Add explicit visibility for class and function templates (refs #27)

Author: scheibel

cmake/Custom.cmake

@@ -44,3 +44,16 @@ function(list_extract OUTPUT REGEX)
     set(${OUTPUT} ${${OUTPUT}} PARENT_SCOPE)
 
 endfunction(list_extract)
+
+
+# Creates an export header similar to generate_export_header, but for templates.
+# The main difference is that for MSVC, templates must not get exported.
+# When the file ${export_file} is included in source code, the macro ${target_id}_TEMPLATE_API
+# may get used to define public visibility for templates on GCC and Clang platforms.
+function(generate_template_export_header target target_id export_file)
+    if ("${CMAKE_CXX_COMPILER_ID}" MATCHES "MSVC")
+        configure_file(${PROJECT_SOURCE_DIR}/source/codegeneration/template_msvc_api.h.in ${CMAKE_CURRENT_BINARY_DIR}/${export_file})
+    else()
+        configure_file(${PROJECT_SOURCE_DIR}/source/codegeneration/template_api.h.in ${CMAKE_CURRENT_BINARY_DIR}/${export_file})
+    endif()
+endfunction()

source/baselib/CMakeLists.txt

@@ -19,9 +19,10 @@ message(STATUS "Lib ${target}")
 # Set API export file and macro
 string(MAKE_C_IDENTIFIER ${target} target_id)
 string(TOUPPER ${target_id} target_id)
-set(feature_file "include/${target}/${target}_features.h")
-set(export_file  "include/${target}/${target}_api.h")
-set(export_macro "${target_id}_API")
+set(feature_file         "include/${target}/${target}_features.h")
+set(export_file          "include/${target}/${target}_export.h")
+set(template_export_file "include/${target}/${target}_api.h")
+set(export_macro         "${target_id}_API")
 
 
 # 
@@ -90,6 +91,10 @@ generate_export_header(${target}
     EXPORT_FILE_NAME  ${export_file}
     EXPORT_MACRO_NAME ${export_macro}
 )
+generate_template_export_header(${target}
+    ${target_id}
+    ${template_export_file}
+)
 
 
 # 

source/codegeneration/template_api.h.in

@@ -0,0 +1,23 @@
+
+#ifndef ${target_id}_TEMPLATE_API_H
+#define ${target_id}_TEMPLATE_API_H
+
+#include <${target}/${target}_export.h>
+
+#ifdef ${target_id}_STATIC_DEFINE
+#  define ${target_id}_TEMPLATE_API
+#  define ${target_id}_TEMPLATE_NO_EXPORT
+#else
+#  ifndef ${target_id}_TEMPLATE_API
+#    ifdef ${target}_EXPORTS
+        /* We are building this library */
+#      define ${target_id}_TEMPLATE_API __attribute__((visibility("default")))
+#    else
+        /* We are using this library */
+#      define ${target_id}_TEMPLATE_API __attribute__((visibility("default")))
+#    endif
+#  endif
+
+#endif
+
+#endif

source/codegeneration/template_msvc_api.in

@@ -0,0 +1,23 @@
+
+#ifndef ${target_id}_TEMPLATE_API_H
+#define ${target_id}_TEMPLATE_API_H
+
+#include <${target}/${target}_export.h>
+
+#ifdef ${target_id}_STATIC_DEFINE
+#  define ${target_id}_TEMPLATE_API
+#  define ${target_id}_TEMPLATE_NO_EXPORT
+#else
+#  ifndef ${target_id}_TEMPLATE_API
+#    ifdef ${target}_EXPORTS
+        /* We are building this library */
+#      define ${target_id}_TEMPLATE_API
+#    else
+        /* We are using this library */
+#      define ${target_id}_TEMPLATE_API
+#    endif
+#  endif
+
+#endif
+
+#endif

source/examples/fibcmd/main.cpp

@@ -3,6 +3,7 @@
 
 #include <baselib/baselib.h>
 
+#include <fiblib/CTFibonacci.h>
 #include <fiblib/Fibonacci.h>
 
 
@@ -15,7 +16,8 @@ int main(int /*argc*/, char* /*argv*/[])
     // Calculate and print fibonacci number
     std::cout << "Fibonacci library" << std::endl;
     std::cout << "========================================" << std::endl;
-    std::cout << "Fibonacci(8) = " << fiblib::Fibonacci()(8) << std::endl;
+    std::cout << "CTFibonacci(6) = " << fiblib::CTFibonacci<6>::value << std::endl;
+    std::cout << "Fibonacci(8)   = " << fiblib::Fibonacci()(8) << std::endl;
     std::cout << std::endl;
 
     return 0;

source/fiblib/CMakeLists.txt

@@ -19,9 +19,10 @@ message(STATUS "Lib ${target}")
 # Set API export file and macro
 string(MAKE_C_IDENTIFIER ${target} target_id)
 string(TOUPPER ${target_id} target_id)
-set(feature_file "include/${target}/${target}_features.h")
-set(export_file  "include/${target}/${target}_api.h")
-set(export_macro "${target_id}_API")
+set(feature_file         "include/${target}/${target}_features.h")
+set(export_file          "include/${target}/${target}_export.h")
+set(template_export_file "include/${target}/${target}_api.h")
+set(export_macro         "${target_id}_API")
 
 
 # 
@@ -32,6 +33,8 @@ set(include_path "${CMAKE_CURRENT_SOURCE_DIR}/include/${target}")
 set(source_path  "${CMAKE_CURRENT_SOURCE_DIR}/source")
 
 set(headers
+    ${include_path}/CTFibonacci.h
+    ${include_path}/CTFibonacci.inl
     ${include_path}/Fibonacci.h
 )
 
@@ -90,6 +93,10 @@ generate_export_header(${target}
     EXPORT_FILE_NAME  ${export_file}
     EXPORT_MACRO_NAME ${export_macro}
 )
+generate_template_export_header(${target}
+    ${target_id}
+    ${template_export_file}
+)
 
 
 # 

source/fiblib/include/fiblib/CTFibonacci.h

@@ -0,0 +1,29 @@
+
+#pragma once
+
+
+#include <fiblib/fiblib_api.h>
+
+
+namespace fiblib
+{
+
+
+/**
+*  @brief
+*    Compile-time computation of fibonacci numbers
+*/
+template <unsigned long long i>
+class FIBLIB_TEMPLATE_API CTFibonacci
+{
+public:
+    enum {
+        value = CTFibonacci<i-2>::value + CTFibonacci<i-1>::value
+    };
+};
+
+
+} // namespace fiblib
+
+
+#include <fiblib/CTFibonacci.inl>

source/fiblib/include/fiblib/CTFibonacci.inl

@@ -0,0 +1,28 @@
+
+#pragma once
+
+
+namespace fiblib
+{
+
+
+template <>
+class FIBLIB_TEMPLATE_API CTFibonacci<0>
+{
+public:
+    enum {
+        value = 0
+    };
+};
+
+template <>
+class FIBLIB_TEMPLATE_API CTFibonacci<1>
+{
+public:
+    enum {
+        value = 1
+    };
+};
+
+
+} // namespace fiblib