Merge pull request #169 from build-cpp/namespace-targets

Support `::mylib` which that target that exists at configure-time

Author: mrexodia

.clang-format

@@ -13,6 +13,7 @@ AllowShortCaseLabelsOnASingleLine: false
 AllowShortFunctionsOnASingleLine: false
 AllowShortIfStatementsOnASingleLine: false
 AllowShortLoopsOnASingleLine: false
+AllowShortLambdasOnASingleLine: None
 AlwaysBreakAfterDefinitionReturnType: None
 AlwaysBreakAfterReturnType: None
 AlwaysBreakBeforeMultilineStrings: false

docs/cmake-toml.md

@@ -272,7 +272,7 @@ A table mapping the cmkr features to the relevant CMake construct and the releva
 | `compile-options` | [`target_compile_options`](https://cmake.org/cmake/help/latest/command/target_compile_options.html) | Adds compiler flags. |
 | `include-directories` | [`target_include_directories`](https://cmake.org/cmake/help/latest/command/target_include_directories.html) | Adds include directories. |
 | `link-directories` | [`target_link_directories`](https://cmake.org/cmake/help/latest/command/target_link_directories.html) | Adds library directories. |
-| `link-libraries` | [`target_link_libraries`](https://cmake.org/cmake/help/latest/command/target_link_libraries.html) | Adds library dependencies. |
+| `link-libraries` | [`target_link_libraries`](https://cmake.org/cmake/help/latest/command/target_link_libraries.html) | Adds library dependencies. Use `::mylib` to make sure a target exists. |
 | `link-options` | [`target_link_options`](https://cmake.org/cmake/help/latest/command/target_link_options.html) | Adds linker flags. |
 | `precompile-headers` | [`target_precompile_headers`](https://cmake.org/cmake/help/latest/command/target_precompile_headers.html) | Specifies precompiled headers. |
 | `properties` | [`set_target_properties`](https://cmake.org/cmake/help/latest/command/set_target_properties.html) | See [properties on targets](https://cmake.org/cmake/help/latest/manual/cmake-properties.7.html#properties-on-targets) for more information. |

src/cmake_generator.cpp

@@ -558,11 +558,15 @@ struct Generator {
     }
 
     void conditional_includes(const parser::ConditionVector &include) {
-        handle_condition(include, [this](const std::string &, const std::vector<std::string> &includes) { inject_includes(includes); });
+        handle_condition(include, [this](const std::string &, const std::vector<std::string> &includes) {
+            inject_includes(includes);
+        });
     }
 
     void conditional_cmake(const parser::Condition<std::string> &cmake) {
-        handle_condition(cmake, [this](const std::string &, const std::string &cmake) { inject_cmake(cmake); });
+        handle_condition(cmake, [this](const std::string &, const std::string &cmake) {
+            inject_cmake(cmake);
+        });
     }
 
     bool if_condition(const std::string &condition) {
@@ -719,9 +723,15 @@ void generate_cmake(const char *path, const parser::Project *parent_project) {
 
     // Helper lambdas for more convenient CMake generation
     auto &ss = gen.ss;
-    auto cmd = [&gen](const std::string &command) { return gen.cmd(command); };
-    auto comment = [&gen](const std::string &comment) { return gen.comment(comment); };
-    auto endl = [&gen]() { gen.endl(); };
+    auto cmd = [&gen](const std::string &command) {
+        return gen.cmd(command);
+    };
+    auto comment = [&gen](const std::string &comment) {
+        return gen.comment(comment);
+    };
+    auto endl = [&gen]() {
+        gen.endl();
+    };
 
     std::string cmkr_url = "https://github.com/build-cpp/cmkr";
     comment("This file is automatically generated from cmake.toml - DO NOT EDIT");
@@ -1145,7 +1155,9 @@ void generate_cmake(const char *path, const parser::Project *parent_project) {
         for (size_t i = 0; i < project.targets.size(); i++) {
             const auto &target = project.targets[i];
 
-            auto throw_target_error = [&target](const std::string &message) { throw std::runtime_error("[target." + target.name + "] " + message); };
+            auto throw_target_error = [&target](const std::string &message) {
+                throw std::runtime_error("[target." + target.name + "] " + message);
+            };
 
             const parser::Template *tmplate = nullptr;
             std::unique_ptr<ConditionScope> tmplate_cs{};
@@ -1384,8 +1396,29 @@ void generate_cmake(const char *path, const parser::Project *parent_project) {
             }
 
             auto target_cmd = [&](const char *command, const parser::ConditionVector &cargs, const std::string &scope) {
-                gen.handle_condition(cargs,
-                                     [&](const std::string &, const std::vector<std::string> &args) { cmd(command)(target.name, scope, args); });
+                gen.handle_condition(cargs, [&](const std::string &, const std::vector<std::string> &args) {
+                    cmd(command)(target.name, scope, args);
+                });
+            };
+
+            auto link_libraries = [&](const parser::ConditionVector &cargs, const std::string &scope) {
+                gen.handle_condition(cargs, [&](const std::string &, const std::vector<std::string> &args) {
+                    std::vector<std::string> targs;
+                    for (const std::string &arg : args) {
+                        if (arg.find("::") == 0) {
+                            auto library = arg.substr(2);
+                            // clang-format off
+                            cmd("if")("NOT", "TARGET", library);
+                                cmd("message")("FATAL_ERROR", "Target \"" + library + "\" referenced by \"" + target.name + "\" does not exist!");
+                            cmd("endif")().endl();
+                            // clang-format on
+                            targs.push_back(std::move(library));
+                        } else {
+                            targs.push_back(arg);
+                        }
+                    }
+                    cmd("target_link_libraries")(target.name, scope, targs);
+                });
             };
 
             auto gen_target_cmds = [&](const parser::Target &t) {
@@ -1404,8 +1437,8 @@ void generate_cmake(const char *path, const parser::Project *parent_project) {
                 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", t.link_libraries, target_scope);
-                target_cmd("target_link_libraries", t.private_link_libraries, "PRIVATE");
+                link_libraries(t.link_libraries, target_scope);
+                link_libraries(t.private_link_libraries, "PRIVATE");
 
                 target_cmd("target_link_options", t.link_options, target_scope);
                 target_cmd("target_link_options", t.private_link_options, "PRIVATE");