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Arithmetic expression parsing #120

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Arithmetic expression parsing #120

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4eeb815
Arithmetic expressions i.e. $((exp)) in CST
ishaangandhi Sep 25, 2020
63b18eb
removed comment
ishaangandhi Sep 25, 2020
f174142
Fix subshell separation bug
ishaangandhi Oct 21, 2020
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1 change: 1 addition & 0 deletions src/CST.ml
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Expand Up @@ -322,6 +322,7 @@ and word_cst = word_component list
and word_component =
| WordSubshell of subshell_kind * program located
| WordName of string
| WordArith of word
| WordAssignmentWord of assignment_word
| WordDoubleQuoted of word
| WordSingleQuoted of word
Expand Down
17 changes: 12 additions & 5 deletions src/prelexer.mll
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Expand Up @@ -381,7 +381,7 @@ rule token current = parse
If the current character is an unquoted '$' or '`', the shell shall
identify the start of any candidates for parameter expansion
(Parameter Expansion), command substitution (Command Substitution),
or ] arithmetic expansion (Arithmetic Expansion) from their
or arithmetic expansion (Arithmetic Expansion) from their
introductory unquoted character sequences: '$' or "${", "$(" or
'`', and "$((", respectively. The shell shall read sufficient input
to determine the end of the unit to be expanded (as explained in
Expand Down Expand Up @@ -432,10 +432,11 @@ rule token current = parse
}

| "$((" {
let current = push_string current "$((" in
debug ~rule:"arithmetic-exp" lexbuf current;
let current = push_arith current in
let current = next_double_rparen 1 current lexbuf in
token current lexbuf
}
}

(*specification:

Expand Down Expand Up @@ -715,16 +716,22 @@ and next_double_rparen dplevel current = parse
let current = push_string current "((" in
next_double_rparen (dplevel+1) current lexbuf
}
| "$((" {
debug ~rule:"arithmetic-exp" lexbuf current;
let current = push_arith current in
let current = next_double_rparen (dplevel+1) current lexbuf in
current
}
| '`' as op | "$" ( '(' as op) {
let escaping_level = 0 in (* FIXME: Probably wrong. *)
let current = push_string current (Lexing.lexeme lexbuf) in
let current = push_separated_string current (Lexing.lexeme lexbuf) in
let current = subshell op escaping_level current lexbuf in
let expected_closing_char = if op = '`' then '`' else ')' in
let current = close_subshell expected_closing_char current lexbuf in
next_double_rparen dplevel current lexbuf
}
| "))" {
let current = push_string current "))" in
let current = pop_arith current in
if dplevel = 1
then current
else if dplevel > 1 then next_double_rparen (dplevel-1) current lexbuf
Expand Down
31 changes: 30 additions & 1 deletion src/prelexerState.ml
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Expand Up @@ -24,6 +24,7 @@ type atom =
| WordComponent of (string * word_component)
| QuotingMark of quote_kind
| AssignmentMark
| ArithMark

and quote_kind = SingleQuote | DoubleQuote | OpeningBrace

Expand Down Expand Up @@ -216,6 +217,7 @@ let string_of_atom = function
| WordComponent (s, _) -> s
| AssignmentMark -> "|=|"
| QuotingMark _ -> "|Q|"
| ArithMark -> "|A|"

let contents_of_atom_list atoms =
String.concat "" (List.rev_map string_of_atom atoms)
Expand All @@ -238,6 +240,32 @@ let components_of_atom_list atoms =
let components b =
components_of_atom_list (buffer b)

let push_arith b =
let cst = ArithMark in
let buffer = AtomBuffer.make (cst :: buffer b) in
{ b with buffer }

let pop_arith b =
let rec aux str_expression expression = function
| [] ->
(str_expression, expression, [])
| ArithMark :: buffer -> (str_expression, expression, buffer)
| (AssignmentMark | QuotingMark _ ) :: buffer ->
aux str_expression expression buffer (* FIXME: Check twice. *)
| WordComponent (w, WordEmpty) :: buffer ->
aux (w ^ str_expression) expression buffer
| WordComponent (w, c) :: buffer ->
aux (w ^ str_expression) (c :: expression) buffer
in
let str_expression, expression, buffer = aux "" [] (buffer b) in
let word = Word (str_expression, expression) in
let expression = WordArith word in
let str_expression = "$((" ^ str_expression ^ "))"
in
let expression = WordComponent (str_expression, expression) in
let buffer = AtomBuffer.make (expression :: buffer) in
{ b with buffer }

