Makefiles: Add support for building Fortran intrinsics

Fixes: #21463

11 files changed, 110 insertions, 41 deletions

diff --git a/Help/manual/cmake-properties.7.rst b/Help/manual/cmake-properties.7.rst
index 5f18a82475..4212913a96 100644
--- a/Help/manual/cmake-properties.7.rst
+++ b/Help/manual/cmake-properties.7.rst
@@ -202,6 +202,7 @@ Properties on Targets
    /prop_tgt/EXPORT_NAME
    /prop_tgt/EXPORT_PROPERTIES
    /prop_tgt/FOLDER
+   /prop_tgt/Fortran_BUILDING_INSTRINSIC_MODULES
    /prop_tgt/Fortran_FORMAT
    /prop_tgt/Fortran_MODULE_DIRECTORY
    /prop_tgt/Fortran_PREPROCESS
diff --git a/Help/prop_tgt/Fortran_BUILDING_INSTRINSIC_MODULES.rst b/Help/prop_tgt/Fortran_BUILDING_INSTRINSIC_MODULES.rst
new file mode 100644
index 0000000000..518bca7268
--- /dev/null
+++ b/Help/prop_tgt/Fortran_BUILDING_INSTRINSIC_MODULES.rst
@@ -0,0 +1,14 @@
+Fortran_BUILDING_INSTRINSIC_MODULES
+-----------------------------------
+
+Instructs the CMake Fortran preprocessor that the target is building
+Fortran intrinsics for building a Fortran compiler.
+
+This property is off by default and should be turned only on projects
+that build a Fortran compiler. It should not be turned on for projects
+that use a Fortran compiler.
+
+Turning this property on will correctly add dependencies for building
+Fortran intrinsic modules whereas turning the property off will ignore
+Fortran intrinsic modules in the dependency graph as they are supplied
+by the compiler itself.
diff --git a/Source/LexerParser/cmFortranParser.cxx b/Source/LexerParser/cmFortranParser.cxx
index 3f3dddeb4e..50e97529bf 100644
--- a/Source/LexerParser/cmFortranParser.cxx
+++ b/Source/LexerParser/cmFortranParser.cxx
@@ -600,12 +600,12 @@ static const yytype_int8 yytranslate[] =
 static const yytype_uint8 yyrline[] =
 {
        0,   101,   101,   101,   104,   108,   113,   122,   128,   135,
-     140,   144,   149,   157,   162,   167,   172,   177,   182,   187,
-     192,   197,   201,   205,   209,   213,   214,   219,   219,   219,
-     220,   220,   221,   221,   222,   222,   223,   223,   224,   224,
-     225,   225,   226,   226,   227,   227,   228,   228,   231,   232,
-     233,   234,   235,   236,   237,   238,   239,   240,   241,   242,
-     243,   244,   245,   246,   247
+     140,   144,   149,   161,   166,   171,   176,   181,   186,   191,
+     196,   201,   205,   209,   213,   217,   218,   223,   223,   223,
+     224,   224,   225,   225,   226,   226,   227,   227,   228,   228,
+     229,   229,   230,   230,   231,   231,   232,   232,   235,   236,
+     237,   238,   239,   240,   241,   242,   243,   244,   245,   246,
+     247,   248,   249,   250,   251
 };
 #endif
 
@@ -1747,142 +1747,146 @@ yyreduce:
       cmFortranParser* parser = cmFortran_yyget_extra(yyscanner);
       cmFortranParser_RuleUse(parser, (yyvsp[-2].string));
     }
+    if (cmsysString_strcasecmp((yyvsp[-4].string), "intrinsic") == 0) {
+      cmFortranParser* parser = cmFortran_yyget_extra(yyscanner);
+      cmFortranParser_RuleUseIntrinsic(parser, (yyvsp[-2].string));
+    }
     free((yyvsp[-4].string));
     free((yyvsp[-2].string));
   }
-#line 1754 "cmFortranParser.cxx"
+#line 1758 "cmFortranParser.cxx"
     break;
 
   case 13: /* stmt: INCLUDE STRING other EOSTMT  */
-#line 157 "cmFortranParser.y"
+#line 161 "cmFortranParser.y"
                               {
     cmFortranParser* parser = cmFortran_yyget_extra(yyscanner);
     cmFortranParser_RuleInclude(parser, (yyvsp[-2].string));
     free((yyvsp[-2].string));
   }
-#line 1764 "cmFortranParser.cxx"
+#line 1768 "cmFortranParser.cxx"
     break;
 
