if (stmt->fields) { DavQLField* firstfield = (DavQLField*)stmt->fields->data; if (firstfield->expr->type == DAVQL_IDENTIFIER) { switch (firstfield->expr->srctext.ptr[0]) { case '*': specialfield = 1; break; case '-': specialfield = 2; break; } } } if (specialfield) { fieldcount--; } printf("Statement: %.*s\nType: %s\nField count: %zu %s\n", sfmtarg(stmt->srctext), _map_querytype(stmt->type), fieldcount, _map_specialfield(specialfield)); dav_debug_ql_fnames_print(stmt); printf("Path: %.*s\nHas where clause: %s\n", sfmtarg(stmt->path), stmt->where ? "yes" : "no"); // WITH attributes if (stmt->depth == DAV_DEPTH_INFINITY) { printf("Depth: infinity\n"); } else if (stmt->depth == DAV_DEPTH_PLACEHOLDER) { printf("Depth: placeholder\n"); } else { printf("Depth: %d\n", stmt->depth); } // order by clause printf("Order by: "); if (stmt->orderby) { UCX_FOREACH(crit, stmt->orderby) { DavQLOrderCriterion *critdata = crit->data; printf("%.*s %s%s", sfmtarg(critdata->column->srctext), critdata->descending ? "desc" : "asc", crit->next ? ", " : "\n"); } } else { printf("nothing\n"); } // error messages if (stmt->errorcode) { printf("\nError code: %d\nError: %s\n", stmt->errorcode, stmt->errormessage); } } static int dav_debug_ql_expr_selected(DavQLExpression *expr) { if (!expr) { printf("Currently no expression selected.\n"); return 0; } else { return 1; } } static void dav_debug_ql_expr_print(DavQLExpression *expr) { if (dav_debug_ql_expr_selected(expr)) { sstr_t empty = ST("(empty)"); printf( "Text: %.*s\nType: %s\nOperator: %s\n", sfmtarg(expr->srctext), _map_exprtype(expr->type), _map_operator(expr->op)); if (expr->left || expr->right) { printf("Left hand: %.*s\nRight hand: %.*s\n", sfmtarg(expr->left?expr->left->srctext:empty), sfmtarg(expr->right?expr->right->srctext:empty)); } } } static void dav_debug_ql_tree_print(DavQLExpression *expr, int depth) { if (expr) { if (expr->left) { printf("%*c%s\n", depth, ' ', _map_operator(expr->op)); dav_debug_ql_tree_print(expr->left, depth+1); dav_debug_ql_tree_print(expr->right, depth+1); } else if (expr->type == DAVQL_UNARY) { printf("%*c%s %.*s\n", depth, ' ', _map_operator(expr->op), sfmtarg(expr->srctext)); } else { printf("%*c%.*s\n", depth, ' ', sfmtarg(expr->srctext)); } } } #define DQLD_CMD_Q 0 #define DQLD_CMD_PS 1 #define DQLD_CMD_PE 2 #define DQLD_CMD_PF 3 #define DQLD_CMD_PT 4 #define DQLD_CMD_F 10 #define DQLD_CMD_W 11 #define DQLD_CMD_O 12 #define DQLD_CMD_L 21 #define DQLD_CMD_R 22 #define DQLD_CMD_N 23 #define DQLD_CMD_P 24 #define DQLD_CMD_H 100 static int dav_debug_ql_command() { printf("> "); char buffer[8]; fgets(buffer, 8, stdin); // discard remaining chars if (!strchr(buffer, '\n')) { int chr; while ((chr = fgetc(stdin) != '\n') && chr != EOF); } if (!strcmp(buffer, "q\n")) { return DQLD_CMD_Q; } else if (!strcmp(buffer, "ps\n")) { return DQLD_CMD_PS; } else if (!strcmp(buffer, "pe\n")) { return DQLD_CMD_PE; } else if (!strcmp(buffer, "pf\n")) { return DQLD_CMD_PF; } else if (!strcmp(buffer, "pt\n")) { return DQLD_CMD_PT; } else if (!strcmp(buffer, "l\n")) { return DQLD_CMD_L; } else if (!strcmp(buffer, "r\n")) { return DQLD_CMD_R; } else if (!strcmp(buffer, "h\n")) { return DQLD_CMD_H; } else if (!strcmp(buffer, "f\n")) { return DQLD_CMD_F; } else if (!strcmp(buffer, "w\n")) { return DQLD_CMD_W; } else if (!strcmp(buffer, "o\n")) { return DQLD_CMD_O; } else if (!strcmp(buffer, "n\n")) { return DQLD_CMD_N; } else if (!strcmp(buffer, "p\n")) { return DQLD_CMD_P; } else { return -1; } } void dav_debug_statement(DavQLStatement *stmt) { if (!stmt) { fprintf(stderr, "Debug DavQLStatement failed: null pointer"); return; } printf("Starting DavQL debugger (type 'h' for help)...