Swift C++ Interoperability example

.gitignore

@@ -56,6 +56,7 @@ venv/
 .pydevproject
 .settings/*
 .ropeproject/*
+**/xcuserdata/
 
 .tox
 CMakeUserPresets.json
@@ -69,6 +70,7 @@ tutorial/versioning/revisions/intro/chat/*
 tutorial/versioning/revisions/intro/hello/*
 examples/libraries/tensorflow-lite/pose-estimation/pose-estimation
 examples/libraries/imgui/introduction/bindings
+examples/languages/swift/cxx_interop/summer.png
 
 # Bazel files
 bazel-*

README.md

@@ -28,6 +28,8 @@ Sources for the [examples section](https://docs.conan.io/2/examples.html) of the
 
 ### [Libraries examples](examples/libraries)
 
+### [Language interoperability examples](examples/languages)
+
 ### [Graph examples](examples/graph)
 
 ### [Security examples](examples/security)

examples/languages/README.md

@@ -0,0 +1,5 @@
+## Language interoperability examples
+
+### [Swift / C++ interop](swift/cxx_interop)
+
+- Consume plain, Swift-unaware ConanCenter C++ packages directly from a Swift app, using Swift's C++ interoperability mode.

examples/languages/swift/cxx_interop/README.md

@@ -0,0 +1,43 @@
+# Swift / C++ interop with Conan-managed dependencies
+
+A Swift app that consumes a plain, Swift-unaware ConanCenter package --
+[lunasvg](https://conan.io/center/recipes/lunasvg) -- directly, via
+[Swift's C++ interoperability mode](https://www.swift.org/documentation/cxx-interop/).
+Swift builds an SVG scene as a string, hands it to lunasvg's C++ `Document`
+and `Bitmap` classes to parse and rasterize, and writes the result to a PNG
+file -- no C wrapper library needed.
+
+Since lunasvg ships no Swift module map, `conanfile.py`'s `generate()` writes
+a small [Clang module map](https://clang.llvm.org/docs/Modules.html) pointing
+at its real installed header (read from `cpp_info`), and sets `OTHER_SWIFT_FLAGS`
+through `XcodeToolchain.build_settings` to pass that to `swiftc` via
+`-Xcc -fmodule-map-file=...` together with `-cxx-interoperability-mode=default`.
+`demo.xcodeproj` is a plain Xcode project whose Release configuration is based
+on the `.xcconfig` files that Conan's `XcodeDeps`/`XcodeToolchain` generators
+write.
+
+## Requirements
+
+- macOS with Xcode (`swiftc`, `xcodebuild`), Swift 5.9+.
+- Conan 2.32 or newer (`XcodeToolchain.build_settings`).
+
+## Build and run
+
+```bash
+git clone https://github.com/conan-io/examples2.git
+cd examples2/examples/languages/swift/cxx_interop
+
+conan install . -s build_type=Release --build=missing
+open demo.xcodeproj
+```
+
+From there it is a normal Xcode project: press Run, and Swift calls into
+lunasvg. The same build also works from the command line:
+
+```bash
+xcodebuild -project demo.xcodeproj -scheme demo -configuration Release \
+    -derivedDataPath build build
+./build/Build/Products/Release/demo
+```
+
+The program renders the SVG and writes `summer.png` to the working directory.

examples/languages/swift/cxx_interop/ci_test_example.py

@@ -0,0 +1,17 @@
+import platform
+
+from conan.tools.scm import Version
+
+from test.examples_tools import run
+
+print("Swift C++ interop: consuming a plain ConanCenter package from Swift")
+
+conan_version = run("conan --version").split()[-1]
+
+if platform.system() != "Darwin" or Version(conan_version).main < Version("2.32").main:
+    print("WARNING: Skipping Swift interop example, requires macOS with swiftc and Conan >= 2.32")
+else:
+    run("conan install . -s build_type=Release --build=missing")
+    run("xcodebuild -project demo.xcodeproj -scheme demo -configuration Release "
+        "-derivedDataPath build build")
+    run("./build/Build/Products/Release/demo")

