Merge pull request #47 from cursey/templates

Add support for target templates

.github/workflows/build.yml

@@ -35,7 +35,7 @@ jobs:
     - name: Test
       run: |
         cd build/tests
-        ctest -C ${{ env.BUILD_TYPE }}
+        ctest -C ${{ env.BUILD_TYPE }} --verbose
 
     - name: Upload artifacts
       uses: actions/upload-artifact@v2

CMakeLists.txt

@@ -86,7 +86,6 @@ list(APPEND cmkr_SOURCES
 	"include/arguments.hpp"
 	"include/build.hpp"
 	"include/cmake_generator.hpp"
-	"include/enum_helper.hpp"
 	"include/error.hpp"
 	"include/fs.hpp"
 	"include/help.hpp"

docs/examples/interface.md

@@ -19,6 +19,7 @@ description = "Header-only library"
 [target.mylib]
 type = "interface"
 include-directories = ["include"]
+compile-features = ["cxx_std_11"]
 
 [target.example]
 type = "executable"

docs/examples/templates.md

@@ -0,0 +1,40 @@
+---
+# Automatically generated from tests/templates/cmake.toml - DO NOT EDIT
+layout: default
+title: Target templates
+permalink: /examples/templates
+parent: Examples
+nav_order: 7
+---
+
+# Target templates
+
+To avoid repeating yourself in targets you can create your own target type (template). All properties of the template are inherited when used as a target type.
+
+```toml
+[project]
+name = "templates"
+description = "Target templates"
+
+[template.app]
+type = "executable"
+sources = ["src/templates.cpp"]
+compile-definitions = ["IS_APP"]
+
+# Unlike interface targets you can also inherit properties
+[template.app.properties]
+CXX_STANDARD = "11"
+CXX_STANDARD_REQUIRED = true
+
+[target.app-a]
+type = "app"
+compile-definitions = ["APP_A"]
+
+[target.app-b]
+type = "app"
+compile-definitions = ["APP_B"]
+```
+
+**Note**: In most cases you probably want to use an [interface](/examples/interface) target instead.
+
+<sup><sub>This page was automatically generated from [tests/templates/cmake.toml](https://github.com/build-cpp/cmkr/tree/main/tests/templates/cmake.toml).</sub></sup>

include/enum_helper.hpp

@@ -1,69 +0,0 @@
-// https://codereview.stackexchange.com/a/14315
-
-#include <algorithm>
-#include <iostream>
-#include <sstream>
-#include <string>
-
-// This is the type that will hold all the strings.
-// Each enumeration type will declare its own specialization.
-// Any enum that does not have a specialization will generate a compiler error
-// indicating that there is no definition of this variable (as there should be
-// be no definition of a generic version).
-template <typename T>
-struct enumStrings {
-    static char const *data[];
-};
-
-// This is a utility type.
-// Created automatically. Should not be used directly.
-template <typename T>
-struct enumRefHolder {
-    T &enumVal;
-    enumRefHolder(T &enumVal) : enumVal(enumVal) {}
-};
-template <typename T>
-struct enumConstRefHolder {
-    T const &enumVal;
-    enumConstRefHolder(T const &enumVal) : enumVal(enumVal) {}
-};
-
-// The next two functions do the actual work of reading/writing an
-// enum as a string.
-template <typename T>
-std::ostream &operator<<(std::ostream &str, enumConstRefHolder<T> const &data) {
-    return str << enumStrings<T>::data[data.enumVal];
-}
-
-template <typename T>
-std::istream &operator>>(std::istream &str, enumRefHolder<T> const &data) {
-    std::string value;
-    str >> value;
-
-    // These two can be made easier to read in C++11
-    // using std::begin() and std::end()
-    //
-    static auto begin = std::begin(enumStrings<T>::data);
-    static auto end = std::end(enumStrings<T>::data);
-
-    auto find = std::find(begin, end, value);
-    if (find != end) {
-        data.enumVal = static_cast<T>(std::distance(begin, find));
-    } else {
-        throw std::invalid_argument("");
-    }
-    return str;
-}
-
-// This is the public interface:
-// use the ability of function to deduce their template type without
-// being explicitly told to create the correct type of enumRefHolder<T>
-template <typename T>
-enumConstRefHolder<T> enumToString(T const &e) {
-    return enumConstRefHolder<T>(e);
-}
-
-template <typename T>
-enumRefHolder<T> enumFromString(T &e) {
-    return enumRefHolder<T>(e);
-}

include/project_parser.hpp

@@ -56,11 +56,16 @@ enum TargetType {
     target_interface,
     target_custom,
     target_object,
+    target_template,
+    target_last,
 };
 
