Initialize global variables before starting main

Author: lucic71

cpp2rust/converter/converter.cpp

@@ -26,6 +26,7 @@ namespace cpp2rust {
 std::unordered_map<std::string, std::string> Converter::inner_structs_;
 std::unordered_set<std::string> Converter::decl_ids_;
 std::unordered_set<std::string> Converter::globals_;
+std::vector<std::string> Converter::global_inits_;
 std::unordered_set<std::string> Converter::abstract_structs_;
 Converter::RecordIndex Converter::record_decls_;
 std::map<std::string, Converter::MethodsOnPtr> Converter::methods_on_ptr_;
@@ -74,6 +75,23 @@ std::string Converter::EmitMethodsOnPtr() {
   return out;
 }
 
+std::string Converter::ForceGlobalInit(const clang::VarDecl *decl) {
+  return std::format("std::cell::LazyCell::force(&*&raw const {});",
+                     GetNamedDeclAsString(decl));
+}
+
+std::string Converter::EmitGlobalInits(Model model) {
+  std::string out = model == Model::kUnsafe
+                        ? "pub unsafe fn __cpp2rust_init_globals() {\n"
+                        : "pub fn __cpp2rust_init_globals() {\n";
+  for (const auto &line : global_inits_) {
+    out += line;
+    out += '\n';
+  }
+  out += "}\n";
+  return out;
+}
+
 std::string Converter::EmitOpaqueRecords() {
   std::string out;
   record_decls_.ForEachUndefined([&](const std::string &name) {
@@ -512,6 +530,7 @@ bool Converter::ConvertVarDeclSkipInit(clang::VarDecl *decl) {
     StrCat(AccessSpecifierAsString(decl->getAccess()), keyword::kStatic,
            keyword_mut_);
     ENSURE(decl_ids_.insert(GetID(decl)).second);
+    global_inits_.push_back(ForceGlobalInit(decl));
   } else if (decl->isStaticLocal()) {
     StrCat(keyword::kStatic, keyword_mut_);
   } else if (decl->isLocalVarDecl()) {
@@ -4180,14 +4199,15 @@ pub fn main() {{
     let mut argv: Vec<*mut libc::c_char> = args.iter().map(|arg| arg.as_ptr() as *mut libc::c_char).collect();
     argv.push(::std::ptr::null_mut());
     unsafe {{
+        __cpp2rust_init_globals();
         ::std::process::exit(main_0((argv.len() - 1) as i32, argv.as_mut_ptr()) as i32)
     }}
 }})",
                        main_function_name));
   } else {
-    StrCat(std::format(
-        "pub fn main() {{ unsafe {{ std::process::exit({}() as i32); }} }}",
-        main_function_name));
+    StrCat(std::format("pub fn main() {{ unsafe {{ __cpp2rust_init_globals(); "
+                       "std::process::exit({}() as i32); }} }}",
+                       main_function_name));
   }
 }
 

cpp2rust/converter/converter.h

@@ -18,6 +18,7 @@
 #include <vector>
 
 #include "converter/converter_lib.h"
+#include "converter/factory.h"
 #include "converter/lex.h"
 #include "converter/translation_rule.h"
 #include "logging.h"
@@ -52,6 +53,7 @@ class Converter : public clang::RecursiveASTVisitor<Converter> {
   virtual void EmitFilePreamble();
 
   static std::string EmitOpaqueRecords();
+  static std::string EmitGlobalInits(Model model);
 
   static std::string EmitMethodsOnPtr();
 
@@ -99,6 +101,7 @@ class Converter : public clang::RecursiveASTVisitor<Converter> {
 
   virtual bool VisitVarDecl(clang::VarDecl *decl);
   virtual bool LazyStaticInit() const { return true; }
+  virtual std::string ForceGlobalInit(const clang::VarDecl *decl);
 
   void ConvertVarDecl(clang::VarDecl *decl);
 
@@ -1016,6 +1019,7 @@ class Converter : public clang::RecursiveASTVisitor<Converter> {
   std::vector<ExprKind> curr_expr_kind_;
   static std::unordered_map<std::string, std::string> inner_structs_;
   static std::unordered_set<std::string> globals_;
+  static std::vector<std::string> global_inits_;
   clang::Sema *sema_ = nullptr;
 };
 } // namespace cpp2rust

cpp2rust/converter/models/converter_refcount.cpp

@@ -2410,6 +2410,12 @@ void ConverterRefCount::ConvertPointerSubscript(
   }
 }
 
+std::string ConverterRefCount::ForceGlobalInit(const clang::VarDecl *decl) {
+  const auto *clone =
+      decl->getType()->isReferenceType() ? "Ptr::clone" : "Value::clone";
+  return std::format("let _ = {}.with({});", GetNamedDeclAsString(decl), clone);
+}
+
 void ConverterRefCount::ConvertFunctionMain(
     const clang::FunctionDecl *decl,
     const std::string_view main_function_name) {
@@ -2423,12 +2429,14 @@ pub fn main() {{
         argv.iter().map(|x| {{ x.borrow_mut().push(0); x.as_pointer() }}).collect(),
     ));
     (*argv.borrow_mut()).push(Ptr::null());
+    __cpp2rust_init_globals();
     ::std::process::exit({}(::std::env::args().len() as i32,
                                 argv.as_pointer()));
 }})",
                        main_function_name));
   } else {
-    StrCat(std::format("pub fn main() {{ std::process::exit({}()); }}",
+    StrCat(std::format("pub fn main() {{ __cpp2rust_init_globals(); "
+                       "std::process::exit({}()); }}",
                        main_function_name));
   }
 }

