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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S F N _ S C A N --
-- --
-- B o d y --
-- --
-- Copyright (C) 2000-2022, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 3, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
-- Public License distributed with GNAT; see file COPYING3. If not, go to --
-- http://www.gnu.org/licenses for a complete copy of the license. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
with Ada.Exceptions; use Ada.Exceptions;
package body SFN_Scan is
use ASCII;
-- Allow easy access to control character definitions
EOF : constant Character := ASCII.SUB;
-- The character SUB (16#1A#) is used in DOS-derived systems, such as
-- Windows to signal the end of a text file. If this character appears as
-- the last character of a file scanned by a call to Scan_SFN_Pragmas, then
-- it is ignored, otherwise it is treated as an illegal character.
type String_Ptr is access String;
S : String_Ptr;
-- Points to the gnat.adc input file
P : Natural;
-- Subscript of next character to process in S
Line_Num : Natural;
-- Current line number
Start_Of_Line : Natural;
-- Subscript of first character at start of current line
----------------------
-- Local Procedures --
----------------------
function Acquire_Integer return Natural;
-- This function skips white space, and then scans and returns
-- an unsigned integer. Raises Error if no integer is present
-- or if the integer is greater than 999.
function Acquire_String (B : Natural; E : Natural) return String;
-- This function takes a string scanned out by Scan_String, strips
-- the enclosing quote characters and any internal doubled quote
-- characters, and returns the result as a String. The arguments
-- B and E are as returned from a call to Scan_String. The lower
-- bound of the string returned is always 1.
function Acquire_Unit_Name return String;
-- Skips white space, and then scans and returns a unit name. The
-- unit name is cased exactly as it appears in the source file.
-- The terminating character must be white space, or a comma or
-- a right parenthesis or end of file.
function At_EOF return Boolean;
pragma Inline (At_EOF);
-- Returns True if at end of file, False if not. Note that this
-- function does NOT skip white space, so P is always unchanged.
procedure Check_Not_At_EOF;
pragma Inline (Check_Not_At_EOF);
-- Skips past white space if any, and then raises Error if at
-- end of file. Otherwise returns with P skipped past whitespace.
function Check_File_Type return Character;
-- Skips white space if any, and then looks for any of the tokens
-- Spec_File_Name, Body_File_Name, or Subunit_File_Name. If one
-- of these is found then the value returned is 's', 'b' or 'u'
-- respectively, and P is bumped past the token. If none of
-- these tokens is found, then P is unchanged (except for
-- possible skip of white space), and a space is returned.
function Check_Token (T : String) return Boolean;
-- Skips white space if any, and then checks if the string at the
-- current location matches the given string T, and the character
-- immediately following is non-alphabetic, non-numeric. If so,
-- P is stepped past the token, and True is returned. If not,
-- P is unchanged (except for possibly skipping past whitespace),
-- and False is returned. T may contain only lower-case letters
-- ('a' .. 'z').
procedure Error (Err : String);
pragma No_Return (Error);
-- Called if an error is detected. Raises Syntax_Error_In_GNAT_ADC
-- with a message of the form gnat.adc:line:col: xxx, where xxx is
-- the string Err passed as a parameter.
procedure Require_Token (T : String);
-- Skips white space if any, and then requires the given string
-- to be present. If it is, the P is stepped past it, otherwise
-- Error is raised, since this is a syntax error. Require_Token
-- is used only for sequences of special characters, so there
-- is no issue of terminators, or casing of letters.
procedure Scan_String (B : out Natural; E : out Natural);
-- Skips white space if any, then requires that a double quote
-- or percent be present (start of string). Raises error if
-- neither of these two characters is found. Otherwise scans
-- out the string, and returns with P pointing past the
-- closing quote and S (B .. E) contains the characters of the
-- string (including the enclosing quotes, with internal quotes
-- still doubled). Raises Error if the string is malformed.
procedure Skip_WS;
-- Skips P past any white space characters (end of line
-- characters, spaces, comments, horizontal tab characters).
---------------------
-- Acquire_Integer --
---------------------
function Acquire_Integer return Natural is
N : Natural := 0;
begin
Skip_WS;
if S (P) not in '0' .. '9' then
Error ("missing index parameter");
end if;
while S (P) in '0' .. '9' loop
N := N * 10 + Character'Pos (S (P)) - Character'Pos ('0');
if N > 999 then
Error ("index value greater than 999");
end if;
P := P + 1;
end loop;
return N;
end Acquire_Integer;
--------------------
-- Acquire_String --
--------------------
function Acquire_String (B : Natural; E : Natural) return String is
Str : String (1 .. E - B - 1);
Q : constant Character := S (B);
J : Natural;
Ptr : Natural;
begin
Ptr := B + 1;
J := 0;
while Ptr < E loop
J := J + 1;
Str (J) := S (Ptr);
if S (Ptr) = Q and then S (Ptr + 1) = Q then
Ptr := Ptr + 2;
else
Ptr := Ptr + 1;
end if;
end loop;
return Str (1 .. J);
end Acquire_String;
-----------------------
-- Acquire_Unit_Name --
-----------------------
function Acquire_Unit_Name return String is
B : Natural;
begin
Check_Not_At_EOF;
B := P;
while not At_EOF loop
exit when S (P) not in '0' .. '9'
and then S (P) /= '.'
