[Lldb-commits] [lldb] r105746 - /lldb/trunk/include/lldb/lldb-enumerations.h

[Eli Friedman]

On Wed, Jun 9, 2010 at 11:33 PM, Greg Clayton <gclayton at apple.com> wrote:
> Eli,
> Can you change this back to somehow use some sort of #ifdeffery on linux? We
> had a working version for Mac OS X, there must be an easy way to do this for
> linux.
> Shared libraries at Apple are not supposed to have any global init
> constructors in them (we have an build exception for this right now for
> other things inside LLVM that have global init ctors) but we would like to
> avoid adding any in the LLDB codebase if at all possible. Also we would like
> to avoid defining a constant in a header file.
> We should probably modify the Host.h time to somehow autodetect this and set
> the define appropriately.
> We currently add the "-Wglobal-constructors" to all C++ compiles to see
> these issues as they arise.
> /Volumes/work/gclayton/Documents/src/lldb/include/lldb/lldb-enumerations.h:86:0
> /Volumes/work/gclayton/Documents/src/lldb/include/lldb/lldb-enumerations.h:86:
> warning: 'lldb::eByteOrderHost' requires global construction
>
> You will see some code (which can sometimes get ugly) around LLDB that deals
> with avoiding global constructors.
> The above example below from SymbolFileDWARF.cpp shows a way to have a
> static variable in a source file without having to have a global init ctor:
> static const ConstString&
> GetSectionNameDebugInfo()
> {
>     static const ConstString g_sect_name("__debug_info");
>     return g_sect_name;
> }
> There are also some ugly examples where multiple functions must access a
> static and a GetAndSet function is made. One such example is in Log.cpp:
> static Stream *
> StreamForSTDOUTAccess (bool set, StreamSP &stream_sp);
> Let me know if you can make the changes for linux, else I might need to back
> out the change.

Globally replacing eByteOrderHost with getHostByteOrder() should be
sufficient here; I can't properly test such a change, though.  It
would be nice if you could do that; otherwise, feel free to back out.

-Eli

> Greg Clayton
>
> On Jun 9, 2010, at 12:26 PM, Eli Friedman wrote:
>
> Author: efriedma
> Date: Wed Jun  9 14:26:51 2010
> New Revision: 105746
>
> URL: http://llvm.org/viewvc/llvm-project?rev=105746&view=rev
> Log:
> Use portable endianness routine from LLVM.
>
>
> Modified:
>    lldb/trunk/include/lldb/lldb-enumerations.h
>
> Modified: lldb/trunk/include/lldb/lldb-enumerations.h
> URL:
> http://llvm.org/viewvc/llvm-project/lldb/trunk/include/lldb/lldb-enumerations.h?rev=105746&r1=105745&r2=105746&view=diff
> ==============================================================================
> --- lldb/trunk/include/lldb/lldb-enumerations.h (original)
> +++ lldb/trunk/include/lldb/lldb-enumerations.h Wed Jun  9 14:26:51 2010
> @@ -10,6 +10,8 @@
> #ifndef LLDB_enumerations_h_
> #define LLDB_enumerations_h_
>
> +#include "llvm/System/Host.h"
> +
> namespace lldb {
>
> //----------------------------------------------------------------------
> @@ -71,18 +73,18 @@
>     eByteOrderInvalid   = 0,
>     eByteOrderLittle    = 1234,
>     eByteOrderBig       = 4321,
> -    eByteOrderPDP       = 3412,
> -#if   defined (__LITTLE_ENDIAN__)
> -    eByteOrderHost      = eByteOrderLittle
> -#elif defined (__BIG_ENDIAN__)
> -    eByteOrderHost      = eByteOrderBig
> -#elif defined (__PDP_ENDIAN__)
> -    eByteOrderHost      = eByteOrderPDP
> -#else
> -#error unable to detect endianness
> -#endif
> +    eByteOrderPDP       = 3412
> } ByteOrder;
>
> +inline ByteOrder getHostByteOrder() {
> +  if (llvm::sys::isLittleEndianHost())
> +    return eByteOrderLittle;
> +  return eByteOrderBig;
> +}
> +
> +// FIXME: Replace uses of eByteOrderHost with getHostByteOrder()!
> +const ByteOrder eByteOrderHost = getHostByteOrder();
> +
> //----------------------------------------------------------------------
> // Register encoding definitions
> //----------------------------------------------------------------------
>
>
> _______________________________________________
> lldb-commits mailing list
> lldb-commits at cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/lldb-commits
>
>