Add ENUMITEMWIDTH error, and apply to X-extended and ranged values.

Changes

@@ -13,6 +13,7 @@ Verilator 5.039 devel
 
 **Other:**
 
+* Add ENUMITEMWIDTH error, and apply to X-extended and ranged values.
 * Support member-level triggers for virtual interfaces (#5166) (#6148). [Yilou Wang]
 * Support disable dotted references (#6154). [Ryszard Rozak, Antmicro Ltd.]
 * Support randomize() on class member selects (#6161). [Igor Zaworski, Antmicro Ltd.]

docs/guide/warnings.rst

@@ -709,6 +709,28 @@ List Of Warnings
    missing."
 
 
+.. option:: ENUMITEMWIDTH
+
+   An error that an enum item value is being assigned from a value which
+   would be truncated (similar to :option:`WIDTHTRUNC`), or from a sized
+   literal constant with a different bit width (similar to
+   :option:`WIDTHTRUNC` or :option:`WIDTHEXPAND`).  IEEE requires this
+   error, but it may be disabled.
+
+   Faulty example:
+
+   .. code-block:: sv
+      :linenos:
+      :emphasize-lines: 2
+
+         typedef enum [3:0] {
+            WRONG_WIDTH = 33'h3  //<--- Warning
+         } enum_t;
+
+   To repair, correct the size of the item's value directly, or use a cast,
+   so the resulting width matches the enum's width.
+
+
 .. option:: ENUMVALUE
 
    An error that an enum data type value is being assigned from another data

src/V3Error.h

@@ -99,6 +99,7 @@ public:
         DEPRECATED,     // Feature will be deprecated
         ENCAPSULATED,   // Error: local/protected violation
         ENDLABEL,       // End lable name mismatch
+        ENUMITEMWIDTH,  // Error: enum item width mismatch
         ENUMVALUE,      // Error: enum type needs explicit cast
         EOFNEWLINE,     // End-of-file missing newline
         GENCLK,         // Generated Clock. Historical, never issued.
@@ -204,8 +205,8 @@ public:
             "CASEINCOMPLETE", "CASEOVERLAP", "CASEWITHX", "CASEX", "CASTCONST", "CDCRSTLOGIC", "CLKDATA",
             "CMPCONST", "COLONPLUS", "COMBDLY", "CONSTRAINTIGN", "CONTASSREG", "COVERIGN",
             "DECLFILENAME", "DEFOVERRIDE", "DEFPARAM", "DEPRECATED",
-            "ENCAPSULATED", "ENDLABEL", "ENUMVALUE", "EOFNEWLINE", "GENCLK",
+            "ENCAPSULATED", "ENDLABEL", "ENUMITEMWIDTH", "ENUMVALUE", "EOFNEWLINE",
-            "GENUNNAMED", "HIERBLOCK",
+            "GENCLK", "GENUNNAMED", "HIERBLOCK",
             "IFDEPTH", "IGNOREDRETURN",
             "IMPERFECTSCH", "IMPLICIT", "IMPLICITSTATIC", "IMPORTSTAR", "IMPURE",
             "INCABSPATH", "INFINITELOOP", "INITIALDLY", "INSECURE",
@@ -219,7 +220,8 @@ public:
             "UNDRIVEN", "UNOPT", "UNOPTFLAT", "UNOPTTHREADS",
             "UNPACKED", "UNSIGNED", "UNUSEDGENVAR",  "UNUSEDLOOP" ,"UNUSEDPARAM", "UNUSEDSIGNAL",
             "USERERROR", "USERFATAL", "USERINFO", "USERWARN",
-            "VARHIDDEN", "WAITCONST", "WIDTH", "WIDTHCONCAT",  "WIDTHEXPAND", "WIDTHTRUNC", "WIDTHXZEXPAND", "ZERODLY", "ZEROREPL",
+            "VARHIDDEN", "WAITCONST", "WIDTH", "WIDTHCONCAT",  "WIDTHEXPAND", "WIDTHTRUNC", "WIDTHXZEXPAND",
+            "ZERODLY", "ZEROREPL",
             " MAX"
         };
         // clang-format on
@@ -249,9 +251,9 @@ public:
     bool pretendError() const VL_MT_SAFE {
         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 == ENUMVALUE || m_e == IMPURE || m_e == MODMISSING
+                || m_e == ENDLABEL || m_e == ENUMITEMWIDTH || m_e == ENUMVALUE || m_e == IMPURE
-                || m_e == PINNOTFOUND || m_e == PKGNODECL || m_e == PROCASSWIRE
+                || m_e == MODMISSING || m_e == PINNOTFOUND || m_e == PKGNODECL
-                || m_e == ZEROREPL  // Says IEEE
+                || m_e == PROCASSWIRE || m_e == ZEROREPL  // Says IEEE
         );
     }
     // Warnings to mention manual

src/V3FileLine.h

@@ -369,6 +369,10 @@ public:
                 && m_lastLineno == rhs.m_lastLineno && m_lastColumn == rhs.m_lastColumn
                 && m_filenameno == rhs.m_filenameno && m_msgEnIdx == rhs.m_msgEnIdx);
     }
+    bool equalFirstLineCol(const FileLine& rhs) const {
+        return (m_filenameno == rhs.m_filenameno && m_firstLineno == rhs.m_firstLineno
+                && m_firstColumn == rhs.m_firstColumn);
+    }
     // Returns -1 if (*this) should come before rhs after sorted. 1 for the opposite case. 0 for
     // equivalent.
     int operatorCompare(const FileLine& rhs) const {

