Re: [Patch V2] Expression spec: update format to support flexible Pcd format

["Gao, Liming" <liming.gao@intel.com>]

Reviewed-by: Liming Gao <liming.gao@intel.com>

>-----Original Message-----
>From: Zhu, Yonghong
>Sent: Wednesday, February 07, 2018 8:36 PM
>To: edk2-devel@lists.01.org
>Cc: Gao, Liming <liming.gao@intel.com>; Kinney, Michael D
><michael.d.kinney@intel.com>; Shaw, Kevin W <kevin.w.shaw@intel.com>
>Subject: [Patch V2] Expression spec: update format to support flexible Pcd
>format
>
>V2: update EBNF for Array format.
>
>Cc: Liming Gao <liming.gao@intel.com>
>Cc: Michael Kinney <michael.d.kinney@intel.com>
>Cc: Kevin W Shaw <kevin.w.shaw@intel.com>
>Contributed-under: TianoCore Contribution Agreement 1.1
>Signed-off-by: Yonghong Zhu <yonghong.zhu@intel.com>
>---
> 2_expression_overview.md |  3 +++
> 3_expression_format.md   | 50
>+++++++++++++++++++++++++++++++++++++++++++-----
> 2 files changed, 48 insertions(+), 5 deletions(-)
>
>diff --git a/2_expression_overview.md b/2_expression_overview.md
>index 34ceb97..c29a632 100644
>--- a/2_expression_overview.md
>+++ b/2_expression_overview.md
>@@ -100,5 +100,8 @@ directives section do not apply.
> 12. Logical operators require operands that are type scalar.
>
> 13. For the Conditional Operator, the first operand must be scalar, while the
>     second and third operands must have the same type (i.e., both being scalar,
>     both being integers, or both being string literals).
>+
>+14. Array format like "{0x10, 0x20}" can't be a operand of any operator
>except
>+    Relational and equality operators.
>diff --git a/3_expression_format.md b/3_expression_format.md
>index 50b94c4..1f90fc9 100644
>--- a/3_expression_format.md
>+++ b/3_expression_format.md
>@@ -93,10 +93,21 @@ GRACEFULLY._
> <HexNumber>             ::= <Base16>
> <Base16>                ::= <HexPrefix> [<HexDigit>]+
> <HexDigit>              ::= (a-fA-F0-9)
> <HexPrefix>             ::= {"0x"} {"0X"}
> <GuidValue>             ::= {<RformatGuid>} {<CformatGuid>}
>+<UINT8>                 ::= <HexPrefix> (\x0 - \xFF)
>+<UINT16>                ::= <HexPrefix> (\x0 - \xFFFF)
>+<UINT32>                ::= <HexPrefix> (\x0 - \xFFFFFFFF)
>+<UINT64>                ::= <HexPrefix> (\x0 - \xFFFFFFFFFFFFFFFF)
>+<ShortNum>              ::= (0-255)
>+<IntNum>                ::= (0-65535)
>+<LongNum>               ::= (0-4294967295)
>+<LongLongNum>           ::= (0-18446744073709551615)
>+<GuidStr>               ::= "GUID(" <GuidVal> ")"
>+<GuidVal>               ::= {<DblQuote> <RformatGuid> <DblQuote>}
>+                            {<CformatGuid>} {<CName>}
> Rhex2                   ::= [<HexDigit>] <HexDigit>
> Rhex4                   ::= [<HexDigit>] [<HexDigit>] Rhex2
> Rhex8                   ::= [<HexDigit>] [<HexDigit>] [<HexDigit>] [<HexDigit>] Rhex4
> <RformatGuid>           ::= Rghex8 "-" Rghex4 "-" Rghex4 "-" Rghex4 "-" Rghex12
> Rghex2                  ::= <HexDigit> <HexDigit>
>@@ -111,19 +122,42 @@ Rghex12                 ::= <HexDigit> <HexDigit> <HexDigit>
><HexDigit> Rghex8
> <CformatGuid>           ::= "{" [<TSP>]* <Hex32> <CSP> <Hex16> <CSP> <Part2>
> <Part2>                 ::= <Hex16> <CSP> "{" [<TSP>]* <Byte> <CSP> <Part3>
> <Part3>                 ::= <Byte> <CSP> <Byte> <CSP> <Byte> <CSP> <Part4>
> <Part4>                 ::= <Byte> <CSP> <Byte> <CSP> <Byte> <CSP> <Part5>
> <Part5>                 ::= <Byte> [<TSP>]* "}" [<TSP>]* "}"
>-<Array>                 ::= {<EmptyArray>} {<Array>}
