Loading clang/docs/ReleaseNotes.rst +18 −18 Original line number Diff line number Diff line Loading @@ -35,6 +35,12 @@ sections with improvements to Clang's support for those languages. Non-comprehensive list of changes in this release ------------------------------------------------- - Support for `retpolines <https://support.google.com/faqs/answer/7625886>`_ was added to help mitigate "branch target injection" (variant #2) of the "Spectre" speculative side channels described by `Project Zero <https://googleprojectzero.blogspot.com/2018/01/reading-privileged-memory-with-side.html>`_ and the `Spectre paper <https://spectreattack.com/spectre.pdf>`_. - Bitrig OS was merged back into OpenBSD, so Bitrig support has been removed from Clang/LLVM. Loading @@ -51,12 +57,6 @@ Non-comprehensive list of changes in this release ``__is_target_vendor``, ``__is_target_os``, and ``__is_target_environment`` can be used to to examine the individual components of the target triple. - Support for `retpolines <https://support.google.com/faqs/answer/7625886>`_ was added to help mitigate "branch target injection" (variant #2) of the "Spectre" speculative side channels described by `Project Zero <https://googleprojectzero.blogspot.com/2018/01/reading-privileged-memory-with-side.html>`_ and the `Spectre paper <https://spectreattack.com/spectre.pdf>`_. Improvements to Clang's diagnostics ----------------------------------- Loading Loading @@ -115,6 +115,18 @@ Improvements to Clang's diagnostics New Compiler Flags ------------------ - Clang supports the ``-mretpoline`` flag to enable `retpolines <https://support.google.com/faqs/answer/7625886>`_. Code compiled with this flag will be hardened against variant #2 of the Spectre attack. Indirect branches from switches or gotos removed from the code, and indirect calls will be made through a "retpoline" thunk. The necessary thunks will automatically be inserted into the generated code. Clang also supports ``-mretpoline-external-thunk`` which works like ``-mretpoline`` but requires the user to provide their own thunk definitions. The external thunk names start with ``__x86_indirect_thunk_`` and end in a register name. For 64-bit platforms, only an ``r11`` thunk is used, but for 32-bit platforms ``eax``, ``ecx``, ``edx``, and ``edi`` thunks are used. - Clang now supports configuration files. These are collections of driver options, which can be applied by specifying the configuration file, either using command line option ``--config foo.cfg`` or encoding it into executable Loading Loading @@ -144,18 +156,6 @@ New Compiler Flags - New ``-nostdlib++`` flag to disable linking the C++ standard library. Similar to using ``clang`` instead of ``clang++`` but doesn't disable ``-lm``. - Clang supports the ``-mretpoline`` flag to enable `retpolines <https://support.google.com/faqs/answer/7625886>`_. Code compiled with this flag will be hardened against variant #2 of the Spectre attack. Indirect branches from switches or gotos removed from the code, and indirect calls will be made through a "retpoline" thunk. The necessary thunks will automatically be inserted into the generated code. Clang also supports ``-mretpoline-external-thunk`` which works like ``-mretpoline`` but requires the user to provide their own thunk definitions. The external thunk names start with ``__x86_indirect_thunk_`` and end in a register name. For 64-bit platforms, only an ``r11`` thunk is used, but for 32-bit platforms ``eax``, ``ecx``, ``edx``, and ``edi`` thunks are used. Attribute Changes in Clang -------------------------- Loading Loading
clang/docs/ReleaseNotes.rst +18 −18 Original line number Diff line number Diff line Loading @@ -35,6 +35,12 @@ sections with improvements to Clang's support for those languages. Non-comprehensive list of changes in this release ------------------------------------------------- - Support for `retpolines <https://support.google.com/faqs/answer/7625886>`_ was added to help mitigate "branch target injection" (variant #2) of the "Spectre" speculative side channels described by `Project Zero <https://googleprojectzero.blogspot.com/2018/01/reading-privileged-memory-with-side.html>`_ and the `Spectre paper <https://spectreattack.com/spectre.pdf>`_. - Bitrig OS was merged back into OpenBSD, so Bitrig support has been removed from Clang/LLVM. Loading @@ -51,12 +57,6 @@ Non-comprehensive list of changes in this release ``__is_target_vendor``, ``__is_target_os``, and ``__is_target_environment`` can be used to to examine the individual components of the target triple. - Support for `retpolines <https://support.google.com/faqs/answer/7625886>`_ was added to help mitigate "branch target injection" (variant #2) of the "Spectre" speculative side channels described by `Project Zero <https://googleprojectzero.blogspot.com/2018/01/reading-privileged-memory-with-side.html>`_ and the `Spectre paper <https://spectreattack.com/spectre.pdf>`_. Improvements to Clang's diagnostics ----------------------------------- Loading Loading @@ -115,6 +115,18 @@ Improvements to Clang's diagnostics New Compiler Flags ------------------ - Clang supports the ``-mretpoline`` flag to enable `retpolines <https://support.google.com/faqs/answer/7625886>`_. Code compiled with this flag will be hardened against variant #2 of the Spectre attack. Indirect branches from switches or gotos removed from the code, and indirect calls will be made through a "retpoline" thunk. The necessary thunks will automatically be inserted into the generated code. Clang also supports ``-mretpoline-external-thunk`` which works like ``-mretpoline`` but requires the user to provide their own thunk definitions. The external thunk names start with ``__x86_indirect_thunk_`` and end in a register name. For 64-bit platforms, only an ``r11`` thunk is used, but for 32-bit platforms ``eax``, ``ecx``, ``edx``, and ``edi`` thunks are used. - Clang now supports configuration files. These are collections of driver options, which can be applied by specifying the configuration file, either using command line option ``--config foo.cfg`` or encoding it into executable Loading Loading @@ -144,18 +156,6 @@ New Compiler Flags - New ``-nostdlib++`` flag to disable linking the C++ standard library. Similar to using ``clang`` instead of ``clang++`` but doesn't disable ``-lm``. - Clang supports the ``-mretpoline`` flag to enable `retpolines <https://support.google.com/faqs/answer/7625886>`_. Code compiled with this flag will be hardened against variant #2 of the Spectre attack. Indirect branches from switches or gotos removed from the code, and indirect calls will be made through a "retpoline" thunk. The necessary thunks will automatically be inserted into the generated code. Clang also supports ``-mretpoline-external-thunk`` which works like ``-mretpoline`` but requires the user to provide their own thunk definitions. The external thunk names start with ``__x86_indirect_thunk_`` and end in a register name. For 64-bit platforms, only an ``r11`` thunk is used, but for 32-bit platforms ``eax``, ``ecx``, ``edx``, and ``edi`` thunks are used. Attribute Changes in Clang -------------------------- Loading
