--- a/parser.cxx Wed Jan 02 23:57:46 2013 +0200
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,1203 +0,0 @@
-/*
- * botc source code
- * Copyright (C) 2012 Santeri `Dusk` Piippo
- * 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.
- * 3. Neither the name of the developer nor the names of its contributors may
- * be used to endorse or promote products derived from this software without
- * specific prior written permission.
- * 4. Redistributions in any form must be accompanied by information on how to
- * obtain complete source code for the software and any accompanying
- * software that uses the software. The source code must either be included
- * in the distribution or be available for no more than the cost of
- * distribution plus a nominal fee, and must be freely redistributable
- * under reasonable conditions. For an executable file, complete source
- * code means the source code for all modules it contains. It does not
- * include source code for modules or files that typically accompany the
- * major components of the operating system on which the executable file
- * runs.
- *
- * 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.
- */
-
-#define __PARSER_CXX__
-
-#include <stdio.h>
-#include <stdlib.h>
-#include "common.h"
-#include "str.h"
-#include "objwriter.h"
-#include "scriptreader.h"
-#include "events.h"
-#include "commands.h"
-#include "stringtable.h"
-#include "variables.h"
-#include "array.h"
-
-#define MUST_TOPLEVEL if (g_CurMode != MODE_TOPLEVEL) \
- ParserError ("%s-statements may only be defined at top level!", token.chars());
-
-#define MUST_NOT_TOPLEVEL if (g_CurMode == MODE_TOPLEVEL) \
- ParserError ("%s-statements may not be defined at top level!", token.chars());
-
-#define SCOPE(n) scopestack[g_ScopeCursor - n]
-
-int g_NumStates = 0;
-int g_NumEvents = 0;
-parsermode_e g_CurMode = MODE_TOPLEVEL;
-str g_CurState = "";
-bool g_stateSpawnDefined = false;
-bool g_GotMainLoop = false;
-unsigned int g_ScopeCursor = 0;
-DataBuffer* g_IfExpression = NULL;
-bool g_CanElse = false;
-str* g_UndefinedLabels[MAX_MARKS];
-bool g_Neurosphere = false; // neurosphere-compat
-array<constinfo_t> g_ConstInfo;
-
-// ============================================================================
-// Main parser code. Begins read of the script file, checks the syntax of it
-// and writes the data to the object file via ObjWriter - which also takes care
-// of necessary buffering so stuff is written in the correct order.
-void ScriptReader::ParseBotScript (ObjWriter* w) {
- // Zero the entire block stack first
- for (int i = 0; i < MAX_SCOPE; i++)
- ZERO(scopestack[i]);
-
- for (int i = 0; i < MAX_MARKS; i++)
- g_UndefinedLabels[i] = NULL;
-
- while (Next()) {
- // Check if else is potentically valid
- if (token == "else" && !g_CanElse)
- ParserError ("else without preceding if");
- if (token != "else")
- g_CanElse = false;
-
- // ============================================================
- if (token == "state") {
- MUST_TOPLEVEL
-
- MustString ();
-
- // State name must be a word.
- if (token.first (" ") != token.len())
- ParserError ("state name must be a single word, got `%s`", token.chars());
- str statename = token;
-
- // stateSpawn is special - it *must* be defined. If we
- // encountered it, then mark down that we have it.
- if (-token == "statespawn")
- g_stateSpawnDefined = true;
-
- // Must end in a colon
- MustNext (":");
-
- // Write the previous state's onenter and
- // mainloop buffers to file now
- if (g_CurState.len())
- w->WriteBuffers();
-
- w->Write (DH_STATENAME);
- w->WriteString (statename);
- w->Write (DH_STATEIDX);
- w->Write (g_NumStates);
-
- g_NumStates++;
- g_CurState = token;
- g_GotMainLoop = false;
- continue;
- }
-
- // ============================================================
- if (token == "event") {
- MUST_TOPLEVEL
-
- // Event definition
- MustString ();
-
- EventDef* e = FindEventByName (token);
- if (!e)
- ParserError ("bad event, got `%s`\n", token.chars());
-
- MustNext ("{");
-
- g_CurMode = MODE_EVENT;
-
- w->Write (DH_EVENT);
- w->Write (e->number);
- g_NumEvents++;
- continue;
- }
-
- // ============================================================
- if (token == "mainloop") {
- MUST_TOPLEVEL
- MustNext ("{");
-
- // Mode must be set before dataheader is written here!
- g_CurMode = MODE_MAINLOOP;
- w->Write (DH_MAINLOOP);
- continue;
- }
-
- // ============================================================
- if (token == "onenter" || token == "onexit") {
- MUST_TOPLEVEL
- bool onenter = token == "onenter";
- MustNext ("{");
-
- // Mode must be set before dataheader is written here,
- // because onenter goes to a separate buffer.
