github: Remove 18.04

.github/workflows/build.yml

@@ -29,7 +29,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-22.04, ubuntu-20.04, ubuntu-18.04]
+        os: [ubuntu-22.04, ubuntu-20.04]
         compiler:
           - { cc: clang, cxx: clang++ }
           - { cc: gcc,   cxx: g++     }
@@ -97,7 +97,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-22.04, ubuntu-20.04, ubuntu-18.04]
+        os: [ubuntu-22.04, ubuntu-20.04]
         compiler:
           - { cc: clang, cxx: clang++ }
           - { cc: gcc,   cxx: g++     }

docs/guide/copyright.rst

@@ -17,3 +17,21 @@ All Verilog and C++/SystemC code quoted within this documentation file is
 released as Creative Commons Public Domain (CC0). Many example files and
 test files are likewise released under CC0 into effectively the Public
 Domain as described in the files themselves.
+
+   Warns that the lifetime of a task or a function was not provided and so
+   was implicitly set to static. The warning is suppressed when no
+   variables inside the task or a function are assigned to.
+
+   This is a warning because the static default differs from C++, differs
+   from class member function/tasks.  Static is a more dangerous default
+   then automatic as static prevents the function from being reinterant,
+   which may be a source of bugs, and/or performance issues.
+
+   If the function does not require static behavior, change it to "function
+   automatic".
+
+   If the function requires static behavior, change it to "function
+   static".
+
+   Ignoring this warning will only suppress the lint check; it will
+   simulate correctly.