and then S (P) /= '_'
and then not (S (P) = '[' and then S (P + 1) = '"')
and then not (S (P) = '"' and then S (P - 1) = '[')
and then not (S (P) = '"' and then S (P + 1) = ']')
and then not (S (P) = ']' and then S (P - 1) = '"')
and then S (P) < 'A';
P := P + 1;
end loop;
if P = B then
Error ("null unit name");
end if;
return S (B .. P - 1);
end Acquire_Unit_Name;
------------
-- At_EOF --
------------
function At_EOF return Boolean is
begin
-- Immediate return (False) if before last character of file
if P < S'Last then
return False;
-- Special case: DOS EOF character as last character of file is
-- allowed and treated as an end of file.
elsif P = S'Last then
return S (P) = EOF;
-- If beyond last character of file, then definitely at EOF
else
return True;
end if;
end At_EOF;
---------------------
-- Check_File_Type --
---------------------
function Check_File_Type return Character is
begin
if Check_Token ("spec_file_name") then
return 's';
elsif Check_Token ("body_file_name") then
return 'b';
elsif Check_Token ("subunit_file_name") then
return 'u';
else
return ' ';
end if;
end Check_File_Type;
----------------------
-- Check_Not_At_EOF --
----------------------
procedure Check_Not_At_EOF is
begin
Skip_WS;
if At_EOF then
Error ("unexpected end of file");
end if;
return;
end Check_Not_At_EOF;
-----------------
-- Check_Token --
-----------------
function Check_Token (T : String) return Boolean is
Save_P : Natural;
C : Character;
begin
Skip_WS;
Save_P := P;
for K in T'Range loop
if At_EOF then
P := Save_P;
return False;
end if;
C := S (P);
if C in 'A' .. 'Z' then
C := Character'Val (Character'Pos (C) +
(Character'Pos ('a') - Character'Pos ('A')));
end if;
if C /= T (K) then
P := Save_P;
return False;
end if;
P := P + 1;
end loop;
if At_EOF then
return True;
end if;
C := S (P);
if C in '0' .. '9'
or else C in 'a' .. 'z'
or else C in 'A' .. 'Z'
or else C > Character'Val (127)
then
P := Save_P;
return False;
else
return True;
end if;
end Check_Token;
-----------
-- Error --
-----------
procedure Error (Err : String) is
C : Natural := 0;
-- Column number
M : String (1 .. 80);
-- Buffer used to build resulting error msg
LM : Natural := 0;
-- Pointer to last set location in M
procedure Add_Nat (N : Natural);
-- Add chars of integer to error msg buffer
-------------
-- Add_Nat --
-------------
procedure Add_Nat (N : Natural) is
begin
if N > 9 then
Add_Nat (N / 10);
end if;
LM := LM + 1;
M (LM) := Character'Val (N mod 10 + Character'Pos ('0'));
end Add_Nat;
-- Start of processing for Error
begin
M (1 .. 9) := "gnat.adc:";
LM := 9;
Add_Nat (Line_Num);
LM := LM + 1;
M (LM) := ':';
-- Determine column number
for X in Start_Of_Line .. P loop
C := C + 1;
if S (X) = HT then
C := (C + 7) / 8 * 8;
end if;
end loop;
Add_Nat (C);
M (LM + 1) := ':';
LM := LM + 1;
M (LM + 1) := ' ';
LM := LM + 1;
M (LM + 1 .. LM + Err'Length) := Err;
LM := LM + Err'Length;
Raise_Exception (Syntax_Error_In_GNAT_ADC'Identity, M (1 .. LM));
end Error;
-------------------
-- Require_Token --
-------------------
procedure Require_Token (T : String) is
SaveP : Natural;
begin
Skip_WS;
SaveP := P;
for J in T'Range loop
if At_EOF or else S (P) /= T (J) then
declare
S : String (1 .. T'Length + 10);
begin
S (1 .. 9) := "missing """;
S (10 .. T'Length + 9) := T;
S (T'Length + 10) := '"';
P := SaveP;
Error (S);
end;
else
P := P + 1;
end if;
end loop;
end Require_Token;
----------------------
-- Scan_SFN_Pragmas --
----------------------
procedure Scan_SFN_Pragmas
(Source : String;
SFN_Ptr : Set_File_Name_Ptr;
SFNP_Ptr : Set_File_Name_Pattern_Ptr)
is
B, E : Natural;
Typ : Character;
Cas : Character;
begin
Line_Num := 1;
S := Source'Unrestricted_Access;
P := Source'First;
Start_Of_Line := P;
-- Loop through pragmas in file
Main_Scan_Loop : loop
Skip_WS;
exit Main_Scan_Loop when At_EOF;
-- Error if something other than pragma
if not Check_Token ("pragma") then
Error ("non pragma encountered");
end if;
-- Source_File_Name pragma case