   case 14: /* stmt: CPP_LINE_DIRECTIVE STRING other EOSTMT  */
-#line 162 "cmFortranParser.y"
+#line 166 "cmFortranParser.y"
                                          {
     cmFortranParser* parser = cmFortran_yyget_extra(yyscanner);
     cmFortranParser_RuleLineDirective(parser, (yyvsp[-2].string));
     free((yyvsp[-2].string));
   }
-#line 1774 "cmFortranParser.cxx"
+#line 1778 "cmFortranParser.cxx"
     break;
 
   case 15: /* stmt: CPP_INCLUDE_ANGLE other EOSTMT  */
-#line 167 "cmFortranParser.y"
+#line 171 "cmFortranParser.y"
                                  {
     cmFortranParser* parser = cmFortran_yyget_extra(yyscanner);
     cmFortranParser_RuleInclude(parser, (yyvsp[-2].string));
     free((yyvsp[-2].string));
   }
-#line 1784 "cmFortranParser.cxx"
+#line 1788 "cmFortranParser.cxx"
     break;
 
   case 16: /* stmt: include STRING other EOSTMT  */
-#line 172 "cmFortranParser.y"
+#line 176 "cmFortranParser.y"
                               {
     cmFortranParser* parser = cmFortran_yyget_extra(yyscanner);
     cmFortranParser_RuleInclude(parser, (yyvsp[-2].string));
     free((yyvsp[-2].string));
   }
-#line 1794 "cmFortranParser.cxx"
+#line 1798 "cmFortranParser.cxx"
     break;
 
   case 17: /* stmt: define WORD other EOSTMT  */
-#line 177 "cmFortranParser.y"
+#line 181 "cmFortranParser.y"
                            {
     cmFortranParser* parser = cmFortran_yyget_extra(yyscanner);
     cmFortranParser_RuleDefine(parser, (yyvsp[-2].string));
     free((yyvsp[-2].string));
   }
-#line 1804 "cmFortranParser.cxx"
+#line 1808 "cmFortranParser.cxx"
     break;
 
   case 18: /* stmt: undef WORD other EOSTMT  */
-#line 182 "cmFortranParser.y"
+#line 186 "cmFortranParser.y"
                           {
     cmFortranParser* parser = cmFortran_yyget_extra(yyscanner);
     cmFortranParser_RuleUndef(parser, (yyvsp[-2].string));
     free((yyvsp[-2].string));
   }
-#line 1814 "cmFortranParser.cxx"
+#line 1818 "cmFortranParser.cxx"
     break;
 
   case 19: /* stmt: ifdef WORD other EOSTMT  */
-#line 187 "cmFortranParser.y"
+#line 191 "cmFortranParser.y"
                           {
     cmFortranParser* parser = cmFortran_yyget_extra(yyscanner);
     cmFortranParser_RuleIfdef(parser, (yyvsp[-2].string));
     free((yyvsp[-2].string));
   }
-#line 1824 "cmFortranParser.cxx"
+#line 1828 "cmFortranParser.cxx"
     break;
 
   case 20: /* stmt: ifndef WORD other EOSTMT  */
-#line 192 "cmFortranParser.y"
+#line 196 "cmFortranParser.y"
                            {
     cmFortranParser* parser = cmFortran_yyget_extra(yyscanner);
     cmFortranParser_RuleIfndef(parser, (yyvsp[-2].string));
     free((yyvsp[-2].string));
   }
-#line 1834 "cmFortranParser.cxx"
+#line 1838 "cmFortranParser.cxx"
     break;
 
   case 21: /* stmt: if other EOSTMT  */
-#line 197 "cmFortranParser.y"
+#line 201 "cmFortranParser.y"
                   {
     cmFortranParser* parser = cmFortran_yyget_extra(yyscanner);
     cmFortranParser_RuleIf(parser);
   }
-#line 1843 "cmFortranParser.cxx"
+#line 1847 "cmFortranParser.cxx"
     break;
 
   case 22: /* stmt: elif other EOSTMT  */
-#line 201 "cmFortranParser.y"
+#line 205 "cmFortranParser.y"
                     {
     cmFortranParser* parser = cmFortran_yyget_extra(yyscanner);
     cmFortranParser_RuleElif(parser);
   }
-#line 1852 "cmFortranParser.cxx"
+#line 1856 "cmFortranParser.cxx"
     break;
 
   case 23: /* stmt: else other EOSTMT  */
-#line 205 "cmFortranParser.y"
+#line 209 "cmFortranParser.y"
                     {
     cmFortranParser* parser = cmFortran_yyget_extra(yyscanner);
     cmFortranParser_RuleElse(parser);
   }
-#line 1861 "cmFortranParser.cxx"
+#line 1865 "cmFortranParser.cxx"
     break;
 
