If: Extract cmConditionEvaluator from if() implementation

1 files changed, 692 insertions, 0 deletions

diff --git a/Source/cmConditionEvaluator.cxx b/Source/cmConditionEvaluator.cxx
new file mode 100644
index 0000000..869d3c5
--- /dev/null
+++ b/Source/cmConditionEvaluator.cxx
@@ -0,0 +1,692 @@
+/*============================================================================
+  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"
+
+cmConditionEvaluator::cmConditionEvaluator(cmMakefile& makefile):
+  Makefile(makefile),
+  Policy12Status(makefile.GetPolicyStatus(cmPolicies::CMP0012))
+{
+
+}
+
+//=========================================================================
+// 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<std::string> &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
+  for(unsigned int i = 0; i < args.size(); ++i)
+    {
+    newArgs.push_back(args[i]);
+    }
+
+  // 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::GetVariableOrString(
+    const std::string& str) const
+{
+  const char* def = this->Makefile.GetDefinition(str);
+
+  if(!def)
+    {
+    def = str.c_str();
+    }
+
+  return def;
+}
+
+//=========================================================================
+bool cmConditionEvaluator::GetBooleanValue(
+  std::string& 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->Makefile.GetDefinition(arg);
+  return !cmSystemTools::IsOff(def);
+}
+
+//=========================================================================
+// Boolean value behavior from CMake 2.6.4 and below.
+bool cmConditionEvaluator::GetBooleanValueOld(
+  std::string 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
+      { return !cmSystemTools::IsOff(this->Makefile.GetDefinition(arg)); }
+    }
+  else
+    {
+    // Old GetVariableOrNumber behavior.
+    const char* def = this->Makefile.GetDefinition(arg);
+    if(!def && atoi(arg.c_str()))
+      {
+      def = arg.c_str();
+      }
+    return !cmSystemTools::IsOff(def);
+    }
+}
+
+//=========================================================================
+// returns the resulting boolean value
+bool cmConditionEvaluator::GetBooleanValueWithAutoDereference(
+  std::string &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:
+        {
+        cmPolicies* policies = this->Makefile.GetPolicies();
+        errorString = "An argument named \"" + newArg
+          + "\" appears in a conditional statement.  "
+          + policies->GetPolicyWarning(cmPolicies::CMP0012);
+        status = cmake::AUTHOR_WARNING;
+        }
+      case cmPolicies::OLD:
+        return oldResult;
+      case cmPolicies::REQUIRED_IF_USED:
+      case cmPolicies::REQUIRED_ALWAYS:
+        {
+        cmPolicies* policies = this->Makefile.GetPolicies();
+        errorString = "An argument named \"" + newArg
+          + "\" appears in a conditional statement.  "
+          + policies->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 = "1";
+    }
+  else
+    {
+    *arg = "0";
+    }
+  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 = "1";
+    }
+  else
+    {
+    *arg = "0";
+    }
+  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;
+    std::list<std::string>::iterator arg = newArgs.begin();
+    while (arg != newArgs.end())
+      {
+      if (*arg == "(")
+        {
+        // search for the closing paren for this opening one
+        std::list<std::string>::iterator argClose;
+        argClose = arg;
+        argClose++;
+        unsigned int depth = 1;
+        while (argClose != newArgs.end() && depth)
+          {
+          if (*argClose == "(")
+            {
+              depth++;
+            }
+          if (*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<std::string> newArgs2;
+
+        // copy to the list structure
+        std::list<std::string>::iterator argP1 = arg;
+        argP1++;
+        for(; argP1 != argClose; argP1++)
+          {
+          newArgs2.push_back(*argP1);
+          }
+        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 = "1";
+          }
+        else
+          {
+          *arg = "0";
+          }
+        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;
+    std::list<std::string>::iterator arg = newArgs.begin();
+    std::list<std::string>::iterator argP1;
+    std::list<std::string>::iterator argP2;
+    while (arg != newArgs.end())
+      {
+      argP1 = arg;
+      this->IncrementArguments(newArgs,argP1,argP2);
+      // does a file exist
+      if (*arg == "EXISTS" && argP1  != newArgs.end())
+        {
+        this->HandlePredicate(
+          cmSystemTools::FileExists((argP1)->c_str()),
+          reducible, arg, newArgs, argP1, argP2);
+        }
+      // does a directory with this name exist
+      if (*arg == "IS_DIRECTORY" && argP1  != newArgs.end())
+        {
+        this->HandlePredicate(
+          cmSystemTools::FileIsDirectory((argP1)->c_str()),
+          reducible, arg, newArgs, argP1, argP2);
+        }
+      // does a symlink with this name exist
+      if (*arg == "IS_SYMLINK" && argP1  != newArgs.end())
+        {
+        this->HandlePredicate(
+          cmSystemTools::FileIsSymlink((argP1)->c_str()),
+          reducible, arg, newArgs, argP1, argP2);
+        }
+      // is the given path an absolute path ?
