Add FUNCTIMCTL now as a named error, so can disable (#6385).

Changes

@@ -21,7 +21,7 @@ Verilator 5.041 devel
 * Add configure `--enable-asan` to compile verilator_bin with the address sanitizer (#6404). [Geza Lore]
 * Add $(LDFLAGS) and $(LIBS) to when building shared libraries (#6425) (#6426). [Ahmed El-Mahmoudy]
 * Add IMPLICITSTATIC also on procedure variables.
-* Add error on function invoking task or time-controlling statements (#6385).
+* Add FUNCTIMCTL error on function invoking task or time-controlling statements (#6385).
 * Deprecate sensitivity list on public_flat_rw attributes (#6443). [Geza Lore]
 * Deprecate clocker attribute and --clk option (#6463). [Geza Lore]
 * Support modports referencing clocking blocks (#4555) (#6436). [Ryszard Rozak, Antmicro Ltd.]

docs/gen/ex_FUNCTIMECTL_faulty.rst

@@ -0,0 +1,7 @@
+.. comment: generated by t_lint_functimectl_bad
+.. code-block:: sv
+   :linenos:
+   :emphasize-lines: 2
+
+     function void calls_timing_ctl;
+       @e; // <--- Bad IEEE 1800-2023 13.4 time-controlling

docs/gen/ex_FUNCTIMECTL_msg.rst

@@ -0,0 +1,4 @@
+.. comment: generated by t_lint_functimectl_bad
+.. code-block::
+
+   %Error-FUNCTIMECTL: example.v:1:5 Functions cannot contain time-controlling statements (IEEE 1800-2023 13.4)

docs/guide/warnings.rst

@@ -835,6 +835,25 @@ List Of Warnings
    with a newline."
 
 
+.. option:: FUNCTIMECTL
+
+   Error that a function contains a time-controlling statement or call of a
+   task.  IEEE 1800-2023 13.4 requires this error.
+
+   Faulty example:
+
+   .. include:: ../../docs/gen/ex_FUNCTIMECTL_faulty.rst
+
+   Results in:
+
+   .. include:: ../../docs/gen/ex_FUNCTIMECTL_msg.rst
+
+   Suppressing this error will only suppress the IEEE-required check; in
+   most cases Verilator treats functions and tasks identically and relies
+   on analysis to determine what functions/tasks need to allow time to
+   pass.
+
+
 .. option:: GENCLK
 
    Historical, never issued since version 5.000.

