Commit 270933b1e9

@@ -10882,7 +10882,9 @@ static IrInstruction *ir_analyze_int_to_c_ptr(IrAnalyze *ira, IrInstruction *sou
             ira->codegen->builtin_types.entry_usize->data.integral.bit_count)
         {
             ir_add_error(ira, source_instr,
-                buf_sprintf("integer type too big for implicit @intToPtr to type '%s'", buf_ptr(&dest_type->name)));
+                buf_sprintf("integer type '%s' too big for implicit @intToPtr to type '%s'",
+                    buf_ptr(&integer->value.type->name),
+                    buf_ptr(&dest_type->name)));
             return ira->codegen->invalid_instruction;
         }
 

@@ -1,6 +1,20 @@
 const tests = @import("tests.zig");
 
 pub fn addCases(cases: *tests.CompileErrorContext) void {
+    cases.addTest(
+        "implicit casting too big integers to C pointers",
+        \\export fn a() void {
+        \\    var ptr: [*c]u8 = (1 << 64) + 1;
+        \\}
+        \\export fn b() void {
+        \\    var x: @IntType(false, 65) = 0x1234;
+        \\    var ptr: [*c]u8 = x;
+        \\}
+    ,
+        ".tmp_source.zig:2:33: error: integer value 71615590737044764481 cannot be implicitly casted to type 'usize'",
+        ".tmp_source.zig:6:23: error: integer type 'u65' too big for implicit @intToPtr to type '[*c]u8'",
+    );
+
     cases.addTest(
         "C pointer pointing to non C ABI compatible type",
         \\const Foo = struct {};