   case 24: /* stmt: endif other EOSTMT  */
-#line 209 "cmFortranParser.y"
+#line 213 "cmFortranParser.y"
                      {
     cmFortranParser* parser = cmFortran_yyget_extra(yyscanner);
     cmFortranParser_RuleEndif(parser);
   }
-#line 1870 "cmFortranParser.cxx"
+#line 1874 "cmFortranParser.cxx"
     break;
 
   case 48: /* misc_code: WORD  */
-#line 231 "cmFortranParser.y"
+#line 235 "cmFortranParser.y"
                       { free ((yyvsp[0].string)); }
-#line 1876 "cmFortranParser.cxx"
+#line 1880 "cmFortranParser.cxx"
     break;
 
   case 55: /* misc_code: STRING  */
-#line 238 "cmFortranParser.y"
+#line 242 "cmFortranParser.y"
                       { free ((yyvsp[0].string)); }
-#line 1882 "cmFortranParser.cxx"
+#line 1886 "cmFortranParser.cxx"
     break;
 
 
-#line 1886 "cmFortranParser.cxx"
+#line 1890 "cmFortranParser.cxx"
 
       default: break;
     }
@@ -2107,6 +2111,6 @@ yyreturn:
   return yyresult;
 }
 
-#line 250 "cmFortranParser.y"
+#line 254 "cmFortranParser.y"
 
 /* End of grammar */
diff --git a/Source/LexerParser/cmFortranParser.y b/Source/LexerParser/cmFortranParser.y
index a3e1c24b12..8ef19035c6 100644
--- a/Source/LexerParser/cmFortranParser.y
+++ b/Source/LexerParser/cmFortranParser.y
@@ -151,6 +151,10 @@ stmt:
       cmFortranParser* parser = cmFortran_yyget_extra(yyscanner);
       cmFortranParser_RuleUse(parser, $5);
     }
+    if (cmsysString_strcasecmp($3, "intrinsic") == 0) {
+      cmFortranParser* parser = cmFortran_yyget_extra(yyscanner);
+      cmFortranParser_RuleUseIntrinsic(parser, $5);
+    }
     free($3);
     free($5);
   }
diff --git a/Source/cmDependsFortran.cxx b/Source/cmDependsFortran.cxx
index bca26b9caa..6024cf6240 100644
--- a/Source/cmDependsFortran.cxx
+++ b/Source/cmDependsFortran.cxx
@@ -163,12 +163,17 @@ bool cmDependsFortran::Finalize(std::ostream& makeDepends,
     mod_dir = this->LocalGenerator->GetCurrentBinaryDirectory();
   }
 
+  bool building_intrinsics =
+    !mf->GetSafeDefinition("CMAKE_Fortran_TARGET_BUILDING_INSTRINSIC_MODULES")
+       .empty();
+
   // Actually write dependencies to the streams.
   using ObjectInfoMap = cmDependsFortranInternals::ObjectInfoMap;
   ObjectInfoMap const& objInfo = this->Internal->ObjectInfo;
   for (auto const& i : objInfo) {
     if (!this->WriteDependenciesReal(i.first, i.second, mod_dir, stamp_dir,
-                                     makeDepends, internalDepends)) {
+                                     makeDepends, internalDepends,
+                                     building_intrinsics)) {
       return false;
     }
   }
@@ -307,7 +312,8 @@ bool cmDependsFortran::WriteDependenciesReal(std::string const& obj,
                                              std::string const& mod_dir,
                                              std::string const& stamp_dir,
                                              std::ostream& makeDepends,
-                                             std::ostream& internalDepends)
+                                             std::ostream& internalDepends,
+                                             bool buildingIntrinsics)
 {
   // Get the source file for this object.
   std::string const& src = info.Source;
@@ -339,8 +345,13 @@ bool cmDependsFortran::WriteDependenciesReal(std::string const& obj,
     makeDepends << '\n';
   }
 
+  std::set<std::string> req = info.Requires;
+  if (buildingIntrinsics) {
+    req.insert(info.Intrinsics.begin(), info.Intrinsics.end());
+  }
+
   // Write module requirements to the output stream.
-  for (std::string const& i : info.Requires) {
+  for (std::string const& i : req) {
     // Require only modules not provided in the same source.
     if (info.Provides.find(i) != info.Provides.cend()) {
       continue;
diff --git a/Source/cmDependsFortran.h b/Source/cmDependsFortran.h
index 0d407bc3bc..a74db91f3d 100644
--- a/Source/cmDependsFortran.h
+++ b/Source/cmDependsFortran.h
@@ -72,7 +72,8 @@ protected:
                              std::string const& mod_dir,
                              std::string const& stamp_dir,
                              std::ostream& makeDepends,
-                             std::ostream& internalDepends);
+                             std::ostream& internalDepends,
+                             bool buildingIntrinsics);
 
