CMake/Source/cmConditionEvaluator.cxx

728 lines
26 KiB
C++

/*============================================================================
CMake - Cross Platform Makefile Generator
Copyright 2014 Kitware, Inc., Insight Software Consortium
Distributed under the OSI-approved BSD License (the "License");
see accompanying file Copyright.txt for details.
This software is distributed WITHOUT ANY WARRANTY; without even the
implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the License for more information.
============================================================================*/
#include "cmConditionEvaluator.h"
#include "cmAlgorithms.h"
#include "cmOutputConverter.h"
static std::string const keyAND = "AND";
static std::string const keyCOMMAND = "COMMAND";
static std::string const keyDEFINED = "DEFINED";
static std::string const keyEQUAL = "EQUAL";
static std::string const keyEXISTS = "EXISTS";
static std::string const keyGREATER = "GREATER";
static std::string const keyIN_LIST = "IN_LIST";
static std::string const keyIS_ABSOLUTE = "IS_ABSOLUTE";
static std::string const keyIS_DIRECTORY = "IS_DIRECTORY";
static std::string const keyIS_NEWER_THAN = "IS_NEWER_THAN";
static std::string const keyIS_SYMLINK = "IS_SYMLINK";
static std::string const keyLESS = "LESS";
static std::string const keyMATCHES = "MATCHES";
static std::string const keyNOT = "NOT";
static std::string const keyOR = "OR";
static std::string const keyParenL = "(";
static std::string const keyParenR = ")";
static std::string const keyPOLICY = "POLICY";
static std::string const keySTREQUAL = "STREQUAL";
static std::string const keySTRGREATER = "STRGREATER";
static std::string const keySTRLESS = "STRLESS";
static std::string const keyTARGET = "TARGET";
static std::string const keyTEST = "TEST";
static std::string const keyVERSION_EQUAL = "VERSION_EQUAL";
static std::string const keyVERSION_GREATER = "VERSION_GREATER";
static std::string const keyVERSION_LESS = "VERSION_LESS";
cmConditionEvaluator::cmConditionEvaluator(cmMakefile& makefile,
const cmListFileContext& context,
const cmListFileBacktrace& bt)
: Makefile(makefile)
, ExecutionContext(context)
, Backtrace(bt)
, Policy12Status(makefile.GetPolicyStatus(cmPolicies::CMP0012))
, Policy54Status(makefile.GetPolicyStatus(cmPolicies::CMP0054))
, Policy57Status(makefile.GetPolicyStatus(cmPolicies::CMP0057))
, Policy64Status(makefile.GetPolicyStatus(cmPolicies::CMP0064))
{
}
//=========================================================================
// order of operations,
// 1. ( ) -- parenthetical groups
// 2. IS_DIRECTORY EXISTS COMMAND DEFINED etc predicates
// 3. MATCHES LESS GREATER EQUAL STRLESS STRGREATER STREQUAL etc binary ops
// 4. NOT
// 5. AND OR
//
// There is an issue on whether the arguments should be values of references,
// for example IF (FOO AND BAR) should that compare the strings FOO and BAR
// or should it really do IF (${FOO} AND ${BAR}) Currently IS_DIRECTORY
// EXISTS COMMAND and DEFINED all take values. EQUAL, LESS and GREATER can
// take numeric values or variable names. STRLESS and STRGREATER take
// variable names but if the variable name is not found it will use the name
// directly. AND OR take variables or the values 0 or 1.