+extern const char *targetTypeNames[target_last];
+
 struct Target {
     std::string name;
-    TargetType type = {};
+    TargetType type = target_last;
+    std::string type_name;
 
     ConditionVector headers;
     ConditionVector sources;
@@ -100,6 +105,12 @@ struct Target {
     ConditionVector include_after;
 };
 
+struct Template {
+    Target outline;
+    std::string add_function;
+    bool pass_sources_to_add_function = false;
+};
+
 struct Test {
     std::string name;
     std::string condition;
@@ -160,6 +171,7 @@ struct Project {
     std::vector<Package> packages;
     Vcpkg vcpkg;
     std::vector<Content> contents;
+    std::vector<Template> templates;
     std::vector<Target> targets;
     std::vector<Test> tests;
     std::vector<Install> installs;

src/cmake_generator.cpp

@@ -6,6 +6,7 @@
 #include "fs.hpp"
 #include <cstdio>
 #include <fstream>
+#include <memory>
 #include <sstream>
 #include <stdexcept>
 
@@ -771,12 +772,31 @@ void generate_cmake(const char *path, const parser::Project *parent_project) {
             }
 
             const auto &target = project.targets[i];
+            const parser::Template *tmplate = nullptr;
+            std::unique_ptr<ConditionScope> tmplate_cs{};
+
             comment("Target " + target.name);
 
+            // Check if this target is using a template.
+            if (target.type == parser::target_template) {
+                for (const auto &t : project.templates) {
+                    if (target.type_name == t.outline.name) {
+                        tmplate = &t;
+                        tmplate_cs = std::unique_ptr<ConditionScope>(new ConditionScope(gen, tmplate->outline.condition));
+                    }
+                }
+            }
+
             ConditionScope cs(gen, target.condition);
 
             cmd("set")("CMKR_TARGET", target.name);
 
+            if (tmplate != nullptr) {
+                gen.handle_condition(tmplate->outline.include_before,
+                                     [&](const std::string &, const std::vector<std::string> &includes) { inject_includes(includes); });
+                gen.handle_condition(tmplate->outline.cmake_before, [&](const std::string &, const std::string &cmake) { inject_cmake(cmake); });
+            }
+
             gen.handle_condition(target.include_before,
                                  [&](const std::string &, const std::vector<std::string> &includes) { inject_includes(includes); });
             gen.handle_condition(target.cmake_before, [&](const std::string &, const std::string &cmake) { inject_cmake(cmake); });
@@ -785,6 +805,18 @@ void generate_cmake(const char *path, const parser::Project *parent_project) {
 
             bool added_toml = false;
             cmd("set")(sources_var, RawArg("\"\"")).endl();
+
+            if (tmplate != nullptr) {
+                gen.handle_condition(tmplate->outline.sources, [&](const std::string &condition, const std::vector<std::string> &condition_sources) {
+                    auto sources = expand_cmake_paths(condition_sources, path);
+                    if (sources.empty()) {
+                        auto source_key = condition.empty() ? "sources" : (condition + ".sources");
+                        throw std::runtime_error(target.name + " " + source_key + " wildcard found 0 files");
+                    }
+                    cmd("list")("APPEND", sources_var, sources);
+                });
+            }
+
             gen.handle_condition(target.sources, [&](const std::string &condition, const std::vector<std::string> &condition_sources) {
                 auto sources = expand_cmake_paths(condition_sources, path);
                 if (sources.empty()) {
@@ -798,66 +830,91 @@ void generate_cmake(const char *path, const parser::Project *parent_project) {
                 cmd("list")("APPEND", sources_var, sources);
             });
 