\n\n"); dav_debug_ql_stmt_print(stmt); if (stmt->errorcode) { return; } DavQLExpression *examineexpr = NULL; UcxList *examineelem = NULL; int examineclause = 0; while(1) { int cmd = dav_debug_ql_command(); switch (cmd) { case DQLD_CMD_Q: return; case DQLD_CMD_PS: dav_debug_ql_stmt_print(stmt); break; case DQLD_CMD_PE: dav_debug_ql_expr_print(examineexpr); break; case DQLD_CMD_PT: dav_debug_ql_tree_print(examineexpr, 1); break; case DQLD_CMD_PF: dav_debug_ql_fnames_print(stmt); break; case DQLD_CMD_F: if (examineclause != DQLD_CMD_F) { examineclause = DQLD_CMD_F; examineelem = stmt->fields; examineexpr = stmt->fields ? ((DavQLField*)stmt->fields->data)->expr : NULL; dav_debug_ql_expr_print(examineexpr); } break; case DQLD_CMD_W: examineclause = 0; examineelem = NULL; examineexpr = stmt->where; dav_debug_ql_expr_print(examineexpr); break; case DQLD_CMD_O: if (examineclause != DQLD_CMD_O) { examineclause = DQLD_CMD_O; examineelem = stmt->orderby; examineexpr = stmt->orderby ? ((DavQLOrderCriterion*)stmt->orderby->data)->column : NULL; dav_debug_ql_expr_print(examineexpr); } break; case DQLD_CMD_N: case DQLD_CMD_P: if (examineelem) { UcxList *newelem = (cmd == DQLD_CMD_N ? examineelem->next : examineelem->prev); if (newelem) { examineelem = newelem; if (examineclause == DQLD_CMD_O) { examineexpr = ((DavQLOrderCriterion*) examineelem->data)->column; } else if (examineclause == DQLD_CMD_F) { examineexpr = ((DavQLField*)examineelem->data)->expr; } else { printf("Examining unknown clause type."); } dav_debug_ql_expr_print(examineexpr); } else { printf("Reached end of list.\n"); } } else { printf("Currently not examining an expression list.\n"); } break; case DQLD_CMD_L: if (dav_debug_ql_expr_selected(examineexpr)) { if (examineexpr->left) { examineexpr = examineexpr->left; dav_debug_ql_expr_print(examineexpr); } else { printf("There is no left subtree.\n"); } } break; case DQLD_CMD_R: if (dav_debug_ql_expr_selected(examineexpr)) { if (examineexpr->right) { examineexpr = examineexpr->right; dav_debug_ql_expr_print(examineexpr); } else { printf("There is no right subtree.\n"); } } break; case DQLD_CMD_H: printf( "\nCommands:\n" "ps: print statement information\n" "o: examine order by clause\n" "f: examine field list\n" "pf: print field names\n" "w: examine where clause\n" "n: examine next expression " "(in order by clause or field list)\n" "p: examine previous expression " "(in order by clause or field list)\n" "q: quit\n\n" "\nExpression examination:\n" "pe: print expression information\n" "pt: print full syntax tree of current (sub-)expression\n" "l: enter left subtree\n" "r: enter right subtree\n"); break; default: printf("unknown command\n"); } } } // ------------------------------------------------------------------------ // P A R S E R // ------------------------------------------------------------------------ #define _error_context "(%.*s [->]%.*s %.