1 files changed, 56 insertions, 16 deletions

diff --git a/Source/cmCMakeMinimumRequired.cxx b/Source/cmCMakeMinimumRequired.cxx
index bcc41fc..2b51976 100644
--- a/Source/cmCMakeMinimumRequired.cxx
+++ b/Source/cmCMakeMinimumRequired.cxx
@@ -42,12 +42,27 @@ bool cmCMakeMinimumRequired::InitialPass(std::vector<std::string> const& args,
 
   // Make sure there was a version to check.
   if (version_string.empty()) {
-    return this->EnforceUnknownArguments();
+    return this->EnforceUnknownArguments(std::string());
+  }
+
+  // Separate the <min> version and any trailing ...<max> component.
+  std::string::size_type const dd = version_string.find("...");
+  std::string const version_min = version_string.substr(0, dd);
+  std::string const version_max = dd != std::string::npos
+    ? version_string.substr(dd + 3, std::string::npos)
+    : std::string();
+  if (dd != std::string::npos &&
+      (version_min.empty() || version_max.empty())) {
+    std::ostringstream e;
+    e << "VERSION \"" << version_string
+      << "\" does not have a version on both sides of \"...\".";
+    this->SetError(e.str());
+    return false;
   }
 
   // Save the required version string.
   this->Makefile->AddDefinition("CMAKE_MINIMUM_REQUIRED_VERSION",
-                                version_string.c_str());
+                                version_min.c_str());
 
   // Get the current version number.
   unsigned int current_major = cmVersion::GetMajorVersion();
@@ -61,10 +76,10 @@ bool cmCMakeMinimumRequired::InitialPass(std::vector<std::string> const& args,
   unsigned int required_minor = 0;
   unsigned int required_patch = 0;
   unsigned int required_tweak = 0;
-  if (sscanf(version_string.c_str(), "%u.%u.%u.%u", &required_major,
+  if (sscanf(version_min.c_str(), "%u.%u.%u.%u", &required_major,
              &required_minor, &required_patch, &required_tweak) < 2) {
     std::ostringstream e;
-    e << "could not parse VERSION \"" << version_string << "\".";
+    e << "could not parse VERSION \"" << version_min << "\".";
     this->SetError(e.str());
     return false;
   }
@@ -78,7 +93,7 @@ bool cmCMakeMinimumRequired::InitialPass(std::vector<std::string> const& args,
        current_patch == required_patch && current_tweak < required_tweak)) {
     // The current version is too low.
     std::ostringstream e;
-    e << "CMake " << version_string
+    e << "CMake " << version_min
       << " or higher is required.  You are running version "
       << cmVersion::GetCMakeVersion();
     this->Makefile->IssueMessage(cmake::FATAL_ERROR, e.str());
@@ -87,7 +102,7 @@ bool cmCMakeMinimumRequired::InitialPass(std::vector<std::string> const& args,
   }
 
   // The version is not from the future, so enforce unknown arguments.
-  if (!this->EnforceUnknownArguments()) {
+  if (!this->EnforceUnknownArguments(version_max)) {
     return false;
   }
 
@@ -95,22 +110,47 @@ bool cmCMakeMinimumRequired::InitialPass(std::vector<std::string> const& args,
     this->Makefile->IssueMessage(
       cmake::AUTHOR_WARNING,
       "Compatibility with CMake < 2.4 is not supported by CMake >= 3.0.");
-    this->Makefile->SetPolicyVersion("2.4");
+    this->Makefile->SetPolicyVersion("2.4", version_max);
   } else {
-    this->Makefile->SetPolicyVersion(version_string.c_str());
+    this->Makefile->SetPolicyVersion(version_min, version_max);
   }
 
   return true;
 }
 
-bool cmCMakeMinimumRequired::EnforceUnknownArguments()
+bool cmCMakeMinimumRequired::EnforceUnknownArguments(
+  std::string const& version_max)
 {
-  if (!this->UnknownArguments.empty()) {
-    std::ostringstream e;
-    e << "called with unknown argument \"" << this->UnknownArguments[0]
-      << "\".";
-    this->SetError(e.str());
-    return false;
+  if (this->UnknownArguments.empty()) {
+    return true;
   }
-  return true;
+
+  // Consider the max version if at least two components were given.
+  unsigned int max_major = 0;
+  unsigned int max_minor = 0;
+  unsigned int max_patch = 0;
+  unsigned int max_tweak = 0;
+  if (sscanf(version_max.c_str(), "%u.%u.%u.%u", &max_major, &max_minor,
+             &max_patch, &max_tweak) >= 2) {
+    unsigned int current_major = cmVersion::GetMajorVersion();
+    unsigned int current_minor = cmVersion::GetMinorVersion();
+    unsigned int current_patch = cmVersion::GetPatchVersion();
+    unsigned int current_tweak = cmVersion::GetTweakVersion();
+
+    if ((current_major < max_major) ||
+        (current_major == max_major && current_minor < max_minor) ||
+        (current_major == max_major && current_minor == max_minor &&
+         current_patch < max_patch) ||
+        (current_major == max_major && current_minor == max_minor &&
+         current_patch == max_patch && current_tweak < max_tweak)) {
+      // A ...<max> version was given that is larger than the current
+      // version of CMake, so tolerate unknown arguments.
+      return true;
+    }
+  }
+
+  std::ostringstream e;
+  e << "called with unknown argument \"" << this->UnknownArguments[0] << "\".";
+  this->SetError(e.str());
+  return false;
 }