-            if (!added_toml && target.type != parser::target_interface) {
+            auto target_type = target.type;
+
+            if (tmplate != nullptr) {
+                target_type = tmplate->outline.type;
+            }
+
+            if (!added_toml && target_type != parser::target_interface) {
                 cmd("list")("APPEND", sources_var, std::vector<std::string>{"cmake.toml"}).endl();
             }
             cmd("set")("CMKR_SOURCES", "${" + sources_var + "}");
 
             std::string add_command;
-            std::string target_type;
+            std::string target_type_string;
             std::string target_scope;
-            switch (target.type) {
+
+            switch (target_type) {
             case parser::target_executable:
                 add_command = "add_executable";
-                target_type = "";
+                target_type_string = "";
                 target_scope = "PRIVATE";
                 break;
             case parser::target_library:
                 add_command = "add_library";
-                target_type = "";
+                target_type_string = "";
                 target_scope = "PUBLIC";
                 break;
             case parser::target_shared:
                 add_command = "add_library";
-                target_type = "SHARED";
+                target_type_string = "SHARED";
                 target_scope = "PUBLIC";
                 break;
             case parser::target_static:
                 add_command = "add_library";
-                target_type = "STATIC";
+                target_type_string = "STATIC";
                 target_scope = "PUBLIC";
                 break;
             case parser::target_interface:
                 add_command = "add_library";
-                target_type = "INTERFACE";
+                target_type_string = "INTERFACE";
                 target_scope = "INTERFACE";
                 break;
             case parser::target_custom:
                 // TODO: add proper support, this is hacky
                 add_command = "add_custom_target";
-                target_type = "SOURCES";
+                target_type_string = "SOURCES";
                 target_scope = "PUBLIC";
                 break;
             case parser::target_object:
                 // NOTE: This is properly supported since 3.12
                 add_command = "add_library";
-                target_type = "OBJECT";
+                target_type_string = "OBJECT";
                 target_scope = "PUBLIC";
                 break;
             default:
                 throw std::runtime_error("Unimplemented enum value");
             }
 
-            cmd(add_command)(target.name, target_type).endl();
+            // Handle custom add commands from templates.
+            if (tmplate != nullptr && !tmplate->add_function.empty()) {
+                add_command = tmplate->add_function;
+                target_type_string = ""; // TODO: let templates supply options to the add_command here?
+
+                if (tmplate->pass_sources_to_add_function) {
+                    cmd(add_command)(target.name, target_type_string, "${" + sources_var + "}");
+                } else {
+                    cmd(add_command)(target.name, target_type_string).endl();
 
                     // clang-format off
                     cmd("if")(sources_var);
-                cmd("target_sources")(target.name, target.type == parser::target_interface ? "INTERFACE" : "PRIVATE", "${" + sources_var + "}");
+                        cmd("target_sources")(target.name, target_type == parser::target_interface ? "INTERFACE" : "PRIVATE", "${" + sources_var + "}");
                     cmd("endif")().endl();
                     // clang-format on
+                }
+            } else {
+                cmd(add_command)(target.name, target_type_string).endl();
+
+                // clang-format off
+                cmd("if")(sources_var);
+                    cmd("target_sources")(target.name, target_type == parser::target_interface ? "INTERFACE" : "PRIVATE", "${" + sources_var + "}");
+                cmd("endif")().endl();
+                // clang-format on
+            }
 
             // The first executable target will become the Visual Studio startup project
-            if (target.type == parser::target_executable) {
+            if (target_type == parser::target_executable) {
                 cmd("get_directory_property")("CMKR_VS_STARTUP_PROJECT", "DIRECTORY", "${PROJECT_SOURCE_DIR}", "DEFINITION", "VS_STARTUP_PROJECT");
                 // clang-format off
                 cmd("if")("NOT", "CMKR_VS_STARTUP_PROJECT");
@@ -879,32 +936,46 @@ void generate_cmake(const char *path, const parser::Project *parent_project) {
                                      [&](const std::string &, const std::vector<std::string> &args) { cmd(command)(target.name, scope, args); });
             };
 
-            target_cmd("target_compile_definitions", target.compile_definitions, target_scope);
-            target_cmd("target_compile_definitions", target.private_compile_definitions, "PRIVATE");
+            auto gen_target_cmds = [&](const parser::Target &t) {
+                target_cmd("target_compile_definitions", t.compile_definitions, target_scope);
+                target_cmd("target_compile_definitions", t.private_compile_definitions, "PRIVATE");
 
-            target_cmd("target_compile_features", target.compile_features, target_scope);
-            target_cmd("target_compile_features", target.private_compile_features, "PRIVATE");
+                target_cmd("target_compile_features", t.compile_features, target_scope);
+                target_cmd("target_compile_features", t.private_compile_features, "PRIVATE");
 
-            target_cmd("target_compile_options", target.compile_options, target_scope);
-            target_cmd("target_compile_options", target.private_compile_options, "PRIVATE");
+                target_cmd("target_compile_options", t.compile_options, target_scope);
+                target_cmd("target_compile_options", t.private_compile_options, "PRIVATE");
 
