translate-c: take address of functions before passing them to @ptrToInt

Fixes #12194

4 files changed, 37 insertions, 1 deletions

diff --git a/test/behavior/translate_c_macros.h b/test/behavior/translate_c_macros.h
index 547194d35a..526ab32abc 100644
--- a/test/behavior/translate_c_macros.h
+++ b/test/behavior/translate_c_macros.h
@@ -40,3 +40,11 @@ union U {
 #define CAST_OR_CALL_WITH_PARENS(type_or_fn, val) ((type_or_fn)(val))
 
 #define NESTED_COMMA_OPERATOR (1, (2, 3))
+
+#include <stdint.h>
+#if !defined(__UINTPTR_MAX__)
+typedef _Bool uintptr_t;
+#endif
+
+#define CAST_TO_BOOL(X) (_Bool)(X)
+#define CAST_TO_UINTPTR(X) (uintptr_t)(X)
diff --git a/test/behavior/translate_c_macros.zig b/test/behavior/translate_c_macros.zig
index 96676b5b78..705c60aa4e 100644
--- a/test/behavior/translate_c_macros.zig
+++ b/test/behavior/translate_c_macros.zig
@@ -99,3 +99,17 @@ test "nested comma operator" {
 
     try expectEqual(@as(c_int, 3), h.NESTED_COMMA_OPERATOR);
 }
+
+test "cast functions" {
+    if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
+
+    const S = struct {
+        fn foo() void {}
+    };
+    try expectEqual(true, h.CAST_TO_BOOL(S.foo));
+    try expect(h.CAST_TO_UINTPTR(S.foo) != 0);
+}
diff --git a/test/run_translated_c.zig b/test/run_translated_c.zig
index 1e8f081c11..cfd7f2d15e 100644
--- a/test/run_translated_c.zig
+++ b/test/run_translated_c.zig
@@ -1861,4 +1861,18 @@ pub fn addCases(cases: *tests.RunTranslatedCContext) void {
         \\    return 0;
         \\}
     , "");
+
+    // The C standard does not require function pointers to be convertible to any integer type.
+    // However, POSIX requires that function pointers have the same representation as `void *`
+    // so that dlsym() can work
+    cases.add("Function to integral",
+        \\#include <stdint.h>
+        \\int main(void) {
+        \\#if defined(__UINTPTR_MAX__) && __has_include(<unistd.h>)
+        \\    uintptr_t x = main;
+        \\    x = (uintptr_t)main;
+        \\#endif
+        \\    return 0;
+        \\}
+    , "");
 }
diff --git a/test/translate_c.zig b/test/translate_c.zig
index a1a1736b2b..5a640c5b4b 100644
--- a/test/translate_c.zig
+++ b/test/translate_c.zig
@@ -3435,7 +3435,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
         \\    var x = arg_x;
         \\    var a: bool = @as(c_int, @boolToInt(x)) != @as(c_int, 1);
         \\    var b: bool = @as(c_int, @boolToInt(a)) != @as(c_int, 0);
-        \\    var c: bool = @ptrToInt(foo) != 0;
+        \\    var c: bool = @ptrToInt(&foo) != 0;
         \\    return foo(@as(c_int, @boolToInt(c)) != @as(c_int, @boolToInt(b)));
         \\}
     });