From 2c102a62e042811097f446ea24a197e03c50304c Mon Sep 17 00:00:00 2001
From: Jeff Young <jeff@rokeby.ie>
Date: Fri, 12 Sep 2025 20:34:54 +0100
Subject: [PATCH] Auto-convert numeric values in fields when referencing them
 in expressions.

Fixes https://gitlab.com/kicad/code/kicad/-/issues/21723
---
 common/eda_units.cpp         | 98 ++++++++++++++++++++++++++++++++++++
 include/eda_units.h          |  3 ++
 pcbnew/pcbexpr_evaluator.cpp | 39 +++++++-------
 3 files changed, 123 insertions(+), 17 deletions(-)

diff --git a/common/eda_units.cpp b/common/eda_units.cpp
index a835cebcd5..7ea9ef5ece 100644
--- a/common/eda_units.cpp
+++ b/common/eda_units.cpp
@@ -708,6 +708,104 @@ double EDA_UNIT_UTILS::UI::DoubleValueFromString( const EDA_IU_SCALE& aIuScale,
 }
 
 
+bool EDA_UNIT_UTILS::UI::DoubleValueFromString( const EDA_IU_SCALE& aIuScale, const wxString& aTextValue,
+                                                double& aDoubleValue )
+{
+    double dtmp = 0;
+
+    // Acquire the 'right' decimal point separator
+    const struct lconv* lc = localeconv();
+
+    wxChar      decimal_point = lc->decimal_point[0];
+    wxString    buf( aTextValue.Strip( wxString::both ) );
+
+    // Convert any entered decimal point separators to the 'right' one
+    buf.Replace( wxT( "." ), wxString( decimal_point, 1 ) );
+    buf.Replace( wxT( "," ), wxString( decimal_point, 1 ) );
+
+    // Find the end of the numeric part
+    unsigned brk_point = 0;
+
+    while( brk_point < buf.Len() )
+    {
+        wxChar ch = buf[brk_point];
+
+        if( !( (ch >= '0' && ch <= '9') || (ch == decimal_point) || (ch == '-') || (ch == '+') ) )
+            break;
+
+        ++brk_point;
+    }
+
+    if( brk_point == 0 )
+        return false;
+
+    // Extract the numeric part
+    buf.Left( brk_point ).ToDouble( &dtmp );
+
+    // Check the unit designator
+    wxString  unit( buf.Mid( brk_point ).Strip( wxString::both ).Lower() );
+    EDA_UNITS units;
+
+    //check for um, μm (µ is MICRO SIGN) and µm (µ is GREEK SMALL LETTER MU) for micrometre
+    if( unit == wxT( "um" ) || unit == wxT( "\u00B5m" ) || unit == wxT( "\u03BCm" ) )
+    {
+        units = EDA_UNITS::UM;
+    }
+    else if( unit == wxT( "mm" ) )
+    {
+        units = EDA_UNITS::MM;
+    }
+    else if( unit == wxT( "cm" ) )
+    {
+        units = EDA_UNITS::CM;
+    }
+    else if( unit == wxT( "mil" ) || unit == wxT( "mils" ) || unit == wxT( "thou" ) )
+    {
+        units = EDA_UNITS::MILS;
+    }
+    else if( unit == wxT( "in" ) || unit == wxT( "\"" ) )
+    {
+        units = EDA_UNITS::INCH;
+    }
+    else if( unit == wxT( "oz" ) ) // 1 oz = 1.37 mils
+    {
+        units = EDA_UNITS::MILS;
+        dtmp *= 1.37;
+    }
+    else if( unit == wxT( "ra" ) ) // Radians
+    {
+        dtmp *= 180.0f / M_PI;
+    }
+    else if( unit == wxT( "fs" ) )
+    {
+        units = EDA_UNITS::FS;
+    }
+    else if( unit == wxT( "ps" ) )
+    {
+        units = EDA_UNITS::PS;
+    }
+    else if( unit == wxT( "ps/in" ) )
+    {
+        units = EDA_UNITS::PS_PER_INCH;
+    }
+    else if( unit == wxT( "ps/cm" ) )
+    {
+        units = EDA_UNITS::PS_PER_CM;
+    }
+    else if( unit == wxT( "ps/mm" ) )
+    {
+        units = EDA_UNITS::PS_PER_MM;
+    }
+    else
+    {
+        return false;
+    }
+
+    aDoubleValue = FromUserUnit( aIuScale, units, dtmp );
+    return true;
+}
+
+
 long long int EDA_UNIT_UTILS::UI::ValueFromString( const EDA_IU_SCALE& aIuScale, EDA_UNITS aUnits,
                                                    const wxString& aTextValue, EDA_DATA_TYPE aType )
 {
diff --git a/include/eda_units.h b/include/eda_units.h
index d70a5e8c58..5820b2f7d8 100644
--- a/include/eda_units.h
+++ b/include/eda_units.h
@@ -256,6 +256,9 @@ namespace EDA_UNIT_UTILS
 