-            target_cmd("target_include_directories", target.include_directories, target_scope);
-            target_cmd("target_include_directories", target.private_include_directories, "PRIVATE");
+                target_cmd("target_include_directories", t.include_directories, target_scope);
+                target_cmd("target_include_directories", t.private_include_directories, "PRIVATE");
 
-            target_cmd("target_link_directories", target.link_directories, target_scope);
-            target_cmd("target_link_directories", target.private_link_directories, "PRIVATE");
+                target_cmd("target_link_directories", t.link_directories, target_scope);
+                target_cmd("target_link_directories", t.private_link_directories, "PRIVATE");
 
-            target_cmd("target_link_libraries", target.link_libraries, target_scope);
-            target_cmd("target_link_libraries", target.private_link_libraries, "PRIVATE");
+                target_cmd("target_link_libraries", t.link_libraries, target_scope);
+                target_cmd("target_link_libraries", t.private_link_libraries, "PRIVATE");
 
-            target_cmd("target_link_options", target.link_options, target_scope);
-            target_cmd("target_link_options", target.private_link_options, "PRIVATE");
+                target_cmd("target_link_options", t.link_options, target_scope);
+                target_cmd("target_link_options", t.private_link_options, "PRIVATE");
 
-            target_cmd("target_precompile_headers", target.precompile_headers, target_scope);
-            target_cmd("target_precompile_headers", target.private_precompile_headers, "PRIVATE");
+                target_cmd("target_precompile_headers", t.precompile_headers, target_scope);
+                target_cmd("target_precompile_headers", t.private_precompile_headers, "PRIVATE");
+            };
+
+            if (tmplate != nullptr) {
+                gen_target_cmds(tmplate->outline);
+            }
+
+            gen_target_cmds(target);
+
+            if (!target.properties.empty() || (tmplate != nullptr && !tmplate->outline.properties.empty())) {
+                auto props = target.properties;
 
-            if (!target.properties.empty()) {
-                gen.handle_condition(target.properties, [&](const std::string &, const tsl::ordered_map<std::string, std::string> &properties) {
+                if (tmplate != nullptr) {
+                    props.insert(tmplate->outline.properties.begin(), tmplate->outline.properties.end());
+                }
+
+                gen.handle_condition(props, [&](const std::string &, const tsl::ordered_map<std::string, std::string> &properties) {
                     cmd("set_target_properties")(target.name, "PROPERTIES", properties);
                 });
             }
@@ -913,6 +984,12 @@ void generate_cmake(const char *path, const parser::Project *parent_project) {
                                  [&](const std::string &, const std::vector<std::string> &includes) { inject_includes(includes); });
             gen.handle_condition(target.cmake_after, [&](const std::string &, const std::string &cmake) { inject_cmake(cmake); });
 
+            if (tmplate != nullptr) {
+                gen.handle_condition(tmplate->outline.include_after,
+                                     [&](const std::string &, const std::vector<std::string> &includes) { inject_includes(includes); });
+                gen.handle_condition(tmplate->outline.cmake_after, [&](const std::string &, const std::string &cmake) { inject_cmake(cmake); });
+            }
+
             cmd("unset")("CMKR_TARGET");
             cmd("unset")("CMKR_SOURCES");
         }

src/project_parser.cpp

@@ -1,39 +1,27 @@
 #include "project_parser.hpp"
 
-#include "enum_helper.hpp"
 #include "fs.hpp"
 #include <deque>
 #include <stdexcept>
 #include <toml.hpp>
 #include <tsl/ordered_map.h>
 
-template <>
-const char *enumStrings<cmkr::parser::TargetType>::data[] = {"executable", "library", "shared", "static", "interface", "custom", "object"};
-
 namespace cmkr {
 namespace parser {
 
-using TomlBasicValue = toml::basic_value<toml::discard_comments, tsl::ordered_map, std::vector>;
+const char *targetTypeNames[target_last] = {"executable", "library", "shared", "static", "interface", "custom", "object", "template"};
 