- g_CurMode = onenter ? MODE_ONENTER : MODE_ONEXIT;
- w->Write (onenter ? DH_ONENTER : DH_ONEXIT);
- continue;
- }
-
- // ============================================================
- if (token == "int" || token == "str" || token == "bool") {
- // For now, only globals are supported
- if (g_CurMode != MODE_TOPLEVEL || g_CurState.len())
- ParserError ("variables must only be global for now");
-
- type_e type = (token == "int") ? TYPE_INT :
- (token == "str") ? TYPE_STRING :
- TYPE_BOOL;
-
- MustNext ();
-
- // Var name must not be a number
- if (token.isnumber())
- ParserError ("variable name must not be a number");
-
- str varname = token;
- ScriptVar* var = DeclareGlobalVariable (this, type, varname);
-
- if (!var)
- ParserError ("declaring %s variable %s failed",
- g_CurState.len() ? "state" : "global", varname.chars());
-
- MustNext (";");
- continue;
- }
-
- // ============================================================
- // Goto
- if (token == "goto") {
- MUST_NOT_TOPLEVEL
-
- // Get the name of the label
- MustNext ();
-
- // Find the mark this goto statement points to
- unsigned int m = w->FindMark (token);
-
- // If not set, define it
- if (m == MAX_MARKS) {
- m = w->AddMark (token);
- g_UndefinedLabels[m] = new str (token);
- }
-
- // Add a reference to the mark.
- w->Write (DH_GOTO);
- w->AddReference (m);
- MustNext (";");
- continue;
- }
-
- // ============================================================
- // If
- if (token == "if") {
- MUST_NOT_TOPLEVEL
- PushScope ();
-
- // Condition
- MustNext ("(");
-
- // Read the expression and write it.
- MustNext ();
- DataBuffer* c = ParseExpression (TYPE_INT);
- w->WriteBuffer (c);
-
- MustNext (")");
- MustNext ("{");
-
- // Add a mark - to here temporarily - and add a reference to it.
- // Upon a closing brace, the mark will be adjusted.
- unsigned int marknum = w->AddMark ("");
-
- // Use DH_IFNOTGOTO - if the expression is not true, we goto the mark
- // we just defined - and this mark will be at the end of the scope block.
- w->Write (DH_IFNOTGOTO);
- w->AddReference (marknum);
-
- // Store it
- SCOPE(0).mark1 = marknum;
- SCOPE(0).type = SCOPETYPE_IF;
- continue;
- }
-
- if (token == "else") {
- MUST_NOT_TOPLEVEL
- MustNext ("{");
-
- // Don't use PushScope as it resets the scope
- g_ScopeCursor++;
- if (g_ScopeCursor >= MAX_SCOPE)
- ParserError ("too deep scope");
-
- if (SCOPE(0).type != SCOPETYPE_IF)
- ParserError ("else without preceding if");
-
- // Write down to jump to the end of the else statement
- // Otherwise we have fall-throughs
- SCOPE(0).mark2 = w->AddMark ("");
-
- // Instruction to jump to the end after if block is complete
- w->Write (DH_GOTO);
- w->AddReference (SCOPE(0).mark2);
-
- // Move the ifnot mark here and set type to else
- w->MoveMark (SCOPE(0).mark1);
- SCOPE(0).type = SCOPETYPE_ELSE;
- continue;
- }
-
- // ============================================================
- // While
- if (token == "while") {
- MUST_NOT_TOPLEVEL
- PushScope ();
-
- // While loops need two marks - one at the start of the loop and one at the
- // end. The condition is checked at the very start of the loop, if it fails,
- // we use goto to skip to the end of the loop. At the end, we loop back to
- // the beginning with a go-to statement.
