Internals: Move timeunit to pragma, in prep for future parser. No user-functional change intended.

src/V3Ast.h

@@ -336,6 +336,7 @@ public:
         NO_INLINE_TASK,
         PUBLIC_MODULE,
         PUBLIC_TASK,
+        TIMEUNIT_SET,
         UNROLL_DISABLE,
         UNROLL_FULL,
         FULL_CASE,

src/V3AstNodeOther.h

@@ -1494,18 +1494,24 @@ public:
 };
 class AstPragma final : public AstNode {
     const VPragmaType m_pragType;  // Type of pragma
+    const VTimescale m_timescale;  // For TIMEUNIT_SET
 public:
     // Pragmas don't result in any output code, they're just flags that affect
     // other processing in verilator.
     AstPragma(FileLine* fl, VPragmaType pragType)
         : ASTGEN_SUPER_Pragma(fl)
         , m_pragType{pragType} {}
+    AstPragma(FileLine* fl, VPragmaType pragType, const VTimescale& timescale)
+        : ASTGEN_SUPER_Pragma(fl)
+        , m_pragType{pragType}
+        , m_timescale(timescale) {}
     ASTGEN_MEMBERS_AstPragma;
     VPragmaType pragType() const { return m_pragType; }  // *=type of the pragma
     bool isPredictOptimizable() const override { return false; }
     bool sameNode(const AstNode* samep) const override {
         return pragType() == VN_DBG_AS(samep, Pragma)->pragType();
     }
+    VTimescale timescale() const { return m_timescale; }
 };
 class AstPropSpec final : public AstNode {
     // A clocked property

src/V3LinkLevel.cpp

@@ -88,9 +88,24 @@ void V3LinkLevel::modSortByLevel() {
 void V3LinkLevel::timescaling(const ModVec& mods) {
     // Timescale determination
     const AstNodeModule* modTimedp = nullptr;
-    VTimescale unit(VTimescale::NONE);
+    VTimescale unit{VTimescale::NONE};
+
+    // Move timeunit attributes from parse to module unit
+    // Grammar only allows timeunit as module_item, so no need to recurse full tree
+    for (AstNodeModule* modp : mods) {
+        for (AstNode *nextp, *childp = modp->stmtsp(); childp; childp = nextp) {
+            nextp = childp->nextp();
+            if (AstPragma* pragp = VN_CAST(childp, Pragma)) {
+                if (pragp->pragType() == VPragmaType::TIMEUNIT_SET) {
+                    modp->timeunit(pragp->timescale());
+                    VL_DO_DANGLING(pragp->unlinkFrBack()->deleteTree(), pragp);
+                }
+            }
+        }
+    }
     // Use highest level module as default unit - already sorted in proper order
-    for (const auto& modp : mods) {
+    // Combine timing into later modules
+    for (AstNodeModule* modp : mods) {
         if (!modTimedp && !modp->timeunit().isNone()) {
             modTimedp = modp;
             unit = modTimedp->timeunit();
@@ -106,24 +121,24 @@ void V3LinkLevel::timescaling(const ModVec& mods) {
         if (!upkgp->timeunit().isNone()) dunitTimed = true;
     }
 
-    for (AstNodeModule* nodep : mods) {
-        if (!v3Global.opt.timeOverrideUnit().isNone()) nodep->timeunit(unit);
-        if (nodep->timeunit().isNone()) {
+    for (AstNodeModule* modp : mods) {
+        if (!v3Global.opt.timeOverrideUnit().isNone()) modp->timeunit(unit);
+        if (modp->timeunit().isNone()) {
             if (modTimedp  // Got previous
                 && !dunitTimed
                 && (  // unit doesn't already include an override
                     v3Global.opt.timeOverrideUnit().isNone()
                     && v3Global.opt.timeDefaultUnit().isNone())
-                && nodep->timescaleMatters()) {
-                nodep->v3warn(TIMESCALEMOD,
-                              "Timescale missing on this module as other modules have "
-                              "it (IEEE 1800-2023 3.14.2.3)\n"
-                                  << nodep->warnContextPrimary() << '\n'
-                                  << modTimedp->warnOther()
-                                  << "... Location of module with timescale\n"
-                                  << modTimedp->warnContextSecondary());
+                && modp->timescaleMatters()) {
+                modp->v3warn(TIMESCALEMOD,
+                             "Timescale missing on this module as other modules have "
+                             "it (IEEE 1800-2023 3.14.2.3)\n"
+                                 << modp->warnContextPrimary() << '\n'
+                                 << modTimedp->warnOther()
+                                 << "... Location of module with timescale\n"
+                                 << modTimedp->warnContextSecondary());
             }
-            nodep->timeunit(unit);
+            modp->timeunit(unit);
         }
     }
 