-template <typename EnumType>
-static EnumType to_enum(const std::string &str, const std::string &help_name) {
-    EnumType value;
-    try {
-        std::stringstream ss(str);
-        ss >> enumFromString(value);
-    } catch (std::invalid_argument &) {
-        std::string supported;
-        for (const auto &s : enumStrings<EnumType>::data) {
-            if (!supported.empty()) {
-                supported += ", ";
-            }
-            supported += s;
+static TargetType parse_targetType(const std::string &name) {
+    for (int i = 0; i < target_last; i++) {
+        if (name == targetTypeNames[i]) {
+            return static_cast<TargetType>(i);
         }
-        throw std::runtime_error("Unknown " + help_name + "'" + str + "'! Supported types are: " + supported);
     }
-    return value;
+    return target_last;
 }
 
+using TomlBasicValue = toml::basic_value<toml::discard_comments, tsl::ordered_map, std::vector>;
+
 static std::string format_key_error(const std::string &error, const toml::key &ky, const TomlBasicValue &value) {
     auto loc = value.location();
     auto line_number_str = std::to_string(loc.line());
@@ -42,7 +30,7 @@ static std::string format_key_error(const std::string &error, const toml::key &k
 
     std::ostringstream oss;
     oss << "[error] " << error << '\n';
-    oss << " --> " << loc.file_name() << '\n';
+    oss << " --> " << loc.file_name() << ':' << loc.line() << '\n';
 
     oss << std::string(line_width + 2, ' ') << "|\n";
     oss << ' ' << line_number_str << " | " << line_str << '\n';
@@ -55,7 +43,6 @@ static std::string format_key_error(const std::string &error, const toml::key &k
     if (key_start != std::string::npos) {
         oss << std::string(key_start + 1, ' ') << std::string(ky.length(), '~');
     }
-    oss << '\n';
 
     return oss.str();
 }
@@ -241,6 +228,7 @@ Project::Project(const Project *parent, const std::string &path, bool build) {
         conditions["x32"] = R"cmake(CMAKE_SIZEOF_VOID_P EQUAL 4)cmake";
     } else {
         conditions = parent->conditions;
+        templates = parent->templates;
     }
 
     if (toml.contains("conditions")) {
@@ -386,19 +374,44 @@ Project::Project(const Project *parent, const std::string &path, bool build) {
         throw std::runtime_error("[[bin]] has been renamed to [[target]]");
     }
 
-    if (toml.contains("target")) {
-        const auto &ts = toml::find(toml, "target").as_table();
+    auto parse_target = [&](const std::string &name, TomlChecker &t, bool isTemplate) {
+        Target target;
+        target.name = name;
 
-        for (const auto &itr : ts) {
-            const auto &value = itr.second;
+        t.required("type", target.type_name);
+        target.type = parse_targetType(target.type_name);
 
-            Target target;
-            target.name = itr.first;
+        // Users cannot set this target type
+        if (target.type == target_template) {
+            target.type = target_last;
+        }
 
-            auto &t = checker.create(value);
-            std::string type;
-            t.required("type", type);
-            target.type = to_enum<TargetType>(type, "target type");
+        if (!isTemplate && target.type == target_last) {
+            for (const auto &tmplate : templates) {
+                if (target.type_name == tmplate.outline.name) {
+                    target.type = target_template;
+                    break;
+                }
+            }
+        }
+
+        if (target.type == target_last) {
+            std::string error = "Unknown target type '" + target.type_name + "'\n";
+            error += "Available types:\n";
+            for (std::string type_name : targetTypeNames) {
+                if (type_name != "template") {
+                    error += "  - " + type_name + "\n";
+                }
+            }
+            if (!isTemplate && !templates.empty()) {
+                error += "Available templates:\n";
+                for (const auto &tmplate : templates) {
+                    error += "  - " + tmplate.outline.name + "\n";
+                }
+            }
+            error.pop_back(); // Remove last newline
+            throw std::runtime_error(format_key_error(error, target.type_name, t.find("type")));
+        }
 
         t.optional("headers", target.headers);
         t.optional("sources", target.sources);
@@ -473,7 +486,42 @@ Project::Project(const Project *parent, const std::string &path, bool build) {
         t.optional("include-before", target.include_before);
         t.optional("include-after", target.include_after);
 