- unsigned int mark1 = w->AddMark (""); // start
- unsigned int mark2 = w->AddMark (""); // end
-
- // Condition
- MustNext ("(");
- MustNext ();
- DataBuffer* expr = ParseExpression (TYPE_INT);
- MustNext (")");
- MustNext ("{");
-
- // Write condition
- w->WriteBuffer (expr);
-
- // Instruction to go to the end if it fails
- w->Write (DH_IFNOTGOTO);
- w->AddReference (mark2);
-
- // Store the needed stuff
- SCOPE(0).mark1 = mark1;
- SCOPE(0).mark2 = mark2;
- SCOPE(0).type = SCOPETYPE_WHILE;
- continue;
- }
-
- // ============================================================
- // For loop
- if (token == "for") {
- MUST_NOT_TOPLEVEL
- PushScope ();
-
- // Initializer
- MustNext ("(");
- MustNext ();
- DataBuffer* init = ParseStatement (w);
- if (!init)
- ParserError ("bad statement for initializer of for");
-
- MustNext (";");
-
- // Condition
- MustNext ();
- DataBuffer* cond = ParseExpression (TYPE_INT);
- if (!cond)
- ParserError ("bad statement for condition of for");
-
- MustNext (";");
-
- // Incrementor
- MustNext ();
- DataBuffer* incr = ParseStatement (w);
- if (!incr)
- ParserError ("bad statement for incrementor of for");
-
- MustNext (")");
- MustNext ("{");
-
- // First, write out the initializer
- w->WriteBuffer (init);
-
- // Init two marks
- int mark1 = w->AddMark ("");
- int mark2 = w->AddMark ("");
-
- // Add the condition
- w->WriteBuffer (cond);
- w->Write (DH_IFNOTGOTO);
- w->AddReference (mark2);
-
- // Store the marks and incrementor
- SCOPE(0).mark1 = mark1;
- SCOPE(0).mark2 = mark2;
- SCOPE(0).buffer1 = incr;
- SCOPE(0).type = SCOPETYPE_FOR;
- continue;
- }
-
- // ============================================================
- // Do/while loop
- if (token == "do") {
- MUST_NOT_TOPLEVEL
- PushScope ();
- MustNext ("{");
- SCOPE(0).mark1 = w->AddMark ("");
- SCOPE(0).type = SCOPETYPE_DO;
- continue;
- }
-
- // ============================================================
- // Switch
- if (token == "switch") {
- /* This goes a bit tricky. switch is structured in the
- * bytecode followingly:
- * (expression)
- * case a: goto casemark1
- * case b: goto casemark2
- * case c: goto casemark3
- * goto mark1 // jump to end if no matches
- * casemark1: ...
- * casemark2: ...
- * casemark3: ...
- * mark1: // end mark
- */
-
- MUST_NOT_TOPLEVEL
- PushScope ();
- MustNext ("(");
- MustNext ();
- w->WriteBuffer (ParseExpression (TYPE_INT));
- MustNext (")");
- MustNext ("{");
- SCOPE(0).type = SCOPETYPE_SWITCH;
- SCOPE(0).mark1 = w->AddMark (""); // end mark
- SCOPE(0).buffer1 = NULL; // default header
- continue;
- }
-
- // ============================================================
- if (token == "case") {
- // case is only allowed inside switch
- if (SCOPE(0).type != SCOPETYPE_SWITCH)
- ParserError ("case label outside switch");
-
- // Get the literal (Zandronum does not support expressions here)
- MustNumber ();
- int num = atoi (token.chars ());
- MustNext (":");
-
- for (int i = 0; i < MAX_CASE; i++)
- if (SCOPE(0).casenumbers[i] == num)
- ParserError ("multiple case %d labels in one switch", num);
-
- // Write down the expression and case-go-to. This builds
- // the case tree. The closing event will write the actual
- // blocks and move the marks appropriately.
- // AddSwitchCase will add the reference to the mark
- // for the case block that this heralds, and takes care
- // of buffering setup and stuff like that.
- // NULL the switch buffer for the case-go-to statement,
- // we want it all under the switch, not into the case-buffers.
- w->SwitchBuffer = NULL;
- w->Write (DH_CASEGOTO);
- w->Write (num);
- AddSwitchCase (w, NULL);
- SCOPE(0).casenumbers[SCOPE(0).casecursor] = num;
- continue;
- }
-
- if (token == "default") {
- if (SCOPE(0).type != SCOPETYPE_SWITCH)
- ParserError ("default label outside switch");
-
- if (SCOPE(0).buffer1)
- ParserError ("multiple default labels in one switch");
-
- MustNext (":");
-
- // The default header is buffered into buffer1, since
- // it has to be the last of the case headers
- //
- // Since the expression is pushed into the switch
- // and is only popped when case succeeds, we have
- // to pop it with DH_DROP manually if we end up in
- // a default.
- DataBuffer* b = new DataBuffer;
- SCOPE(0).buffer1 = b;
- b->Write (DH_DROP);
- b->Write (DH_GOTO);
- AddSwitchCase (w, b);
- continue;
- }
-
- // ============================================================
- // Break statement.
- if (token == "break") {
- if (!g_ScopeCursor)
- ParserError ("unexpected `break`");
-
- w->Write (DH_GOTO);
-
- // switch and if use mark1 for the closing point,
- // for and while use mark2.
