From 3c1f9d059e491977eb88ee04854fe71e0b7eadfc Mon Sep 17 00:00:00 2001
From: Brad King <brad.king@kitware.com>
Date: Thu, 26 Feb 2026 14:03:03 -0500
Subject: [PATCH] cmExprParserHelper: Factor operation bodies out of the parser

---
 Source/LexerParser/cmExprParser.cxx | 96 ++++++++++++++---------------
 Source/LexerParser/cmExprParser.y   | 28 ++++-----
 Source/cmExprParserHelper.cxx       | 41 ++++++++++++
 Source/cmExprParserHelper.h         |  8 +++
 4 files changed, 111 insertions(+), 62 deletions(-)

diff --git a/Source/LexerParser/cmExprParser.cxx b/Source/LexerParser/cmExprParser.cxx
index b63fbf4173..128e502cd0 100644
--- a/Source/LexerParser/cmExprParser.cxx
+++ b/Source/LexerParser/cmExprParser.cxx
@@ -90,7 +90,6 @@ Run bison like this:
 
 #include <stdlib.h>
 #include <string.h>
-#include <stdexcept>
 
 /*-------------------------------------------------------------------------*/
 #define YYDEBUG 1
@@ -126,7 +125,7 @@ static void cmExpr_yyerror(yyscan_t yyscanner, const char* message);
 #  pragma diag_suppress 550 /* variable set but never used */
 #endif
 
-#line 130 "cmExprParser.cxx"
+#line 129 "cmExprParser.cxx"
 
 # ifndef YY_CAST
 #  ifdef __cplusplus
@@ -568,8 +567,8 @@ static const yytype_int8 yytranslate[] =
 /* YYRLINE[YYN] -- Source line where rule number YYN was defined.  */
 static const yytype_uint8 yyrline[] =
 {
-       0,    87,    87,    92,    95,   100,   103,   108,   111,   116,
-     119,   122,   127,   130,   133,   138,   141,   144,   150,   158,
+       0,    86,    86,    91,    94,    99,   102,   107,   110,   115,
+     118,   122,   128,   131,   135,   141,   144,   148,   152,   158,
      161,   164,   167,   172,   175
 };
 #endif
@@ -1431,73 +1430,74 @@ yyreduce:
   switch (yyn)
     {
   case 2: /* start: exp  */
-#line 87 "cmExprParser.y"
+#line 86 "cmExprParser.y"
       {
     cmExpr_yyget_extra(yyscanner)->SetResult((yyvsp[0].Number));
   }
-#line 1439 "cmExprParser.cxx"
+#line 1438 "cmExprParser.cxx"
     break;
 
   case 3: /* exp: bitwiseor  */
-#line 92 "cmExprParser.y"
+#line 91 "cmExprParser.y"
             {
     (yyval.Number) = (yyvsp[0].Number);
   }
-#line 1447 "cmExprParser.cxx"
+#line 1446 "cmExprParser.cxx"
     break;
 
   case 4: /* exp: exp exp_OR bitwiseor  */
-#line 95 "cmExprParser.y"
+#line 94 "cmExprParser.y"
                        {
     (yyval.Number) = (yyvsp[-2].Number) | (yyvsp[0].Number);
   }
-#line 1455 "cmExprParser.cxx"
+#line 1454 "cmExprParser.cxx"
     break;
 
   case 5: /* bitwiseor: bitwisexor  */
-#line 100 "cmExprParser.y"
+#line 99 "cmExprParser.y"
              {
     (yyval.Number) = (yyvsp[0].Number);
   }
-#line 1463 "cmExprParser.cxx"
+#line 1462 "cmExprParser.cxx"
     break;
 
   case 6: /* bitwiseor: bitwiseor exp_XOR bitwisexor  */
-#line 103 "cmExprParser.y"
+#line 102 "cmExprParser.y"
                                {
     (yyval.Number) = (yyvsp[-2].Number) ^ (yyvsp[0].Number);
   }
-#line 1471 "cmExprParser.cxx"
+#line 1470 "cmExprParser.cxx"
     break;
 
   case 7: /* bitwisexor: bitwiseand  */
-#line 108 "cmExprParser.y"
+#line 107 "cmExprParser.y"
              {
     (yyval.Number) = (yyvsp[0].Number);
   }
-#line 1479 "cmExprParser.cxx"
+#line 1478 "cmExprParser.cxx"
     break;
 
   case 8: /* bitwisexor: bitwisexor exp_AND bitwiseand  */
-#line 111 "cmExprParser.y"
+#line 110 "cmExprParser.y"
                                 {
     (yyval.Number) = (yyvsp[-2].Number) & (yyvsp[0].Number);
   }
-#line 1487 "cmExprParser.cxx"
+#line 1486 "cmExprParser.cxx"
     break;
 
   case 9: /* bitwiseand: shift  */
-#line 116 "cmExprParser.y"
+#line 115 "cmExprParser.y"
         {
     (yyval.Number) = (yyvsp[0].Number);
   }
-#line 1495 "cmExprParser.cxx"
+#line 1494 "cmExprParser.cxx"
     break;
 