>+<Array>                 ::= {<EmptyArray>} {<NonEmptyArray>}
> <EmptyArray>            ::= "{" <TSP>* "}"
>-<ByteArray>             ::= "{" <TSP>* <Byte> [<CSP> <Byte>]* "}"
>+<NonEmptyArray>         ::= "{" <TSP>* [<Lable>] <ArrayVal>
>+                             [<CSP> [<Lable>] <ArrayVal>]* "}"
>+<ArrayVal>              ::= {<Num8Array>} {<GuidStr>} {<DevicePath>}
>+<DevicePath>            ::= "DEVICE_PATH(" <DevicePathStr> ")"
>+<DevicePathStr>         ::= A double quoted string that follow the device path
>+                            as string format defined in UEFI Specification 2.6
>+                            Section 9.6
>+<Lable>                 ::= "LABEL(" <CName> ")"
>+<Offset>                ::= "OFFSET_OF(" <CName> ")"
> <StringLiteral>         ::= {<QuotedString>} {"L" <QuotedString>}
>+                            {<SglQuotedString>} {"L" <SglQuotedString>}
> <DblQuote>              ::= 0x22
>+<SglQuote>              ::= 0x27
> <QuotedString>          ::= <DblQuote> [<CCHAR>]* <DblQuote>
>+<SglQuotedString>       ::= <SglQuote> [<CCHAR>]* <SglQuote>
> <CCHAR>                 ::= {<SingleChars>} {<EscapeCharSeq>}
>-<SingleChars>           ::= {0x20} {0x21} {(0x23 - 0x5B)} {(0x5D - 0x7E)}
>-<EscapeCharSeq>         ::= "\" {"n"} {"r"} {"t"} {"f"} {"b"} {"0"} {"\"}
>{<DblQuote>}
>+<SingleChars>           ::= {0x21} {(0x23 - 0x26)} {(0x28 - 0x5B)}
>+                            {(0x5D - 0x7E)} {<EscapeSequence>}
>+<EscapeCharSeq>         ::= "\" {"n"} {"r"} {"t"} {"f"} {"b"} {"0"} {"\"}
>+                            {<DblQuote>} {<SglQuote>}
>+<NonNumType>            ::= {<TrueFalse>} {<StringLiteral>} {<Offset>}
>{<UintMac>}
>+<Num8Array>             ::= {<NonNumType>} {<ShortNum>} {<UINT8>}
>+<Num16Array>            ::= {<NonNumType>} {<IntNum>} {<UINT16>}
>+<Num32Array>            ::= {<NonNumType>} {<LongNum>} {<UINT32>}
>+<Num64Array>            ::= {<NonNumType>} {<LongLongNum>} {<UINT64>}
>+<UintMac>               ::= {<Uint8Mac>} {<Uint16Mac>} {<Uint32Mac>}
>{<Uint64Mac>}
>+<Uint8Mac>              ::= "UINT8(" <Num8Array> ")"
>+<Uint16Mac>             ::= "UINT16(" <Num16Array> ")"
>+<Uint32Mac>             ::= "UINT32(" <Num32Array> ")"
>+<Uint64Mac>             ::= "UINT64(" <Num64Array> ")"
> <PostFixExpression>     ::= {<PrimaryExpression>} {<PcdName>}
> <PcdName>               ::= <CName> "." <CName>
> <UnaryExpression>       ::= {<PostFixExpression>} {<UnaryOp>
><UnaryExpression>}
> <UnaryOp>               ::= {<IntegerOps>} {<ScalarOps>}
> <IntegerOps>            ::= {"+"} {"-"} {"~"}
>@@ -187,13 +221,19 @@
>gUefiCpuPkgTokenSpaceGuid.PcdCpuLocalApicBaseAddress
>| !gCrownBayTokenSpaceGuid.
>
> This is the value of the MACRO assigned in a DEFINE statement.
>
> **Expressions**
>
>-If the "|" character is used in an expression, the expression must be
>+If the "|" or "||"character is used in an expression, the expression must be
> encapsulated by parenthesis.
>
>+**OFFSET_OF()**
>+
>+LABEL() macro in byte arrays to tag the byte offset of a location in a byte
>+array. OFFSET_OF() macro in byte arrays that returns the byte offset of a
>+LABEL() declared in a byte array.
>+
> ## 3.2 Conditional Directive Expressions
>
> Conditional directive statements are defined in the EDK II Platform
>Description
> (DSC) File and Flash Definition (FDF) File. The following EBNF describes the
> format for expressions used in conditional directives. The format is based on
>--
>2.6.1.windows.1