ppsspp/Common/Math/expression_parser.cpp
Unknown W. Brackets 9cfcbc46e6 Global: Cleanup initialization/pointer checks.
Cleaning up a lot of cases of uninitialized data, unchecked return values
for failures, and similar.
2022-12-10 21:13:36 -08:00

603 lines
15 KiB
C++

#include "expression_parser.h"
#include <ctype.h>
#include <cstring>
#include <cstdio>
#include <cstdlib>
typedef enum {
EXOP_BRACKETL, EXOP_BRACKETR, EXOP_MEML, EXOP_MEMR, EXOP_MEMSIZE, EXOP_SIGNPLUS, EXOP_SIGNMINUS,
EXOP_BITNOT, EXOP_LOGNOT, EXOP_MUL, EXOP_DIV, EXOP_MOD, EXOP_ADD, EXOP_SUB,
EXOP_SHL, EXOP_SHR, EXOP_GREATEREQUAL, EXOP_GREATER, EXOP_LOWEREQUAL, EXOP_LOWER,
EXOP_EQUAL, EXOP_NOTEQUAL, EXOP_BITAND, EXOP_XOR, EXOP_BITOR, EXOP_LOGAND,
EXOP_LOGOR, EXOP_TERTIF, EXOP_TERTELSE, EXOP_NUMBER, EXOP_MEM, EXOP_NONE, EXOP_COUNT
} ExpressionOpcodeType;
typedef enum { EXCOMM_CONST, EXCOMM_CONST_FLOAT, EXCOMM_REF, EXCOMM_OP } ExpressionCommand;
static char expressionError[512];
typedef struct {
char Name[4];
unsigned char Priority;
unsigned char len;
unsigned char args;
bool sign;
} ExpressionOpcode;
const ExpressionOpcode ExpressionOpcodes[] = {
{ "(", 25, 1, 0, false }, // EXOP_BRACKETL
{ ")", 25, 1, 0, false }, // EXOP_BRACKETR
{ "[", 4, 1, 0, false }, // EXOP_MEML
{ "]", 4, 1, 0, false }, // EXOP_MEMR
{ ",", 5, 1, 2, false }, // EXOP_MEMSIZE
{ "+", 22, 1, 1, true }, // EXOP_SIGNPLUS
{ "-", 22, 1, 1, true }, // EXOP_SIGNMINUS
{ "~", 22, 1, 1, false }, // EXOP_BITNOT
{ "!", 22, 1, 1, false }, // EXOP_LOGNOT
{ "*", 21, 1, 2, false }, // EXOP_MUL
{ "/", 21, 1, 2, false }, // EXOP_DIV
{ "%", 21, 1, 2, false }, // EXOP_MOD
{ "+", 20, 1, 2, false }, // EXOP_ADD
{ "-", 20, 1, 2, false }, // EXOP_SUB
{ "<<", 19, 2, 2, false }, // EXOP_SHL
{ ">>", 19, 2, 2, false }, // EXOP_SHR
{ ">=", 18, 2, 2, false }, // EXOP_GREATEREQUAL
{ ">", 18, 1, 2, false }, // EXOP_GREATER
{ "<=", 18, 2, 2, false }, // EXOP_LOWEREQUAL
{ "<", 18, 1, 2, false }, // EXOP_LOWER
{ "==", 17, 2, 2, false }, // EXOP_EQUAL
{ "!=", 17, 2, 2, false }, // EXOP_NOTEQUAL
{ "&", 16, 1, 2, false }, // EXOP_BITAND
{ "^", 15, 1, 2, false }, // EXOP_XOR
{ "|", 14, 1, 2, false }, // EXOP_BITOR
{ "&&", 13, 2, 2, false }, // EXOP_LOGAND
{ "||", 12, 2, 2, false }, // EXOP_LOGOR
{ "?", 10, 1, 0, false }, // EXOP_TERTIF
{ ":", 11, 1, 3, false }, // EXOP_TERTELSE
{ "", 0, 0, 0, false }, // EXOP_NUMBER
{ "[]", 0, 0, 1, false }, // EXOP_MEM
{ "", 0, 0, 0, false } // EXOP_NONE
};
static int radixFromZeroPrefix(char c) {
switch (tolower(c)) {
case 'b': return 2;
case 'o': return 8;
case 'x': return 16;
// Inventing a prefix since we default to hex.