   // The source file from which to start scanning.
   std::string SourceFile;
diff --git a/Source/cmFortranParser.h b/Source/cmFortranParser.h
index 1b14d17772..70fe5374ce 100644
--- a/Source/cmFortranParser.h
+++ b/Source/cmFortranParser.h
@@ -40,6 +40,8 @@ int cmFortranParser_GetOldStartcond(cmFortranParser* parser);
 /* Callbacks for parser.  */
 void cmFortranParser_Error(cmFortranParser* parser, const char* message);
 void cmFortranParser_RuleUse(cmFortranParser* parser, const char* module_name);
+void cmFortranParser_RuleUseIntrinsic(cmFortranParser* parser,
+                                      const char* module_name);
 void cmFortranParser_RuleLineDirective(cmFortranParser* parser,
                                        const char* filename);
 void cmFortranParser_RuleInclude(cmFortranParser* parser, const char* name);
@@ -99,6 +101,9 @@ public:
   std::set<std::string> Provides;
   std::set<std::string> Requires;
 
+  // Set of intrinsic modules.
+  std::set<std::string> Intrinsics;
+
   // Set of files included in the translation unit.
   std::set<std::string> Includes;
 };
diff --git a/Source/cmFortranParserImpl.cxx b/Source/cmFortranParserImpl.cxx
index 054a2a93e6..efcc5bb2e6 100644
--- a/Source/cmFortranParserImpl.cxx
+++ b/Source/cmFortranParserImpl.cxx
@@ -197,6 +197,19 @@ void cmFortranParser_RuleUse(cmFortranParser* parser, const char* module_name)
   parser->Info.Requires.insert(parser->ModName(mod_name));
 }
 
+void cmFortranParser_RuleUseIntrinsic(cmFortranParser* parser,
+                                      const char* module_name)
+{
+  if (parser->InPPFalseBranch) {
+    return;
+  }
+
+  // syntax:   "use, intrinsic:: module_name"
+  // requires: "module_name.mod"
+  std::string const& mod_name = cmSystemTools::LowerCase(module_name);
+  parser->Info.Intrinsics.insert(parser->ModName(mod_name));
+}
+
 void cmFortranParser_RuleLineDirective(cmFortranParser* parser,
                                        const char* filename)
 {
diff --git a/Source/cmGeneratorTarget.cxx b/Source/cmGeneratorTarget.cxx
index f268c6c3e6..34797c5c53 100644
--- a/Source/cmGeneratorTarget.cxx
+++ b/Source/cmGeneratorTarget.cxx
@@ -6175,6 +6175,14 @@ std::string cmGeneratorTarget::GetFortranModuleDirectory(
   return this->FortranModuleDirectory;
 }
 
+bool cmGeneratorTarget::IsFortranBuildingInstrinsicModules() const
+{
+  if (cmProp prop = this->GetProperty("Fortran_BUILDING_INSTRINSIC_MODULES")) {
+    return cmIsOn(*prop);
+  }
+  return false;
+}
+
 std::string cmGeneratorTarget::CreateFortranModuleDirectory(
   std::string const& working_dir) const
 {
diff --git a/Source/cmGeneratorTarget.h b/Source/cmGeneratorTarget.h
index ed66fb1a81..0619279cfc 100644
--- a/Source/cmGeneratorTarget.h
+++ b/Source/cmGeneratorTarget.h
@@ -832,6 +832,7 @@ public:
                                     std::string const& config) const;
 
   std::string GetFortranModuleDirectory(std::string const& working_dir) const;
+  bool IsFortranBuildingInstrinsicModules() const;
 
   const std::string& GetSourcesProperty() const;
 
diff --git a/Source/cmMakefileTargetGenerator.cxx b/Source/cmMakefileTargetGenerator.cxx
index 6d8376c678..d6145f8566 100644
--- a/Source/cmMakefileTargetGenerator.cxx
+++ b/Source/cmMakefileTargetGenerator.cxx
@@ -1380,6 +1380,13 @@ void cmMakefileTargetGenerator::WriteTargetDependRules()
     << "set(CMAKE_Fortran_TARGET_MODULE_DIR \""
     << this->GeneratorTarget->GetFortranModuleDirectory(working_dir)
     << "\")\n";
+
+  if (this->GeneratorTarget->IsFortranBuildingInstrinsicModules()) {
+    *this->InfoFileStream
+      << "\n"
+      << "# Fortran compiler is building intrinsic modules.\n"
+      << "set(CMAKE_Fortran_TARGET_BUILDING_INSTRINSIC_MODULES ON) \n";
+  }
   /* clang-format on */
 
   // and now write the rule to use it