Should #include <CoreFoundation/CFNumber.h> work? Only #include </Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreFoundation.framework/Versions/A/Headers/CFNumber.h> does.

[dhpiggott]

In https://github.com/dhpiggott/plutus/blob/c2edf3b0265a75b78332a15e6cae2d012eee7706/macos/macos.h I found the only way to get bindings to generate is to fully specify the paths to the macOS SDK headers. However, I am able to use the short form at https://github.com/dhpiggott/plutus/blob/c2edf3b0265a75b78332a15e6cae2d012eee7706/build.sbt#L24.

I would expect #include <CoreFoundation/CFNumber.h> etc. to work, but when I try that form, sn-bindgen itself runs without errors, but it simply doesn't generate the bindings, (and so compilation of the app itself fails).

I've attempted to figure this out a few times since I first ran into it but each time without success.

So I thought I should check - is my expectation that the short form should work valid?

[keynmol]

It is possible that something is going wrong with system header detector.

The detector is there to avoid generating thousands of definitions for system headers – because that becomes unwieldy very quickly.

if you run bindgen CLI with --trace you will see that bindgen does discover a ton of definitions in those files, but then after that it just says

[bindgen] trace Defined or used in main file: Set()
[bindgen] trace Binding information after computing closure:
[bindgen] trace Deduplicating 0 functions
[bindgen] trace After deduplication 0 functions will be removed

E.g. this definition from CFNumber.h:

                   DefName(CFNumberIsFloatType,Function)  BindingDefinition(Function(CFNumberIsFloatType,Reference(Model(Boolean,Meta(None,Some(/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/MacTypes.h)))),List(FunctionParameter(number,Reference(Model(CFNumberRef,Meta(None,Some(/Library/Developer/CommandLineTools/SDKs/MacOSX15.sdk/System/Library/Frameworks/CoreFoundation.framework/Headers/CFNumber.h)))),OriginalCType(Reference(Model(CFNumberRef,Meta(None,Some(/Library/Developer/CommandLineTools/SDKs/MacOSX15.sdk/System/Library/Frameworks/CoreFoundation.framework/Headers/CFNumber.h)))),CFNumberRef),false)),OriginalCType(Reference(Model(Boolean,Meta(None,Some(/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/MacTypes.h)))),Boolean),1,false,Meta(None,Some(/Library/Developer/CommandLineTools/SDKs/MacOSX15.sdk/System/Library/Frameworks/CoreFoundation.framework/Headers/CFNumber.h))),Location(false,true))

Location(false,true) means "not from the main file AND is in the system header":

sn-bindgen/modules/bindgen/src/main/scala/Def.scala

Lines 7 to 8 in fefbcd3

	case class Location(isFromMainFile: Boolean, isFromSystemHeader: Boolean):
	inline def shouldBeIncluded: Boolean = isFromMainFile || !isFromSystemHeader

Which is technically correct, but there should be a way around that..

--exclude-system-path /Library/Developer/CommandLineTools/SDKs/MacOSX15.sdk/System/Library/Frameworks/CoreFoundation.framework/Headers/CFNumber.h

should work but doesn't

[dhpiggott]

Thanks!

Looking at where isSystem is called I'm wondering if the expression it's used in is correct. If Clang is reporting something as being a system header, it will short-circuit, preventing the system header detector's own decision from being evaluated, which would account for --exclude-system-path having no effect.

sn-bindgen/modules/bindgen/src/main/scala/analysis/ClangVisitor.scala

Line 30 in fefbcd3

loc.isFromSystemHeader || systemDetector.isSystem(loc.getFilename)

Could it be that loc.isFromSystemHeader needs to be passed through to the system header detector? val isInSystemLocation = includes.exists(isChild) would become val isInSystemLocation = isFromClangSystemHeader || includes.exists(isChild).