src/V3LinkParse.cpp

@@ -267,16 +267,17 @@ class LinkParseVisitor final : public VNVisitor {
             const int left = nodep->rangep()->leftConst();
             const int right = nodep->rangep()->rightConst();
             const int increment = (left > right) ? -1 : 1;
-            int offset_from_init = 0;
+            uint32_t offset_from_init = 0;
             AstEnumItem* addp = nullptr;
             FileLine* const flp = nodep->fileline();
-            for (int i = left; i != (right + increment); i += increment, offset_from_init++) {
+            for (int i = left; i != (right + increment); i += increment, ++offset_from_init) {
                 const string name = nodep->name() + cvtToStr(i);
                 AstNodeExpr* valuep = nullptr;
                 if (nodep->valuep()) {
+                    // V3Width looks for Adds with same fileline as the EnumItem
                     valuep
                         = new AstAdd{flp, nodep->valuep()->cloneTree(true),
-                                     new AstConst(flp, AstConst::Unsized32{}, offset_from_init)};
+                                     new AstConst{flp, AstConst::Unsized32{}, offset_from_init}};
                 }
                 addp = AstNode::addNext(addp, new AstEnumItem{flp, name, nullptr, valuep});
             }

src/V3Number.cpp

@@ -1188,7 +1188,7 @@ uint32_t V3Number::countOnes() const {
 
 uint32_t V3Number::mostSetBitP1() const {
     for (int bit = width() - 1; bit >= 0; bit--) {
-        if (bitIs1(bit)) return bit + 1;
+        if (!bitIs0(bit)) return bit + 1;
     }
     return 0;
 }

src/V3Width.cpp

@@ -2553,9 +2553,16 @@ class WidthVisitor final : public VNVisitor {
             // Default type is int, but common to assign narrower values, so minwidth from value
             userIterateAndNext(nodep->valuep(), WidthVP{CONTEXT_DET, PRELIM}.p());
             bool warnOn = true;
-            if (const AstConst* const constp = VN_CAST(nodep->valuep(), Const)) {
+            AstNodeExpr* valuep = nodep->valuep();
+            if (const AstAdd* const anodep = VN_CAST(valuep, Add)) {
+                // If constructed by V3LinkParse due to "enumitem[N_REPEATS] value"
+                if (anodep->fileline()->equalFirstLineCol(*(nodep->fileline())))
+                    valuep = anodep->lhsp();
+            }
+            if (const AstConst* const constp = VN_CAST(valuep, Const)) {
                 if (static_cast<int>(constp->num().mostSetBitP1()) > nodep->width()) {
-                    constp->v3error("Enum value exceeds width of enum type (IEEE 1800-2023 6.19)");
+                    constp->v3warn(ENUMITEMWIDTH,
+                                   "Enum value exceeds width of enum type (IEEE 1800-2023 6.19)");
                     warnOn = false;  // Prevent normal WIDTHTRUNC
                 }
             }

test_regress/t/t_enum_bad_value.out

@@ -1,6 +1,20 @@
-%Error: t/t_enum_bad_value.v:10:19: Enum value exceeds width of enum type (IEEE 1800-2023 6.19)
+%Error-ENUMITEMWIDTH: t/t_enum_bad_value.v:12:37: Enum value exceeds width of enum type (IEEE 1800-2023 6.19)
-                                  : ... note: In instance 't'
+                                                : ... note: In instance 't'
-   10 |       VALUE_BAD = 8
+   12 |   typedef enum [2:0] { VALUE_BAD1 = 8 } enum_t;
-      |                   ^
+      |                                     ^
-        ... See the manual at https://verilator.org/verilator_doc.html?v=latest for more assistance.
+                      ... For error description see https://verilator.org/warn/ENUMITEMWIDTH?v=latest
+%Error-ENUMITEMWIDTH: t/t_enum_bad_value.v:14:29: Enum value exceeds width of enum type (IEEE 1800-2023 6.19)
+                                                : ... note: In instance 't'
+   14 |   enum bit [4:0] {BAD2[4] = 100} bad2;
+      |                             ^~~
+%Warning-WIDTHTRUNC: t/t_enum_bad_value.v:14:19: Operator ADD expects 5 bits on the LHS, but LHS's CONST '?32?sh64' generates 32 or 7 bits.
+                                               : ... note: In instance 't'
+   14 |   enum bit [4:0] {BAD2[4] = 100} bad2;
+      |                   ^~~~
+                     ... For warning description see https://verilator.org/warn/WIDTHTRUNC?v=latest
+                     ... Use "/* verilator lint_off WIDTHTRUNC */" and lint_on around source to disable this message.
+%Error-ENUMITEMWIDTH: t/t_enum_bad_value.v:16:28: Enum value exceeds width of enum type (IEEE 1800-2023 6.19)
+                                                : ... note: In instance 't'
+   16 |   enum logic [3:0] {BAD3 = 5'bxxxxx} bad3;
+      |                            ^~~~~~~~
 %Error: Exiting due to

test_regress/t/t_enum_bad_value.v

@@ -6,8 +6,14 @@
 
 module t();
 
-   typedef enum [2:0] {
+  enum bit signed [3:0] {OK1 = -1} ok1_t;  // As is signed, loss of 1 bits is ok per IEEE
-      VALUE_BAD = 8
+  enum bit signed [3:0] {OK2 = 3} ok2_t;
-   } enum_t;
 
+  typedef enum [2:0] { VALUE_BAD1 = 8 } enum_t;
+
+  enum bit [4:0] {BAD2[4] = 100} bad2;
+
+  enum logic [3:0] {BAD3 = 5'bxxxxx} bad3;
+
+  initial $stop;
 endmodule