         KICOMMON_API double DoubleValueFromString( const wxString& aTextValue );
 
+        KICOMMON_API bool DoubleValueFromString( const EDA_IU_SCALE& aIuScale, const wxString& aTextValue,
+                                                 double& aDoubleValue );
+
         /**
          * Convert \a aTextValue in \a aUnits to internal units used by the application.
          *
diff --git a/pcbnew/pcbexpr_evaluator.cpp b/pcbnew/pcbexpr_evaluator.cpp
index 0089de2e0a..78b2524b53 100644
--- a/pcbnew/pcbexpr_evaluator.cpp
+++ b/pcbnew/pcbexpr_evaluator.cpp
@@ -447,28 +447,33 @@ LIBEVAL::VALUE* PCBEXPR_VAR_REF::GetValue( LIBEVAL::CONTEXT* aCtx )
 
                 if( it->second->Name() == wxT( "Pin Type" ) )
                     return new PCBEXPR_PINTYPE_VALUE( str );
-                else
-                    return new LIBEVAL::VALUE( str );
+
+                // If it quacks like a duck, it is a duck
+                double doubleVal;
+
+                if( EDA_UNIT_UTILS::UI::DoubleValueFromString( pcbIUScale, str, doubleVal ) )
+                    return new LIBEVAL::VALUE( doubleVal );
+
+                return new LIBEVAL::VALUE( str );
             }
-            else
+            else if( it->second->Name() == wxT( "Layer" )
+                        || it->second->Name() == wxT( "Layer Top" )
+                        || it->second->Name() == wxT( "Layer Bottom" ) )
             {
                 const wxAny& any = item->Get( it->second );
                 PCB_LAYER_ID layer;
 
-                if( it->second->Name() == wxT( "Layer" )
-                        || it->second->Name() == wxT( "Layer Top" )
-                        || it->second->Name() == wxT( "Layer Bottom" ) )
-                {
-                    if( any.GetAs<PCB_LAYER_ID>( &layer ) )
-                        return new PCBEXPR_LAYER_VALUE( layer );
-                    else if( any.GetAs<wxString>( &str ) )
-                        return new PCBEXPR_LAYER_VALUE( context->GetBoard()->GetLayerID( str ) );
-                }
-                else
-                {
-                    if( any.GetAs<wxString>( &str ) )
-                        return new LIBEVAL::VALUE( str );
-                }
+                if( any.GetAs<PCB_LAYER_ID>( &layer ) )
+                    return new PCBEXPR_LAYER_VALUE( layer );
+                else if( any.GetAs<wxString>( &str ) )
+                    return new PCBEXPR_LAYER_VALUE( context->GetBoard()->GetLayerID( str ) );
+            }
+            else
+            {
+                const wxAny& any = item->Get( it->second );
+
+                if( any.GetAs<wxString>( &str ) )
+                    return new LIBEVAL::VALUE( str );
             }
 
             return new LIBEVAL::VALUE();