-            targets.push_back(target);
+        return target;
+    };
+
+    if (toml.contains("template")) {
+        const auto &ts = toml::find(toml, "template").as_table();
+        for (const auto &itr : ts) {
+            auto &t = checker.create(itr.second);
+            const auto &name = itr.first;
+
+            for (const auto &type_name : targetTypeNames) {
+                if (name == type_name) {
+                    throw std::runtime_error(format_key_error("Reserved template name '" + name + "'", name, itr.second));
+                }
+            }
+
+            for (const auto &tmplate : templates) {
+                if (name == tmplate.outline.name) {
+                    throw std::runtime_error(format_key_error("Template '" + name + "' already defined", name, itr.second));
+                }
+            }
+
+            Template tmplate;
+            tmplate.outline = parse_target(name, t, true);
+
+            t.optional("add-function", tmplate.add_function);
+            t.optional("pass-sources-to-add-function", tmplate.pass_sources_to_add_function);
+
+            templates.push_back(tmplate);
+        }
+    }
+
+    if (toml.contains("target")) {
+        const auto &ts = toml::find(toml, "target").as_table();
+        for (const auto &itr : ts) {
+            auto &t = checker.create(itr.second);
+            targets.push_back(parse_target(itr.first, t, false));
         }
     }
 

tests/CMakeLists.txt

@@ -78,3 +78,13 @@ add_test(
 		build
 )
 
+add_test(
+	NAME
+		templates
+	WORKING_DIRECTORY
+		"${CMAKE_CURRENT_LIST_DIR}/templates"
+	COMMAND
+		$<TARGET_FILE:cmkr>
+		build
+)
+

tests/cmake.toml

@@ -1,41 +1,47 @@
 [[test]]
 name = "basic"
-command = "$<TARGET_FILE:cmkr>"
 working-directory = "basic"
+command = "$<TARGET_FILE:cmkr>"
 arguments = ["build"]
 
 [[test]]
 name = "interface"
-command = "$<TARGET_FILE:cmkr>"
 working-directory = "interface"
+command = "$<TARGET_FILE:cmkr>"
 arguments = ["build"]
 
 [[test]]
 name = "fetch-content"
-command = "$<TARGET_FILE:cmkr>"
 working-directory = "fetch-content"
+command = "$<TARGET_FILE:cmkr>"
 arguments = ["build"]
 
 [[test]]
 name = "conditions"
-command = "$<TARGET_FILE:cmkr>"
 working-directory = "conditions"
+command = "$<TARGET_FILE:cmkr>"
 arguments = ["build"]
 
 [[test]]
 name = "vcpkg"
-command = "$<TARGET_FILE:cmkr>"
 working-directory = "vcpkg"
+command = "$<TARGET_FILE:cmkr>"
 arguments = ["build"]
 
 [[test]]
 name = "cxx-standard"
-command = "$<TARGET_FILE:cmkr>"
 working-directory = "cxx-standard"
+command = "$<TARGET_FILE:cmkr>"
 arguments = ["build"]
 
 [[test]]
 name = "globbing"
-command = "$<TARGET_FILE:cmkr>"
 working-directory = "globbing"
+command = "$<TARGET_FILE:cmkr>"
+arguments = ["build"]
+
+[[test]]
+name = "templates"
+working-directory = "templates"
+command = "$<TARGET_FILE:cmkr>"
 arguments = ["build"]

tests/interface/cmake.toml

@@ -5,6 +5,7 @@ description = "Header-only library"
 [target.mylib]
 type = "interface"
 include-directories = ["include"]
+compile-features = ["cxx_std_11"]
 
 [target.example]
 type = "executable"

tests/templates/cmake.toml

@@ -0,0 +1,25 @@
+# To avoid repeating yourself in targets you can create your own target type (template). All properties of the template are inherited when used as a target type.
+
+[project]
+name = "templates"
+description = "Target templates"
+
+[template.app]
+type = "executable"
+sources = ["src/templates.cpp"]
+compile-definitions = ["IS_APP"]
+
+# Unlike interface targets you can also inherit properties
+[template.app.properties]
+CXX_STANDARD = "11"
+CXX_STANDARD_REQUIRED = true
+
+[target.app-a]
+type = "app"
+compile-definitions = ["APP_A"]
+
+[target.app-b]
+type = "app"
+compile-definitions = ["APP_B"]
+
+# **Note**: In most cases you probably want to use an [interface](/examples/interface) target instead.

tests/templates/src/templates.cpp

@@ -0,0 +1,13 @@
+#include <cstdio>
+
+#if !defined(IS_APP)
+#error Something went wrong with the template
+#endif // IS_APP
+
+int main() {
+#if defined(APP_A)
+    puts("Hello from app A!");
+#elif defined(APP_B)
+    puts("Hello from app B!");
+#endif
+}