- switch (SCOPE(0).type) {
- case SCOPETYPE_IF:
- case SCOPETYPE_SWITCH:
- w->AddReference (SCOPE(0).mark1);
- break;
- case SCOPETYPE_FOR:
- case SCOPETYPE_WHILE:
- w->AddReference (SCOPE(0).mark2);
- break;
- default:
- ParserError ("unexpected `break`");
- break;
- }
-
- MustNext (";");
- continue;
- }
-
- // ============================================================
- // Continue
- if (token == "continue") {
- MustNext (";");
-
- int curs;
- bool found = false;
-
- // Drop through the scope until we find a loop block
- for (curs = g_ScopeCursor; curs > 0 && !found; curs--) {
- switch (scopestack[curs].type) {
- case SCOPETYPE_FOR:
- case SCOPETYPE_WHILE:
- case SCOPETYPE_DO:
- w->Write (DH_GOTO);
- w->AddReference (scopestack[curs].mark1);
- found = true;
- break;
- default:
- break;
- }
- }
-
- // No loop blocks
- if (!found)
- ParserError ("`continue`-statement not inside a loop");
-
- continue;
- }
-
- // ============================================================
- // Label
- if (PeekNext() == ":") {
- MUST_NOT_TOPLEVEL
-
- // want no conflicts..
- if (IsKeyword (token))
- ParserError ("label name `%s` conflicts with keyword\n", token.chars());
- if (FindCommand (token))
- ParserError ("label name `%s` conflicts with command name\n", token.chars());
- if (FindGlobalVariable (token))
- ParserError ("label name `%s` conflicts with variable\n", token.chars());
-
- // See if a mark already exists for this label
- int mark = -1;
- for (int i = 0; i < MAX_MARKS; i++) {
- if (g_UndefinedLabels[i] && *g_UndefinedLabels[i] == token) {
- mark = i;
- w->MoveMark (i);
-
- // No longer undefinde
- delete g_UndefinedLabels[i];
- g_UndefinedLabels[i] = NULL;
- }
- }
-
- // Not found in unmarked lists, define it now
- if (mark == -1)
- w->AddMark (token);
-
- MustNext (":");
- continue;
- }
-
- // ============================================================
- if (token == "const") {
- constinfo_t info;
-
- // Get the type
- MustNext ();
- info.type = GetTypeByName (token);
-
- if (info.type == TYPE_UNKNOWN || info.type == TYPE_VOID)
- ParserError ("unknown type `%s` for constant", (char*)token);
-
- MustNext ();
- info.name = token;
-
- MustNext ("=");
-
- switch (info.type) {
- case TYPE_BOOL:
- case TYPE_INT:
- MustNumber (false);
- info.val = token;
- break;
- case TYPE_STRING:
- MustString ();
- info.val = token;
- break;
- case TYPE_UNKNOWN:
- case TYPE_VOID:
- break;
- }
-
- g_ConstInfo << info;
-
- MustNext (";");
- continue;
- }
-
- // ============================================================
- if (token == "}") {
- // Closing brace
-
- // If we're in the block stack, we're descending down from it now
- if (g_ScopeCursor > 0) {
- switch (SCOPE(0).type) {
- case SCOPETYPE_IF:
- // Adjust the closing mark.
- w->MoveMark (SCOPE(0).mark1);
-
- // We're returning from if, thus else can be next
- g_CanElse = true;
- break;
- case SCOPETYPE_ELSE:
- // else instead uses mark1 for itself (so if expression
- // fails, jump to else), mark2 means end of else
- w->MoveMark (SCOPE(0).mark2);
- break;
- case SCOPETYPE_FOR:
- // Write the incrementor at the end of the loop block
- w->WriteBuffer (SCOPE(0).buffer1);
- // fall-thru
- case SCOPETYPE_WHILE:
- // Write down the instruction to go back to the start of the loop
- w->Write (DH_GOTO);
- w->AddReference (SCOPE(0).mark1);
-
- // Move the closing mark here since we're at the end of the while loop
- w->MoveMark (SCOPE(0).mark2);
- break;
- case SCOPETYPE_DO: {
- MustNext ("while");
- MustNext ("(");
- MustNext ();
- DataBuffer* expr = ParseExpression (TYPE_INT);
- MustNext (")");
- MustNext (";");
-
- // If the condition runs true, go back to the start.
- w->WriteBuffer (expr);
- w->Write (DH_IFGOTO);
- w->AddReference (SCOPE(0).mark1);
- break;
- }
- case SCOPETYPE_SWITCH: {
- // Switch closes. Move down to the record buffer of
- // the lower block.
- if (SCOPE(1).casecursor != -1)
- w->SwitchBuffer = SCOPE(1).casebuffers[SCOPE(1).casecursor];
- else
- w->SwitchBuffer = NULL;
-
- // If there was a default in the switch, write its header down now.
- // If not, write instruction to jump to the end of switch after
- // the headers (thus won't fall-through if no case matched)
- if (SCOPE(0).buffer1)
- w->WriteBuffer (SCOPE(0).buffer1);
- else {
- w->Write (DH_DROP);
- w->Write (DH_GOTO);
- w->AddReference (SCOPE(0).mark1);
- }
-
- // Go through all of the buffers we
- // recorded down and write them.
