[edk2-DscSpecification PATCH] Declare Pre/Post build scripts in [Defines] section

[Michael Kinney <michael.d.kinney@intel.com>]

https://bugzilla.tianocore.org/show_bug.cgi?id=484

Add support for PREBUILD and POSTBUILD defines in
the [Defines] section of an DSC to declare scripts
that are executed before and after normal DSC/FDF
file processing.

Cc: Liming Gao <liming.gao@intel.com>
Cc: Yonghong Zhu <yonghong.zhu@intel.com>
Cc: Kevin W Shaw <kevin.w.shaw@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Michael Kinney <michael.d.kinney@intel.com>
---
 2_dsc_overview/23_[defines]_section_processing.md | 11 +++++++++++
 3_edk_ii_dsc_file_format/35_[defines]_section.md  |  2 ++
 README.md                                         |  1 +
 3 files changed, 14 insertions(+)

diff --git a/2_dsc_overview/23_[defines]_section_processing.md b/2_dsc_overview/23_[defines]_section_processing.md
index 7f3c56d..f44ec57 100644
--- a/2_dsc_overview/23_[defines]_section_processing.md
+++ b/2_dsc_overview/23_[defines]_section_processing.md
@@ -53,6 +53,17 @@ The format for entries in this section is:
 
 `Name = Value`
 
+If the `PREBUILD` and/or `POSTBUILD` entries are specified, value must be a
+tool that can be executed.  If the value contains space characters, then the
+value must be a quoted string. The `build` tool suspends processing of the DSC
+file if the `PREBUILD` entry is present, calls the script, and either terminates
+or continues processing the DSC file depending on the exit code from the script.
+If the `POSTBUILD` entry is present, prior to the successful `build` exit, the
+script is called. If the script fails (non-zero exit code from the script)
+`build` terminates immediately using the exit code returned from the script,
+otherwise, `build` terminates normally. The author of the script is responsible
+for ensuring that the script terminates with a non-zero exit code when it fails.
+
 All defined elements of the DSC file's `[Defines]` section are valid when
 parsing the FDF file. The these elements must be treated as Macros when using
 them in other sections of the DSC and FDF file, as in $(PLATFORM_NAME).
diff --git a/3_edk_ii_dsc_file_format/35_[defines]_section.md b/3_edk_ii_dsc_file_format/35_[defines]_section.md
index 0785061..3ac6847 100644
--- a/3_edk_ii_dsc_file_format/35_[defines]_section.md
+++ b/3_edk_ii_dsc_file_format/35_[defines]_section.md
@@ -125,6 +125,8 @@ The `!include` statement may be used in a `[Defines]` section.
                    [<TS> "VPD_TOOL_GUID" <Eq> <RegistryFormatGUID>
                    <EOL>]
                    [<TS> "PCD_VAR_CHECK_GENERATION" <Eq> <TF> <EOL>]
+                   [<TS> "PREBUILD" <Eq> {<AsciiString>} {<QuotedString>} <EOL>]
+                   [<TS> "POSTBUILD" <Eq> {<AsciiString>} {<QuotedString>} <EOL>]
                    [<TS> <AddressStmts>]
                    <IncludeStatement>*
                    <MacroDefinition>*
diff --git a/README.md b/README.md
index 64bf2b7..31eebe4 100644
--- a/README.md
+++ b/README.md
@@ -178,3 +178,4 @@ Copyright (c) 2006-2017, Intel Corporation. All rights reserved.
 |            | Added new system environment variables used by the build system.                                                                                                                                                                                                                             |                |
 | 1.27       | Convert to GitBooks                                                                                                                                                                                                                                                                          | April 2017     |
 |            | [#351](https://bugzilla.tianocore.org/show_bug.cgi?id=351) [DSC Spec] Extend macro usage in the !include statement                                                                                                                                                                           |                |
+|            | [#484](https://bugzilla.tianocore.org/show_bug.cgi?id=484) DSC spec: support Prebuild and Postbuild in the [Defines] section                                                                                                                                                                 |                |
-- 
2.6.3.windows.1