src/V3Error.h

@@ -105,6 +105,7 @@ public:
         ENUMITEMWIDTH,  // Error: enum item width mismatch
         ENUMVALUE,      // Error: enum type needs explicit cast
         EOFNEWLINE,     // End-of-file missing newline
+        FUNCTIMECTL,    // Functions cannot have timing/delay/wait
         GENCLK,         // Generated Clock. Historical, never issued.
         GENUNNAMED,     // Generate unnamed, without label
         HIERBLOCK,      // Ignored hierarchical block setting
@@ -213,19 +214,19 @@ public:
             "BSSPACE", "CASEINCOMPLETE", "CASEOVERLAP", "CASEWITHX", "CASEX", "CASTCONST",
             "CDCRSTLOGIC", "CLKDATA", "CMPCONST", "COLONPLUS", "COMBDLY", "CONSTRAINTIGN",
             "CONTASSREG", "COVERIGN", "DECLFILENAME", "DEFOVERRIDE", "DEFPARAM", "DEPRECATED",
-            "ENCAPSULATED", "ENDLABEL", "ENUMITEMWIDTH", "ENUMVALUE", "EOFNEWLINE", "GENCLK",
+            "ENCAPSULATED", "ENDLABEL", "ENUMITEMWIDTH", "ENUMVALUE", "EOFNEWLINE", "FUNCTIMECTL",
-            "GENUNNAMED", "HIERBLOCK", "HIERPARAM", "IFDEPTH", "IGNOREDRETURN", "IMPERFECTSCH",
+            "GENCLK", "GENUNNAMED", "HIERBLOCK", "HIERPARAM", "IFDEPTH", "IGNOREDRETURN",
-            "IMPLICIT", "IMPLICITSTATIC", "IMPORTSTAR", "IMPURE", "INCABSPATH", "INFINITELOOP",
+            "IMPERFECTSCH", "IMPLICIT", "IMPLICITSTATIC", "IMPORTSTAR", "IMPURE", "INCABSPATH",
-            "INITIALDLY", "INSECURE", "LATCH", "LITENDIAN", "MINTYPMAXDLY", "MISINDENT", "MODDUP",
+            "INFINITELOOP", "INITIALDLY", "INSECURE", "LATCH", "LITENDIAN", "MINTYPMAXDLY",
-            "MODMISSING", "MULTIDRIVEN", "MULTITOP", "NEWERSTD", "NOEFFECT", "NOLATCH", "NONSTD",
+            "MISINDENT", "MODDUP", "MODMISSING", "MULTIDRIVEN", "MULTITOP", "NEWERSTD", "NOEFFECT",
-            "NULLPORT", "PARAMNODEFAULT", "PINCONNECTEMPTY", "PINMISSING", "PINNOCONNECT",
+            "NOLATCH", "NONSTD", "NULLPORT", "PARAMNODEFAULT", "PINCONNECTEMPTY", "PINMISSING",
-            "PINNOTFOUND", "PKGNODECL", "PREPROCZERO", "PROCASSINIT", "PROCASSWIRE",
+            "PINNOCONNECT", "PINNOTFOUND", "PKGNODECL", "PREPROCZERO", "PROCASSINIT",
-            "PROFOUTOFDATE", "PROTECTED", "PROTOTYPEMIS", "RANDC", "REALCVT", "REDEFMACRO",
+            "PROCASSWIRE", "PROFOUTOFDATE", "PROTECTED", "PROTOTYPEMIS", "RANDC", "REALCVT",
-            "RISEFALLDLY", "SELRANGE", "SHORTREAL", "SIDEEFFECT", "SPECIFYIGN", "SPLITVAR",
+            "REDEFMACRO", "RISEFALLDLY", "SELRANGE", "SHORTREAL", "SIDEEFFECT", "SPECIFYIGN",
-            "STATICVAR", "STMTDLY", "SYMRSVDWORD", "SYNCASYNCNET", "TICKCOUNT", "TIMESCALEMOD",
+            "SPLITVAR", "STATICVAR", "STMTDLY", "SYMRSVDWORD", "SYNCASYNCNET", "TICKCOUNT",
-            "UNDRIVEN", "UNOPT", "UNOPTFLAT", "UNOPTTHREADS", "UNPACKED", "UNSIGNED",
+            "TIMESCALEMOD", "UNDRIVEN", "UNOPT", "UNOPTFLAT", "UNOPTTHREADS", "UNPACKED",
-            "UNUSEDGENVAR", "UNUSEDLOOP", "UNUSEDPARAM", "UNUSEDSIGNAL", "USERERROR", "USERFATAL",
+            "UNSIGNED", "UNUSEDGENVAR", "UNUSEDLOOP", "UNUSEDPARAM", "UNUSEDSIGNAL", "USERERROR",
-            "USERINFO", "USERWARN", "VARHIDDEN", "WAITCONST", "WIDTH", "WIDTHCONCAT",
+            "USERFATAL", "USERINFO", "USERWARN", "VARHIDDEN", "WAITCONST", "WIDTH", "WIDTHCONCAT",
             "WIDTHEXPAND", "WIDTHTRUNC", "WIDTHXZEXPAND", "ZERODLY", "ZEROREPL", " MAX"};
         return names[m_e];
     }
@@ -254,9 +255,9 @@ public:
         return (m_e == ASSIGNIN || m_e == BADSTDPRAGMA || m_e == BADVLTPRAGMA || m_e == BLKANDNBLK
                 || m_e == BLKLOOPINIT || m_e == CONTASSREG || m_e == ENCAPSULATED
                 || m_e == ENDLABEL || m_e == ENUMITEMWIDTH || m_e == ENUMVALUE || m_e == HIERPARAM
-                || m_e == IMPURE || m_e == MODMISSING || m_e == PARAMNODEFAULT
+                || m_e == FUNCTIMECTL || m_e == IMPURE || m_e == MODMISSING
-                || m_e == PINNOTFOUND || m_e == PKGNODECL || m_e == PROCASSWIRE
+                || m_e == PARAMNODEFAULT || m_e == PINNOTFOUND || m_e == PKGNODECL
-                || m_e == PROTOTYPEMIS || m_e == ZEROREPL  // Says IEEE
+                || m_e == PROCASSWIRE || m_e == PROTOTYPEMIS || m_e == ZEROREPL  // Says IEEE
         );
     }
     // Warnings to mention manual