*s)" #define _error_invalid "invalid statement" #define _error_unhandled "unhandled error " _error_context #define _error_unexpected_token "unexpected token " _error_context #define _error_invalid_token "invalid token " _error_context #define _error_missing_path "expected path " _error_context #define _error_missing_from "expecting FROM keyword " _error_context #define _error_missing_by "expecting BY keyword " _error_context #define _error_invalid_depth "invalid depth " _error_context #define _error_missing_expr "missing expression " _error_context #define _error_invalid_expr "invalid expression " _error_context #define _error_invalid_unary_op "invalid unary operator " _error_context #define _error_invalid_fmtspec "invalid format specifier " _error_context #define token_sstr(token) (((DavQLToken*)(token)->data)->value) static void dav_error_in_context(int errorcode, const char *errormsg, DavQLStatement *stmt, UcxList *token) { sstr_t emptystring = ST(""); stmt->errorcode = errorcode; stmt->errormessage = ucx_sprintf(errormsg, sfmtarg(token->prev?token_sstr(token->prev):emptystring), sfmtarg(token_sstr(token)), sfmtarg(token->next?token_sstr(token->next):emptystring)).ptr; } // special symbols are single tokens - the % sign MUST NOT be a special symbol static const char *special_token_symbols = ",()+-*/&|^~=!<>"; static _Bool iskeyword(DavQLToken *token) { sstr_t keywords[] = {ST("get"), ST("set"), ST("from"), ST("at"), ST("as"), ST("where"), ST("with"), ST("order"), ST("by"), ST("asc"), ST("desc") }; for (int i = 0 ; i < sizeof(keywords)/sizeof(char*) ; i++) { if (!sstrcasecmp(token->value, keywords[i])) { return 1; } } return 0; } static UcxList* dav_parse_add_token(UcxList *tokenlist, DavQLToken *token) { // determine token class (order of if-statements is very important!) char firstchar = token->value.ptr[0]; if (isdigit(firstchar)) { token->tokenclass = DAVQL_TOKEN_NUMBER; } else if (firstchar == '%') { token->tokenclass = DAVQL_TOKEN_FMTSPEC; } else if (token->value.length == 1) { switch (firstchar) { case '(': token->tokenclass = DAVQL_TOKEN_OPENP; break; case ')': token->tokenclass = DAVQL_TOKEN_CLOSEP; break; case ',': token->tokenclass = DAVQL_TOKEN_COMMA; break; case '=': token->tokenclass = DAVQL_TOKEN_EQ; break; case '<': token->tokenclass = DAVQL_TOKEN_LT; break; case '>': token->tokenclass = DAVQL_TOKEN_GT; break; case '!': token->tokenclass = DAVQL_TOKEN_EXCLAIM; break; default: token->tokenclass = strchr(special_token_symbols, firstchar) ? DAVQL_TOKEN_OPERATOR : DAVQL_TOKEN_IDENTIFIER; } } else if (firstchar == '\'') { token->tokenclass = DAVQL_TOKEN_STRING; } else if (firstchar == '`') { token->tokenclass = DAVQL_TOKEN_IDENTIFIER; } else if (iskeyword(token)) { token->tokenclass = DAVQL_TOKEN_KEYWORD; } else { token->tokenclass = DAVQL_TOKEN_IDENTIFIER; } // remove quotes (extreme cool feature) if (token->tokenclass == DAVQL_TOKEN_STRING || (token->tokenclass == DAVQL_TOKEN_IDENTIFIER && firstchar == '`')) { char lastchar = token->value.ptr[token->value.length-1]; if (firstchar == lastchar) { token->value.ptr++; token->value.length -= 2; } else { token->tokenclass = DAVQL_TOKEN_INVALID; } } return ucx_list_append(tokenlist, token); } static UcxList* dav_parse_tokenize(sstr_t src) { UcxList *tokens = NULL; DavQLToken *token = NULL; char insequence = '\0'; for (size_t i = 0 ; i < src.length ; i++) { // quoted strings / identifiers are a single token if (src.ptr[i] == '\'' || src.ptr[i] == '`') { if (src.ptr[i] == insequence) { // add