case 'd': return 10;
}
return -1;
}
static int radixFromSuffix(char c, int defaultrad) {
switch (tolower(c)) {
case 'o': return 8;
case 'h': return 16;
case 'i': return 10;
case 'u': return 10;
case 'b': return defaultrad == 16 ? -1 : 2;
}
return -1;
}
bool parseNumber(char *str, int defaultrad, int len, uint32_t &result) {
int val = 0;
int r = 0;
if (len == 0)
len = (int)strlen(str);
if (str[0] == '0' && radixFromZeroPrefix(str[1]) != -1) {
r = radixFromZeroPrefix(str[1]);
str += 2;
len -= 2;
} else if (str[0] == '$') {
r = 16;
str++;
len--;
} else if (str[0] >= '0' && str[0] <= '9') {
int suffix = radixFromSuffix(str[len - 1], defaultrad);
if (suffix != -1) {
r = suffix;
len--;
} else {
r = defaultrad;
}
} else {
return false;
}
switch (r)
{
case 2: // bin
while (len--)
{
if (*str != '0' && *str != '1') return false;
val = val << 1;
if (*str++ == '1')
{
val++;
}
}
break;
case 8: // oct
while (len--)
{
if (*str < '0' || *str > '7') return false;
val = val << 3;
val+=(*str++-'0');
}
break;
case 10: // dec
while (len--)
{
if (*str < '0' || *str > '9') return false;
val = val * 10;
val += (*str++ - '0');
}
break;
case 16: // hex
while (len--)
{
char c = tolower(*str++);
if ((c < '0' || c > '9') && (c < 'a' || c > 'f')) return false;
val = val << 4;
if (c >= 'a') val += c-'a'+10;
else val += c-'0';
}
break;
default:
return false;
}
result = val;
return true;
}
// Parse only a float, and return as float bits.
static bool parseFloat(const char *str, int len, uint32_t &result)
{
bool foundDecimal = false;
for (int i = 0; i < len; ++i)
{
if (str[i] == '.')
{
if (foundDecimal)
return false;
foundDecimal = true;
continue;
}
if (str[i] < '0' || str[i] > '9')
return false;
}
float f = (float)atof(str);
memcpy(&result, &f, sizeof(result));
return foundDecimal;
}
ExpressionOpcodeType getExpressionOpcode(const char* str, int& ReturnLen, ExpressionOpcodeType LastOpcode)
{
int longestlen = 0;
ExpressionOpcodeType result = EXOP_NONE;
for (int i = 0; i < EXOP_NUMBER; i++)
{
if (ExpressionOpcodes[i].sign == true &&
(LastOpcode == EXOP_NUMBER || LastOpcode == EXOP_BRACKETR)) continue;
int len = ExpressionOpcodes[i].len;
if (len > longestlen)
{
if (strncmp(ExpressionOpcodes[i].Name,str,len) == 0)
{
result = (ExpressionOpcodeType) i;
longestlen = len;
}
}
}
ReturnLen = longestlen;
return result;
}
bool isAlphaNum(char c)
{
if ((c >= '0' && c <= '9') ||
(c >= 'A' && c <= 'Z') ||
(c >= 'a' && c <= 'z') ||
c == '@' || c == '_' || c == '$' || c == '.')
{
return true;
} else {
return false;
}
}
bool initPostfixExpression(const char* infix, IExpressionFunctions* funcs, PostfixExpression& dest)
{
expressionError[0] = 0;
int infixPos = 0;
int infixLen = (int)strlen(infix);
ExpressionOpcodeType lastOpcode = EXOP_NONE;
std::vector<ExpressionOpcodeType> opcodeStack;
dest.clear();
while (infixPos < infixLen)
{
char first = tolower(infix[infixPos]);
char subStr[256];
int subPos = 0;
if (first == ' ' || first == '\t')
{
infixPos++;
continue;
}
if (first >= '0' && first <= '9')
{
while (isAlphaNum(infix[infixPos]))
{
subStr[subPos++] = infix[infixPos++];
}
subStr[subPos] = 0;
uint32_t value;
bool isFloat = false;
if (parseFloat(subStr,subPos,value) == true)
isFloat = true;
else if (parseNumber(subStr,16,subPos,value) == false)
{
snprintf(expressionError, sizeof(expressionError), "Invalid number \"%s\"",subStr);
return false;
}
dest.push_back(ExpressionPair(isFloat?EXCOMM_CONST_FLOAT:EXCOMM_CONST,value));
lastOpcode = EXOP_NUMBER;
} else if ((first >= 'a' && first <= 'z') || first == '@')
{
while (isAlphaNum(infix[infixPos]))
{
subStr[subPos++] = infix[infixPos++];
}
subStr[subPos] = 0;
uint32_t value;
if (funcs->parseReference(subStr,value) == true)
{
