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| author | Zachary Turner <zturner@google.com> | 2016-11-29 22:14:56 +0000 |
|---|---|---|
| committer | Zachary Turner <zturner@google.com> | 2016-11-29 22:14:56 +0000 |
| commit | 3f0627c5e486d1759950f3b86e1a7a0a22e3b9eb (patch) | |
| tree | 99f7ec1c7d795690ac2aef3c427a940a55a8daec /llvm/docs/PDB/ModiStream.rst | |
| parent | 8b19a0a1004aa574461ac793b0427323140ad998 (diff) | |
| download | bcm5719-llvm-3f0627c5e486d1759950f3b86e1a7a0a22e3b9eb.tar.gz bcm5719-llvm-3f0627c5e486d1759950f3b86e1a7a0a22e3b9eb.zip | |
Add documentation for the PDB Module Info stream.
llvm-svn: 288205
Diffstat (limited to 'llvm/docs/PDB/ModiStream.rst')
| -rw-r--r-- | llvm/docs/PDB/ModiStream.rst | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/llvm/docs/PDB/ModiStream.rst b/llvm/docs/PDB/ModiStream.rst index 3eb4505c5ae..7e500bd921c 100644 --- a/llvm/docs/PDB/ModiStream.rst +++ b/llvm/docs/PDB/ModiStream.rst @@ -1,3 +1,80 @@ =====================================
The Module Information Stream
=====================================
+
+.. contents::
+ :local:
+
+.. _modi_stream_intro:
+
+Introduction
+============
+
+The Module Info Stream (henceforth referred to as the Modi stream) contains
+information about a single module (object file, import library, etc that
+contributes to the binary this PDB contains debug information about. There
+is one modi stream for each module, and the mapping between modi stream index
+and module is contained in the :doc:`DBI Stream <DbiStream>`. The modi stream
+for a single module contains line information for the compiland, as well as
+all CodeView information for the symbols defined in the compiland. Finally,
+there is a "global refs" substream which is not well understood.
+
+.. _modi_stream_layout:
+
+Stream Layout
+=============
+
+A modi stream is laid out as follows:
+
+
+.. code-block:: c++
+
+ struct ModiStream {
+ uint32_t Signature;
+ uint8_t Symbols[SymbolSize-4];
+ uint8_t C11LineInfo[C11Size];
+ uint8_t C13LineInfo[C13Size];
+
+ uint32_t GlobalRefsSize;
+ uint8_t GlobalRefs[GlobalRefsSize];
+ };
+
+- **Signature** - Unknown. In practice only the value of ``4`` has been
+ observed. It is hypothesized that this value corresponds to the set of
+ ``CV_SIGNATURE_xx`` defines in ``cvinfo.h``, with the value of ``4``
+ meaning that this module has C13 line information (as opposed to C11 line
+ information). A corollary of this is that we expect to only ever see
+ C13 line info, and that we do not understand the format of C11 line info.
+
+- **Symbols** - The :ref:`CodeView Symbol Substream <modi_symbol_substream>`.
+ ``SymbolSize`` is equal to the value of ``SymByteSize`` for the
+ corresponding module's entry in the :ref:`Module Info Substream <dbi_mod_info_substream>`
+ of the :doc:`DBI Stream <DbiStream>`.
+
+- **C11LineInfo** - A block containing CodeView line information in C11
+ format. ``C11Size`` is equal to the value of ``C11ByteSize`` from the
+ :ref:`Module Info Substream <dbi_mod_info_substream>` of the
+ :doc:`DBI Stream <DbiStream>`. If this value is ``0``, then C11 line
+ information is not present. As mentioned previously, the format of
+ C11 line info is not understood and we assume all line in modern PDBs
+ to be in C13 format.
+
+- **C13LineInfo** - A block containing CodeView line information in C13
+ format. ``C13Size`` is equal to the value of ``C13ByteSize`` from the
+ :ref:`Module Info Substream <dbi_mod_info_substream>` of the
+ :doc:`DBI Stream <DbiStream>`. If this value is ``0``, then C13 line
+ information is not present.
+
+- **GlobalRefs** - The meaning of this substream is not understood.
+
+.. _modi_symbol_substream:
+
+The CodeView Symbol Substream
+=============================
+
+The CodeView Symbol Substream. This is an array of variable length
+records describing the functions, variables, inlining information,
+and other symbols defined in the compiland. The entire array consumes
+``SymbolSize-4`` bytes. The format of a CodeView Symbol Record (and
+thusly, an array of CodeView Symbol Records) is described in
+:doc:`CodeViewSymbols`.
|
