Fix wrong expected output for default_in_statics.cpp/unsafe test and shared reference to mutable static errors

[Copilot]

• Understand the root cause (rule template &a1 text fragment not going through ConvertVarInit)
• Revert the ConvertVarInit change
• Fix ConvertIRFragment to upgrade & → &raw const/mut before global variable placeholders
• Run tests to validate

[lucic71]

Use PushParen instead

[nunoplopes]

@copilot comply with this review.

[lucic71]

Use PushParen instead

[nunoplopes]

@copilot comply with this review.

[nunoplopes]

@copilot Use PushParen instead instead of explicitly outputting open and close parenthesis here and in the other changed code.

[nunoplopes]

@lucic71 please have a look

[nunoplopes]

@copilot woff2 and brunsli still don't compile:

error: creating a shared reference to mutable static
    --> src/bin/woff2_compress.rs:1421:9
     |
1421 |         &kDsigTableTag_3,
     |         ^^^^^^^^^^^^^^^^ shared reference to mutable static
     |
     = note: shared references to mutable statics are dangerous; it's undefined behavior if the static is mutated or if a mutable reference is created for it while the shared reference lives
     = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2024/static-mut-references.html>
     = note: `#[deny(static_mut_refs)]` (part of `#[deny(rust_2024_compatibility)]`) on by default
help: use `&raw const` instead to create a raw pointer
     |
1421 |         &raw const kDsigTableTag_3,
     |          +++++++++

error: could not compile `woff2_unsafe` (bin "woff2_compress") due to 1 previous error

C++ code:

static const uint32_t kDsigTableTag = 0x44534947;

bool RemoveDigitalSignature(Font* font) {
  std::map<uint32_t, Font::Table>::iterator it =
      font->tables.find(kDsigTableTag);
  if (it != font->tables.end()) {
    font->tables.erase(it);
    font->num_tables = font->tables.size();
  }
  return true;
}

Rust code currently generated:

pub unsafe fn RemoveDigitalSignature_48(mut font: *mut woff2_Font) -> bool {
    let mut it: UnsafeMapIterator<u32, woff2_Font_Table> = UnsafeMapIterator::find_key(
        &(*font).tables as *const BTreeMap<u32, Box<woff2_Font_Table>>,
        &kDsigTableTag_3,
    );
    if it != UnsafeMapIterator::end(&(*font).tables as *const BTreeMap<u32, Box<woff2_Font_Table>>)
    {
        UnsafeMapIterator::erase(
            &(*font).tables as *const BTreeMap<u32, Box<woff2_Font_Table>>,
            &it.clone(),
        );
        (*font).num_tables = ((*font).tables.len() as u64 as u16).clone();
    }
    return true;
}

[Copilot]

@copilot woff2 and brunsli still don't compile:

error: creating a shared reference to mutable static

...

Fixed in the latest commit. The root cause was in ConvertVarInit: when a file-scope static variable was implicitly bound to a const T& (or T&) parameter, the code emitted &varname (a Rust shared/mutable reference), which is forbidden for static mut in Rust 2024.

The fix checks IsGlobalVar(expr) at the point where the reference prefix is emitted and substitutes &raw const / &raw mut accordingly:

// Before
StrCat(token::kRef);
if (IsMut(qual_type)) { StrCat(keyword_mut_); }

// After
if (IsGlobalVar(expr)) {
    StrCat("&raw");
    StrCat(IsMut(qual_type) ? keyword_mut_ : keyword::kConst);
} else {
    StrCat(token::kRef);
    if (IsMut(qual_type)) { StrCat(keyword_mut_); }
}

This produces &raw const kDsigTableTag_3 as *const u32 instead of &kDsigTableTag_3 as *const u32.

[lucic71]

Doing string manipulation on the text fragments is fragile. Prefer adding new attributes in the IR if this change is necessary.

[lucic71]

This is not the right place to check against global variables. Prefer to propagate a flag from here to VisitVarDecl

[lucic71]

This is not good. The logic here should go into VisitMemberExpr and VisitArraySubscriptExpr