if Check_Token ("source_file_name")
or else
Check_Token ("source_file_name_project")
then
Require_Token ("(");
Typ := Check_File_Type;
-- First format, with unit name first
if Typ = ' ' then
if Check_Token ("unit_name") then
Require_Token ("=>");
end if;
declare
U : constant String := Acquire_Unit_Name;
begin
Require_Token (",");
Typ := Check_File_Type;
if Typ /= 's' and then Typ /= 'b' then
Error ("bad pragma");
end if;
Require_Token ("=>");
Scan_String (B, E);
declare
F : constant String := Acquire_String (B, E);
X : Natural;
begin
-- Scan Index parameter if present
if Check_Token (",") then
if Check_Token ("index") then
Require_Token ("=>");
end if;
X := Acquire_Integer;
else
X := 0;
end if;
Require_Token (")");
Require_Token (";");
SFN_Ptr.all (Typ, U, F, X);
end;
end;
-- Second format with pattern string
else
Require_Token ("=>");
Scan_String (B, E);
declare
Pat : constant String := Acquire_String (B, E);
Nas : Natural := 0;
begin
-- Check exactly one asterisk
for J in Pat'Range loop
if Pat (J) = '*' then
Nas := Nas + 1;
end if;
end loop;
if Nas /= 1 then
Error ("** not allowed");
end if;
B := 0;
E := 0;
Cas := ' ';
-- Loop to scan out Casing or Dot_Replacement parameters
loop
Check_Not_At_EOF;
exit when S (P) = ')';
Require_Token (",");
if Check_Token ("casing") then
Require_Token ("=>");
if Cas /= ' ' then
Error ("duplicate casing argument");
elsif Check_Token ("lowercase") then
Cas := 'l';
elsif Check_Token ("uppercase") then
Cas := 'u';
elsif Check_Token ("mixedcase") then
Cas := 'm';
else
Error ("invalid casing argument");
end if;
elsif Check_Token ("dot_replacement") then
Require_Token ("=>");
if E /= 0 then
Error ("duplicate dot_replacement");
else
Scan_String (B, E);
end if;
else
Error ("invalid argument");
end if;
end loop;
Require_Token (")");
Require_Token (";");
if Cas = ' ' then
Cas := 'l';
end if;
if E = 0 then
SFNP_Ptr.all (Pat, Typ, ".", Cas);
else
declare
Dot : constant String := Acquire_String (B, E);
begin
SFNP_Ptr.all (Pat, Typ, Dot, Cas);
end;
end if;
end;
end if;
-- Some other pragma, scan to semicolon at end of pragma
else
Skip_Loop : loop
Skip_WS;
exit Main_Scan_Loop when At_EOF;
exit Skip_Loop when S (P) = ';';
if S (P) = '"' or else S (P) = '%' then
Scan_String (B, E);
else
P := P + 1;
end if;
end loop Skip_Loop;
-- We successfully skipped to semicolon, so skip past it
P := P + 1;
end if;
end loop Main_Scan_Loop;
exception
when others =>
pragma Assert (P'Valid);
Cursor := P - S'First + 1;
raise;
end Scan_SFN_Pragmas;
-----------------
-- Scan_String --
-----------------
procedure Scan_String (B : out Natural; E : out Natural) is
Q : Character;
begin
Check_Not_At_EOF;
if S (P) = '"' then
Q := '"';
elsif S (P) = '%' then
Q := '%';
else
Error ("bad string");
end if;
-- Scan out the string, B points to first char
B := P;
P := P + 1;
loop
if At_EOF or else S (P) = LF or else S (P) = CR then
Error -- CODEFIX
("missing string quote");
elsif S (P) = HT then
Error ("tab character in string");
elsif S (P) /= Q then
P := P + 1;
-- We have a quote
else
P := P + 1;
-- Check for doubled quote
if not At_EOF and then S (P) = Q then
P := P + 1;
-- Otherwise this is the terminating quote
else
E := P - 1;
return;
end if;
end if;
end loop;
end Scan_String;
-------------
-- Skip_WS --
-------------
procedure Skip_WS is
begin
WS_Scan : while not At_EOF loop
case S (P) is
-- End of physical line
when CR | LF =>
Line_Num := Line_Num + 1;
P := P + 1;
while not At_EOF
and then (S (P) = CR or else S (P) = LF)
loop
Line_Num := Line_Num + 1;
P := P + 1;
end loop;
Start_Of_Line := P;
-- All other cases of white space characters
when ' ' | FF | VT | HT =>
P := P + 1;
-- Comment
when '-' =>
P := P + 1;
if At_EOF then
Error ("bad comment");
elsif S (P) = '-' then
P := P + 1;
while not At_EOF loop
case S (P) is
when CR | LF | FF | VT =>
exit;
when others =>
P := P + 1;
end case;
end loop;
else
P := P - 1;
exit WS_Scan;
end if;
when others =>
exit WS_Scan;
end case;
end loop WS_Scan;
end Skip_WS;
end SFN_Scan;