bool cmConditionEvaluator::IsTrue(
const std::vector<cmExpandedCommandArgument>& args, std::string& errorString,
cmake::MessageType& status)
{
errorString = "";
// handle empty invocation
if (args.size() < 1) {
return false;
}
// store the reduced args in this vector
cmArgumentList newArgs;
// copy to the list structure
newArgs.insert(newArgs.end(), args.begin(), args.end());
// now loop through the arguments and see if we can reduce any of them
// we do this multiple times. Once for each level of precedence
// parens
if (!this->HandleLevel0(newArgs, errorString, status)) {
return false;
}
// predicates
if (!this->HandleLevel1(newArgs, errorString, status)) {
return false;
}
// binary ops
if (!this->HandleLevel2(newArgs, errorString, status)) {
return false;
}
// NOT
if (!this->HandleLevel3(newArgs, errorString, status)) {
return false;
}
// AND OR
if (!this->HandleLevel4(newArgs, errorString, status)) {
return false;
}
// now at the end there should only be one argument left
if (newArgs.size() != 1) {
errorString = "Unknown arguments specified";
status = cmake::FATAL_ERROR;
return false;
}
return this->GetBooleanValueWithAutoDereference(*(newArgs.begin()),
errorString, status, true);
}
//=========================================================================
const char* cmConditionEvaluator::GetDefinitionIfUnquoted(
cmExpandedCommandArgument const& argument) const
{
if ((this->Policy54Status != cmPolicies::WARN &&
this->Policy54Status != cmPolicies::OLD) &&
argument.WasQuoted()) {
return 0;
}
const char* def = this->Makefile.GetDefinition(argument.GetValue());
if (def && argument.WasQuoted() &&
this->Policy54Status == cmPolicies::WARN) {
if (!this->Makefile.HasCMP0054AlreadyBeenReported(
this->ExecutionContext)) {
std::ostringstream e;
e << (cmPolicies::GetPolicyWarning(cmPolicies::CMP0054)) << "\n";
e << "Quoted variables like \"" << argument.GetValue()
<< "\" will no longer be dereferenced "
"when the policy is set to NEW. "
"Since the policy is not set the OLD behavior will be used.";
this->Makefile.GetCMakeInstance()->IssueMessage(
cmake::AUTHOR_WARNING, e.str(), this->Backtrace);
}
}
return def;
}
//=========================================================================
const char* cmConditionEvaluator::GetVariableOrString(
const cmExpandedCommandArgument& argument) const
{
const char* def = this->GetDefinitionIfUnquoted(argument);
if (!def) {
def = argument.c_str();
}
return def;
}
//=========================================================================
bool cmConditionEvaluator::IsKeyword(std::string const& keyword,
cmExpandedCommandArgument& argument) const
{
if ((this->Policy54Status != cmPolicies::WARN &&
this->Policy54Status != cmPolicies::OLD) &&
argument.WasQuoted()) {
return false;
}
bool isKeyword = argument.GetValue() == keyword;
if (isKeyword && argument.WasQuoted() &&
this->Policy54Status == cmPolicies::WARN) {
if (!this->Makefile.HasCMP0054AlreadyBeenReported(
this->ExecutionContext)) {
std::ostringstream e;
e << cmPolicies::GetPolicyWarning(cmPolicies::CMP0054) << "\n";
e << "Quoted keywords like \"" << argument.GetValue()
<< "\" will no longer be interpreted as keywords "
"when the policy is set to NEW. "
"Since the policy is not set the OLD behavior will be used.";
this->Makefile.GetCMakeInstance()->IssueMessage(
cmake::AUTHOR_WARNING, e.str(), this->Backtrace);
}
}
return isKeyword;
}
//=========================================================================
bool cmConditionEvaluator::GetBooleanValue(
cmExpandedCommandArgument& arg) const
{
// Check basic constants.
if (arg == "0") {
return false;
}
if (arg == "1") {
return true;
}
// Check named constants.
if (cmSystemTools::IsOn(arg.c_str())) {
return true;
}
if (cmSystemTools::IsOff(arg.c_str())) {
return false;
}
// Check for numbers.
if (!arg.empty()) {
char* end;
double d = strtod(arg.c_str(), &end);
if (*end == '\0') {
// The whole string is a number. Use C conversion to bool.
return d ? true : false;
}
}
// Check definition.
const char* def = this->GetDefinitionIfUnquoted(arg);
return !cmSystemTools::IsOff(def);
}
//=========================================================================
// Boolean value behavior from CMake 2.6.4 and below.
bool cmConditionEvaluator::GetBooleanValueOld(
cmExpandedCommandArgument const& arg, bool one) const
{
if (one) {
// Old IsTrue behavior for single argument.
if (arg == "0") {
return false;
} else if (arg == "1") {
return true;
} else {
const char* def = this->GetDefinitionIfUnquoted(arg);
return !cmSystemTools::IsOff(def);
}
} else {
// Old GetVariableOrNumber behavior.
