Add support for more compiler options

Fixes foonathan/standardese#115.

include/cppast/compile_config.hpp

@@ -74,6 +74,13 @@ public:
         do_set_flags(standard, flags);
     }
 
+    /// \effects Enables an `-fXXX` flag.
+    /// \returns Whether or not it was a known feature and enabled.
+    bool enable_feature(std::string name)
+    {
+        return do_enable_feature(name);
+    }
+
     /// \effects Adds the given path to the set of include directories.
     void add_include_dir(std::string path)
     {
@@ -121,6 +128,14 @@ private:
     /// \effects Sets the given C++ standard and compilation flags.
     virtual void do_set_flags(cpp_standard standard, compile_flags flags) = 0;
 
+    /// \effects Sets the given feature flags.
+    /// \returns Whether or not it was a known feature and set.
+    virtual bool do_enable_feature(std::string name)
+    {
+        (void)name;
+        return false;
+    }
+
     /// \effects Adds the given path to the set of include directories.
     virtual void do_add_include_dir(std::string path) = 0;
 

include/cppast/libclang_parser.hpp

@@ -157,6 +157,8 @@ public:
 private:
     void do_set_flags(cpp_standard standard, compile_flags flags) override;
 
+    bool do_enable_feature(std::string name) override;
+
     void do_add_include_dir(std::string path) override;
 
     void do_add_macro_definition(std::string name, std::string definition) override;

src/libclang/libclang_parser.cpp

@@ -237,7 +237,7 @@ libclang_compile_config::libclang_compile_config(const libclang_compilation_data
             else if (flag == "-std")
                 // standard
                 add_flag(std::move(flag) + "=" + std::move(args));
-            else if (flag == "-f" && (args == "ms-compatibility" || args == "ms-extensions"))
+            else if (flag == "-f")
                 // other options
                 add_flag(std::move(flag) + std::move(args));
         });
@@ -386,6 +386,12 @@ void libclang_compile_config::do_set_flags(cpp_standard standard, compile_flags
         add_flag("-fms-extensions");
 }
 
+bool libclang_compile_config::do_enable_feature(std::string name)
+{
+    add_flag("-f" + std::move(name));
+    return true;
+}
+
 void libclang_compile_config::do_add_include_dir(std::string path)
 {
     add_flag("-I" + std::move(path));

test/libclang_parser.cpp

@@ -58,7 +58,7 @@ TEST_CASE("libclang_compile_config")
 },
 {
     "directory": "",
-    "command": "/usr/bin/clang++ -std=c++14 -fms-extensions -fms-compatibility -c -o c.o c.cpp",
+    "command": "/usr/bin/clang++ -std=c++14 -fms-extensions -fms-compatibility -fno-strict-aliasing -c -o c.o c.cpp",
     "file": "C:/c.cpp",
 }
 ])";
@@ -84,7 +84,7 @@ TEST_CASE("libclang_compile_config")
 },
 {
     "directory": "",
-    "command": "/usr/bin/clang++ -std=c++14 -fms-extensions -fms-compatibility -c -o c.o c.cpp",
+    "command": "/usr/bin/clang++ -std=c++14 -fms-extensions -fms-compatibility -fno-strict-aliasing -c -o c.o c.cpp",
     "file": "/c.cpp",
 }
 ])";
@@ -104,5 +104,5 @@ TEST_CASE("libclang_compile_config")
                      "/absolute -DB(X)=X");
 
     libclang_compile_config c(database, CPPAST_DETAIL_DRIVE "/c.cpp");
-    require_flags(c, "-std=c++14 -fms-extensions -fms-compatibility");
+    require_flags(c, "-std=c++14 -fms-extensions -fms-compatibility -fno-strict-aliasing");
 }

tool/main.cpp

@@ -207,6 +207,8 @@ int main(int argc, char* argv[]) try
          cxxopts::value<std::vector<std::string>>())
         ("U,macro_undefinition", "undefine a macro on the command line",
          cxxopts::value<std::vector<std::string>>())
+        ("f,feature", "enable a custom feature (-fXX flag)",
+         cxxopts::value<std::vector<std::string>>())
         ("gnu_extensions", "enable GNU extensions (equivalent to -std=gnu++XX)")
         ("msvc_extensions", "enable MSVC extensions (equivalent to -fms-extensions)")
         ("msvc_compatibility", "enable MSVC compatibility (equivalent to -fms-compatibility)")
@@ -275,6 +277,9 @@ int main(int argc, char* argv[]) try
         if (options.count("macro_undefinition"))
             for (auto& name : options["macro_undefinition"].as<std::vector<std::string>>())
                 config.undefine_macro(name);
+        if (options.count("feature"))
+            for (auto& name : options["feature"].as<std::vector<std::string>>())
+                config.enable_feature(name);
 
         // the compile_flags are generic flags
         cppast::compile_flags flags;