dest.push_back(ExpressionPair(EXCOMM_REF,value));
lastOpcode = EXOP_NUMBER;
continue;
}
if (funcs->parseSymbol(subStr,value) == true)
{
dest.push_back(ExpressionPair(EXCOMM_CONST,value));
lastOpcode = EXOP_NUMBER;
continue;
}
snprintf(expressionError, sizeof(expressionError), "Invalid symbol \"%s\"",subStr);
return false;
} else {
int len;
ExpressionOpcodeType type = getExpressionOpcode(&infix[infixPos],len,lastOpcode);
if (type == EXOP_NONE)
{
snprintf(expressionError, sizeof(expressionError), "Invalid operator at \"%s\"",&infix[infixPos]);
return false;
}
switch (type)
{
case EXOP_BRACKETL:
case EXOP_MEML:
opcodeStack.push_back(type);
break;
case EXOP_BRACKETR:
while (true)
{
if (opcodeStack.empty())
{
snprintf(expressionError, sizeof(expressionError), "Closing parenthesis without opening one");
return false;
}
ExpressionOpcodeType t = opcodeStack[opcodeStack.size()-1];
opcodeStack.pop_back();
if (t == EXOP_BRACKETL) break;
dest.push_back(ExpressionPair(EXCOMM_OP,t));
}
break;
case EXOP_MEMR:
while (true)
{
if (opcodeStack.empty())
{
snprintf(expressionError, sizeof(expressionError), "Closing bracket without opening one");
return false;
}
ExpressionOpcodeType t = opcodeStack[opcodeStack.size()-1];
opcodeStack.pop_back();
if (t == EXOP_MEML)
{
dest.push_back(ExpressionPair(EXCOMM_OP,EXOP_MEM));
break;
}
dest.push_back(ExpressionPair(EXCOMM_OP,t));
}
type = EXOP_NUMBER;
break;
default:
if (opcodeStack.empty() == false)
{
int CurrentPriority = ExpressionOpcodes[type].Priority;
while (!opcodeStack.empty())
{
ExpressionOpcodeType t = opcodeStack[opcodeStack.size()-1];
opcodeStack.pop_back();
if (t == EXOP_BRACKETL || t == EXOP_MEML)
{
opcodeStack.push_back(t);
break;
}
if (ExpressionOpcodes[t].Priority >= CurrentPriority)
{
dest.push_back(ExpressionPair(EXCOMM_OP,t));
} else {
opcodeStack.push_back(t);
break;
}
}
}
opcodeStack.push_back(type);
break;
}
infixPos += len;
lastOpcode = type;
}
}
while (!opcodeStack.empty())
{
ExpressionOpcodeType t = opcodeStack[opcodeStack.size()-1];
opcodeStack.pop_back();
if (t == EXOP_BRACKETL) // opening bracket without closing one
{
snprintf(expressionError, sizeof(expressionError), "Parenthesis not closed");
return false;
}
dest.push_back(ExpressionPair(EXCOMM_OP,t));
}
#if 0 // only for testing
char test[1024];
int testPos = 0;
for (int i = 0; i < dest.size(); i++)
{
switch (dest[i].first)
{
case EXCOMM_CONST:
case EXCOMM_CONST_FLOAT:
testPos += sprintf(&test[testPos],"0x%04X ",dest[i].second);
break;
case EXCOMM_REF:
testPos += sprintf(&test[testPos],"r%d ",dest[i].second);
break;
case EXCOMM_OP:
testPos += sprintf(&test[testPos],"%s ",ExpressionOpcodes[dest[i].second].Name);
break;
};
}
#endif
return true;
}
bool parsePostfixExpression(PostfixExpression& exp, IExpressionFunctions* funcs, uint32_t& dest)
{
size_t num = 0;
uint32_t opcode;
std::vector<uint32_t> valueStack;
unsigned int arg[5]{};
float fArg[5]{};
bool useFloat = false;
while (num < exp.size())
{
switch (exp[num].first)
{
case EXCOMM_CONST: // konstante zahl
valueStack.push_back(exp[num++].second);
break;
case EXCOMM_CONST_FLOAT:
useFloat = true;
valueStack.push_back(exp[num++].second);
break;
case EXCOMM_REF:
useFloat = useFloat || funcs->getReferenceType(exp[num].second) == EXPR_TYPE_FLOAT;
opcode = funcs->getReferenceValue(exp[num++].second);
valueStack.push_back(opcode);
break;
case EXCOMM_OP: // opcode
opcode = exp[num++].second;
if (valueStack.size() < ExpressionOpcodes[opcode].args)
{
snprintf(expressionError, sizeof(expressionError), "Not enough arguments");
return false;
}
for (int l = 0; l < ExpressionOpcodes[opcode].args; l++)
{
arg[l] = valueStack[valueStack.size()-1];
valueStack.pop_back();
}
// In case of float representation.
