From 8b1013b3e75b4d06f67c9346ddcb632c264648ec Mon Sep 17 00:00:00 2001
From: David Gonzalez Martin <davidgmbb@gmail.com>
Date: Mon, 24 Mar 2025 12:44:18 +0100
Subject: [PATCH] Implement `integer_max`

---
 src/compiler.bbb       | 14 +++++++++++++-
 src/converter.zig      | 33 ++++++++++++++++++++++++++++++++-
 src/converter_test.zig |  4 ++++
 tests/integer_max.bbb  |  5 +++++
 4 files changed, 54 insertions(+), 2 deletions(-)
 create mode 100644 tests/integer_max.bbb

diff --git a/src/compiler.bbb b/src/compiler.bbb
index 51cff58..f42a28d 100644
--- a/src/compiler.bbb
+++ b/src/compiler.bbb
@@ -38,6 +38,8 @@ OS_Linux_MAP = bits u32
     _: u5,
 }
 
+[extern] mmap = fn [cc(c)] (address: u64, size: u64, protection: OS_Linux_PROT, map: OS_Linux_MAP, file_descriptor: s32, offset: s64) &u8;
+
 OS_ProtectionFlags = bits
 {
     read: u1,
@@ -74,8 +76,18 @@ os_linux_map_flags = fn(map_flags: OS_MapFlags) OS_Linux_MAP
     };
 }
 
-os_reserve = fn (base: u64, protection: OS_ProtectionFlags, map: OS_MapFlags) &u8
+os_reserve = fn (base: u64, size: u64, protection: OS_ProtectionFlags, map: OS_MapFlags) &u8
 {
+    >protection_flags = os_linux_protection_flags(protection);
+    >map_flags = os_linux_map_flags(map);
+    >address = mmap(base, size, protection_flags, map_flags, -1, 0);
+    //if (address == #integer_max(u64))
+    //{
+    //    unreachable;
+    //}
+    //else
+    //{
+    //}
 }
 
 Arena = struct
diff --git a/src/converter.zig b/src/converter.zig
index 9ad76b2..5991c67 100644
--- a/src/converter.zig
+++ b/src/converter.zig
@@ -1802,7 +1802,7 @@ const Converter = struct {
                             };
                             _ = &v;
 
-                            if (coerce_to_type != v.type) {
+                            if (!coerce_to_type.is_abi_equal(v.type)) {
                                 switch (v.type) {
                                     else => @trap(),
                                 }
@@ -2637,6 +2637,7 @@ const Converter = struct {
         cast,
         cast_to,
         extend,
+        integer_max,
         int_from_enum,
         select,
         trap,
@@ -2735,6 +2736,36 @@ const Converter = struct {
 
                 return value;
             },
+            .integer_max => {
+                converter.skip_space();
+                const ty = converter.parse_type(module);
+                converter.expect_character(right_parenthesis);
+                if (ty.bb != .integer) {
+                    converter.report_error();
+                }
+                const bit_count = ty.bb.integer.bit_count;
+                const max_value = if (bit_count == 64) ~@as(u64, 0) else (@as(u64, 1) << @intCast(bit_count - @intFromBool(ty.bb.integer.signed))) - 1;
+                const expected_ty = expected_type orelse ty;
+                if (ty.get_bit_size() > expected_ty.get_bit_size()) {
+                    converter.report_error();
+                }
+                const constant_integer = expected_ty.llvm.handle.to_integer().get_constant(max_value, @intFromBool(false));
+                const value = module.values.add();
+                value.* = .{
+                    .llvm = constant_integer.to_value(),
+                    .type = expected_ty,
+                    .bb = .{
+                        .constant_integer = .{
+                            .value = max_value,
+                            .signed = false,
+                        },
+                    },
+                    .lvalue = false,
+                    .dereference_to_assign = false,
+                };
+
+                return value;
+            },
             .int_from_enum => {
                 const source_value = converter.parse_value(module, null, .value);
                 converter.skip_space();
diff --git a/src/converter_test.zig b/src/converter_test.zig
index bf03b6e..0e944ef 100644
--- a/src/converter_test.zig
+++ b/src/converter_test.zig
@@ -400,3 +400,7 @@ test "select" {
 test "bits_return_u1" {
     try invsrc(@src());
 }
+
+test "integer_max" {
+    try invsrc(@src());
+}
diff --git a/tests/integer_max.bbb b/tests/integer_max.bbb
new file mode 100644
index 0000000..585cf43
--- /dev/null
+++ b/tests/integer_max.bbb
@@ -0,0 +1,5 @@
+[export] main = fn [cc(c)] () s32
+{
+    >a = #integer_max(u64);
+    return #truncate(a + 1);
+}