   case 10: /* bitwiseand: bitwiseand exp_SHIFTLEFT shift  */
-#line 119 "cmExprParser.y"
+#line 118 "cmExprParser.y"
                                  {
-    (yyval.Number) = (yyvsp[-2].Number) << (yyvsp[0].Number);
+    (yyval.Number) = cmExpr_yyget_extra(yyscanner)
+      ->ShL((yyvsp[-2].Number), (yyvsp[0].Number));
   }
 #line 1503 "cmExprParser.cxx"
     break;
@@ -1505,69 +1505,69 @@ yyreduce:
   case 11: /* bitwiseand: bitwiseand exp_SHIFTRIGHT shift  */
 #line 122 "cmExprParser.y"
                                   {
-    (yyval.Number) = (yyvsp[-2].Number) >> (yyvsp[0].Number);
+    (yyval.Number) = cmExpr_yyget_extra(yyscanner)
+      ->ShR((yyvsp[-2].Number), (yyvsp[0].Number));
   }
-#line 1511 "cmExprParser.cxx"
+#line 1512 "cmExprParser.cxx"
     break;
 
   case 12: /* shift: term  */
-#line 127 "cmExprParser.y"
+#line 128 "cmExprParser.y"
        {
     (yyval.Number) = (yyvsp[0].Number);
   }
-#line 1519 "cmExprParser.cxx"
+#line 1520 "cmExprParser.cxx"
     break;
 
   case 13: /* shift: shift exp_PLUS term  */
-#line 130 "cmExprParser.y"
+#line 131 "cmExprParser.y"
                       {
-    (yyval.Number) = (yyvsp[-2].Number) + (yyvsp[0].Number);
+    (yyval.Number) = cmExpr_yyget_extra(yyscanner)
+      ->Add((yyvsp[-2].Number), (yyvsp[0].Number));
   }
-#line 1527 "cmExprParser.cxx"
+#line 1529 "cmExprParser.cxx"
     break;
 
   case 14: /* shift: shift exp_MINUS term  */
-#line 133 "cmExprParser.y"
+#line 135 "cmExprParser.y"
                        {
-    (yyval.Number) = (yyvsp[-2].Number) - (yyvsp[0].Number);
+    (yyval.Number) = cmExpr_yyget_extra(yyscanner)
+      ->Sub((yyvsp[-2].Number), (yyvsp[0].Number));
   }
-#line 1535 "cmExprParser.cxx"
+#line 1538 "cmExprParser.cxx"
     break;
 
   case 15: /* term: unary  */
-#line 138 "cmExprParser.y"
+#line 141 "cmExprParser.y"
         {
     (yyval.Number) = (yyvsp[0].Number);
   }
-#line 1543 "cmExprParser.cxx"
+#line 1546 "cmExprParser.cxx"
     break;
 
   case 16: /* term: term exp_TIMES unary  */
-#line 141 "cmExprParser.y"
+#line 144 "cmExprParser.y"
                        {
-    (yyval.Number) = (yyvsp[-2].Number) * (yyvsp[0].Number);
+    (yyval.Number) = cmExpr_yyget_extra(yyscanner)
+      ->Mul((yyvsp[-2].Number), (yyvsp[0].Number));
   }
-#line 1551 "cmExprParser.cxx"
+#line 1555 "cmExprParser.cxx"
     break;
 
   case 17: /* term: term exp_DIVIDE unary  */
-#line 144 "cmExprParser.y"
+#line 148 "cmExprParser.y"
                         {
-    if (yyvsp[0].Number == 0) {
-      throw std::overflow_error("divide by zero");
-    }
-    (yyval.Number) = (yyvsp[-2].Number) / (yyvsp[0].Number);
+    (yyval.Number) = cmExpr_yyget_extra(yyscanner)
+      ->Div((yyvsp[-2].Number), (yyvsp[0].Number));
   }
-#line 1562 "cmExprParser.cxx"
+#line 1564 "cmExprParser.cxx"
     break;
 
   case 18: /* term: term exp_MOD unary  */
-#line 150 "cmExprParser.y"
+#line 152 "cmExprParser.y"
                      {
-    if (yyvsp[0].Number == 0) {
-      throw std::overflow_error("modulo by zero");
-    }
-    (yyval.Number) = (yyvsp[-2].Number) % (yyvsp[0].Number);
+    (yyval.Number) = cmExpr_yyget_extra(yyscanner)
+      ->Mod((yyvsp[-2].Number), (yyvsp[0].Number));
   }
 #line 1573 "cmExprParser.cxx"
     break;
diff --git a/Source/LexerParser/cmExprParser.y b/Source/LexerParser/cmExprParser.y
index 0cb120cbb5..52ac337b5c 100644
--- a/Source/LexerParser/cmExprParser.y
+++ b/Source/LexerParser/cmExprParser.y
@@ -15,7 +15,6 @@ Run bison like this:
 
