[PDB Docs] Add info about the hash adjustment buffer.

This necessitates adding a document describing the serialized
hash table format.  This document is currently empty, although
it will be filled out in followup patches.

llvm-svn: 357784

4 files changed, 15 insertions, 8 deletions

diff --git a/llvm/docs/PDB/HashStream.rst b/llvm/docs/PDB/HashStream.rst
deleted file mode 100644
index a758db4d03d..00000000000
--- a/llvm/docs/PDB/HashStream.rst
+++ /dev/null
@@ -1,3 +0,0 @@
-=====================================

-The TPI & IPI Hash Streams

-=====================================

diff --git a/llvm/docs/PDB/HashTable.rst b/llvm/docs/PDB/HashTable.rst
new file mode 100644
index 00000000000..fbf4a1de528
--- /dev/null
+++ b/llvm/docs/PDB/HashTable.rst
@@ -0,0 +1,2 @@
+The PDB Serialized Hash Table Format

+====================================

diff --git a/llvm/docs/PDB/TpiStream.rst b/llvm/docs/PDB/TpiStream.rst
index 74f2c37b083..99f9a73bb11 100644
--- a/llvm/docs/PDB/TpiStream.rst
+++ b/llvm/docs/PDB/TpiStream.rst
@@ -289,7 +289,15 @@ accurate.
   index.  This can be used to do a binary search followed bin a linear search to

   get amortized O(log n) lookup by type index.

 

-- **HashAdjBufferOffset / HashAdjBufferLength** - 

+- **HashAdjBufferOffset / HashAdjBufferLength** - The offset and size within

+  the TPI hash stream of a serialized hash table whose keys are the hash values

+  in the hash value buffer and whose values are type indices.  This appears to

+  be useful in incremental linking scenarios, so that if a type is modified an

+  entry can be created mapping the old hash value to the new type index so that

+  a PDB file consumer can always have the most up to date version of the type

+  without forcing the incremental linker to garbage collect and update

+  references that point to the old version to now point to the new version.

+  The layout of this hash table is described in :doc:`HashTable`.

 

 .. _tpi_records:

 

diff --git a/llvm/docs/PDB/index.rst b/llvm/docs/PDB/index.rst
index d1b4379dbf8..a6054d720bd 100644
--- a/llvm/docs/PDB/index.rst
+++ b/llvm/docs/PDB/index.rst
@@ -52,7 +52,7 @@ File Layout
    ModiStream

    PublicStream

    GlobalStream

-   HashStream

+   HashTable

    CodeViewSymbols

    CodeViewTypes

 

@@ -158,9 +158,9 @@ following pages:
 :doc:`GlobalStream`

    Information about the Global Symbol Stream.

 

-:doc:`HashStream`

-   Information about the Hash Table stream, and how it can be used to quickly look up records

-   by name.

+:doc:`HashTable`

+   Information about the serialized hash table format used internally to represent things such

+   as the Named Stream Map and the Hash Adjusters in the :doc:`TPI/IPI Stream <TpiStream>`.

 

 CodeView

 ========