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as: parse: simplify <expr_list> and <expr> parsning

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This commit is contained in:
Mikael Pettersson
2020-01-06 21:58:25 +01:00
parent 726098c315
commit 5d346bd28a
1 changed files with 22 additions and 34 deletions
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56
erlang/apps/as/src/parse.erl
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@@ -296,7 +296,7 @@ dot_ascii(ScanState, Location, Lexeme, Z) ->
end.
dot_byte(ScanState, Location) ->
integer_data_directive(ScanState, Location, ".byte",
integer_data_directive(ScanState, Location,
fun(Exprs) -> #s_dot_byte{exprs = Exprs} end).
dot_data(ScanState, Location) ->
@@ -341,22 +341,15 @@ dot_globl(ScanState, Location) ->
end.
dot_hword(ScanState, Location) ->
dot_short(ScanState, Location, ".hword").
dot_short(ScanState, Location).
dot_long(ScanState, Location) ->
dot_long(ScanState, Location, ".long").
dot_long(ScanState, Location, Lexeme) ->
integer_data_directive(ScanState, Location, Lexeme,
integer_data_directive(ScanState, Location,
fun(Exprs) -> #s_dot_long{exprs = Exprs} end).
integer_data_directive(ScanState, Location, Lexeme, MkStmt) ->
integer_data_directive(ScanState, Location, MkStmt) ->
case expr_list(ScanState) of
{ok, {Exprs, Follow}} ->
case Follow of
{_Location, ?T_NEWLINE} -> {ok, {Location, MkStmt(Exprs)}};
_ -> badtok("junk after " ++ Lexeme ++ " <exprs>", {ok, Follow})
end;
{ok, Exprs} -> {ok, {Location, MkStmt(Exprs)}};
{error, _Reason} = Error -> Error
end.
@@ -373,10 +366,7 @@ dot_previous(ScanState, Location) ->
end.
dot_short(ScanState, Location) ->
dot_short(ScanState, Location, ".short").
dot_short(ScanState, Location, Lexeme) ->
integer_data_directive(ScanState, Location, Lexeme,
integer_data_directive(ScanState, Location,
fun(Exprs) -> #s_dot_short{exprs = Exprs} end).
%% For now only accepts ".size <sym>,.-<sym>". TODO: extend
@@ -451,7 +441,7 @@ dot_type(ScanState, Location) ->
end.
dot_word(ScanState, Location) ->
dot_long(ScanState, Location, ".word").
dot_long(ScanState, Location).
%% .section/.pushsection directives --------------------------------------------
%%
@@ -629,12 +619,15 @@ section_name(ScanState) ->
%% Expressions -----------------------------------------------------------------
%% <expr_list> ::= (<expr> ("," <expr>)*)?
%% <expr_list> ::= (<expr> ("," <expr>)*)? \n
expr_list(ScanState) ->
case expr_opt(ScanState) of
{false, Follow} -> {ok, {[], Follow}};
{ok, Expr} -> expr_list(ScanState, [Expr]);
{error, _Reason} = Error -> Error
case scan:token(ScanState) of
{ok, {_Location, ?T_NEWLINE}} -> {ok, []};
First ->
case do_expr(First) of
{ok, Expr} -> expr_list(ScanState, [Expr]);
{error, _Reason} = Error -> Error
end
end.
expr_list(ScanState, Exprs) ->
@@ -644,28 +637,23 @@ expr_list(ScanState, Exprs) ->
{ok, Expr} -> expr_list(ScanState, [Expr | Exprs]);
{error, _Reason} = Error -> Error
end;
{ok, Follow} -> {ok, {lists:reverse(Exprs), Follow}};
{error, _Reason} = Error -> Error
{ok, {_Location, ?T_NEWLINE}} -> {ok, lists:reverse(Exprs)};
ScanRes -> badtok("expected comma or newline", ScanRes)
end.
expr(ScanState) ->
case expr_opt(ScanState) of
{false, First} -> badtok("invalid start of expr", {ok, First});
OkOrError -> OkOrError
end.
do_expr(scan:token(ScanState)).
expr_opt(ScanState) ->
case scan:token(ScanState) of
do_expr(First) ->
case First of
{ok, {_Location, {?T_UINTEGER, UInt}}} ->
{ok, #e_integer{value = UInt}};
{ok, {_Location, {?T_LOCAL_LABEL, Number, Direction}}} ->
{ok, #e_local_label{number = Number, direction = Direction}};
{ok, {_Location, {?T_SYMBOL, Symbol}}} ->
{ok, #e_symbol{name = Symbol}};
{ok, First} ->
{false, First};
{error, _Reason} = Error ->
Error
_ ->
badtok("invalid start of expr", First)
end.
%% String Lists ----------------------------------------------------------------