Fix bug15702: require generic association in direct entity instantiation.

1 files changed, 48 insertions, 0 deletions

diff --git a/testsuite/gna/bug15702/example.vhd b/testsuite/gna/bug15702/example.vhd
new file mode 100644
index 0000000..3f0c8e7
--- /dev/null
+++ b/testsuite/gna/bug15702/example.vhd
@@ -0,0 +1,48 @@
+library ieee;
+use ieee.std_logic_1164.all;
+
+-- COMPONENT
+entity a is
+   -- N_BITS_DATA is nowhere initialized. This problem should be catched during
+   -- elaboration but it isn't !
+   -- During simulation I found that the value of N_BITS_DATA is -2147483648 and
+   -- that the value of N_BITS_DATA-1 is 2147483647 !!!!
+   generic (N_BITS_DATA : integer);
+end entity;
+
+architecture arch_a of a is
+   --~ -- Here data_s will have 4_194_305 elements and this will make ghdl
+   --~ -- take about 650 MB of memory. According to that, each element take about 150 B
+   --~ signal data_s : std_logic_vector((N_BITS_DATA-1)/512 downto 0);
+
+   -- This line make ghdl eat all the free memory because it is trying to make a
+   -- vector of 2**31 elements !!!! And there isn't enough memory because we need
+   -- about 2**31 * 150 B = ~ 300 GB !!!!
+   signal data_s : std_logic_vector(N_BITS_DATA-1 downto 0);
+
+   --~ -- Strangely this line doesn't make the simulation failed because N_BITS_DATA
+   --~ -- is negativ, but it doesn't increase the use of memory either.
+   --~ signal data_s : std_logic_vector(N_BITS_DATA downto 0);
+begin
+   process begin
+      -- N_BITS_DATA = -2147483648 = -2**31
+      report integer'image(N_BITS_DATA);
+      --
+      -- N_BITS_DATA-1 = 2147483647 = 2**31 - 1
+      report integer'image(N_BITS_DATA-1);
+      --
+      -- (N_BITS_DATA-1)/512 = 4_194_304 = 2**22
+      report integer'image((N_BITS_DATA-1)/512);
+      --
+   end process;
+end;
+--
+
+-- TESTBENCH
+entity tb is end entity;
+
+architecture arch_tb of tb is
+begin
+   X1: entity work.a;
+end;
+--