From cc1a060dfff7ce792aab99364638a85efdbeb2a0 Mon Sep 17 00:00:00 2001
From: Tete17 <miguel_tete17@hotmail.com>
Date: Sun, 29 Mar 2026 13:55:10 +0200
Subject: [PATCH] Fix strict-aliasing violations in number.vala,
 math-equation.vala, and buttons-programming.vala

Replace pointer type-punning casts with Memory.copy (memcpy) to comply
with C strict-aliasing rules. The old casts (e.g. *(uint32*) &real)
caused compilation failures with -Werror=strict-aliasing.

Also add -Werror=strict-aliasing to the default GCC project arguments
to prevent future regressions.

Closes #520
---
 lib/math-equation.vala       | 21 +++++++++++++++++----
 lib/number.vala              | 30 ++++++++++++++++++++++++------
 meson.build                  |  1 +
 src/buttons-programming.vala |  8 ++++++--
 4 files changed, 48 insertions(+), 12 deletions(-)

diff --git a/lib/math-equation.vala b/lib/math-equation.vala
index 0619022b..ed05607d 100644
--- a/lib/math-equation.vala
+++ b/lib/math-equation.vala
@@ -1635,12 +1635,16 @@ public class MathEquation : GtkSource.Buffer
             if (word_size == 64)
             {
                 double d = x.to_double ();
-                bits = *(uint64*) &d;
+                uint64 dbits = 0;
+                Memory.copy (&dbits, &d, sizeof (double));
+                bits = dbits;
             }
             else
             {
                 float f = x.to_float ();
-                bits = *(uint32*) &f;
+                uint32 fbits = 0;
+                Memory.copy (&fbits, &f, sizeof (float));
+                bits = fbits;
             }
         }
         else if (x.is_negative ())
@@ -1656,9 +1660,18 @@ public class MathEquation : GtkSource.Buffer
         if (is_float)
         {
             if (word_size == 64)
-                x = new Number.double (*(double*) &bits);
+            {
+                double d = 0;
+                Memory.copy (&d, &bits, sizeof (double));
+                x = new Number.double (d);
+            }
             else
-                x = new Number.float (*(float*) &bits);
+            {
+                uint32 fbits = (uint32) bits;
+                float f = 0;
+                Memory.copy (&f, &fbits, sizeof (float));
+                x = new Number.float (f);
+            }
             x.set_force_float (true);
         }
         else if (x.is_negative ())
diff --git a/lib/number.vala b/lib/number.vala
index ddab6fe6..f45565b0 100644
--- a/lib/number.vala
+++ b/lib/number.vala
@@ -87,7 +87,9 @@ public class Number : GLib.Object
             num.set_double (real, imag);
         else
         {
-            num.set_unsigned_integer ((ulong) *(uint32*) &real, 0);
+            uint32 bits = 0;
+            Memory.copy (&bits, &real, sizeof (uint32));
+            num.set_unsigned_integer ((ulong) bits, 0);
             finite = false;
         }
     }
@@ -98,7 +100,9 @@ public class Number : GLib.Object
             num.set_double (real, imag);
         else
         {
-            num.set_unsigned_integer ((ulong) *(uint64*) &real, 0);
+            uint64 bits = 0;
+            Memory.copy (&bits, &real, sizeof (uint64));
+            num.set_unsigned_integer ((ulong) bits, 0);
             finite = false;
         }
     }
@@ -162,8 +166,15 @@ public class Number : GLib.Object
         {
             uint64 bits = to_unsigned_integer ();
             if (bits > uint32.MAX)
-                return (float) *(double*) &bits;
-            return *(float*) &bits;
+            {
+                double d = 0;
+                Memory.copy (&d, &bits, sizeof (double));
+                return (float) d;
+            }
+            uint32 bits32 = (uint32) bits;
+            float f = 0;
+            Memory.copy (&f, &bits32, sizeof (float));
+            return f;
         }
         return num.get_real ().val.get_float (MPFR.Round.NEAREST);
     }
@@ -174,8 +185,15 @@ public class Number : GLib.Object
         {
             uint64 bits = to_unsigned_integer ();
             if (bits > uint32.MAX)
-                return *(double*) &bits;
-            return (double) *(float*) &bits;
+            {
+                double d = 0;
+                Memory.copy (&d, &bits, sizeof (double));
+                return d;
+            }
+            uint32 bits32 = (uint32) bits;
+            float f = 0;
+            Memory.copy (&f, &bits32, sizeof (float));
+            return (double) f;
         }
         return num.get_real ().val.get_double (MPFR.Round.NEAREST);
     }
diff --git a/meson.build b/meson.build
index 1b669de9..c86389c0 100644
--- a/meson.build
+++ b/meson.build
@@ -58,6 +58,7 @@ if cc.get_id() == 'gcc'
     '-Wno-discarded-qualifiers',
     '-DVALA_STRICT_C', '-Wno-incompatible-pointer-types',
     '-Wno-unused-variable', '-Wno-unused-but-set-variable',
+    '-Werror=strict-aliasing',
     language : 'c'
   )
 endif
diff --git a/src/buttons-programming.vala b/src/buttons-programming.vala
index 33f2e08c..81f48411 100644
--- a/src/buttons-programming.vala
+++ b/src/buttons-programming.vala
@@ -231,12 +231,16 @@ public class ProgrammingButtonPanel : Adw.BreakpointBin
                 if (equation.word_size == 64)
                 {
                     double d = x.to_double ();
-                    bits = *(uint64*) &d;
+                    uint64 dbits = 0;
+                    Memory.copy (&dbits, &d, sizeof (double));
+                    bits = dbits;
                 }
                 else if (equation.word_size == 32)
                 {
                     float f = x.to_float ();
-                    bits = *(uint32*) &f;
+                    uint32 fbits = 0;
+                    Memory.copy (&fbits, &f, sizeof (float));
+                    bits = fbits;
                 }
                 else
                     enabled = false;
-- 
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