Previously we allowed this definition to persist outside our header.
This would cause conflicts across multiple such headers because the name
was always the same. Fix this by avoiding the definition altogether.
The CMAKE_CXX_COMPILER_ID and CMAKE_C_COMPILER_ID variables are set to
"Borland" for older versions of the compiler. Newer CodeGear/Embarcadero
compilers will have those variables set to "Embarcadero". Search for lines of
code referencing both the variable name and Borland to be sure that they also
refer to Embarcadero.
When testing CMAKE_CXX_COMPILER_ID values with if(MATCHES),
do not explicitly dereference or quote CMAKE_CXX_COMPILER_ID.
We want if() to auto-dereference the variable and not its value.
The variables in this module are used to configure a header file
with defines whose name depends on the name of the target.
As valid names of targets may be invalid for use as defines, convert
the names of the defines used to C identifiers first. This is already
done in C++ code for the DEFINE_SYMBOL property.
This is not as simple as ensuring that the BASE_NAME is a C identifier,
because most of the define names are configurable, and because use of
a BASE_NAME which is not a C identifier, such as 4square can become a
C identifier by specifying a prefix in the generate_export_header
macro.
The significant issue with MODULEs is that on Windows, the exported
symbols must be dllexported and they are not imported.
In other export macro implementations this is done by defining an
export macro outside of any ifdef which depends on definitions set
on the command line. However, with cmake we already expect the
DEFINE_SYMBOL to be defined, so the regular EXPORT macro can be
used by such plugins.
Use CMAKE_<LANG>_COMPILER_VERSION instead of calling the compiler. This macro
predates those useful variables. This also fixes the issue that g++ version
detection was not working if C language was not enabled.
The GenerateExportHeaders test was failing on one machine, the version
could not be determined there, so the _gcc_version was empty,
so the first argument to if() was empty, so it complained:
http://open.cdash.org/testDetails.php?test=135623436&build=2016288
Use double quotes to turn the non-existant first argument into an empty
string.
Alex
Making this a macro had unintended issues on (among others) Windows
compilers. Moving it back to being a function using PARENT_SCOPE still
satisfies the use case where we simply want to obtain the extra flags.
Daniel Pfeifer
Felix Geyer
Brad King
Andreas Schuh
James Johnston
Tony Kelman
Daniele E. Domenichelli
Ben Boeckel
Stephen Kelly
Kitware Robot
Marcus D. Hanwell
David Cole
Rolf Eike Beer
Alex Neundorf
Michael Wild
David Faure