Add module name validation in cabal check command

This change ensures that Cabal warns about modules with names that would cause
portability issues, especially on Windows systems where certain names like "aux",
"con", "nul", etc. are reserved by the operating system.

Fixes #10295

Author: mpickering

Cabal/src/Distribution/PackageDescription/Check/Paths.hs

@@ -10,6 +10,7 @@
 module Distribution.PackageDescription.Check.Paths
   ( checkGlob
   , checkPath
+  , checkPackageFileNamesWithGlob
   , fileExtensionSupportedLanguage
   , isGoodRelativeDirectoryPath
   , isGoodRelativeFilePath

Cabal/src/Distribution/PackageDescription/Check/Target.hs

@@ -21,7 +21,7 @@ import Prelude ()
 import Distribution.CabalSpecVersion
 import Distribution.Compat.Lens
 import Distribution.Compiler
-import Distribution.ModuleName (ModuleName)
+import Distribution.ModuleName (ModuleName, toFilePath)
 import Distribution.Package
 import Distribution.PackageDescription
 import Distribution.PackageDescription.Check.Common
@@ -61,6 +61,8 @@ checkLibrary
           _libVisibility_
           libBuildInfo_
         ) = do
+    mapM_ checkModuleName (explicitLibModules lib)
+
     checkP
       (libName_ == LMainLibName && isSub)
       (PackageBuildImpossible UnnamedInternal)
@@ -144,6 +146,8 @@ checkExecutable
     let cet = CETExecutable exeName_
         modulePath_ = getSymbolicPath symbolicModulePath_
 
+    mapM_ checkModuleName (exeModules exe)
+
     -- § Exe specific checks
     checkP
       (null modulePath_)
@@ -205,6 +209,9 @@ checkTestSuite
       TestSuiteUnsupported tt ->
         tellP (PackageBuildWarning $ TestsuiteNotSupported tt)
       _ -> return ()
+
+    mapM_ checkModuleName (testModules ts)
+
     checkP
       mainIsWrongExt
       (PackageBuildImpossible NoHsLhsMain)
@@ -257,6 +264,8 @@ checkBenchmark
     -- Target type/name (benchmark).
     let cet = CETBenchmark benchmarkName_
 
+    mapM_ checkModuleName (benchmarkModules bm)
+
     -- § Interface & bm specific tests.
     case benchmarkInterface_ of
       BenchmarkUnsupported tt@(BenchmarkTypeUnknown _ _) ->
@@ -294,6 +303,11 @@ checkBenchmark
           BenchmarkExeV10 _ f -> takeExtension (getSymbolicPath f) `notElem` [".hs", ".lhs"]
           _ -> False
 
+-- | Check if a module name is valid on both Windows and Posix systems
+checkModuleName :: Monad m => ModuleName -> CheckM m ()
+checkModuleName moduleName =
+  checkPackageFileNamesWithGlob PathKindFile (toFilePath moduleName)
+
 -- ------------------------------------------------------------
 -- Build info
 -- ------------------------------------------------------------

cabal-testsuite/PackageTests/Check/InvalidModuleName/InvalidModuleName.cabal

@@ -0,0 +1,44 @@
+name:                InvalidModuleName
+version:             0.1.0.0
+license:             BSD3
+license-file:        LICENSE
+category:            development
+author:              Foo Bar
+maintainer:          cabal-dev@haskell.org
+build-type:          Simple
+cabal-version:       >=1.10
+synopsis:            Test for invalid module names
+description:         Tests that invalid module names are properly rejected by cabal check
+
+library
+  exposed-modules:     Aux
+  build-depends:       base < 5
+  hs-source-dirs:      src
+  default-language:    Haskell2010
+
+executable invalid-exe
+  main-is:             Main.hs
+  other-modules:       Exe.Aux
+                     , Exe.Aux.Test
+  build-depends:       base < 5
+  hs-source-dirs:      exe
+  default-language:    Haskell2010
+
+test-suite invalid-test
+  type:                exitcode-stdio-1.0
+  main-is:             Main.hs
+  other-modules:       Test.Aux
+                     , Test.Aux.Test
+  build-depends:       base < 5
+  hs-source-dirs:      test
+  default-language:    Haskell2010
+
+benchmark invalid-bench
+  type:                exitcode-stdio-1.0
+  main-is:             Main.hs
+  other-modules:       Bench.Aux
+                     , Bench.Aux.Test
+  build-depends:       base < 5
+  hs-source-dirs:      bench
+  default-language:    Haskell2010
+