- for (unsigned int u = 0; u < MAX_CASE; u++) {
- if (!SCOPE(0).casebuffers[u])
- continue;
-
- w->MoveMark (SCOPE(0).casemarks[u]);
- w->WriteBuffer (SCOPE(0).casebuffers[u]);
- }
-
- // Move the closing mark here
- w->MoveMark (SCOPE(0).mark1);
- break;
- }
- case SCOPETYPE_UNKNOWN:
- break;
- }
-
- // Descend down the stack
- g_ScopeCursor--;
- continue;
- }
-
- int dataheader = (g_CurMode == MODE_EVENT) ? DH_ENDEVENT :
- (g_CurMode == MODE_MAINLOOP) ? DH_ENDMAINLOOP :
- (g_CurMode == MODE_ONENTER) ? DH_ENDONENTER :
- (g_CurMode == MODE_ONEXIT) ? DH_ENDONEXIT : -1;
-
- if (dataheader == -1)
- ParserError ("unexpected `}`");
-
- // Data header must be written before mode is changed because
- // onenter and mainloop go into special buffers, and we want
- // the closing data headers into said buffers too.
- w->Write (dataheader);
- g_CurMode = MODE_TOPLEVEL;
-
- if (PeekNext() == ";")
- MustNext (";");
- continue;
- }
-
- // Check if it's a command
- CommandDef* comm = FindCommand (token);
- if (comm) {
- w->GetCurrentBuffer()->Merge (ParseCommand (comm));
- MustNext (";");
- continue;
- }
-
- // ============================================================
- // If nothing else, parse it as a statement
- DataBuffer* b = ParseStatement (w);
- if (!b)
- ParserError ("unknown token `%s`", token.chars());
-
- w->WriteBuffer (b);
- MustNext (";");
- }
-
- // ===============================================================================
- // Script file ended. Do some last checks and write the last things to main buffer
- if (g_CurMode != MODE_TOPLEVEL)
- ParserError ("script did not end at top level; did you forget a `}`?");
-
- // stateSpawn must be defined!
- if (!g_stateSpawnDefined)
- ParserError ("script must have a state named `stateSpawn`!");
-
- for (int i = 0; i < MAX_MARKS; i++)
- if (g_UndefinedLabels[i])
- ParserError ("label `%s` is referenced via `goto` but isn't defined\n", g_UndefinedLabels[i]->chars());
-
- // Dump the last state's onenter and mainloop
- w->WriteBuffers ();
-
- // String table
- w->WriteStringTable ();
-}
-
-// ============================================================================
-// Parses a command call
-DataBuffer* ScriptReader::ParseCommand (CommandDef* comm) {
- DataBuffer* r = new DataBuffer(64);
- if (g_CurMode == MODE_TOPLEVEL)
- ParserError ("command call at top level");
-
- MustNext ("(");
- MustNext ();
-
- int curarg = 0;
- while (1) {
- if (token == ")") {
- if (curarg < comm->numargs)
- ParserError ("too few arguments passed to %s\n\tprototype: %s",
- comm->name.chars(), GetCommandPrototype (comm).chars());
- break;
- curarg++;
- }
-
- if (curarg >= comm->maxargs)
- ParserError ("too many arguments passed to %s\n\tprototype: %s",
- comm->name.chars(), GetCommandPrototype (comm).chars());
-
- r->Merge (ParseExpression (comm->argtypes[curarg]));
- MustNext ();
-
- if (curarg < comm->numargs - 1) {
- MustThis (",");
- MustNext ();
- } else if (curarg < comm->maxargs - 1) {
- // Can continue, but can terminate as well.
- if (token == ")") {
- curarg++;
- break;
- } else {
- MustThis (",");
- MustNext ();
- }
- }
-
- curarg++;
- }
-
- // If the script skipped any optional arguments, fill in defaults.
- while (curarg < comm->maxargs) {
- r->Write (DH_PUSHNUMBER);
- r->Write (comm->defvals[curarg]);
- curarg++;
- }
-
- r->Write (DH_COMMAND);
- r->Write (comm->number);
- r->Write (comm->maxargs);
-
- return r;
-}
-
-// ============================================================================
-// Is the given operator an assignment operator?