examples/languages/swift/cxx_interop/conanfile.py

@@ -0,0 +1,40 @@
+import os
+import textwrap
+from conan import ConanFile
+from conan.tools.apple import XcodeDeps, XcodeToolchain
+from conan.tools.build import cppstd_flag
+from conan.tools.files import save
+
+
+class SwiftCppDemo(ConanFile):
+    settings = "os", "arch", "compiler", "build_type"
+
+    def layout(self):
+        self.folders.generators = "generators"
+
+    def requirements(self):
+        self.requires("lunasvg/3.5.0")
+
+    def generate(self):
+        XcodeDeps(self).generate()
+
+        include_dir = self.dependencies["lunasvg"].cpp_info.includedir
+        header = f"{include_dir}/lunasvg/lunasvg.h"
+
+        modulemap_path = os.path.join(self.generators_folder, "lunasvg.modulemap")
+        modulemap = textwrap.dedent(f'''\
+            module LunaSVGMod {{
+                header "{header}"
+                export *
+            }}
+            ''')
+        save(self, modulemap_path, modulemap)
+
+        cppstd = cppstd_flag(self)
+
+        tc = XcodeToolchain(self)
+        tc.build_settings["OTHER_SWIFT_FLAGS"] = (
+            f'$(inherited) -cxx-interoperability-mode=default '
+            f'-Xcc {cppstd} -Xcc -fmodule-map-file="{modulemap_path}"'
+        )
+        tc.generate()