let push_quoting_mark k b =
let cst = QuotingMark k in
let buffer = AtomBuffer.make (cst :: buffer b) in
Expand All @@ -249,7 +277,7 @@ let pop_quotation k b =
(squote, quote, [])
| QuotingMark k' :: buffer when k = k' ->
(squote, quote, buffer)
| (AssignmentMark | QuotingMark _) :: buffer ->
| (AssignmentMark | QuotingMark _ | ArithMark) :: buffer ->
aux squote quote buffer (* FIXME: Check twice. *)
| WordComponent (w, WordEmpty) :: buffer ->
aux (w ^ squote) quote buffer
Expand Down Expand Up @@ -404,6 +432,7 @@ let return ?(with_newline=false) lexbuf (current : prelexer_state) tokens =
| WordComponent (_, s) -> [s]
| AssignmentMark -> []
| QuotingMark _ -> []
| ArithMark -> []
) (buffer current)))
in
let csts = TildePrefix.recognize csts in
Expand Down
9 changes: 8 additions & 1 deletion tests/good/2.2-quoting/quoting-equal-sign.sh.expected
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Expand Up @@ -268,7 +268,14 @@
[
"Word",
"a$((=))b",
[ [ "WordLiteral", "a$((=))b" ] ]
[
[ "WordLiteral", "a" ],
[
"WordArith",
[ "Word", "=", [ [ "WordLiteral", "=" ] ] ]
],
[ "WordLiteral", "b" ]
]
]
]
]
Expand Down
3 changes: 3 additions & 0 deletions tests/good/2.3-token-recognition/arith_exp.sh
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@@ -0,0 +1,3 @@
echo $((1 * $((2*3)) * 42))

echo $((x+=`echo 2`))
166 changes: 166 additions & 0 deletions tests/good/2.3-token-recognition/arith_exp.sh.expected
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@@ -0,0 +1,166 @@
[
"Program_LineBreak_CompleteCommands_LineBreak",
[ "LineBreak_Empty" ],
[
"CompleteCommands_CompleteCommands_NewlineList_CompleteCommand",
[
"CompleteCommands_CompleteCommand",
[
"CompleteCommand_CList",
[
"CList_AndOr",
[
"AndOr_Pipeline",
[
"Pipeline_PipeSequence",
[
"PipeSequence_Command",
[
"Command_SimpleCommand",
[
"SimpleCommand_CmdName_CmdSuffix",
[
"CmdName_Word",
[ "Word", "echo", [ [ "WordName", "echo" ] ] ]
],
[
"CmdSuffix_Word",
[
"Word",
"$((1 * $((2*3)) * 42))",
[
[
"WordArith",
[
"Word",
"1 * $((2*3)) * 42",
[
[ "WordLiteral", "1 * " ],
[
"WordArith",
[
"Word",
"2*3",
[ [ "WordLiteral", "2*3" ] ]
]
],
[ "WordLiteral", " * 42" ]
]
]
]
]
]
]
]
]
]
]
]
]
]
],
[ "NewLineList_NewLine" ],
[
"CompleteCommand_CList",
[
"CList_AndOr",
[
"AndOr_Pipeline",
[
"Pipeline_PipeSequence",
[
"PipeSequence_Command",
[
"Command_SimpleCommand",
[
"SimpleCommand_CmdName_CmdSuffix",
[
"CmdName_Word",
[ "Word", "echo", [ [ "WordName", "echo" ] ] ]
],
[
"CmdSuffix_Word",
[
"Word",
"$((x+=`echo 2`))",
[
[
"WordArith",
[
"Word",
"x+=`echo 2`",
[
[ "WordLiteral", "x+=" ],
[
"WordSubshell",
[ "SubShellKindBackQuote" ],
[
"Program_LineBreak_CompleteCommands_LineBreak",
[ "LineBreak_Empty" ],
[
"CompleteCommands_CompleteCommand",
[
"CompleteCommand_CList",
[
"CList_AndOr",
[
"AndOr_Pipeline",
[
"Pipeline_PipeSequence",
[
"PipeSequence_Command",
[
"Command_SimpleCommand",
[
"SimpleCommand_CmdName_CmdSuffix",
[
"CmdName_Word",
[
"Word",
"echo",
[
[
"WordName", "echo"
]
]
]
],
[
"CmdSuffix_Word",
[
"Word",
"2",
[
[
"WordLiteral", "2"
]
]
]
]
]
]
]
]
]
]
]
],
[ "LineBreak_Empty" ]
]
]
]
]
]
]
]
]
]
]
]
]
]
]
]
],
[ "LineBreak_Empty" ]
]
11 changes: 10 additions & 1 deletion ...tion/2.7.5_duplicating-an-input-file-descriptor/redirection_input_duplication.sh.expected
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Expand Up @@ -484,7 +484,16 @@
[
"Word",
"$((3 + 1))",
[ [ "WordLiteral", "$((3 + 1))" ] ]
[
[
"WordArith",
[
"Word",
"3 + 1",
[ [ "WordLiteral", "3 + 1" ] ]
]
]
]
]
]
]
Expand Down
11 changes: 10 additions & 1 deletion ...on/2.7.6_duplicating-an-output-file-descriptor/redirection_output_duplication.sh.expected
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Expand Up @@ -484,7 +484,16 @@
[
"Word",
"$((3 + 1))",
[ [ "WordLiteral", "$((3 + 1))" ] ]
[
[
"WordArith",
[
"Word",
"3 + 1",
[ [ "WordLiteral", "3 + 1" ] ]
]
]
]
]
]
]
Expand Down