-static bool IsAssignmentOperator (int oper) {
- switch (oper) {
- case OPER_ASSIGNADD:
- case OPER_ASSIGNSUB:
- case OPER_ASSIGNMUL:
- case OPER_ASSIGNDIV:
- case OPER_ASSIGNMOD:
- case OPER_ASSIGNLEFTSHIFT:
- case OPER_ASSIGNRIGHTSHIFT:
- case OPER_ASSIGN:
- return true;
- }
- return false;
-}
-
-// ============================================================================
-// Finds an operator's corresponding dataheader
-static word DataHeaderByOperator (ScriptVar* var, int oper) {
- if (IsAssignmentOperator (oper)) {
- if (!var)
- error ("operator %d requires left operand to be a variable\n", oper);
-
- // TODO: At the moment, vars only are global
- // OPER_ASSIGNLEFTSHIFT and OPER_ASSIGNRIGHTSHIFT do not
- // have data headers, instead they are expanded out in
- // the operator parser
- switch (oper) {
- case OPER_ASSIGNADD: return DH_ADDGLOBALVAR;
- case OPER_ASSIGNSUB: return DH_SUBGLOBALVAR;
- case OPER_ASSIGNMUL: return DH_MULGLOBALVAR;
- case OPER_ASSIGNDIV: return DH_DIVGLOBALVAR;
- case OPER_ASSIGNMOD: return DH_MODGLOBALVAR;
- case OPER_ASSIGN: return DH_ASSIGNGLOBALVAR;
- default: error ("bad assignment operator!!\n");
- }
- }
-
- switch (oper) {
- case OPER_ADD: return DH_ADD;
- case OPER_SUBTRACT: return DH_SUBTRACT;
- case OPER_MULTIPLY: return DH_MULTIPLY;
- case OPER_DIVIDE: return DH_DIVIDE;
- case OPER_MODULUS: return DH_MODULUS;
- case OPER_EQUALS: return DH_EQUALS;
- case OPER_NOTEQUALS: return DH_NOTEQUALS;
- case OPER_LESSTHAN: return DH_LESSTHAN;
- case OPER_GREATERTHAN: return DH_GREATERTHAN;
- case OPER_LESSTHANEQUALS: return DH_LESSTHANEQUALS;
- case OPER_GREATERTHANEQUALS: return DH_GREATERTHANEQUALS;
- case OPER_LEFTSHIFT: return DH_LSHIFT;
- case OPER_RIGHTSHIFT: return DH_RSHIFT;
- case OPER_OR: return DH_ORLOGICAL;
- case OPER_AND: return DH_ANDLOGICAL;
- case OPER_BITWISEOR: return DH_ORBITWISE;
- case OPER_BITWISEEOR: return DH_EORBITWISE;
- case OPER_BITWISEAND: return DH_ANDBITWISE;
- }
-
- error ("DataHeaderByOperator: couldn't find dataheader for operator %d!\n", oper);
- return 0;
-}
-
-// ============================================================================
-// Parses an expression, potentially recursively
-DataBuffer* ScriptReader::ParseExpression (type_e reqtype) {
- DataBuffer* retbuf = new DataBuffer (64);
-
- // Parse first operand
- retbuf->Merge (ParseExprValue (reqtype));
-
- // Parse any and all operators we get
- int oper;
- while ((oper = ParseOperator (true)) != -1) {
- // We peeked the operator, move forward now
- Next ();
-
- // Can't be an assignement operator, those belong in assignments.
- if (IsAssignmentOperator (oper))
- ParserError ("assignment operator inside expression");
-
- // Parse the right operand.
- MustNext ();
- DataBuffer* rb = ParseExprValue (reqtype);
-
- if (oper == OPER_TERNARY) {
- // Ternary operator requires - naturally - a third operand.
- MustNext (":");
- MustNext ();
- DataBuffer* tb = ParseExprValue (reqtype);
-
- // It also is handled differently: there isn't a dataheader for ternary
- // operator. Instead, we abuse PUSHNUMBER and IFNOTGOTO for this.
- // Behold, big block of writing madness! :P
- int mark1 = retbuf->AddMark (""); // start of "else" case
- int mark2 = retbuf->AddMark (""); // end of expression
- retbuf->Write (DH_IFNOTGOTO); // if the first operand (condition)
- retbuf->AddMarkReference (mark1); // didn't eval true, jump into mark1
- retbuf->Merge (rb); // otherwise, perform second operand (true case)
- retbuf->Write (DH_GOTO); // afterwards, jump to the end, which is
- retbuf->AddMarkReference (mark2); // marked by mark2.
- retbuf->MoveMark (mark1); // move mark1 at the end of the true case
- retbuf->Merge (tb); // perform third operand (false case)
- retbuf->MoveMark (mark2); // move the ending mark2 here
- } else {
- // Write to buffer
- retbuf->Merge (rb);
- retbuf->Write (DataHeaderByOperator (NULL, oper));
- }
- }
-
- return retbuf;
-}
-
-// ============================================================================
-// Parses an operator string. Returns the operator number code.