const char* def = this->GetDefinitionIfUnquoted(arg);
if (!def && atoi(arg.c_str())) {
def = arg.c_str();
}
return !cmSystemTools::IsOff(def);
}
}
//=========================================================================
// returns the resulting boolean value
bool cmConditionEvaluator::GetBooleanValueWithAutoDereference(
cmExpandedCommandArgument& newArg, std::string& errorString,
cmake::MessageType& status, bool oneArg) const
{
// Use the policy if it is set.
if (this->Policy12Status == cmPolicies::NEW) {
return GetBooleanValue(newArg);
} else if (this->Policy12Status == cmPolicies::OLD) {
return GetBooleanValueOld(newArg, oneArg);
}
// Check policy only if old and new results differ.
bool newResult = this->GetBooleanValue(newArg);
bool oldResult = this->GetBooleanValueOld(newArg, oneArg);
if (newResult != oldResult) {
switch (this->Policy12Status) {
case cmPolicies::WARN: {
errorString = "An argument named \"" + newArg.GetValue() +
"\" appears in a conditional statement. " +
cmPolicies::GetPolicyWarning(cmPolicies::CMP0012);
status = cmake::AUTHOR_WARNING;
}
case cmPolicies::OLD:
return oldResult;
case cmPolicies::REQUIRED_IF_USED:
case cmPolicies::REQUIRED_ALWAYS: {
errorString = "An argument named \"" + newArg.GetValue() +
"\" appears in a conditional statement. " +
cmPolicies::GetRequiredPolicyError(cmPolicies::CMP0012);
status = cmake::FATAL_ERROR;
}
case cmPolicies::NEW:
break;
}
}
return newResult;
}
//=========================================================================
void cmConditionEvaluator::IncrementArguments(
cmArgumentList& newArgs, cmArgumentList::iterator& argP1,
cmArgumentList::iterator& argP2) const
{
if (argP1 != newArgs.end()) {
argP1++;
argP2 = argP1;
if (argP1 != newArgs.end()) {
argP2++;
}
}
}
//=========================================================================
// helper function to reduce code duplication
void cmConditionEvaluator::HandlePredicate(
bool value, int& reducible, cmArgumentList::iterator& arg,
cmArgumentList& newArgs, cmArgumentList::iterator& argP1,
cmArgumentList::iterator& argP2) const
{
if (value) {
*arg = cmExpandedCommandArgument("1", true);
} else {
*arg = cmExpandedCommandArgument("0", true);
}
newArgs.erase(argP1);
argP1 = arg;
this->IncrementArguments(newArgs, argP1, argP2);
reducible = 1;
}
//=========================================================================
// helper function to reduce code duplication
void cmConditionEvaluator::HandleBinaryOp(bool value, int& reducible,
cmArgumentList::iterator& arg,
cmArgumentList& newArgs,
cmArgumentList::iterator& argP1,
cmArgumentList::iterator& argP2)
{
if (value) {
*arg = cmExpandedCommandArgument("1", true);
} else {
*arg = cmExpandedCommandArgument("0", true);
}
newArgs.erase(argP2);
newArgs.erase(argP1);
argP1 = arg;
this->IncrementArguments(newArgs, argP1, argP2);
reducible = 1;
}
//=========================================================================
// level 0 processes parenthetical expressions
bool cmConditionEvaluator::HandleLevel0(cmArgumentList& newArgs,
std::string& errorString,
cmake::MessageType& status)
{
int reducible;
do {
reducible = 0;
cmArgumentList::iterator arg = newArgs.begin();
while (arg != newArgs.end()) {
if (IsKeyword(keyParenL, *arg)) {
// search for the closing paren for this opening one
cmArgumentList::iterator argClose;
argClose = arg;
argClose++;
unsigned int depth = 1;
while (argClose != newArgs.end() && depth) {
if (this->IsKeyword(keyParenL, *argClose)) {
depth++;
}
if (this->IsKeyword(keyParenR, *argClose)) {
depth--;
}
argClose++;
}
if (depth) {
errorString = "mismatched parenthesis in condition";
status = cmake::FATAL_ERROR;
return false;
}
// store the reduced args in this vector
std::vector<cmExpandedCommandArgument> newArgs2;
// copy to the list structure
cmArgumentList::iterator argP1 = arg;
argP1++;
newArgs2.insert(newArgs2.end(), argP1, argClose);
newArgs2.pop_back();
// now recursively invoke IsTrue to handle the values inside the
// parenthetical expression
bool value = this->IsTrue(newArgs2, errorString, status);
if (value) {
*arg = cmExpandedCommandArgument("1", true);
} else {
*arg = cmExpandedCommandArgument("0", true);
}
argP1 = arg;
argP1++;
// remove the now evaluated parenthetical expression