 #include <stdlib.h>
 #include <string.h>
-#include <stdexcept>
 
 /*-------------------------------------------------------------------------*/
 #define YYDEBUG 1
@@ -117,10 +116,12 @@ bitwiseand:
     $<Number>$ = $<Number>1;
   }
 | bitwiseand exp_SHIFTLEFT shift {
-    $<Number>$ = $<Number>1 << $<Number>3;
+    $<Number>$ = cmExpr_yyget_extra(yyscanner)
+      ->ShL($<Number>1, $<Number>3);
   }
 | bitwiseand exp_SHIFTRIGHT shift {
-    $<Number>$ = $<Number>1 >> $<Number>3;
+    $<Number>$ = cmExpr_yyget_extra(yyscanner)
+      ->ShR($<Number>1, $<Number>3);
   }
 
 shift:
@@ -128,10 +129,12 @@ shift:
     $<Number>$ = $<Number>1;
   }
 | shift exp_PLUS term {
-    $<Number>$ = $<Number>1 + $<Number>3;
+    $<Number>$ = cmExpr_yyget_extra(yyscanner)
+      ->Add($<Number>1, $<Number>3);
   }
 | shift exp_MINUS term {
-    $<Number>$ = $<Number>1 - $<Number>3;
+    $<Number>$ = cmExpr_yyget_extra(yyscanner)
+      ->Sub($<Number>1, $<Number>3);
   }
 
 term:
@@ -139,19 +142,16 @@ term:
     $<Number>$ = $<Number>1;
   }
 | term exp_TIMES unary {
-    $<Number>$ = $<Number>1 * $<Number>3;
+    $<Number>$ = cmExpr_yyget_extra(yyscanner)
+      ->Mul($<Number>1, $<Number>3);
   }
 | term exp_DIVIDE unary {
-    if (yyvsp[0].Number == 0) {
-      throw std::overflow_error("divide by zero");
-    }
-    $<Number>$ = $<Number>1 / $<Number>3;
+    $<Number>$ = cmExpr_yyget_extra(yyscanner)
+      ->Div($<Number>1, $<Number>3);
   }
 | term exp_MOD unary {
-    if (yyvsp[0].Number == 0) {
-      throw std::overflow_error("modulo by zero");
-    }
-    $<Number>$ = $<Number>1 % $<Number>3;
+    $<Number>$ = cmExpr_yyget_extra(yyscanner)
+      ->Mod($<Number>1, $<Number>3);
   }
 
 unary:
diff --git a/Source/cmExprParserHelper.cxx b/Source/cmExprParserHelper.cxx
index d9aade4272..82f62f8464 100644
--- a/Source/cmExprParserHelper.cxx
+++ b/Source/cmExprParserHelper.cxx
@@ -118,3 +118,44 @@ void cmExprParserHelper::SetError(std::string errorString)
 {
   this->ErrorString = std::move(errorString);
 }
+
+std::int64_t cmExprParserHelper::ShL(std::int64_t l, std::int64_t r)
+{
+  return l << r;
+}
+
+std::int64_t cmExprParserHelper::ShR(std::int64_t l, std::int64_t r)
+{
+  return l >> r;
+}
+
+std::int64_t cmExprParserHelper::Add(std::int64_t l, std::int64_t r)
+{
+  return l + r;
+}
+
+std::int64_t cmExprParserHelper::Sub(std::int64_t l, std::int64_t r)
+{
+  return l - r;
+}
+
+std::int64_t cmExprParserHelper::Mul(std::int64_t l, std::int64_t r)
+{
+  return l * r;
+}
+
+std::int64_t cmExprParserHelper::Div(std::int64_t l, std::int64_t r)
+{
+  if (r == 0) {
+    throw std::overflow_error("divide by zero");
+  }
+  return l / r;
+}
+
+std::int64_t cmExprParserHelper::Mod(std::int64_t l, std::int64_t r)
+{
+  if (r == 0) {
+    throw std::overflow_error("modulo by zero");
+  }
+  return l % r;
+}
diff --git a/Source/cmExprParserHelper.h b/Source/cmExprParserHelper.h
index a476c4b80e..90cce78e22 100644
--- a/Source/cmExprParserHelper.h
+++ b/Source/cmExprParserHelper.h
@@ -34,6 +34,14 @@ public:
 
   std::string const& GetWarning() const { return this->WarningString; }
 
+  std::int64_t ShL(std::int64_t l, std::int64_t r);
+  std::int64_t ShR(std::int64_t l, std::int64_t r);
+  std::int64_t Add(std::int64_t l, std::int64_t r);
+  std::int64_t Sub(std::int64_t l, std::int64_t r);
+  std::int64_t Mul(std::int64_t l, std::int64_t r);
+  std::int64_t Div(std::int64_t l, std::int64_t r);
+  std::int64_t Mod(std::int64_t l, std::int64_t r);
+
 private:
   std::string::size_type InputBufferPos;
   std::string InputBuffer;