src/V3ParseImp.cpp

@@ -126,8 +126,8 @@ void V3ParseImp::lexTimescaleParse(FileLine* fl, const char* textp) {
     m_timeLastUnit = v3Global.opt.timeComputeUnit(unit);
     v3Global.rootp()->timeprecisionMerge(fl, prec);
 }
-void V3ParseImp::timescaleMod(FileLine* fl, AstNodeModule* modp, bool unitSet, double unitVal,
-                              bool precSet, double precVal) {
+AstPragma* V3ParseImp::createTimescale(FileLine* fl, bool unitSet, double unitVal, bool precSet,
+                                       double precVal) {
     VTimescale unit{VTimescale::NONE};
     if (unitSet) {
         bool bad;
@@ -146,16 +146,13 @@ void V3ParseImp::timescaleMod(FileLine* fl, AstNodeModule* modp, bool unitSet, d
             fl->v3error("timeprecision illegal value");
         }
     }
-    if (!unit.isNone()) {
-        unit = v3Global.opt.timeComputeUnit(unit);
-        if (modp) {
-            modp->timeunit(unit);
-        } else {
-            v3Global.rootp()->timeunit(unit);
-            unitPackage(fl)->timeunit(unit);
-        }
-    }
     v3Global.rootp()->timeprecisionMerge(fl, prec);
+    if (unit.isNone()) {
+        return nullptr;
+    } else {
+        unit = v3Global.opt.timeComputeUnit(unit);
+        return new AstPragma{fl, VPragmaType::TIMEUNIT_SET, unit};
+    }
 }
 
 void V3ParseImp::lexVerilatorCmtLintSave(const FileLine* fl) { m_lexLintState.push_back(*fl); }

src/V3ParseImp.h

@@ -181,8 +181,8 @@ public:
     void tagNodep(AstNode* nodep) { m_tagNodep = nodep; }
     AstNode* tagNodep() const { return m_tagNodep; }
     void lexTimescaleParse(FileLine* fl, const char* textp) VL_MT_DISABLED;
-    void timescaleMod(FileLine* fl, AstNodeModule* modp, bool unitSet, double unitVal,
-                      bool precSet, double precVal) VL_MT_DISABLED;
+    AstPragma* createTimescale(FileLine* fl, bool unitSet, double unitVal, bool precSet,
+                               double precVal) VL_MT_DISABLED;
     VTimescale timeLastUnit() const { return m_timeLastUnit; }
 
     void lexFileline(FileLine* fl) { m_lexFileline = fl; }

src/verilog.y

@@ -1227,14 +1227,11 @@ description:                    // ==IEEE: description
 
 timeunits_declaration<nodep>:   // ==IEEE: timeunits_declaration
                 yTIMEUNIT yaTIMENUM ';'
-                        { PARSEP->timescaleMod($<fl>2, SYMP->findTopNodeModule($<fl>1, false), true, $2, false, 0);
-                          $$ = nullptr; }
+                        { $$ = PARSEP->createTimescale($<fl>2, true, $2, false, 0); }
         |       yTIMEUNIT yaTIMENUM '/' yaTIMENUM ';'
-                        { PARSEP->timescaleMod($<fl>2, SYMP->findTopNodeModule($<fl>1, false), true, $2, true, $4);
-                          $$ = nullptr; }
+                        { $$ = PARSEP->createTimescale($<fl>2, true, $2, true, $4); }
         |       yTIMEPRECISION yaTIMENUM ';'
-                        { PARSEP->timescaleMod($<fl>2, SYMP->findTopNodeModule($<fl>1, false), false, 0, true, $2);
-                          $$ = nullptr; }
+                        { $$ = PARSEP->createTimescale($<fl>2, false, 0, true, $2); }
         ;
 
 //**********************************************************************