cpp2rust/converter/models/converter_refcount.h

@@ -80,6 +80,7 @@ class ConverterRefCount final : public Converter {
 
   bool VisitVarDecl(clang::VarDecl *decl) override;
   bool LazyStaticInit() const override { return false; }
+  std::string ForceGlobalInit(const clang::VarDecl *decl) override;
 
   void ConvertGlobalVarDecl(clang::VarDecl *decl) override;
 

cpp2rust/cpp2rust_lib.cpp

@@ -32,6 +32,7 @@ std::string TranspileSrc(std::string_view cc_code, Model model,
       filename.ends_with(".c") ? CLANG_C_COMPILER : CLANG_CXX_COMPILER);
   rs_code += Converter::EmitOpaqueRecords();
   rs_code += Converter::EmitMethodsOnPtr();
+  rs_code += Converter::EmitGlobalInits(model);
   return rs_code;
 }
 
@@ -73,6 +74,7 @@ std::string TranspileDir(std::string_view build_dir, Model model,
   Tool.run(&factory);
   rs_code += Converter::EmitOpaqueRecords();
   rs_code += Converter::EmitMethodsOnPtr();
+  rs_code += Converter::EmitGlobalInits(model);
   return rs_code;
 }
 } // namespace cpp2rust

tests/multi-file/cross_tu_anon_enum_collision/out/refcount/cross_tu_anon_enum_collision.rs

@@ -14,6 +14,7 @@ pub fn a_value_1() -> i32 {
     return (*x.borrow());
 }
 pub fn main() {
+    __cpp2rust_init_globals();
     std::process::exit(main_0());
 }
 fn main_0() -> i32 {
@@ -28,3 +29,4 @@ pub fn b_value_2() -> i32 {
     (*x.borrow_mut()) |= (anon_3_BETA as i32);
     return (*x.borrow());
 }
+pub fn __cpp2rust_init_globals() {}

tests/multi-file/cross_tu_anon_enum_collision/out/unsafe/cross_tu_anon_enum_collision.rs

@@ -15,6 +15,7 @@ pub unsafe fn a_value_1() -> i32 {
 }
 pub fn main() {
     unsafe {
+        __cpp2rust_init_globals();
         std::process::exit(main_0() as i32);
     }
 }
@@ -30,3 +31,4 @@ pub unsafe fn b_value_2() -> i32 {
     x |= (anon_3_BETA as i32);
     return x;
 }
+pub unsafe fn __cpp2rust_init_globals() {}

tests/multi-file/cross_tu_tag_collision/out/refcount/cross_tu_tag_collision.rs

@@ -36,6 +36,7 @@ pub fn a_value_0() -> i32 {
     return (*(*w.borrow()).id.borrow());
 }
 pub fn main() {
+    __cpp2rust_init_globals();
     std::process::exit(main_0());
 }
 fn main_0() -> i32 {
@@ -51,3 +52,4 @@ pub fn b_value_1() -> i32 {
     let w: Value<widget_enum> = Rc::new(RefCell::new(widget_enum_WIDGET_C));
     return ((*w.borrow()) as i32);
 }
+pub fn __cpp2rust_init_globals() {}

tests/multi-file/cross_tu_tag_collision/out/unsafe/cross_tu_tag_collision.rs

@@ -18,6 +18,7 @@ pub unsafe fn a_value_0() -> i32 {
 }
 pub fn main() {
     unsafe {
+        __cpp2rust_init_globals();
         std::process::exit(main_0() as i32);
     }
 }
@@ -34,3 +35,4 @@ pub unsafe fn b_value_1() -> i32 {
     let mut w: widget_enum = widget_enum_WIDGET_C;
     return (w as i32);
 }
+pub unsafe fn __cpp2rust_init_globals() {}

tests/multi-file/extern_functions/out/refcount/extern_functions.rs

@@ -7,6 +7,7 @@ use std::io::{Read, Seek, Write};
 use std::os::fd::AsFd;
 use std::rc::{Rc, Weak};
 pub fn main() {
+    __cpp2rust_init_globals();
     std::process::exit(main_0());
 }
 fn main_0() -> i32 {
@@ -29,3 +30,4 @@ pub fn helper_0(x: i32) -> i32 {
     &({ unrelated3_3() });
     return ((*x.borrow()) + 1);
 }
+pub fn __cpp2rust_init_globals() {}