recognize source file extensions ".ccm", ".cxxm", and ".c++m"

[15knots]

cmake 3.27 release notes: The "CXX" language now treats source file extensions ".ccm", ".cxxm", and ".c++m" as C++.

[15knots]

Maybe the default preferences in C/C++ | Files Types should be updated, too. But I could not find it.

[jonahgraham]

Maybe the default preferences in C/C++ | Files Types should be updated, too. But I could not find it.

I think there are multiple places, based on different uses:

File types:

cdt/core/org.eclipse.cdt.core/plugin.xml

Lines 615 to 624 in c91d0f7

	<!-- declares a content type for C++ source files -->
	<content-type id="cxxSource" name="%cxxSourceName"
	base-type="org.eclipse.cdt.core.cSource"
	file-extensions="C,cpp,cxx,cc,c++"
	priority="high"/>
	<!-- declares a content type for C++ header files -->
	<content-type id="cxxHeader" name="%cxxHeaderName"
	base-type="org.eclipse.cdt.core.cxxSource"
	file-extensions="h,hpp,hh,hxx,inc"
	priority="high"/>

Diff viewer with structure:

cdt/core/org.eclipse.cdt.ui/plugin.xml

Lines 1746 to 1749 in 14dfefd

	<viewer
	class="org.eclipse.cdt.internal.ui.compare.CContentViewerCreator"
	extensions="c,cc,cxx,cpp,c++,h,hh,hxx,hpp,inc,c2"
	id="org.eclipse.cdt.ui.compare.CContentViewerCreator">

Managed make builder:

cdt/build/org.eclipse.cdt.managedbuilder.gnu.ui/plugin.xml

Lines 2089 to 2096 in 45a6e79

	<inputType
	sourceContentType="org.eclipse.cdt.core.cxxSource"
	sources="c,C,cc,cxx,cpp,cp,CPP"
	dependencyContentType="org.eclipse.cdt.core.cxxHeader"
	dependencyExtensions="h,H,hpp,hh,hp,hxx,HPP,h++,tcc"
	dependencyCalculator="org.eclipse.cdt.managedbuilder.makegen.gnu.DefaultGCCDependencyCalculator2"
	id="cdt.managedbuild.tool.gnu.cpp.compiler.input"
	languageId="org.eclipse.cdt.core.g++">

[15knots]

@jonahgraham Actually source file extensions ".ccm", ".cxxm", and ".c++m" are for C++ 20 module files.
Maybe we should mentions this in the N&N if the indexer support module syntax.

I will look in the places you mentioned tomorrow.

[jonahgraham]

@jonahgraham Actually source file extensions ".ccm", ".cxxm", and ".c++m" are for C++ 20 module files. Maybe we should mentions this in the N&N if the indexer support module syntax.

I haven't tried, but I doubt CDT indexer supports C++20 modules as I don't recall anyone working on that. More reason for the clangd indexer work being done in cdt-lsp!

[jonahgraham]

Needs rebase now that #421 is merged.

[jonahgraham]

This change seems to have introduced a bunch of regressions. I am not sure why the reporting was inconsistent. If I can't quickly fix this I am going to revert it and retry applying it from scratch.