fix(Cabal): Apply pkgconfig-depends flags to foreign-library c-sources

Cabal/src/Distribution/Simple/Configure.hs

@@ -2556,13 +2556,15 @@ configurePkgconfigPackages verbosity pkg_descr progdb enabled
       traverse_ requirePkg allpkgs
       mlib' <- traverse addPkgConfigBILib (library pkg_descr)
       libs' <- traverse addPkgConfigBILib (subLibraries pkg_descr)
+      flibs' <- traverse addPkgConfigBIFLib (foreignLibs pkg_descr)
       exes' <- traverse addPkgConfigBIExe (executables pkg_descr)
       tests' <- traverse addPkgConfigBITest (testSuites pkg_descr)
       benches' <- traverse addPkgConfigBIBench (benchmarks pkg_descr)
       let pkg_descr' =
             pkg_descr
               { library = mlib'
               , subLibraries = libs'
+              , foreignLibs = flibs'
               , executables = exes'
               , testSuites = tests'
               , benchmarks = benches'
@@ -2607,6 +2609,10 @@ configurePkgconfigPackages verbosity pkg_descr progdb enabled
     addPkgConfigBILib = addPkgConfigBI libBuildInfo $
       \lib bi -> lib{libBuildInfo = bi}
 
+    -- Adds pkgconfig dependencies to the build info for a foreign library
+    addPkgConfigBIFLib = addPkgConfigBI foreignLibBuildInfo $
+      \flib bi -> flib{foreignLibBuildInfo = bi}
+
     -- Adds pkgconfig dependencies to the build info for an executable
     addPkgConfigBIExe = addPkgConfigBI buildInfo $
       \exe bi -> exe{buildInfo = bi}

cabal-testsuite/PackageTests/PkgConfigForeignLib/cabal.project

@@ -0,0 +1 @@
+packages: *.cabal

cabal-testsuite/PackageTests/PkgConfigForeignLib/csrc/foo.c

@@ -0,0 +1,5 @@
+#include <mylib.h>
+
+int mylib_value(void) {
+    return MYLIB_VALUE;
+}

cabal-testsuite/PackageTests/PkgConfigForeignLib/include/mylib.h

@@ -0,0 +1,6 @@
+#ifndef MYLIB_H
+#define MYLIB_H
+
+#define MYLIB_VALUE 42
+
+#endif

cabal-testsuite/PackageTests/PkgConfigForeignLib/my.cabal

@@ -0,0 +1,16 @@
+name: PkgConfigForeignLib
+version: 0.1
+license: BSD3
+synopsis: Test that pkgconfig-depends cflags reach foreign-library c-sources
+category: PackageTests
+build-type: Simple
+cabal-version: 2.0
+
+foreign-library myforeignlib
+  type: native-shared
+  pkgconfig-depends: mypkg
+  other-modules: MyForeignLib
+  hs-source-dirs: src
+  c-sources: csrc/foo.c
+  build-depends: base
+  default-language: Haskell2010

cabal-testsuite/PackageTests/PkgConfigForeignLib/pkg-config

@@ -0,0 +1,40 @@
+#!/bin/sh
+
+set -eu
+
+# Resolve the directory containing this shim so we can point pkg-config's
+# --cflags at the header shipped next to it.
+dir="$(CDPATH= cd -- "$(dirname -- "$0")" && pwd)"
+
+case "$*" in
+  '--version')
+    echo 0.29.2
+    ;;
+
+  '--variable pc_path pkg-config')
+    echo '.'
+    ;;
+
+  '--list-all')
+    printf 'mypkg  mypkg - my test package\n'
+    ;;
+
+  '--modversion mypkg')
+    echo 1.0
+    ;;
+
+  '--cflags mypkg')
+    echo "-I$dir/include"
+    ;;
+
+  '--libs mypkg')
+    ;;
+
+  '--libs --static mypkg')
+    ;;
+
+  *)
+    echo >&2 "pkg-config: unrecognised arguments $* (this is an incomplete shim)"
+    exit 1
+    ;;
+esac

cabal-testsuite/PackageTests/PkgConfigForeignLib/setup.out

@@ -0,0 +1,8 @@
+# cabal v2-build
+Resolving dependencies...
+Build profile: -w ghc-<GHCVER> -O1
+In order, the following will be built:
+ - PkgConfigForeignLib-0.1 (flib:myforeignlib) (first run)
+Configuring foreign library 'myforeignlib' for PkgConfigForeignLib-0.1...
+Preprocessing foreign library 'myforeignlib' for PkgConfigForeignLib-0.1...
+Building foreign library 'myforeignlib' for PkgConfigForeignLib-0.1...

cabal-testsuite/PackageTests/PkgConfigForeignLib/setup.test.hs

@@ -0,0 +1,8 @@
+import Test.Cabal.Prelude
+
+-- Test that pkgconfig-depends cflags are propagated to the C compiler
+-- when compiling the c-sources of a foreign-library (see #11297).
+main = cabalTest $ do
+  when isWindows $ skip "pkg-config shim requires sh"
+  cdir <- testCurrentDir <$> getTestEnv
+  cabal "v2-build" ["--extra-prog-path=" ++ cdir]

cabal-testsuite/PackageTests/PkgConfigForeignLib/src/MyForeignLib.hs

@@ -0,0 +1,5 @@
+{-# LANGUAGE ForeignFunctionInterface #-}
+
+module MyForeignLib (mylibValue) where
+
+foreign import ccall "mylib_value" mylibValue :: IO Int

changelog.d/12265.md

@@ -0,0 +1,12 @@
+---
+synopsis: Apply pkgconfig-depends flags to foreign-library c-sources
+packages: [Cabal]
+prs: 12265
+issues: 11297
+---
+
+The `pkgconfig-depends` flags (e.g. `--cflags` include directories) were not
+propagated to the C compiler when compiling the `c-sources` of a
+`foreign-library`, unlike for `library` and `executable` components. This is now
+fixed so that C sources in foreign libraries can use headers provided by
+pkg-config dependencies.