src/V3WidthCommit.cpp

@@ -67,12 +67,13 @@ private:
         // Called by every visitor. Edit dtypes for this node, also check for some warnings
         nodep->dtypep(editOneDType(nodep->dtypep()));
         if (m_ftaskp && m_ftaskp->verilogFunction() && m_taskRefWarn && nodep->isTimingControl())
-            nodep->v3error(
+            nodep->v3warn(
+                FUNCTIMECTL,
                 "Functions cannot contain time-controlling statements (IEEE 1800-2023 13.4)\n"
-                << nodep->warnContextPrimary() << "\n"
+                    << nodep->warnContextPrimary() << "\n"
-                << nodep->warnMore() << "... Suggest make caller 'function "
+                    << nodep->warnMore() << "... Suggest make caller 'function "
-                << m_ftaskp->prettyName() << "' a task\n"
+                    << m_ftaskp->prettyName() << "' a task\n"
-                << m_ftaskp->warnContextSecondary());
+                    << m_ftaskp->warnContextSecondary());
     }
     AstNodeDType* editOneDType(AstNodeDType* nodep) {
         // See if the dtype/refDType can be converted to a standard one
@@ -439,14 +440,15 @@ private:
         classEncapCheck(nodep, nodep->taskp(), VN_CAST(nodep->classOrPackagep(), Class));
         if (nodep->taskp() && nodep->taskp()->verilogTask() && m_ftaskp
             && m_ftaskp->verilogFunction() && m_taskRefWarn) {
-            nodep->v3error("Functions cannot invoke tasks (IEEE 1800-2023 13.4)\n"
+            nodep->v3warn(FUNCTIMECTL,
-                           << nodep->warnContextPrimary() << "\n"
+                          "Functions cannot invoke tasks (IEEE 1800-2023 13.4)\n"
-                           << nodep->warnMore() << "... Suggest make caller 'function "
+                              << nodep->warnContextPrimary() << "\n"
-                           << m_ftaskp->prettyName() << "' a task\n"
+                              << nodep->warnMore() << "... Suggest make caller 'function "
-                           << m_ftaskp->warnContextSecondary() << "\n"
+                              << m_ftaskp->prettyName() << "' a task\n"
-                           << nodep->warnMore() << "... Or, suggest make called 'task "
+                              << m_ftaskp->warnContextSecondary() << "\n"
-                           << nodep->taskp()->prettyName() << "' a function void\n"
+                              << nodep->warnMore() << "... Or, suggest make called 'task "
-                           << nodep->taskp()->warnContextSecondary());
+                              << nodep->taskp()->prettyName() << "' a function void\n"
+                              << nodep->taskp()->warnContextSecondary());
         }
         if (nodep->taskp()) nodep->taskp()->user2(1);
         if (AstNew* const newp = VN_CAST(nodep, New)) {

