Toolchain: Normalize dwarf, sjlj and seh eh

This is a re-apply of r319294.

adds -fseh-exceptions and -fdwarf-exceptions flags

clang will check if the user has specified an exception model flag,
in the absense of specifying the exception model clang will then check
the driver default and append the model flag for that target to cc1

-fno-exceptions has a higher priority then specifying the model

move __SEH__ macro definitions out of Targets into InitPreprocessor
behind the -fseh-exceptions flag

move __ARM_DWARF_EH__ macrodefinitions out of verious targets and into
InitPreprocessor behind the -fdwarf-exceptions flag and arm|thumb check

remove unused USESEHExceptions from the MinGW Driver

fold USESjLjExceptions into a new GetExceptionModel function that
gives the toolchain classes more flexibility with eh models

Reviewers: rnk, mstorsjo

Differential Revision: https://reviews.llvm.org/D39673

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@319297 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 8 insertions, 0 deletions

diff --git a/docs/ClangCommandLineReference.rst b/docs/ClangCommandLineReference.rst
index 7596afadc8..434297b2c8 100644
--- a/docs/ClangCommandLineReference.rst
+++ b/docs/ClangCommandLineReference.rst
@@ -1706,10 +1706,18 @@ Which overload candidates to show when overload resolution fails: best\|all; def
 
 Enable C++14 sized global deallocation functions
 
+.. option:: -fdwarf-exceptions
+
+Use DWARF style exceptions
+
 .. option:: -fsjlj-exceptions
 
 Use SjLj style exceptions
 
+.. option:: -fseh-exceptions
+
+Use SEH style exceptions
+
 .. option:: -fslp-vectorize, -fno-slp-vectorize, -ftree-slp-vectorize
 
 Enable the superword-level parallelism vectorization passes