vhdl: handle CR+LF for readline in grt. Fix #1145

Previously CR+LF was handled in std.textio.readline.  But that
doesn't work if CR is at position 128 because we would need to read the
next character.  Now untruncated_text_read handles CR/CR+LF/LF and
calls ungetc if needed.

3 files changed, 65 insertions, 23 deletions

diff --git a/libraries/std/textio-body.vhdl b/libraries/std/textio-body.vhdl
index 235da706a..8ea3dc789 100644
--- a/libraries/std/textio-body.vhdl
+++ b/libraries/std/textio-body.vhdl
@@ -428,16 +428,14 @@ package body textio is
     loop
       untruncated_text_read (f, str, len);
       exit when len = 0;
-      if str (len) = LF or str (len) = CR then
+      if str (len) = LF then
         --  LRM 14.3
         --  The representation of the line does not contain the representation
         --  of the end of the line.
         is_eol := true;
         len := len - 1;
-        --  End of line is any of LF/CR/CR+LF/LF+CR.
-        if len > 0 and (str (len) = LF or str (len) = CR) then
-          len := len - 1;
-        end if;
+        --  End of line is any of LF/CR/CR+LF.  This is now handled
+        --  by untruncated_text_read because we need to do a look-ahead.
       elsif endfile (f) then
         is_eol := true;
       else
diff --git a/src/grt/grt-files.adb b/src/grt/grt-files.adb
index 826e9b05f..5d214052e 100644
--- a/src/grt/grt-files.adb
+++ b/src/grt/grt-files.adb
@@ -34,6 +34,10 @@ pragma Elaborate_All (Grt.Table);
 package body Grt.Files is
    subtype C_Files is Grt.Stdio.FILEs;
 
+   --  The end of lines
+   C_LF : constant int := 10;   --  \n
+   C_CR : constant int := 13;   --  \r
+
    Auto_Flush : constant Boolean := False;
 
    type File_Entry_Type is record
@@ -470,22 +474,37 @@ package body Grt.Files is
    is
       Stream : C_Files;
       Max_Len : int;
+      C : int;
+      L : Ghdl_Index_Type;
    begin
       Stream := Get_File (File);
       Check_Read (File, True);
 
       Max_Len := int (Str.Bounds.Dim_1.Length);
-      if fgets (Str.Base (0)'Address, Max_Len, Stream) = Null_Address then
-         Internal_Error ("ghdl_untruncated_text_read: end of file");
-      end if;
 
-      --  Compute the length.
-      for I in Ghdl_Index_Type loop
-         if Str.Base (I) = NUL then
-            Len.all := Std_Integer (I);
-            exit;
+      --  Read at most LEN characters, stop at EOL.
+      L := 0;
+      for I in 1 .. Max_Len loop
+         C := fgetc (Stream);
+         exit when C < 0;
+         --  Be nice with DOS files: handle CR/CR+LF/LF.
+         --  Note: LF+CR is not handled, so that on unix we don't need
+         --  to read the next line.
+         --  Always return LF as end of line.
+         if C = C_CR then
+            C := fgetc (Stream);
+            if C > 0 and C /= C_LF then
+               C := ungetc (C, Stream);
+               pragma Assert (C >= 0);
+            end if;
+            C := C_LF;
          end if;
+         Str.Base (L) := Character'Val (C);
+         L := L + 1;
+         exit when C = C_LF;
       end loop;
+
+      Len.all := Std_Integer (L);
    end Ghdl_Untruncated_Text_Read;
 
    procedure File_Close (File : Ghdl_File_Index; Is_Text : Boolean)
diff --git a/src/grt/grt-files_operations.adb b/src/grt/grt-files_operations.adb
index c7770b5f3..b1f504dc9 100644
--- a/src/grt/grt-files_operations.adb
+++ b/src/grt/grt-files_operations.adb
@@ -31,6 +31,10 @@ pragma Elaborate_All (Grt.Table);
 package body Grt.Files_Operations is
    subtype C_Files is Grt.Stdio.FILEs;
 
+   --  The end of lines
+   C_LF : constant int := 10;   --  \n
+   C_CR : constant int := 13;   --  \r
+
    Auto_Flush : constant Boolean := False;
 
    type File_Entry_Type is record
@@ -518,7 +522,7 @@ package body Grt.Files_Operations is
             Str.Base (I) := Character'Val (C);
          end if;
          --  End of line is '\n' or LF or character # 10.
-         if C = 10 then
+         if C = C_LF then
             Length := Std_Integer (I + 1);
             Status := Op_Ok;
             return;
@@ -534,7 +538,8 @@ package body Grt.Files_Operations is
                                          Status : out Op_Status)
    is
       Stream : C_Files;
-      Max_Len : int;
+      L : Natural;
+      C : int;
    begin
       Get_File (File, Stream, Status);
       if Status /= Op_Ok then
@@ -545,15 +550,35 @@ package body Grt.Files_Operations is
          return;
       end if;
 
-      Max_Len := int (Len);
-      if fgets (To_Address (Buf), Max_Len, Stream) = Null_Address then
-         Status := Op_End_Of_File;
-         return;
-      end if;
-
-      --  Compute the length.
-      Len := Std_Integer (strlen (Buf));
+      --  Default status.
       Status := Op_Ok;
+
+      --  Read at most LEN characters, stop at EOL.
+      L := 0;
+      for I in 1 .. Len loop
+         C := fgetc (Stream);
+         if C < 0 then
+            Status := Op_End_Of_File;
+            exit;
+         end if;
+         --  Be nice with DOS files: handle CR/CR+LF/LF.
+         --  Note: LF+CR is not handled, so that on unix we don't need
+         --  to read the next line.
+         --  Always return LF as end of line.
+         if C = C_CR then
+            C := fgetc (Stream);
+            if C > 0 and C /= C_LF then
+               C := ungetc (C, Stream);
+               pragma Assert (C >= 0);
+            end if;
+            C := C_LF;
+         end if;
+         L := L + 1;
+         Buf (L) := Character'Val (C);
+         exit when C = C_LF;
+      end loop;
+
+      Len := Std_Integer (L);
    end Ghdl_Untruncated_Text_Read;
 
    procedure File_Close