-#define ISNEXT(char) (!PeekNext (peek ? 1 : 0) == char)
-int ScriptReader::ParseOperator (bool peek) {
- str oper;
- if (peek)
- oper += PeekNext ();
- else
- oper += token;
-
- if (-oper == "strlen")
- return OPER_STRLEN;
-
- // Check one-char operators
- bool equalsnext = ISNEXT ("=");
-
- int o = (oper == "=" && !equalsnext) ? OPER_ASSIGN :
- (oper == ">" && !equalsnext && !ISNEXT (">")) ? OPER_GREATERTHAN :
- (oper == "<" && !equalsnext && !ISNEXT ("<")) ? OPER_LESSTHAN :
- (oper == "&" && !ISNEXT ("&")) ? OPER_BITWISEAND :
- (oper == "|" && !ISNEXT ("|")) ? OPER_BITWISEOR :
- (oper == "+" && !equalsnext) ? OPER_ADD :
- (oper == "-" && !equalsnext) ? OPER_SUBTRACT :
- (oper == "*" && !equalsnext) ? OPER_MULTIPLY :
- (oper == "/" && !equalsnext) ? OPER_DIVIDE :
- (oper == "%" && !equalsnext) ? OPER_MODULUS :
- (oper == "^") ? OPER_BITWISEEOR :
- (oper == "?") ? OPER_TERNARY :
- -1;
-
- if (o != -1) {
- return o;
- }
-
- // Two-char operators
- oper += PeekNext (peek ? 1 : 0);
- equalsnext = PeekNext (peek ? 2 : 1) == ("=");
-
- o = (oper == "+=") ? OPER_ASSIGNADD :
- (oper == "-=") ? OPER_ASSIGNSUB :
- (oper == "*=") ? OPER_ASSIGNMUL :
- (oper == "/=") ? OPER_ASSIGNDIV :
- (oper == "%=") ? OPER_ASSIGNMOD :
- (oper == "==") ? OPER_EQUALS :
- (oper == "!=") ? OPER_NOTEQUALS :
- (oper == ">=") ? OPER_GREATERTHANEQUALS :
- (oper == "<=") ? OPER_LESSTHANEQUALS :
- (oper == "&&") ? OPER_AND :
- (oper == "||") ? OPER_OR :
- (oper == "<<" && !equalsnext) ? OPER_LEFTSHIFT :
- (oper == ">>" && !equalsnext) ? OPER_RIGHTSHIFT :
- -1;
-
- if (o != -1) {
- MustNext ();
- return o;
- }
-
- // Three-char opers
- oper += PeekNext (peek ? 2 : 1);
- o = oper == "<<=" ? OPER_ASSIGNLEFTSHIFT :
- oper == ">>=" ? OPER_ASSIGNRIGHTSHIFT :
- -1;
-
- if (o != -1) {
- MustNext ();
- MustNext ();
- }
-
- return o;
-}
-
-// ============================================================================
-str ScriptReader::ParseFloat () {
- MustNumber (true);
- str floatstring = token;
-
- // Go after the decimal point
- if (PeekNext () == ".") {
- Next (".");
- MustNumber (false);
- floatstring += ".";
- floatstring += token;
- }
-
- return floatstring;
-}
-
-// ============================================================================
-// Parses a value in the expression and returns the data needed to push
-// it, contained in a data buffer. A value can be either a variable, a command,
-// a literal or an expression.
-DataBuffer* ScriptReader::ParseExprValue (type_e reqtype) {
- DataBuffer* b = new DataBuffer(16);
-
- ScriptVar* g;
-
- // Prefixing "!" means negation.
- bool negate = (token == "!");
- if (negate) // Jump past the "!"
- Next ();
-
- // Handle strlen
- if (token == "strlen") {
- MustNext ("(");
- MustNext ();
-
- // By this token we should get a string constant.
- constinfo_t* constant = FindConstant (token);
- if (!constant || constant->type != TYPE_STRING)
- ParserError ("strlen only works with const str");
-
- if (reqtype != TYPE_INT)
- ParserError ("strlen returns int but %s is expected\n", (char*)GetTypeName (reqtype));
-
- b->Write (DH_PUSHNUMBER);
- b->Write (constant->val.len ());
-
- MustNext (")");
- } else if (token == "(") {
- // Expression
- MustNext ();
- DataBuffer* c = ParseExpression (reqtype);
- b->Merge (c);
- MustNext (")");
- } else if (CommandDef* comm = FindCommand (token)) {
- delete b;
-
- // Command
- if (reqtype && comm->returnvalue != reqtype)
- ParserError ("%s returns an incompatible data type", comm->name.chars());
- b = ParseCommand (comm);
- } else if (constinfo_t* constant = FindConstant (token)) {
- // Type check
- if (reqtype != constant->type)
- ParserError ("constant `%s` is %s, expression requires %s\n",
- (char*)constant->name, (char*)GetTypeName (constant->type),
- (char*)GetTypeName (reqtype));
-
- switch (constant->type) {
- case TYPE_BOOL:
- case TYPE_INT:
- b->Write (DH_PUSHNUMBER);
- b->Write (atoi (constant->val));
- break;
- case TYPE_STRING:
- b->WriteString (constant->val);
- break;
- case TYPE_VOID:
- case TYPE_UNKNOWN:
- break;
- }
- } else if ((g = FindGlobalVariable (token))) {
- // Global variable
- b->Write (DH_PUSHGLOBALVAR);
- b->Write (g->index);
- } else {
- // If nothing else, check for literal
- switch (reqtype) {
- case TYPE_VOID:
- case TYPE_UNKNOWN:
- ParserError ("unknown identifier `%s` (expected keyword, function or variable)", token.chars());
- break;
- case TYPE_BOOL:
- case TYPE_INT: {
- MustNumber (true);
-
- // All values are written unsigned - thus we need to write the value's
- // absolute value, followed by an unary minus for negatives.
