Revert changes done to 'make apidoc' target

This partially reverts 1989caf71c (only the changes to Makefile and
CMakeLists, the addition to scripts/config.pl is kept).

Modifying config.h in the apidoc target creates a race condition with

    make -j4 all apidoc

where some parts of the library, tests or programs could be built with the
wrong config.h, resulting in all kinds of (semi-random) errors. Recent
versions of CMake mitigate this by adding a .NOTPARALLEL target to the
generated Makefile, but people would still get errors with older CMake
versions that are still in use (eg in RHEL 5), and with plain make.

An additional issue is that, by failing to use cp -p, the apidoc target was
updating the timestamp on config.h, which seems to cause further build issues.

Let's get back to the previous, safe, situation. The improved apidoc building
will be resurrected in a script in the next commit.

fixes #390
fixes #391

CMakeLists.txt

@@ -85,20 +85,9 @@ if(ENABLE_PROGRAMS)
     add_subdirectory(programs)
 endif()
 
-# targets for doxygen only work on Unix
-if(UNIX)
-    ADD_CUSTOM_TARGET(apidoc
-        COMMAND mkdir -p apidoc
-        COMMAND cp include/mbedtls/config.h include/mbedtls/config.h.bak
-        COMMAND scripts/config.pl realfull
-        COMMAND doxygen doxygen/mbedtls.doxyfile
-        COMMAND mv include/mbedtls/config.h.bak include/mbedtls/config.h
-        WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR})
-
-    ADD_CUSTOM_TARGET(apidoc_clean
-        COMMAND rm -rf apidoc
-        WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR})
-endif(UNIX)
+ADD_CUSTOM_TARGET(apidoc
+    COMMAND doxygen doxygen/mbedtls.doxyfile
+    WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR})
 
 if(ENABLE_TESTING)
     enable_testing()

ChangeLog

@@ -6,6 +6,8 @@ Bugfix
    * Fix bug in mbedtls_mpi_add_mpi() that caused wrong results when the three
      arguments where the same (in-place doubling). Found and fixed by Janos
      Follath.
+   * Fix potential build failures related to the 'apidoc' target, introduced
+     in the previous patch release. Found by Robert Scheck. #390 #391
 
 = mbed TLS 2.2.1 released 2016-01-05
 

Makefile

@@ -87,10 +87,7 @@ lcov:
 
 apidoc:
 	mkdir -p apidoc
-	cp include/mbedtls/config.h include/mbedtls/config.h.bak
-	scripts/config.pl realfull
 	doxygen doxygen/mbedtls.doxyfile
-	mv include/mbedtls/config.h.bak include/mbedtls/config.h
 
 apidoc_clean:
 	rm -rf apidoc