type_traits header in libstdc++ 4.8 does not define is_trivially_contructible
so the code doesn't compile with it.
In this file we are using the trait for assertion to provide a better
error message. Removing it doesn't change the meaning of the code.
Differential Revision: http://reviews.llvm.org/D20719
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@270957 91177308-0d34-0410-b5e6-96231b3b80d8
PDBs can be extremely large. We're already mapping the entire
PDB into the process's address space, but to make matters worse
the blocks of the PDB are not arranged contiguously. So, when
we have something like an array or a string embedded into the
stream, we have to make a copy. Since it's convenient to use
traditional data structures to iterate and manipulate these
records, we need the memory to be contiguous.
As a result of this, we were using roughly twice as much memory
as the file size of the PDB, because every stream was copied
out and re-stitched together contiguously.
This patch addresses this by improving the MappedBlockStream
to allocate from a BumpPtrAllocator only when a read requires
a discontiguous read. Furthermore, it introduces some data
structures backed by a stream which can iterate over both
fixed and variable length records of a PDB. Since everything
is backed by a stream and not a buffer, we can read almost
everything from the PDB with zero copies.
Differential Revision: http://reviews.llvm.org/D20654
Reviewed By: ruiu
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@270951 91177308-0d34-0410-b5e6-96231b3b80d8
