Implement textio read procedure for time

nickg · Apr 17, 2021 · 71e18ae · 71e18ae
1 parent a9d5d6d
commit 71e18ae
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Showing 3 changed files with 58 additions and 3 deletions.
diff --git a/HISTORY.md b/HISTORY.md
@@ -1,6 +1,6 @@
 ## 1.5.2 - unreleased
 - Link libexecinfo on FreeBSD.
-- Add missing textio read subprogram for bit (#408).
+- Implement textio READ procedure for BIT and TIME (#408).
 
 ## 1.5.1 - 2021-09-04
 - Fix a compiler warning in vcode.c.

diff --git a/lib/std/textio.vhd b/lib/std/textio.vhd
@@ -426,9 +426,44 @@ package body textio is
     procedure read (l     : inout line;
                     value : out time;
                     good  : out boolean ) is
+        type unit_spec_t is record
+            name   : string(1 to 3);
+            length : positive;
+            unit   : time;
+        end record;
+
+        type unit_map_t is array (natural range <>) of unit_spec_t;
+
+        constant unit_map : unit_map_t := (
+            ( "fs ", 2, fs ),
+            ( "ps ", 2, ps ),
+            ( "ns ", 2, ns ),
+            ( "us ", 2, us ),
+            ( "ms ", 2, ms ),
+            ( "sec", 3, sec ),
+            ( "min", 3, min ),
+            ( "hr ", 2, hr ) );
+
+        variable scale, len : integer;
+        variable scale_good : boolean;
     begin
-        -- TODO
-        report "unimplemented" severity failure;
+        good := false;
+        skip_whitespace(l);
+        read(l, scale, scale_good);
+        if not scale_good then
+            return;
+        end if;
+        skip_whitespace(l);
+        for i in unit_map'range loop
+            len := unit_map(i).length;
+            if l'length >= len
+                and l.all(1 to len) = unit_map(i).name(1 to len)
+            then
+                value := scale * unit_map(i).unit;
+                consume(l, len);
+                good := true;
+            end if;
+        end loop;
     end procedure;
 
     procedure read (l     : inout line;

diff --git a/test/regress/textio4.vhd b/test/regress/textio4.vhd
@@ -188,4 +188,24 @@ begin
         wait;
     end process;
 
+    check_time: process is
+        variable l : line;
+        variable t : time;
+        variable good : boolean;
+    begin
+        l := new string'(" 1 ns 15 sec 1 hr");
+        read(l, t, good);
+        assert good;
+        assert t = 1 ns;
+        read(l, t, good);
+        assert good;
+        assert t = 15 sec;
+        read(l, t, good);
+        assert good;
+        assert t = 1 hr;
+        read(l, t, good);
+        assert not good;
+        wait;
+    end process;
+
 end architecture;