[cxxmodules] Move foreachHeader to TClingUtils

We weant to use this functionality in other parts of ROOT, so
we should move it out of rootcling.

Author: Teemperor

core/clingutils/res/TClingUtils.h

@@ -14,13 +14,16 @@
 
 #include "RConversionRuleParser.h"
 
+#include <functional>
 #include <set>
 #include <string>
 #include <unordered_set>
 
 //#include <atomic>
 #include <stdlib.h>
 
+#include "clang/Basic/Module.h"
+
 namespace llvm {
    class StringRef;
 }
@@ -38,7 +41,6 @@ namespace clang {
    class DeclaratorDecl;
    class FieldDecl;
    class FunctionDecl;
-   class Module;
    class NamedDecl;
    class ParmVarDecl;
    class PresumedLoc;
@@ -457,6 +459,9 @@ ROOT::ESTLType IsSTLContainer(const clang::FieldDecl &m);
 //______________________________________________________________________________
 int IsSTLContainer(const clang::CXXBaseSpecifier &base);
 
+void foreachHeaderInModule(const clang::Module &module,
+                           const std::function<void(const clang::Module::Header &)> &closure);
+
 //______________________________________________________________________________
 const char *ShortTypeName(const char *typeDesc);
 

core/clingutils/src/TClingUtils.cxx

@@ -2556,6 +2556,33 @@ int ROOT::TMetaUtils::IsSTLContainer(const clang::CXXBaseSpecifier &base)
    else return ROOT::kNotSTL;
 }
 
+////////////////////////////////////////////////////////////////////////////////
+/// Calls the given lambda on every header in the given module.
+void ROOT::TMetaUtils::foreachHeaderInModule(const clang::Module &module,
+                                             const std::function<void(const clang::Module::Header &)> &closure)
+{
+   // Iterates over all headers in a module and calls the closure on each.
+
+   // FIXME: We currently have to hardcode '4' to do this. Maybe we
+   // will have a nicer way to do this in the future.
+   // NOTE: This is on purpose '4', not '5' which is the size of the
+   // vector. The last element is the list of excluded headers which we
+   // obviously don't want to check here.
+   const std::size_t publicHeaderIndex = 4;
+
+   // Integrity check in case this array changes its size at some point.
+   const std::size_t maxArrayLength = ((sizeof module.Headers) / (sizeof *module.Headers));
+   static_assert(publicHeaderIndex + 1 == maxArrayLength,
+                 "'Headers' has changed it's size, we need to update publicHeaderIndex");
+
+   for (std::size_t i = 0; i < publicHeaderIndex; i++) {
+      auto &headerList = module.Headers[i];
+      for (const clang::Module::Header &moduleHeader : headerList) {
+         closure(moduleHeader);
+      }
+   }
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 /// Return the absolute type of typeDesc.
 /// E.g.: typeDesc = "class TNamed**", returns "TNamed".

core/dictgen/src/rootcling_impl.cxx

@@ -2240,31 +2240,6 @@ static bool GenerateAllDict(TModuleGenerator &modGen, clang::CompilerInstance *c
    return WriteAST(modGen.GetModuleFileName(), compilerInstance, iSysRoot);
 }
 
-static void
-foreachHeaderInModule(const clang::Module &module, const std::function<void(const clang::Module::Header &)> &closure)
-{
-   // Iterates over all headers in a module and calls the closure on each.
-
-   // FIXME: We currently have to hardcode '4' to do this. Maybe we
-   // will have a nicer way to do this in the future.
-   // NOTE: This is on purpose '4', not '5' which is the size of the
-   // vector. The last element is the list of excluded headers which we
-   // obviously don't want to check here.
-   const std::size_t publicHeaderIndex = 4;
-
-   // Integrity check in case this array changes its size at some point.
-   const std::size_t maxArrayLength = ((sizeof module.Headers) / (sizeof *module.Headers));
-   static_assert(publicHeaderIndex + 1 == maxArrayLength,
-                 "'Headers' has changed it's size, we need to update publicHeaderIndex");
-
-   for (std::size_t i = 0; i < publicHeaderIndex; i++) {
-      auto &headerList = module.Headers[i];
-      for (const clang::Module::Header &moduleHeader : headerList) {
-         closure(moduleHeader);
-      }
-   }
-}
-
 ////////////////////////////////////////////////////////////////////////////////
 /// Includes all headers in the given module from this interpreter.
 static void IncludeModuleHeaders(TModuleGenerator &modGen, clang::Module *module, cling::Interpreter &interpreter)
@@ -2287,7 +2262,7 @@ static void IncludeModuleHeaders(TModuleGenerator &modGen, clang::Module *module
    // of doing this and 'import' each header in its own submodule, then let
    // the visibility of the decls handle this situation nicely.
    for (clang::Module *module : modules) {
-      foreachHeaderInModule(*module, [&includes](const clang::Module::Header &h) {
+      ROOT::TMetaUtils::foreachHeaderInModule(*module, [&includes](const clang::Module::Header &h) {
          includes << "#include \"" << h.NameAsWritten << "\"\n";
       });
    }
@@ -2319,7 +2294,7 @@ static bool ModuleContainsHeaders(TModuleGenerator &modGen, clang::Module *modul
    // Now we collect all header files from the previously collected modules.
    std::set<std::string> moduleHeaders;
    for (clang::Module *module : modules) {
-      foreachHeaderInModule(
+      ROOT::TMetaUtils::foreachHeaderInModule(
          *module, [&moduleHeaders](const clang::Module::Header &h) { moduleHeaders.insert(h.NameAsWritten); });
    }