Add generator expressions for compiler versions.

New generator expressions allow retrieval of the version per language,
as well as equality comparison.

2 files changed, 107 insertions, 0 deletions

diff --git a/Source/cmDocumentGeneratorExpressions.h b/Source/cmDocumentGeneratorExpressions.h
index 7358a36..841061c 100644
--- a/Source/cmDocumentGeneratorExpressions.h
+++ b/Source/cmDocumentGeneratorExpressions.h
@@ -54,6 +54,13 @@
   "else '0'.\n"                                                         \
   "  $<VERSION_EQUAL:v1,v2>    = '1' if v1 is the same version as v2, " \
   "else '0'.\n"                                                         \
+  "  $<C_COMPILER_VERSION>     = The version of the C compiler used.\n" \
+  "  $<C_COMPILER_VERSION:ver> = '1' if the version of the C "          \
+  "compiler matches ver, otherwise '0'.\n"                              \
+  "  $<CXX_COMPILER_VERSION>   = The version of the CXX compiler "      \
+  "used.\n"                                                             \
+  "  $<CXX_COMPILER_VERSION:ver> = '1' if the version of the CXX "      \
+  "compiler matches ver, otherwise '0'.\n"                              \
   "  $<TARGET_FILE:tgt>        = main file (.exe, .so.1.2, .a)\n"       \
   "  $<TARGET_LINKER_FILE:tgt> = file used to link (.a, .lib, .so)\n"   \
   "  $<TARGET_SONAME_FILE:tgt> = file with soname (.so.3)\n"            \
diff --git a/Source/cmGeneratorExpressionEvaluator.cxx b/Source/cmGeneratorExpressionEvaluator.cxx
index 037ef31..05bbc1c 100644
--- a/Source/cmGeneratorExpressionEvaluator.cxx
+++ b/Source/cmGeneratorExpressionEvaluator.cxx
@@ -342,6 +342,102 @@ static const struct CXXCompilerIdNode : public CompilerIdNode
 } cxxCompilerIdNode;
 
 //----------------------------------------------------------------------------
+struct CompilerVersionNode : public cmGeneratorExpressionNode
+{
+  CompilerVersionNode() {}
+
+  virtual int NumExpectedParameters() const { return ZeroOrMoreParameters; }
+
+  std::string EvaluateWithLanguage(const std::vector<std::string> &parameters,
+                       cmGeneratorExpressionContext *context,
+                       const GeneratorExpressionContent *content,
+                       cmGeneratorExpressionDAGChecker *,
+                       const std::string &lang) const
+  {
+    const char *compilerVersion = context->Makefile ?
+                              context->Makefile->GetSafeDefinition((
+                        "CMAKE_" + lang + "_COMPILER_VERSION").c_str()) : "";
+    if (parameters.size() == 0)
+      {
+      return compilerVersion ? compilerVersion : "";
+      }
+
+    cmsys::RegularExpression compilerIdValidator;
+    compilerIdValidator.compile("^[0-9\\.]*$");
+    if (!compilerIdValidator.find(parameters.begin()->c_str()))
+      {
+      reportError(context, content->GetOriginalExpression(),
+                  "Expression syntax not recognized.");
+      return std::string();
+      }
+    if (!compilerVersion)
+      {
+      return parameters.front().empty() ? "1" : "0";
+      }
+
+    return cmSystemTools::VersionCompare(cmSystemTools::OP_EQUAL,
+                                      parameters.begin()->c_str(),
+                                      compilerVersion) ? "1" : "0";
+  }
+};
+
+//----------------------------------------------------------------------------
+static const struct CCompilerVersionNode : public CompilerVersionNode
+{
+  CCompilerVersionNode() {}
+
+  std::string Evaluate(const std::vector<std::string> &parameters,
+                       cmGeneratorExpressionContext *context,
+                       const GeneratorExpressionContent *content,
+                       cmGeneratorExpressionDAGChecker *dagChecker) const
+  {
+    if (parameters.size() != 0 && parameters.size() != 1)
+      {
+      reportError(context, content->GetOriginalExpression(),
+          "$<C_COMPILER_VERSION> expression requires one or two parameters");
+      return std::string();
+      }
+    if (!context->HeadTarget)
+      {
+      reportError(context, content->GetOriginalExpression(),
+          "$<C_COMPILER_VERSION> may only be used with targets.  It may not "
+          "be used with add_custom_command.");
+      }
+    return this->EvaluateWithLanguage(parameters, context, content,
+                                      dagChecker, "C");
+  }
+} cCompilerVersionNode;
+
+//----------------------------------------------------------------------------
+static const struct CxxCompilerVersionNode : public CompilerVersionNode
+{
+  CxxCompilerVersionNode() {}
+
+  std::string Evaluate(const std::vector<std::string> &parameters,
+                       cmGeneratorExpressionContext *context,
+                       const GeneratorExpressionContent *content,
+                       cmGeneratorExpressionDAGChecker *dagChecker) const
+  {
+    if (parameters.size() != 0 && parameters.size() != 1)
+      {
+      reportError(context, content->GetOriginalExpression(),
+          "$<CXX_COMPILER_VERSION> expression requires one or two "
+          "parameters");
+      return std::string();
+      }
+    if (!context->HeadTarget)
+      {
+      reportError(context, content->GetOriginalExpression(),
+          "$<CXX_COMPILER_VERSION> may only be used with targets.  It may "
+          "not be used with add_custom_command.");
+      }
+    return this->EvaluateWithLanguage(parameters, context, content,
+                                      dagChecker, "CXX");
+  }
+} cxxCompilerVersionNode;
+
+
+//----------------------------------------------------------------------------
 static const struct VersionGreaterNode : public cmGeneratorExpressionNode
 {
   VersionGreaterNode() {}
@@ -1247,6 +1343,10 @@ cmGeneratorExpressionNode* GetNode(const std::string &identifier)
     return &versionLessNode;
   else if (identifier == "VERSION_EQUAL")
     return &versionEqualNode;
+  else if (identifier == "C_COMPILER_VERSION")
+    return &cCompilerVersionNode;
+  else if (identifier == "CXX_COMPILER_VERSION")
+    return &cxxCompilerVersionNode;
   else if (identifier == "CONFIGURATION")
     return &configurationNode;
   else if (identifier == "CONFIG")