examples/languages/swift/cxx_interop/demo.xcodeproj/project.pbxproj

@@ -0,0 +1,198 @@
+// !$*UTF8*$!
+{
+	archiveVersion = 1;
+	classes = {
+	};
+	objectVersion = 77;
+	objects = {
+
+/* Begin PBXBuildFile section */
+		134B726B92DC37149DD8FB1A /* main.swift in Sources */ = {isa = PBXBuildFile; fileRef = 08895F9843B6FA00C49130BF /* main.swift */; };
+/* End PBXBuildFile section */
+
+/* Begin PBXFileReference section */
+		0507141398EC23BB262BA813 /* demo */ = {isa = PBXFileReference; includeInIndex = 0; path = demo; sourceTree = BUILT_PRODUCTS_DIR; };
+		08895F9843B6FA00C49130BF /* main.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = main.swift; sourceTree = "<group>"; };
+		A080ABC67B6FC4B3732B7606 /* conan_config.xcconfig */ = {isa = PBXFileReference; lastKnownFileType = text.xcconfig; path = conan_config.xcconfig; sourceTree = "<group>"; };
+/* End PBXFileReference section */
+
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+		253DD428CCB2178AB212D9C6 = {
+			isa = PBXGroup;
+			children = (
+				08895F9843B6FA00C49130BF /* main.swift */,
+				5D676B908F57C1AF87D8AC72 /* generators */,
+				CBA6EB5BDDD3CD851F85C932 /* Products */,
+			);
+			sourceTree = "<group>";
+		};
+		5D676B908F57C1AF87D8AC72 /* generators */ = {
+			isa = PBXGroup;
+			children = (
+				A080ABC67B6FC4B3732B7606 /* conan_config.xcconfig */,
+			);
+			path = generators;
+			sourceTree = "<group>";
+		};
+		CBA6EB5BDDD3CD851F85C932 /* Products */ = {
+			isa = PBXGroup;
+			children = (
+				0507141398EC23BB262BA813 /* demo */,
+			);
+			name = Products;
+			sourceTree = "<group>";
+		};
+/* End PBXGroup section */
+
+/* Begin PBXNativeTarget section */
+		25BF8E1F96134B86B979D8A6 /* demo */ = {
+			isa = PBXNativeTarget;
+			buildConfigurationList = EED75AB90447BE0300554485 /* Build configuration list for PBXNativeTarget "demo" */;
+			buildPhases = (
+				5227B068F7CA093BC3C8FF22 /* Sources */,
+			);
+			buildRules = (
+			);
+			dependencies = (
+			);
+			name = demo;
+			packageProductDependencies = (
+			);
+			productName = demo;
+			productReference = 0507141398EC23BB262BA813 /* demo */;
+			productType = "com.apple.product-type.tool";
+		};
+/* End PBXNativeTarget section */
+
+/* Begin PBXProject section */
+		EE8D0A5E600AE5890BCA0377 /* Project object */ = {
+			isa = PBXProject;
+			attributes = {
+				BuildIndependentTargetsInParallel = YES;
+				LastUpgradeCheck = 1430;
+				TargetAttributes = {
+				};
+			};
+			buildConfigurationList = 069786E56D7D9BA850EF6E04 /* Build configuration list for PBXProject "demo" */;
+			developmentRegion = en;
+			hasScannedForEncodings = 0;
+			knownRegions = (
+				Base,
+				en,
+			);
+			mainGroup = 253DD428CCB2178AB212D9C6;
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+			preferredProjectObjectVersion = 77;
+			productRefGroup = CBA6EB5BDDD3CD851F85C932 /* Products */;
+			projectDirPath = "";
+			projectRoot = "";
+			targets = (
+				25BF8E1F96134B86B979D8A6 /* demo */,
+			);
+		};
+/* End PBXProject section */
+
+/* Begin PBXSourcesBuildPhase section */
+		5227B068F7CA093BC3C8FF22 /* Sources */ = {
+			isa = PBXSourcesBuildPhase;
+			buildActionMask = 2147483647;
+			files = (
+				134B726B92DC37149DD8FB1A /* main.swift in Sources */,
+			);
+			runOnlyForDeploymentPostprocessing = 0;
+		};
+/* End PBXSourcesBuildPhase section */
+
+/* Begin XCBuildConfiguration section */
+		13750F1439DABFE631C7C9E4 /* Release */ = {
+			isa = XCBuildConfiguration;
+			baseConfigurationReference = A080ABC67B6FC4B3732B7606 /* conan_config.xcconfig */;
+			buildSettings = {
+				COMBINE_HIDPI_IMAGES = YES;
+				LD_RUNPATH_SEARCH_PATHS = (
+					"$(inherited)",
+					"@executable_path/../Frameworks",
+				);
+				PRODUCT_BUNDLE_IDENTIFIER = io.conan.examples.demo;
+				SDKROOT = macosx;
+			};
+			name = Release;
+		};
+		CE5C8F26EC586CE7B2176121 /* Release */ = {
+			isa = XCBuildConfiguration;
+			buildSettings = {
+				ALWAYS_SEARCH_USER_PATHS = NO;
+				CLANG_ANALYZER_NONNULL = YES;
+				CLANG_ANALYZER_NUMBER_OBJECT_CONVERSION = YES_AGGRESSIVE;
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++14";
+				CLANG_CXX_LIBRARY = "libc++";
+				CLANG_ENABLE_MODULES = YES;
+				CLANG_ENABLE_OBJC_ARC = YES;
+				CLANG_ENABLE_OBJC_WEAK = YES;
+				CLANG_WARN_BLOCK_CAPTURE_AUTORELEASING = YES;
+				CLANG_WARN_BOOL_CONVERSION = YES;
+				CLANG_WARN_COMMA = YES;
+				CLANG_WARN_CONSTANT_CONVERSION = YES;
+				CLANG_WARN_DEPRECATED_OBJC_IMPLEMENTATIONS = YES;
+				CLANG_WARN_DIRECT_OBJC_ISA_USAGE = YES_ERROR;
+				CLANG_WARN_DOCUMENTATION_COMMENTS = YES;
+				CLANG_WARN_EMPTY_BODY = YES;
+				CLANG_WARN_ENUM_CONVERSION = YES;
+				CLANG_WARN_INFINITE_RECURSION = YES;
+				CLANG_WARN_INT_CONVERSION = YES;
+				CLANG_WARN_NON_LITERAL_NULL_CONVERSION = YES;
+				CLANG_WARN_OBJC_IMPLICIT_RETAIN_SELF = YES;
+				CLANG_WARN_OBJC_LITERAL_CONVERSION = YES;
+				CLANG_WARN_OBJC_ROOT_CLASS = YES_ERROR;
+				CLANG_WARN_QUOTED_INCLUDE_IN_FRAMEWORK_HEADER = YES;
+				CLANG_WARN_RANGE_LOOP_ANALYSIS = YES;
+				CLANG_WARN_STRICT_PROTOTYPES = YES;
+				CLANG_WARN_SUSPICIOUS_MOVE = YES;
+				CLANG_WARN_UNGUARDED_AVAILABILITY = YES_AGGRESSIVE;
+				CLANG_WARN_UNREACHABLE_CODE = YES;
+				CLANG_WARN__DUPLICATE_METHOD_MATCH = YES;
+				COPY_PHASE_STRIP = NO;
+				DEBUG_INFORMATION_FORMAT = "dwarf-with-dsym";
+				ENABLE_NS_ASSERTIONS = NO;
+				ENABLE_STRICT_OBJC_MSGSEND = YES;
+				GCC_C_LANGUAGE_STANDARD = gnu11;
+				GCC_NO_COMMON_BLOCKS = YES;
+				GCC_WARN_64_TO_32_BIT_CONVERSION = YES;
+				GCC_WARN_ABOUT_RETURN_TYPE = YES_ERROR;
+				GCC_WARN_UNDECLARED_SELECTOR = YES;
+				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
+				GCC_WARN_UNUSED_FUNCTION = YES;
+				GCC_WARN_UNUSED_VARIABLE = YES;
+				MTL_ENABLE_DEBUG_INFO = NO;
+				MTL_FAST_MATH = YES;
+				PRODUCT_NAME = "$(TARGET_NAME)";
+				SDKROOT = macosx;
+				SWIFT_COMPILATION_MODE = wholemodule;
+				SWIFT_OPTIMIZATION_LEVEL = "-O";
+				SWIFT_VERSION = 5.0;
+			};
+			name = Release;
+		};
+/* End XCBuildConfiguration section */
+
+/* Begin XCConfigurationList section */
+		069786E56D7D9BA850EF6E04 /* Build configuration list for PBXProject "demo" */ = {
+			isa = XCConfigurationList;
+			buildConfigurations = (
+				CE5C8F26EC586CE7B2176121 /* Release */,
+			);
+			defaultConfigurationIsVisible = 0;
+			defaultConfigurationName = Release;
+		};
+		EED75AB90447BE0300554485 /* Build configuration list for PBXNativeTarget "demo" */ = {
+			isa = XCConfigurationList;
+			buildConfigurations = (
+				13750F1439DABFE631C7C9E4 /* Release */,
+			);
+			defaultConfigurationIsVisible = 0;
+			defaultConfigurationName = Release;
+		};
+/* End XCConfigurationList section */
+	};
+	rootObject = EE8D0A5E600AE5890BCA0377 /* Project object */;
+}