newArgs.erase(argP1, argClose);
}
++arg;
}
} while (reducible);
return true;
}
//=========================================================================
// level one handles most predicates except for NOT
bool cmConditionEvaluator::HandleLevel1(cmArgumentList& newArgs, std::string&,
cmake::MessageType&)
{
int reducible;
do {
reducible = 0;
cmArgumentList::iterator arg = newArgs.begin();
cmArgumentList::iterator argP1;
cmArgumentList::iterator argP2;
while (arg != newArgs.end()) {
argP1 = arg;
this->IncrementArguments(newArgs, argP1, argP2);
// does a file exist
if (this->IsKeyword(keyEXISTS, *arg) && argP1 != newArgs.end()) {
this->HandlePredicate(cmSystemTools::FileExists(argP1->c_str()),
reducible, arg, newArgs, argP1, argP2);
}
// does a directory with this name exist
if (this->IsKeyword(keyIS_DIRECTORY, *arg) && argP1 != newArgs.end()) {
this->HandlePredicate(cmSystemTools::FileIsDirectory(argP1->c_str()),
reducible, arg, newArgs, argP1, argP2);
}
// does a symlink with this name exist
if (this->IsKeyword(keyIS_SYMLINK, *arg) && argP1 != newArgs.end()) {
this->HandlePredicate(cmSystemTools::FileIsSymlink(argP1->c_str()),
reducible, arg, newArgs, argP1, argP2);
}
// is the given path an absolute path ?
if (this->IsKeyword(keyIS_ABSOLUTE, *arg) && argP1 != newArgs.end()) {
this->HandlePredicate(cmSystemTools::FileIsFullPath(argP1->c_str()),
reducible, arg, newArgs, argP1, argP2);
}
// does a command exist
if (this->IsKeyword(keyCOMMAND, *arg) && argP1 != newArgs.end()) {
cmCommand* command =
this->Makefile.GetState()->GetCommand(argP1->c_str());
this->HandlePredicate(command ? true : false, reducible, arg, newArgs,
argP1, argP2);
}
// does a policy exist
if (this->IsKeyword(keyPOLICY, *arg) && argP1 != newArgs.end()) {
cmPolicies::PolicyID pid;
this->HandlePredicate(cmPolicies::GetPolicyID(argP1->c_str(), pid),
reducible, arg, newArgs, argP1, argP2);
}
// does a target exist
if (this->IsKeyword(keyTARGET, *arg) && argP1 != newArgs.end()) {
this->HandlePredicate(
this->Makefile.FindTargetToUse(argP1->GetValue()) ? true : false,
reducible, arg, newArgs, argP1, argP2);
}
// does a test exist
if (this->Policy64Status != cmPolicies::OLD &&
this->Policy64Status != cmPolicies::WARN) {
if (this->IsKeyword(keyTEST, *arg) && argP1 != newArgs.end()) {
const cmTest* haveTest = this->Makefile.GetTest(argP1->c_str());
this->HandlePredicate(haveTest ? true : false, reducible, arg,
newArgs, argP1, argP2);
}
} else if (this->Policy64Status == cmPolicies::WARN &&
this->IsKeyword(keyTEST, *arg)) {
std::ostringstream e;
e << cmPolicies::GetPolicyWarning(cmPolicies::CMP0064) << "\n";
e << "TEST will be interpreted as an operator "
"when the policy is set to NEW. "
"Since the policy is not set the OLD behavior will be used.";
this->Makefile.IssueMessage(cmake::AUTHOR_WARNING, e.str());
}
// is a variable defined
if (this->IsKeyword(keyDEFINED, *arg) && argP1 != newArgs.end()) {
size_t argP1len = argP1->GetValue().size();
bool bdef = false;
if (argP1len > 4 && argP1->GetValue().substr(0, 4) == "ENV{" &&
argP1->GetValue().operator[](argP1len - 1) == '}') {
std::string env = argP1->GetValue().substr(4, argP1len - 5);
bdef = cmSystemTools::GetEnv(env.c_str()) ? true : false;
} else {
bdef = this->Makefile.IsDefinitionSet(argP1->GetValue());
}
this->HandlePredicate(bdef, reducible, arg, newArgs, argP1, argP2);
}
++arg;
}
} while (reducible);
return true;
}
//=========================================================================
// level two handles most binary operations except for AND OR
bool cmConditionEvaluator::HandleLevel2(cmArgumentList& newArgs,
std::string& errorString,
cmake::MessageType& status)
{
int reducible;
std::string def_buf;
const char* def;
const char* def2;
do {
reducible = 0;
cmArgumentList::iterator arg = newArgs.begin();
cmArgumentList::iterator argP1;
cmArgumentList::iterator argP2;
while (arg != newArgs.end()) {
argP1 = arg;
this->IncrementArguments(newArgs, argP1, argP2);
if (argP1 != newArgs.end() && argP2 != newArgs.end() &&
IsKeyword(keyMATCHES, *argP1)) {
def = this->GetVariableOrString(*arg);
if (def != arg->c_str() // yes, we compare the pointer value
&& cmHasLiteralPrefix(arg->GetValue(), "CMAKE_MATCH_")) {
// The string to match is owned by our match result variables.
