Use -I for other packages

Author: aciidgh

Fixtures/DependencyResolution/External/CUsingCDep/Bar/Package.swift

@@ -0,0 +1,8 @@
+import PackageDescription
+
+let package = Package(
+    name: "Bar",
+    dependencies: [
+        .Package(url: "../Foo", majorVersion: 1)
+	]
+)

Fixtures/DependencyResolution/External/CUsingCDep/Bar/Sources/SeaLover/Sea.c

@@ -0,0 +1,5 @@
+#include <Foo/Foo.h>
+
+void cool() {
+    foo();
+}

Fixtures/DependencyResolution/External/CUsingCDep/Bar/Sources/SeaLover/include/Sea.h

@@ -0,0 +1,5 @@
+module SeaLover {
+  header "Sea/Sea.h"
+  link "SeaLover"
+  export *
+}

Fixtures/DependencyResolution/External/CUsingCDep/Bar/Sources/SeaLover/include/module.modulemap

@@ -0,0 +1,3 @@
+import Foo
+
+foo()

Fixtures/DependencyResolution/External/CUsingCDep/Bar/Sources/SwiftExec/main.swift

@@ -0,0 +1,3 @@
+void foo() {
+    
+}

Fixtures/DependencyResolution/External/CUsingCDep/Foo/Foo.c

@@ -0,0 +1 @@
+void foo();

Fixtures/DependencyResolution/External/CUsingCDep/Foo/Package.swift

@@ -0,0 +1,5 @@
+module Foo {
+  header "Foo/Foo.h"
+  link "Foo"
+  export *
+}

Fixtures/DependencyResolution/External/CUsingCDep/Foo/include/Foo/Foo.h

@@ -125,11 +125,20 @@ public func describe(prefix: String, _ conf: Configuration, _ modules: [Module],
         mkdirs.insert(wd)
 
         var args: [String] = []
+    #if os(Linux)
+         args += ["-fPIC"]
+    #endif
         args += ["-fmodules", "-fmodule-name=\(module.name)"]
         args += ["-L\(prefix)"]
 
         for case let dep as ClangModule in module.dependencies {
-            args += ["-iquote", dep.path]
+            let includeFlag: String
+            if dep.path.parentDirectory.parentDirectory.basename == "Packages" { //Do better
+                includeFlag = "-I"
+            } else {
+                includeFlag = "-iquote"
+            }
+            args += [includeFlag, dep.path]
             args += ["-l\(dep.c99name)"] //FIXME: giving path to other module's -fmodule-map-file is not linking that module
         }
 

Fixtures/DependencyResolution/External/CUsingCDep/Foo/include/module.modulemap

@@ -55,6 +55,14 @@ class TestClangModulesTestCase: XCTestCase {
             XCTAssertFileExists(prefix, ".build", "debug", "libBar.so")
         }
     }
+    
+    func testCUsingCDep() {
+        fixture(name: "DependencyResolution/External/CUsingCDep") { prefix in
+            XCTAssertBuilds(prefix, "Bar")
+            XCTAssertFileExists(prefix, "Bar/.build/debug/libFoo.so")
+            XCTAssertDirectoryExists(prefix, "Bar/Packages/Foo-1.2.3")
+        }
+    }
 }
 
 
@@ -65,6 +73,8 @@ extension TestClangModulesTestCase {
             ("testSingleModuleCLibraryInSources", testSingleModuleCLibraryInSources),
             ("testMixedSwiftAndC", testMixedSwiftAndC),
             ("testExternalSimpleCDep", testExternalSimpleCDep),
+            ("testiquoteDep", testiquoteDep),
+            ("testCUsingCDep", testCUsingCDep),
         ]
     }
 }