memcpy(fArg, arg, sizeof(fArg));
switch (opcode)
{
case EXOP_MEMSIZE: // must be followed by EXOP_MEM
if (exp[num++].second != EXOP_MEM)
{
snprintf(expressionError, sizeof(expressionError), "Invalid memsize operator");
return false;
}
uint32_t val;
if(funcs->getMemoryValue(arg[1],arg[0],val,expressionError) == false)
{
return false;
}
valueStack.push_back(val);
break;
case EXOP_MEM:
{
uint32_t val;
if (funcs->getMemoryValue(arg[0],4,val,expressionError) == false)
{
return false;
}
valueStack.push_back(val);
}
break;
case EXOP_SIGNPLUS: // keine aktion nötig
break;
case EXOP_SIGNMINUS: // -0
if (useFloat)
valueStack.push_back((uint32_t)(0.0f - fArg[0]));
else
valueStack.push_back(0-arg[0]);
break;
case EXOP_BITNOT: // ~b
valueStack.push_back(~arg[0]);
break;
case EXOP_LOGNOT: // !b
valueStack.push_back(!arg[0]);
break;
case EXOP_MUL: // a*b
if (useFloat)
valueStack.push_back((uint32_t)(fArg[1] * fArg[0]));
else
valueStack.push_back(arg[1]*arg[0]);
break;
case EXOP_DIV: // a/b
if (arg[0] == 0)
{
snprintf(expressionError, sizeof(expressionError), "Division by zero");
return false;
}
if (useFloat)
valueStack.push_back((uint32_t)(fArg[1] / fArg[0]));
else
valueStack.push_back(arg[1]/arg[0]);
break;
case EXOP_MOD: // a%b
if (arg[0] == 0)
{
snprintf(expressionError, sizeof(expressionError), "Modulo by zero");
return false;
}
valueStack.push_back(arg[1]%arg[0]);
break;
case EXOP_ADD: // a+b
if (useFloat)
valueStack.push_back((uint32_t)(fArg[1] + fArg[0]));
else
valueStack.push_back(arg[1]+arg[0]);
break;
case EXOP_SUB: // a-b
if (useFloat)
valueStack.push_back((uint32_t)(fArg[1] - fArg[0]));
else
valueStack.push_back(arg[1]-arg[0]);
break;
case EXOP_SHL: // a<<b
valueStack.push_back(arg[1]<<arg[0]);
break;
case EXOP_SHR: // a>>b
valueStack.push_back(arg[1]>>arg[0]);
break;
case EXOP_GREATEREQUAL: // a >= b
if (useFloat)
valueStack.push_back(fArg[1]>=fArg[0]);
else
valueStack.push_back(arg[1]>=arg[0]);
break;
case EXOP_GREATER: // a > b
if (useFloat)
valueStack.push_back(fArg[1]>fArg[0]);
else
valueStack.push_back(arg[1]>arg[0]);
break;
case EXOP_LOWEREQUAL: // a <= b
if (useFloat)
valueStack.push_back(fArg[1]<=fArg[0]);
else
valueStack.push_back(arg[1]<=arg[0]);
break;
case EXOP_LOWER: // a < b
if (useFloat)
valueStack.push_back(fArg[1]<fArg[0]);
else
valueStack.push_back(arg[1]<arg[0]);
break;
case EXOP_EQUAL: // a == b
valueStack.push_back(arg[1]==arg[0]);
break;
case EXOP_NOTEQUAL: // a != b
valueStack.push_back(arg[1]!=arg[0]);
break;
case EXOP_BITAND: // a&b
valueStack.push_back(arg[1]&arg[0]);
break;
case EXOP_XOR: // a^b
valueStack.push_back(arg[1]^arg[0]);
break;
case EXOP_BITOR: // a|b
valueStack.push_back(arg[1]|arg[0]);
break;
case EXOP_LOGAND: // a && b
valueStack.push_back(arg[1]&&arg[0]);
break;
case EXOP_LOGOR: // a || b
valueStack.push_back(arg[1]||arg[0]);
break;
case EXOP_TERTIF: // darf so nicht vorkommen
return false;
case EXOP_TERTELSE: // exp ? exp : exp, else muss zuerst kommen!
if (exp[num++].second != EXOP_TERTIF)
{
snprintf(expressionError, sizeof(expressionError), "Invalid tertiary operator");
return false;
}
valueStack.push_back(arg[2]?arg[1]:arg[0]);
break;
}
break;
}
}
if (valueStack.size() != 1) return false;
dest = valueStack[0];
return true;
}
bool parseExpression(const char *exp, IExpressionFunctions *funcs, uint32_t &dest) {
PostfixExpression postfix;
if (initPostfixExpression(exp,funcs,postfix) == false) return false;
return parsePostfixExpression(postfix,funcs,dest);
}
const char* getExpressionError()
{
if (expressionError[0] == 0) snprintf(expressionError, sizeof(expressionError), "Invalid expression");
return expressionError;
}