+      if (*arg == "IS_ABSOLUTE" && argP1  != newArgs.end())
+        {
+        this->HandlePredicate(
+          cmSystemTools::FileIsFullPath((argP1)->c_str()),
+          reducible, arg, newArgs, argP1, argP2);
+        }
+      // does a command exist
+      if (*arg == "COMMAND" && argP1  != newArgs.end())
+        {
+        this->HandlePredicate(
+          this->Makefile.CommandExists((argP1)->c_str()),
+          reducible, arg, newArgs, argP1, argP2);
+        }
+      // does a policy exist
+      if (*arg == "POLICY" && argP1 != newArgs.end())
+        {
+        cmPolicies::PolicyID pid;
+        this->HandlePredicate(
+          this->Makefile.GetPolicies()->GetPolicyID((argP1)->c_str(), pid),
+          reducible, arg, newArgs, argP1, argP2);
+        }
+      // does a target exist
+      if (*arg == "TARGET" && argP1 != newArgs.end())
+        {
+        this->HandlePredicate(
+          this->Makefile.FindTargetToUse(*argP1)?true:false,
+          reducible, arg, newArgs, argP1, argP2);
+        }
+      // is a variable defined
+      if (*arg == "DEFINED" && argP1  != newArgs.end())
+        {
+        size_t argP1len = argP1->size();
+        bool bdef = false;
+        if(argP1len > 4 && argP1->substr(0, 4) == "ENV{" &&
+           argP1->operator[](argP1len-1) == '}')
+          {
+          std::string env = argP1->substr(4, argP1len-5);
+          bdef = cmSystemTools::GetEnv(env.c_str())?true:false;
+          }
+        else
+          {
+          bdef = this->Makefile.IsDefinitionSet(*(argP1));
+          }
+        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;
+  const char *def;
+  const char *def2;
+  do
+    {
+    reducible = 0;
+    std::list<std::string>::iterator arg = newArgs.begin();
+    std::list<std::string>::iterator argP1;
+    std::list<std::string>::iterator argP2;
+    while (arg != newArgs.end())
+      {
+      argP1 = arg;
+      this->IncrementArguments(newArgs,argP1,argP2);
+      if (argP1 != newArgs.end() && argP2 != newArgs.end() &&
+        *(argP1) == "MATCHES")
+        {
+        def = this->GetVariableOrString(*arg);
+        const char* rex = (argP2)->c_str();
+        this->Makefile.ClearMatches();
+        cmsys::RegularExpression regEntry;
+        if ( !regEntry.compile(rex) )
+          {
+          cmOStringStream 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 = "1";
+          }
+        else
+          {
+          *arg = "0";
+          }
+        newArgs.erase(argP2);
+        newArgs.erase(argP1);
+        argP1 = arg;
+        this->IncrementArguments(newArgs,argP1,argP2);
+        reducible = 1;
+        }
+
+      if (argP1 != newArgs.end() && *arg == "MATCHES")
+        {
+        *arg = "0";
+        newArgs.erase(argP1);
+        argP1 = arg;
+        this->IncrementArguments(newArgs,argP1,argP2);
+        reducible = 1;
+        }
+
+      if (argP1 != newArgs.end() && argP2 != newArgs.end() &&
+        (*(argP1) == "LESS" || *(argP1) == "GREATER" ||
+         *(argP1) == "EQUAL"))
+        {
+        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) == "LESS")
+          {
+          result = (lhs < rhs);
+          }
+        else if (*(argP1) == "GREATER")
+          {
+          result = (lhs > rhs);
+          }
+        else
+          {
+          result = (lhs == rhs);
+          }
+        HandleBinaryOp(result,
+          reducible, arg, newArgs, argP1, argP2);
+        }
+
+      if (argP1 != newArgs.end() && argP2 != newArgs.end() &&
+        (*(argP1) == "STRLESS" ||
+         *(argP1) == "STREQUAL" ||
+         *(argP1) == "STRGREATER"))
+        {
+        def = this->GetVariableOrString(*arg);
+        def2 = this->GetVariableOrString(*argP2);
+        int val = strcmp(def,def2);
+        bool result;
+        if (*(argP1) == "STRLESS")
+          {
+          result = (val < 0);
+          }
+        else if (*(argP1) == "STRGREATER")
+          {
+          result = (val > 0);
+          }
+        else // strequal
+          {
+          result = (val == 0);
+          }
+        this->HandleBinaryOp(result,
+          reducible, arg, newArgs, argP1, argP2);
+        }
+
+      if (argP1 != newArgs.end() && argP2 != newArgs.end() &&
+        (*(argP1) == "VERSION_LESS" || *(argP1) == "VERSION_GREATER" ||
+         *(argP1) == "VERSION_EQUAL"))
+        {
+        def = this->GetVariableOrString(*arg);
+        def2 = this->GetVariableOrString(*argP2);
+        cmSystemTools::CompareOp op = cmSystemTools::OP_EQUAL;
+        if(*argP1 == "VERSION_LESS")
+          {
+          op = cmSystemTools::OP_LESS;
+          }
+        else if(*argP1 == "VERSION_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() &&
+          *(argP1) == "IS_NEWER_THAN")
+        {
+        int fileIsNewer=0;
+        bool success=cmSystemTools::FileTimeCompare(arg->c_str(),
+            (argP2)->c_str(),
+            &fileIsNewer);
+        this->HandleBinaryOp(
+          (success==false || fileIsNewer==1 || fileIsNewer==0),
+          reducible, arg, newArgs, argP1, argP2);
+        }
+
+      ++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;
+    std::list<std::string>::iterator arg = newArgs.begin();
+    std::list<std::string>::iterator argP1;
+    std::list<std::string>::iterator argP2;
+    while (arg != newArgs.end())
+      {
+      argP1 = arg;
+      IncrementArguments(newArgs,argP1,argP2);
+      if (argP1 != newArgs.end() && *arg == "NOT")
+        {
+        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;
+    std::list<std::string>::iterator arg = newArgs.begin();
+    std::list<std::string>::iterator argP1;
+    std::list<std::string>::iterator argP2;
+    while (arg != newArgs.end())
+      {
+      argP1 = arg;
+      IncrementArguments(newArgs,argP1,argP2);
+      if (argP1 != newArgs.end() && *(argP1) == "AND" &&
+        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() && *(argP1) == "OR" &&
+        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;
+}