quoted token to list token->value.length++; tokens = dav_parse_add_token(tokens, token); token = NULL; insequence = '\0'; } else if (insequence == '\0') { insequence = src.ptr[i]; // always create new token for quoted strings if (token) { tokens = dav_parse_add_token(tokens, token); } token = malloc(sizeof(DavQLToken)); token->value.ptr = src.ptr + i; token->value.length = 1; } else { // add other kind of quotes to token token->value.length++; } } else if (insequence) { token->value.length++; } else if (isspace(src.ptr[i])) { // add token before spaces to list (if any) if (token) { tokens = dav_parse_add_token(tokens, token); token = NULL; } } else if (strchr(special_token_symbols, src.ptr[i])) { // add token before special symbol to list (if any) if (token) { tokens = dav_parse_add_token(tokens, token); token = NULL; } // add special symbol as single token to list token = malloc(sizeof(DavQLToken)); token->value.ptr = src.ptr + i; token->value.length = 1; tokens = dav_parse_add_token(tokens, token); // set tokenizer ready to read more tokens token = NULL; } else { // if this is a new token, create memory for it if (!token) { token = malloc(sizeof(DavQLToken)); token->value.ptr = src.ptr + i; token->value.length = 0; } // extend token length when reading more bytes token->value.length++; } } if (token) { tokens = dav_parse_add_token(tokens, token); } return tokens; } static void dav_free_expression(DavQLExpression *expr) { if (expr->left) { dav_free_expression(expr->left); } if (expr->right) { dav_free_expression(expr->right); } free(expr); } static void dav_free_field(DavQLField *field) { dav_free_expression(field->expr); free(field); } static void dav_free_order_criterion(DavQLOrderCriterion *crit) { if (crit->column) { // do it null-safe though column is expected to be set dav_free_expression(crit->column); } free(crit); } #define token_is(token, expectedclass) (token && \ (((DavQLToken*)(token)->data)->tokenclass == expectedclass)) #define tokenvalue_is(token, expectedvalue) (token && \ !sstrcasecmp(((DavQLToken*)(token)->data)->value, S(expectedvalue))) typedef int(*exprparser_f)(DavQLStatement*,UcxList*,DavQLExpression*); static int dav_parse_binary_expr(DavQLStatement* stmt, UcxList* token, DavQLExpression* expr, exprparser_f parseL, char* opc, int* opv, exprparser_f parseR) { if (!token) { return 0; } int total_consumed = 0, consumed; // save temporarily on stack (copy to heap later on) DavQLExpression left, right; // RULE: LEFT, [Operator, RIGHT] memset(&left, 0, sizeof(DavQLExpression)); consumed = parseL(stmt, token, &left); if (!consumed) { return 0; } total_consumed += consumed; token = ucx_list_get(token, consumed); char *op; if (token_is(token, DAVQL_TOKEN_OPERATOR) && (op = strchr(opc, token_sstr(token).ptr[0]))) { expr->op = opv[op-opc]; expr->type = DAVQL_BINARY; total_consumed++; token = token->next; memset(&right, 0, sizeof(DavQLExpression)); consumed = parseR(stmt, token, &right); if (!consumed) { dav_error_in_context(DAVQL_ERROR_MISSING_EXPR, _error_missing_expr, stmt, token); return 0; } total_consumed += consumed; } if (expr->op == DAVQL_NOOP) { memcpy(expr, &left, sizeof(DavQLExpression)); } else { expr->left = malloc(sizeof(DavQLExpression)); memcpy(expr->left, &left, sizeof(DavQLExpression)); expr->right = malloc(sizeof(DavQLExpression)); memcpy(expr->right, &right, sizeof(DavQLExpression)); expr->srctext.ptr = expr->left->srctext.ptr; expr->srctext.length = expr->right->srctext.ptr - expr->left->srctext.ptr + expr->right->srctext.length; } return total_consumed; } static int dav_parse_literal(DavQLStatement* stmt, UcxList* token, DavQLExpression* expr) { expr->srctext = token_sstr(token); if (token_is(token, DAVQL_TOKEN_NUMBER)) { expr->type = DAVQL_NUMBER; } else if (token_is(token, DAVQL_TOKEN_STRING)) { expr->type = DAVQL_STRING; } else if (token_is(token, DAVQL_TOKEN_TIMESTAMP)) { expr->type = DAVQL_TIMESTAMP; } else if (token_is(token, DAVQL_TOKEN_FMTSPEC) && expr->srctext.length == 2) { switch (expr->srctext.ptr[1]) { case 'd': expr->type = DAVQL_NUMBER; break; case 's': expr->type = DAVQL_STRING; break; case 't': expr->type = DAVQL_TIMESTAMP; break; default: dav_error_in_context(DAVQL_ERROR_INVALID_FMTSPEC, _error_invalid_fmtspec, stmt, token); return 0; } } else { return 0; } return 1; } static int dav_parse_funccall(DavQLStatement* stmt, UcxList* token, DavQLExpression* expr) { // TODO: make it so return 0; } static int dav_parse_unary_expr(DavQLStatement* stmt, UcxList* token, DavQLExpression* expr) { DavQLExpression* atom = expr; expr->srctext.ptr = token_sstr(token).ptr; int total_consumed = 0; // optional unary operator if (token_is(token, DAVQL_TOKEN_OPERATOR)) { char *op = strchr("+-~", token_sstr(token).ptr[0]); if (op) { expr->type = DAVQL_UNARY; switch (*op) { case '+': expr->op = DAVQL_ADD; break; case '-': expr->op = DAVQL_SUB; break; case '~': expr->op = DAVQL_NEG; break; } expr->left = calloc(sizeof(DavQLExpression), 1); atom = expr->left; total_consumed++; token = token->next; } else { dav_error_in_context(DAVQL_ERROR_INVALID_UNARY_OP, _error_invalid_unary_op, stmt, token); return 0; } } // RULE: (ParExpression | AtomicExpression) if (token_is(token, DAVQL_TOKEN_OPENP)) { // TODO: make it so (and don't forget CLOSEP) } else { // RULE: FunctionCall int consumed = dav_parse_funccall(stmt, token, atom); if (consumed) { total_consumed += consumed; } else if (token_is(token, DAVQL_TOKEN_IDENTIFIER)) { // RULE: Identifier total_consumed++; atom->type = DAVQL_IDENTIFIER; atom->srctext = token_sstr(token); } else { // RULE: Literal total_consumed += dav_parse_literal(stmt, token, atom); } } // recover source text if (atom != expr) { expr->srctext.length = atom->srctext.ptr - expr->srctext.ptr + atom->srctext.length; } return total_consumed; } static int dav_parse_bitexpr(DavQLStatement* stmt, UcxList* token, DavQLExpression* expr) { return dav_parse_binary_expr(stmt, token, expr, dav_parse_unary_expr, "&|^", (int[]){DAVQL_AND, DAVQL_OR, DAVQL_XOR}, dav_parse_bitexpr); } static int dav_parse_multexpr(DavQLStatement* stmt, UcxList* token, DavQLExpression* expr) { return dav_parse_binary_expr(stmt, token, expr, dav_parse_bitexpr, "*/", (int[]){DAVQL_MUL, DAVQL_DIV}, dav_parse_multexpr); } static int dav_parse_expression(DavQLStatement* stmt, UcxList* token, DavQLExpression* expr) { return dav_parse_binary_expr(stmt, token, expr, dav_parse_multexpr, "+-", (int[]){DAVQL_ADD, DAVQL_SUB}, dav_parse_expression); } static int dav_parse_fieldlist(DavQLStatement *stmt, UcxList *token) { // RULE: "-" if (token_is(token, DAVQL_TOKEN_OPERATOR) && tokenvalue_is(token, "-")) { DavQLField *field = malloc(sizeof(DavQLField)); field->expr = calloc(sizeof(DavQLExpression), 