cabal-testsuite/PackageTests/Check/InvalidModuleName/LICENSE

@@ -0,0 +1,14 @@
+# cabal check
+The following errors are likely to affect your build negatively:
+Error: [unknown-directory] 'hs-source-dirs: bench' specifies a directory which does not exist.
+Error: [unknown-directory] 'hs-source-dirs: exe' specifies a directory which does not exist.
+Error: [unknown-directory] 'hs-source-dirs: test' specifies a directory which does not exist.
+The following errors will cause portability problems on other environments:
+Error: [invalid-path-win] The path 'Aux' is invalid on Windows, which would cause portability problems for this package. Windows file names cannot contain any of the characters ":*?<>|", and there are a few reserved names including "aux", "nul", "con", "prn", "com{1-9}", "lpt{1-9}" and "clock$".
+Error: [invalid-path-win] The path 'Bench/Aux' is invalid on Windows, which would cause portability problems for this package. Windows file names cannot contain any of the characters ":*?<>|", and there are a few reserved names including "aux", "nul", "con", "prn", "com{1-9}", "lpt{1-9}" and "clock$".
+Error: [invalid-path-win] The path 'Bench/Aux/Test' is invalid on Windows, which would cause portability problems for this package. Windows file names cannot contain any of the characters ":*?<>|", and there are a few reserved names including "aux", "nul", "con", "prn", "com{1-9}", "lpt{1-9}" and "clock$".
+Error: [invalid-path-win] The path 'Exe/Aux' is invalid on Windows, which would cause portability problems for this package. Windows file names cannot contain any of the characters ":*?<>|", and there are a few reserved names including "aux", "nul", "con", "prn", "com{1-9}", "lpt{1-9}" and "clock$".
+Error: [invalid-path-win] The path 'Exe/Aux/Test' is invalid on Windows, which would cause portability problems for this package. Windows file names cannot contain any of the characters ":*?<>|", and there are a few reserved names including "aux", "nul", "con", "prn", "com{1-9}", "lpt{1-9}" and "clock$".
+Error: [invalid-path-win] The path 'Test/Aux' is invalid on Windows, which would cause portability problems for this package. Windows file names cannot contain any of the characters ":*?<>|", and there are a few reserved names including "aux", "nul", "con", "prn", "com{1-9}", "lpt{1-9}" and "clock$".
+Error: [invalid-path-win] The path 'Test/Aux/Test' is invalid on Windows, which would cause portability problems for this package. Windows file names cannot contain any of the characters ":*?<>|", and there are a few reserved names including "aux", "nul", "con", "prn", "com{1-9}", "lpt{1-9}" and "clock$".
+Error: Hackage would reject this package.

cabal-testsuite/PackageTests/Check/InvalidModuleName/cabal.out

@@ -0,0 +1,13 @@
+import Test.Cabal.Prelude
+
+main = cabalTest $ do
+    r <- fails $ cabal' "check" []
+    assertOutputContains "is invalid on Windows" r
+    assertOutputContains "Aux" r
+    assertOutputContains "Exe/Aux" r
+    assertOutputContains "Test/Aux" r
+    assertOutputContains "Bench/Aux" r
+    assertOutputContains "Exe/Aux/Test" r
+    assertOutputContains "Test/Aux/Test" r
+    assertOutputContains "Bench/Aux/Test" r
+

cabal-testsuite/PackageTests/Check/InvalidModuleName/cabal.test.hs

@@ -0,0 +1,23 @@
+synopsis: "Add checks for Windows reserved filenames in module paths"
+packages: Cabal cabal-install
+prs: #10816
+issues: #10295
+
+description: {
+
+On Windows, certain filenames are reserved by the operating system such as
+"aux", "con", "prn", "nul", etc. When these names appear in module paths they
+can cause build failures on Windows systems.
+
+`cabal check` now properly warns about module paths that contain Windows reserved
+filenames, not just filepaths which contain these reserved tokens. These warnings
+are controlled by the existing `invalid-win-path` category.
+
+For example, module paths like:
+- `Exe.Aux.Test`
+- `Test.Aux.Module`
+- `Bench.Aux.Helpers`
+
+will now trigger appropriate warnings during `cabal check`.
+
+}