test_regress/t/t_func_bad_time.out

@@ -1,16 +0,0 @@
-%Error: t/t_func_bad_time.v:12:5: Functions cannot contain time-controlling statements (IEEE 1800-2023 13.4)
-                                : ... note: In instance 't'
-   12 |     @e;  
-      |     ^
-                                : ... Suggest make caller 'function calls_timing_ctl' a task
-   11 |   function void calls_timing_ctl;
-      |                 ^~~~~~~~~~~~~~~~
-        ... See the manual at https://verilator.org/verilator_doc.html?v=latest for more assistance.
-%Error: t/t_func_bad_time.v:17:5: Functions cannot contain time-controlling statements (IEEE 1800-2023 13.4)
-                                : ... note: In instance 't'
-   17 |     wait (s);  
-      |     ^~~~
-                                : ... Suggest make caller 'function calls_timing_ctl' a task
-   11 |   function void calls_timing_ctl;
-      |                 ^~~~~~~~~~~~~~~~
-%Error: Exiting due to

test_regress/t/t_func_task_bad2.out

@@ -1,12 +1,12 @@
-%Error: t/t_func_task_bad2.v:14:5: Functions cannot invoke tasks (IEEE 1800-2023 13.4)
+%Error-FUNCTIMECTL: t/t_func_task_bad2.v:14:5: Functions cannot invoke tasks (IEEE 1800-2023 13.4)
-                                 : ... note: In instance 't'
+                                             : ... note: In instance 't'
    14 |     a_task(1'b0);   
       |     ^~~~~~
-                                 : ... Suggest make caller 'function func_calls_task' a task
+                                             : ... Suggest make caller 'function func_calls_task' a task
    13 |   function void func_calls_task;
       |                 ^~~~~~~~~~~~~~~
-                                 : ... Or, suggest make called 'task a_task' a function void
+                                             : ... Or, suggest make called 'task a_task' a function void
     9 |   task a_task;
       |        ^~~~~~
-        ... See the manual at https://verilator.org/verilator_doc.html?v=latest for more assistance.
+                    ... For error description see https://verilator.org/warn/FUNCTIMECTL?v=latest
 %Error: Exiting due to

test_regress/t/t_lint_functimectl_bad.out

@@ -0,0 +1,16 @@
+%Error-FUNCTIMECTL: t/t_lint_functimectl_bad.v:12:5: Functions cannot contain time-controlling statements (IEEE 1800-2023 13.4)
+                                                   : ... note: In instance 't'
+   12 |     @e;  
+      |     ^
+                                                   : ... Suggest make caller 'function calls_timing_ctl' a task
+   11 |   function void calls_timing_ctl;
+      |                 ^~~~~~~~~~~~~~~~
+                    ... For error description see https://verilator.org/warn/FUNCTIMECTL?v=latest
+%Error-FUNCTIMECTL: t/t_lint_functimectl_bad.v:17:5: Functions cannot contain time-controlling statements (IEEE 1800-2023 13.4)
+                                                   : ... note: In instance 't'
+   17 |     wait (s);  
+      |     ^~~~
+                                                   : ... Suggest make caller 'function calls_timing_ctl' a task
+   11 |   function void calls_timing_ctl;
+      |                 ^~~~~~~~~~~~~~~~
+%Error: Exiting due to

test_regress/t/t_lint_functimectl_bad.py

@@ -13,4 +13,12 @@ test.scenarios('linter')
 
 test.lint(verilator_flags2=['--timing'], fails=test.vlt_all, expect_filename=test.golden_filename)
 
+test.extract(in_filename=test.top_filename,
+             out_filename=test.root + "/docs/gen/ex_FUNCTIMECTL_faulty.rst",
+             lines="11-12")
+
+test.extract(in_filename=test.golden_filename,
+             out_filename=test.root + "/docs/gen/ex_FUNCTIMECTL_msg.rst",
+             lines="1-1")
+
 test.passes()