// Move it to our own buffer before clearing them.
def_buf = def;
def = def_buf.c_str();
}
const char* rex = argP2->c_str();
this->Makefile.ClearMatches();
cmsys::RegularExpression regEntry;
if (!regEntry.compile(rex)) {
std::ostringstream error;
error << "Regular expression \"" << rex << "\" cannot compile";
errorString = error.str();
status = cmake::FATAL_ERROR;
return false;
}
if (regEntry.find(def)) {
this->Makefile.StoreMatches(regEntry);
*arg = cmExpandedCommandArgument("1", true);
} else {
*arg = cmExpandedCommandArgument("0", true);
}
newArgs.erase(argP2);
newArgs.erase(argP1);
argP1 = arg;
this->IncrementArguments(newArgs, argP1, argP2);
reducible = 1;
}
if (argP1 != newArgs.end() && this->IsKeyword(keyMATCHES, *arg)) {
*arg = cmExpandedCommandArgument("0", true);
newArgs.erase(argP1);
argP1 = arg;
this->IncrementArguments(newArgs, argP1, argP2);
reducible = 1;
}
if (argP1 != newArgs.end() && argP2 != newArgs.end() &&
(this->IsKeyword(keyLESS, *argP1) ||
this->IsKeyword(keyGREATER, *argP1) ||
this->IsKeyword(keyEQUAL, *argP1))) {
def = this->GetVariableOrString(*arg);
def2 = this->GetVariableOrString(*argP2);
double lhs;
double rhs;
bool result;
if (sscanf(def, "%lg", &lhs) != 1 || sscanf(def2, "%lg", &rhs) != 1) {
result = false;
} else if (*(argP1) == keyLESS) {
result = (lhs < rhs);
} else if (*(argP1) == keyGREATER) {
result = (lhs > rhs);
} else {
result = (lhs == rhs);
}
this->HandleBinaryOp(result, reducible, arg, newArgs, argP1, argP2);
}
if (argP1 != newArgs.end() && argP2 != newArgs.end() &&
(this->IsKeyword(keySTRLESS, *argP1) ||
this->IsKeyword(keySTREQUAL, *argP1) ||
this->IsKeyword(keySTRGREATER, *argP1))) {
def = this->GetVariableOrString(*arg);
def2 = this->GetVariableOrString(*argP2);
int val = strcmp(def, def2);
bool result;
if (*(argP1) == keySTRLESS) {
result = (val < 0);
} else if (*(argP1) == keySTRGREATER) {
result = (val > 0);
} else // strequal
{
result = (val == 0);
}
this->HandleBinaryOp(result, reducible, arg, newArgs, argP1, argP2);
}
if (argP1 != newArgs.end() && argP2 != newArgs.end() &&
(this->IsKeyword(keyVERSION_LESS, *argP1) ||
this->IsKeyword(keyVERSION_GREATER, *argP1) ||
this->IsKeyword(keyVERSION_EQUAL, *argP1))) {
def = this->GetVariableOrString(*arg);
def2 = this->GetVariableOrString(*argP2);
cmSystemTools::CompareOp op = cmSystemTools::OP_EQUAL;
if (*argP1 == keyVERSION_LESS) {
op = cmSystemTools::OP_LESS;
} else if (*argP1 == keyVERSION_GREATER) {
op = cmSystemTools::OP_GREATER;
}
bool result = cmSystemTools::VersionCompare(op, def, def2);
this->HandleBinaryOp(result, reducible, arg, newArgs, argP1, argP2);
}
// is file A newer than file B
if (argP1 != newArgs.end() && argP2 != newArgs.end() &&
this->IsKeyword(keyIS_NEWER_THAN, *argP1)) {
int fileIsNewer = 0;
bool success = cmSystemTools::FileTimeCompare(
arg->GetValue(), (argP2)->GetValue(), &fileIsNewer);
this->HandleBinaryOp(