examples/languages/swift/cxx_interop/main.swift

@@ -0,0 +1,32 @@
+import CxxStdlib
+import LunaSVGMod
+
+// lunasvg has no styling of its own; this stylesheet colors the markup below.
+let svg = """
+<svg xmlns="http://www.w3.org/2000/svg" width="400" height="300">
+  <rect class="sky" x="0" y="0" width="400" height="230"/>
+  <polygon class="hills" points="0,230 90,140 170,230 240,160 330,230 400,180 400,230"/>
+  <rect class="ground" x="0" y="215" width="400" height="85"/>
+  <g class="cloud" transform="translate(70,55)">
+    <ellipse cx="0" cy="0" rx="26" ry="14"/>
+    <ellipse cx="20" cy="-6" rx="20" ry="12"/>
+    <ellipse cx="-20" cy="4" rx="18" ry="10"/>
+  </g>
+  <text class="title" x="200" y="40" text-anchor="middle" font-size="24">Swift + C++ + Conan</text>
+  <g class="cloud" transform="translate(230,85)">
+    <ellipse cx="0" cy="0" rx="22" ry="12"/>
+    <ellipse cx="18" cy="-4" rx="16" ry="10"/>
+    <ellipse cx="-16" cy="3" rx="15" ry="9"/>
+  </g>
+</svg>
+"""
+
+let css = ".sky{fill:#8ECBEB} .hills{fill:#8FA89B} .ground{fill:#8FC77E} .cloud{fill:#FFFFFF} .title{fill:#3B4A40}"
+
+let document = lunasvg.Document.loadFromData(std.string(svg))
+document.pointee.applyStyleSheet(std.string(css))
+
+let bitmap = document.pointee.renderToBitmap()
+_ = bitmap.writeToPng(std.string("summer.png"))
+
+print("Generated summer.png")