1); field->expr->type = DAVQL_IDENTIFIER; field->expr->srctext = field->name = token_sstr(token); stmt->fields = ucx_list_append(stmt->fields, field); return 1; } // RULE: "*", {",", Expression, " as ", Identifier} if (token_is(token, DAVQL_TOKEN_OPERATOR) && tokenvalue_is(token, "*")) { DavQLField *field = malloc(sizeof(DavQLField)); field->expr = calloc(sizeof(DavQLExpression), 1); field->expr->type = DAVQL_IDENTIFIER; field->expr->srctext = field->name = token_sstr(token); stmt->fields = ucx_list_append(stmt->fields, field); int total_consumed = 0; int consumed = 1; do { token = ucx_list_get(token, consumed); total_consumed += consumed; if (token_is(token, DAVQL_TOKEN_COMMA)) { total_consumed++; token = token->next; DavQLExpression * expr = calloc(sizeof(DavQLExpression), 1); consumed = dav_parse_expression(stmt, token, expr); if (expr->type == DAVQL_UNDEFINED_TYPE) { dav_free_expression(expr); consumed = 0; dav_error_in_context(DAVQL_ERROR_INVALID_EXPR, _error_invalid_expr, stmt, token); } else { DavQLField *field = malloc(sizeof(DavQLField)); field->expr = expr; field->name = expr->srctext; stmt->fields = ucx_list_append(stmt->fields, field); } // TODO: parse "as" } else { consumed = 0; } } while (consumed > 0); return total_consumed; } // RULE: FieldExpression, {",", FieldExpression} // TODO: make it so return 0; } static int dav_parse_where_clause(DavQLStatement *stmt, UcxList *token) { return 0; } static int dav_parse_with_clause(DavQLStatement *stmt, UcxList *token) { int total_consumed = 0; // RULE: "depth", "=", (Number | "infinity") if (tokenvalue_is(token, "depth")) { token = token->next; total_consumed++; if (token_is(token, DAVQL_TOKEN_EQ)) { token = token->next; total_consumed++; if (tokenvalue_is(token, "infinity")) { stmt->depth = DAV_DEPTH_INFINITY; token = token->next; total_consumed++; } else { DavQLExpression *depthexpr = calloc(sizeof(DavQLExpression), 1); int consumed = dav_parse_expression(stmt, token, depthexpr); if (consumed) { if (depthexpr->type == DAVQL_NUMBER) { if (depthexpr->srctext.ptr[0] == '%') { stmt->depth = DAV_DEPTH_PLACEHOLDER; } else { sstr_t depthstr = depthexpr->srctext; char *conv = malloc(depthstr.length+1); char *chk; memcpy(conv, depthstr.ptr, depthstr.length); conv[depthstr.length] = '\0'; stmt->depth = strtol(conv, &chk, 10); if (*chk || stmt->depth < -1) { dav_error_in_context(DAVQL_ERROR_INVALID_DEPTH, _error_invalid_depth, stmt, token); } free(conv); } total_consumed += consumed; } else { dav_error_in_context(DAVQL_ERROR_INVALID_DEPTH, _error_invalid_depth, stmt, token); } } dav_free_expression(depthexpr); } } } return total_consumed; } static int dav_parse_orderby_clause(DavQLStatement *stmt, UcxList *token) { return 0; } /** * Semantic analysis of a get statement. * @param stmt the statement to analyze. */ static void dav_analyze_get_statement(DavQLStatement *stmt) { // TODO: make it so } /** * Parser of a get statement. * @param stmt the statement object that shall contain the syntax tree * @param tokens the token list */ static void dav_parse_get_statement(DavQLStatement *stmt, UcxList *tokens) { stmt->type = DAVQL_GET; // Consume field list tokens = ucx_list_get(tokens, dav_parse_fieldlist(stmt, tokens)); if (stmt->errorcode) { return; } // Consume from keyword if (token_is(tokens, DAVQL_TOKEN_KEYWORD) && tokenvalue_is(tokens, "from")) { tokens = tokens->next; } else { dav_error_in_context(DAVQL_ERROR_MISSING_TOKEN, _error_missing_from, stmt, tokens); return; } // Consume path if (token_is(tokens, DAVQL_TOKEN_STRING)) { stmt->path = token_sstr(tokens); tokens = tokens->next; } else if (token_is(tokens, DAVQL_TOKEN_OPERATOR) && tokenvalue_is(tokens, "/")) { stmt->path.ptr = token_sstr(tokens).ptr; tokens = tokens->next; while (!token_is(tokens, DAVQL_TOKEN_KEYWORD)) { sstr_t toksstr = token_sstr(tokens); stmt->path.length = toksstr.ptr-stmt->path.ptr+toksstr.length; tokens = tokens->next; } } else if (token_is(tokens, DAVQL_TOKEN_FMTSPEC) && tokenvalue_is(tokens, "%s")) { stmt->path = token_sstr(tokens); tokens = tokens->next; } else { dav_error_in_context(DAVQL_ERROR_MISSING_TOKEN, _error_missing_path, stmt, tokens); return; } // Consume with clause (if any) if (token_is(tokens, DAVQL_TOKEN_KEYWORD) && tokenvalue_is(tokens, "with")) { tokens = tokens->next; tokens = ucx_list_get(tokens, dav_parse_with_clause(stmt, tokens)); } if (stmt->errorcode) { return; } // Consume where clause (if any) if (token_is(tokens, DAVQL_TOKEN_KEYWORD) && tokenvalue_is(tokens, "where")) { tokens = tokens->next; tokens = ucx_list_get(tokens, dav_parse_where_clause(stmt, tokens)); } if (stmt->errorcode) { return; } // Consume order by clause (if any) if (token_is(tokens, DAVQL_TOKEN_KEYWORD) && tokenvalue_is(tokens, "order")) { tokens = tokens->next; if (token_is(tokens, DAVQL_TOKEN_KEYWORD) && tokenvalue_is(tokens, "by")) { tokens = tokens->next; tokens = ucx_list_get(tokens, dav_parse_orderby_clause(stmt, tokens)); } else { dav_error_in_context(DAVQL_ERROR_MISSING_TOKEN, _error_missing_by, stmt, tokens); return; } } if (stmt->errorcode) { return; } if (tokens) { if (token_is(tokens, DAVQL_TOKEN_INVALID)) { dav_error_in_context(DAVQL_ERROR_INVALID_TOKEN, _error_invalid_token, stmt, tokens); } else { dav_error_in_context(DAVQL_ERROR_UNEXPECTED_TOKEN, _error_unexpected_token, stmt, tokens); } } else { dav_analyze_get_statement(stmt); } } static void dav_parse_set_statement(DavQLStatement *stmt, UcxList *tokens) { stmt->type = DAVQL_SET; // TODO: make it so } DavQLStatement* dav_parse_statement(sstr_t srctext) { DavQLStatement *stmt = calloc(1, sizeof(DavQLStatement)); // default values stmt->type = -1; stmt->depth = 1; // save trimmed source text stmt->srctext = sstrtrim(srctext); // tokenization UcxList* tokens = dav_parse_tokenize(stmt->srctext); if (tokens) { // use first token to determine query type if (tokenvalue_is(tokens, "get")) { dav_parse_get_statement(stmt, tokens->next); } else if (tokenvalue_is(tokens, "set")) { dav_parse_set_statement(stmt, tokens->next); } else { stmt->type = DAVQL_ERROR; stmt->errorcode = DAVQL_ERROR_INVALID; stmt->errormessage = strdup(_error_invalid); } // free token data UCX_FOREACH(token, tokens) { free(token->data); } ucx_list_free(tokens); } else { stmt->type = DAVQL_ERROR; stmt->errorcode = DAVQL_ERROR_INVALID; stmt->errormessage = strdup(_error_invalid); } return stmt; } void dav_free_statement(DavQLStatement *stmt) { UCX_FOREACH(expr, stmt->fields) { dav_free_field(expr->data); } ucx_list_free(stmt->fields); if (stmt->where) { dav_free_expression(stmt->where); } if (stmt->errormessage) { free(stmt->errormessage); } UCX_FOREACH(crit, stmt->orderby) { dav_free_order_criterion(crit->data); } ucx_list_free(stmt->orderby); free(stmt); }