(success == false || fileIsNewer == 1 || fileIsNewer == 0),
reducible, arg, newArgs, argP1, argP2);
}
if (argP1 != newArgs.end() && argP2 != newArgs.end() &&
this->IsKeyword(keyIN_LIST, *argP1)) {
if (this->Policy57Status != cmPolicies::OLD &&
this->Policy57Status != cmPolicies::WARN) {
bool result = false;
def = this->GetVariableOrString(*arg);
def2 = this->Makefile.GetDefinition(argP2->GetValue());
if (def2) {
std::vector<std::string> list;
cmSystemTools::ExpandListArgument(def2, list, true);
result = std::find(list.begin(), list.end(), def) != list.end();
}
this->HandleBinaryOp(result, reducible, arg, newArgs, argP1, argP2);
} else if (this->Policy57Status == cmPolicies::WARN) {
std::ostringstream e;
e << cmPolicies::GetPolicyWarning(cmPolicies::CMP0057) << "\n";
e << "IN_LIST will be interpreted as an operator "
"when the policy is set to NEW. "
"Since the policy is not set the OLD behavior will be used.";
this->Makefile.IssueMessage(cmake::AUTHOR_WARNING, e.str());
}
}
++arg;
}
} while (reducible);
return true;
}
//=========================================================================
// level 3 handles NOT
bool cmConditionEvaluator::HandleLevel3(cmArgumentList& newArgs,
std::string& errorString,
cmake::MessageType& status)
{
int reducible;
do {
reducible = 0;
cmArgumentList::iterator arg = newArgs.begin();
cmArgumentList::iterator argP1;
cmArgumentList::iterator argP2;
while (arg != newArgs.end()) {
argP1 = arg;
IncrementArguments(newArgs, argP1, argP2);
if (argP1 != newArgs.end() && IsKeyword(keyNOT, *arg)) {
bool rhs = this->GetBooleanValueWithAutoDereference(
*argP1, errorString, status);
this->HandlePredicate(!rhs, reducible, arg, newArgs, argP1, argP2);
}
++arg;
}
} while (reducible);
return true;
}
//=========================================================================
// level 4 handles AND OR
bool cmConditionEvaluator::HandleLevel4(cmArgumentList& newArgs,
std::string& errorString,
cmake::MessageType& status)
{
int reducible;
bool lhs;
bool rhs;
do {
reducible = 0;
cmArgumentList::iterator arg = newArgs.begin();
cmArgumentList::iterator argP1;
cmArgumentList::iterator argP2;
while (arg != newArgs.end()) {
argP1 = arg;
IncrementArguments(newArgs, argP1, argP2);
if (argP1 != newArgs.end() && IsKeyword(keyAND, *argP1) &&
argP2 != newArgs.end()) {
lhs =
this->GetBooleanValueWithAutoDereference(*arg, errorString, status);
rhs = this->GetBooleanValueWithAutoDereference(*argP2, errorString,
status);
this->HandleBinaryOp((lhs && rhs), reducible, arg, newArgs, argP1,
argP2);
}
if (argP1 != newArgs.end() && this->IsKeyword(keyOR, *argP1) &&
argP2 != newArgs.end()) {
lhs =
this->GetBooleanValueWithAutoDereference(*arg, errorString, status);
rhs = this->GetBooleanValueWithAutoDereference(*argP2, errorString,
status);
this->HandleBinaryOp((lhs || rhs), reducible, arg, newArgs, argP1,
argP2);
}
++arg;
}
} while (reducible);
return true;
}