Add a compatibility feature to suppress WLOGMIXUP

RELEASENOTES.docu

@@ -1797,5 +1797,9 @@ extern typedef struct { } my_type_t;</pre> </add-note></build-id>
       for the identifier <bug number="SIMICS-22472"/>.</add-note></build-id>
   <build-id _6="next" _7="next"><add-note> Added the warning <tt>WBIGUNROLL</tt>
       which is emitted when a <tt>#select</tt> or <tt>#foreach</tt> statement is
-      compiled to a large unrolled loop.</add-note></build-id>
+      compiled to a large unrolled loop.
+      This warning is only enabled by default with Simics API version 8 or
+      above. With version 7 and below it must be explicitly enabledby passing
+      either <tt>--no-compat=suppress_WBIGUNROLL</tt> or
+      <tt>--warn=WBIGUNROLL</tt> to DMLC.</add-note></build-id>
 </rn>

lib/1.2/dml-builtins.dml

@@ -215,6 +215,7 @@ template device {
     parameter _compat_io_memory auto;
     parameter _compat_shared_logs_on_device auto;
     parameter _compat_suppress_WLOGMIXUP auto;
+    parameter _compat_suppress_WBIGUNROLL auto;
     parameter _compat_legacy_attributes auto;
     parameter _compat_lenient_typechecking auto;
     parameter _compat_dml12_inline auto;

lib/1.4/dml-builtins.dml

@@ -561,6 +561,7 @@ template device {
     param _compat_io_memory auto;
     param _compat_shared_logs_on_device auto;
     param _compat_suppress_WLOGMIXUP auto;
+    param _compat_suppress_WBIGUNROLL auto;
     param _compat_legacy_attributes auto;
     param _compat_lenient_typechecking auto;
     param _compat_dml12_inline auto;

py/dml/compat.py

@@ -198,6 +198,30 @@ class suppress_WLOGMIXUP(CompatFeature):
     short = "Suppress the warning 'WLOGMIXUP' by default"
     last_api_version = api_6
 
+@feature
+class suppress_WBIGUNROLL(CompatFeature):
+    '''This compatibility feature makes it so the warning `WBIGUNROLL` is
+    suppressed by default. `WBIGUNROLL` warns about `#foreach` and `#select`
+    statements that compile to large unrolled loops — for more
+    information, see the documentation of `WBIGUNROLL` in the
+    [Messages](messages.html) section.
+
+    `WBIGUNROLL` is suppressed by default below Simics API version 8 in order
+    to avoid overwhelming users with warnings. Addressing occurences of large
+    unrolled loops should be done before or as part of migration to Simics API
+    version 8.
+
+    Passing `--no-compat=suppress_WBUGUNROLL` to DMLC has almost the same effect
+    as passing `--warn=WBIGUNROLL`; either will cause DMLC to report the warning
+    even when the Simics API version in use is below 8. The only difference
+    between these two options is that if `--no-compat=suppress_WBIGUNROLL` is
+    used (and `--warn=WBIGUNROLL` is not), then `WBIGUNROLL` may still be
+    explicitly suppressed via `--no-warn=WBIGUNROLL`. In contrast,
+    `--warn=WBIGUNROLL` doesn't allow for `WBIGUNROLL` to be suppressed at
+    all.'''
+    short = "Suppress the warning 'WBIGUNROLL' by default"
+    last_api_version = api_7
+
 @feature
 class legacy_attributes(CompatFeature):
     '''This compatibility feature makes DMLC register all attributes using the

py/dml/dmlc.py

@@ -599,6 +599,8 @@ def main(argv):
 
     if compat.suppress_WLOGMIXUP in dml.globals.enabled_compat:
         ignore_warning('WLOGMIXUP')
+    if compat.suppress_WBIGUNROLL in dml.globals.enabled_compat:
+        ignore_warning('WBIGUNROLL')
 
     for w in options.disabled_warnings:
         if not is_warning_tag(w):

py/dml/messages.py

@@ -2309,6 +2309,9 @@ class WBIGUNROLL(DMLWarning):
       list instead as a `session` array or an `extern`ed C array, and iterate
       through it using traditional `for` loops. For more information, see [the
       various answers to this Stack Overflow question.](https://stackoverflow.com/questions/75073681/cannot-use-variable-index-in-a-constant-list)
+
+    This warning is only enabled by default with Simics API version 8 or above
+    (due to the compatibility feature `suppress_WBIGUNROLL`.)
     """
     fmt = ("This '%s' statement compiles to an unrolled loop where the loop "
            + "body is studied and generated %s times. This may dramatically "

test/1.2/legacy/T_suppress_WBIGUNROLL_disabled.dml

@@ -0,0 +1,15 @@
+/*
+  © 2024 Intel Corporation
+  SPDX-License-Identifier: MPL-2.0
+*/
+dml 1.2;
+
+device test;
+
+/// COMPILE-ONLY
+/// NO-CC
+
+/// DMLC-FLAG --no-compat=suppress_WBIGUNROLL
+
+/// SCAN-FOR-TAGS suppress_WBIGUNROLL.dml
+import "suppress_WBIGUNROLL.dml";

test/1.2/legacy/T_suppress_WBIGUNROLL_enabled.dml

@@ -0,0 +1,14 @@
+/*
+  © 2024 Intel Corporation
+  SPDX-License-Identifier: MPL-2.0
+*/
+dml 1.2;
+
+device test;
+
+/// COMPILE-ONLY
+/// NO-CC
+
+/// DMLC-FLAG --simics-api=7
+
+import "suppress_WBIGUNROLL.dml";

test/1.2/errors/T_WBIGUNROLL.dml → test/1.2/legacy/suppress_WBIGUNROLL.dml

@@ -1,13 +1,10 @@
 /*
-  © 2023 Intel Corporation
+  © 2024 Intel Corporation
   SPDX-License-Identifier: MPL-2.0
 */
 dml 1.2;
 
-device test;
-
-/// COMPILE-ONLY
-/// NO-CC
+// expectations in this file are selectively enabled using SCAN-FOR-TAGS
 
 data int zero = 0;