- b->Write (DH_PUSHNUMBER);
-
- long v = atol (token);
- b->Write (static_cast<word> (abs (v)));
- if (v < 0)
- b->Write (DH_UNARYMINUS);
- break;
- }
- case TYPE_STRING:
- // PushToStringTable either returns the string index of the
- // string if it finds it in the table, or writes it to the
- // table and returns it index if it doesn't find it there.
- MustString (true);
- b->WriteString (token);
- break;
- }
- }
-
- // Negate it now if desired
- if (negate)
- b->Write (DH_NEGATELOGICAL);
-
- return b;
-}
-
-// ============================================================================
-// Parses an assignment. An assignment starts with a variable name, followed
-// by an assignment operator, followed by an expression value. Expects current
-// token to be the name of the variable, and expects the variable to be given.
-DataBuffer* ScriptReader::ParseAssignment (ScriptVar* var) {
- bool global = !var->statename.len ();
-
- // Get an operator
- MustNext ();
- int oper = ParseOperator ();
- if (!IsAssignmentOperator (oper))
- ParserError ("expected assignment operator");
-
- if (g_CurMode == MODE_TOPLEVEL) // TODO: lift this restriction
- ParserError ("can't alter variables at top level");
-
- // Parse the right operand
- MustNext ();
- DataBuffer* retbuf = new DataBuffer;
- DataBuffer* expr = ParseExpression (var->type);
-
- // <<= and >>= do not have data headers. Solution: expand them.
- // a <<= b -> a = a << b
- // a >>= b -> a = a >> b
- if (oper == OPER_ASSIGNLEFTSHIFT || oper == OPER_ASSIGNRIGHTSHIFT) {
- retbuf->Write (global ? DH_PUSHGLOBALVAR : DH_PUSHLOCALVAR);
- retbuf->Write (var->index);
- retbuf->Merge (expr);
- retbuf->Write ((oper == OPER_ASSIGNLEFTSHIFT) ? DH_LSHIFT : DH_RSHIFT);
- retbuf->Write (global ? DH_ASSIGNGLOBALVAR : DH_ASSIGNLOCALVAR);
- retbuf->Write (var->index);
- } else {
- retbuf->Merge (expr);
- long dh = DataHeaderByOperator (var, oper);
- retbuf->Write (dh);
- retbuf->Write (var->index);
- }
-
- return retbuf;
-}
-
-void ScriptReader::PushScope () {
- g_ScopeCursor++;
- if (g_ScopeCursor >= MAX_SCOPE)
- ParserError ("too deep scope");
-
- ScopeInfo* info = &SCOPE(0);
- info->type = SCOPETYPE_UNKNOWN;
- info->mark1 = 0;
- info->mark2 = 0;
- info->buffer1 = NULL;
- info->casecursor = -1;
- for (int i = 0; i < MAX_CASE; i++) {
- info->casemarks[i] = MAX_MARKS;
- info->casebuffers[i] = NULL;
- info->casenumbers[i] = -1;
- }
-}
-
-DataBuffer* ScriptReader::ParseStatement (ObjWriter* w) {
- if (FindConstant (token)) // There should not be constants here.
- ParserError ("invalid use for constant\n");
-
- // If it's a variable, expect assignment.
- if (ScriptVar* var = FindGlobalVariable (token))
- return ParseAssignment (var);
-
- return NULL;
-}
-
-void ScriptReader::AddSwitchCase (ObjWriter* w, DataBuffer* b) {
- ScopeInfo* info = &SCOPE(0);
-
- info->casecursor++;
- if (info->casecursor >= MAX_CASE)
- ParserError ("too many cases in one switch");
-
- // Init a mark for the case buffer
- int m = w->AddMark ("");
- info->casemarks[info->casecursor] = m;
-
- // Add a reference to the mark. "case" and "default" both
- // add the necessary bytecode before the reference.
- if (b)
- b->AddMarkReference (m);
- else
- w->AddReference (m);
-
- // Init a buffer for the case block and tell the object
- // writer to record all written data to it.
- info->casebuffers[info->casecursor] = w->SwitchBuffer = new DataBuffer;
-}
-
-constinfo_t* FindConstant (str token) {
- for (uint i = 0; i < g_ConstInfo.size(); i++)
- if (g_ConstInfo[i].name == token)
- return &g_ConstInfo[i];
- return NULL;
-}
\ No newline at end of file