Run static initializers

Author: bjorn3

src/tools/miri/src/bin/miri.rs

@@ -32,8 +32,9 @@ use rustc_driver::Compilation;
 use rustc_hir::{selfas hir,Node};
 use rustc_interface::interface::Config;
 use rustc_middle::{
- middle::exported_symbols::{
-ExportedSymbol,SymbolExportInfo,SymbolExportKind,SymbolExportLevel,
+ middle::{
+ codegen_fn_attrs::CodegenFnAttrFlags,
+ exported_symbols::{ExportedSymbol,SymbolExportInfo,SymbolExportKind,SymbolExportLevel},
 },
  query::LocalCrate,
  ty::TyCtxt,
@@ -136,6 +137,8 @@ impl rustc_driver::Callbacks for MiriBeRustCompilerCalls {
  config.override_queries = Some(|_, local_providers| {
 // `exported_symbols` and `reachable_non_generics` provided by rustc always returns
 // an empty result if `tcx.sess.opts.output_types.should_codegen()` is false.
+// In addition we need to add #[used] symbols to exported_symbols for .init_array
+// handling.
  local_providers.exported_symbols = |tcx,LocalCrate| {
 let reachable_set = tcx.with_stable_hashing_context(|hcx| {
  tcx.reachable_set(()).to_sorted(&hcx,true)
@@ -160,19 +163,28 @@ impl rustc_driver::Callbacks for MiriBeRustCompilerCalls {
 })
 if !tcx.generics_of(local_def_id).requires_monomorphization(tcx)
 );
-(is_reachable_non_generic
- && tcx.codegen_fn_attrs(local_def_id).contains_extern_indicator())
-.then_some((
-ExportedSymbol::NonGeneric(local_def_id.to_def_id()),
-// Some dummy `SymbolExportInfo` here. We only use
-// `exported_symbols` in shims/foreign_items.rs and the export info
-// is ignored.
-SymbolExportInfo{
-level:SymbolExportLevel::C,
-kind:SymbolExportKind::Text,
-used:false,
-},
-))
+if !is_reachable_non_generic {
+returnNone;
+}
+let codegen_fn_attrs = tcx.codegen_fn_attrs(local_def_id);
+if codegen_fn_attrs.contains_extern_indicator()
+ || codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::USED)
+ || codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::USED_LINKER)
+{
+Some((
+ExportedSymbol::NonGeneric(local_def_id.to_def_id()),
+// Some dummy `SymbolExportInfo` here. We only use
+// `exported_symbols` in shims/foreign_items.rs and the export info
+// is ignored.
+SymbolExportInfo{
+level:SymbolExportLevel::C,
+kind:SymbolExportKind::Text,
+used:false,
+},
+))
+}else{
+None
+}
 }),
 )
 }

src/tools/miri/src/shims/foreign_items.rs

@@ -158,6 +158,81 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
 Ok(())
 }
 
+fnlookup_init_array(&mutself) -> InterpResult<'tcx,Vec<ty::Instance<'tcx>>>{
+let this = self.eval_context_mut();
+let tcx = this.tcx.tcx;
+
+letmut init_arrays = vec![];
+
+let dependency_formats = tcx.dependency_formats(());
+let dependency_format = dependency_formats
+.iter()
+.find(|(crate_type, _)| *crate_type == CrateType::Executable)
+.expect("interpreting a non-executable crate");
+for cnum in iter::once(LOCAL_CRATE).chain(
+ dependency_format.1.iter().enumerate().filter_map(|(num,&linkage)| {
+// We add 1 to the number because that's what rustc also does everywhere it
+// calls `CrateNum::new`...
+#[allow(clippy::arithmetic_side_effects)]
+(linkage != Linkage::NotLinked).then_some(CrateNum::new(num + 1))
+}),
+){
+for&(symbol, _export_info)in tcx.exported_symbols(cnum){
+ifletExportedSymbol::NonGeneric(def_id) = symbol {
+let attrs = tcx.codegen_fn_attrs(def_id);
+let link_section = ifletSome(link_section) = attrs.link_section{
+if !link_section.as_str().starts_with(".init_array"){
+continue;
+}
+ link_section
+}else{
+continue;
+};
+
+ init_arrays.push((link_section, def_id));
+}
+}
+}
+
+ init_arrays.sort_by(|(a, _),(b, _)| a.as_str().cmp(b.as_str()));
+
+let endianness = tcx.data_layout.endian;
+let ptr_size = tcx.data_layout.pointer_size;
+
+letmut init_array = vec![];
+
+for(_, def_id)in init_arrays {
+let alloc = tcx.eval_static_initializer(def_id)?.inner();
+letmut expected_offset = Size::ZERO;
+for&(offset, prov)in alloc.provenance().ptrs().iter(){
+if offset != expected_offset {
+throw_ub_format!(".init_array.* may not contain any non-function pointer data");
+}
+ expected_offset += ptr_size;
+
+let alloc_id = prov.alloc_id();
+
+let reloc_target_alloc = tcx.global_alloc(alloc_id);
+match reloc_target_alloc {
+GlobalAlloc::Function(instance) => {
+let addend = {
+let offset = offset.bytes()asusize;
+let bytes = &alloc.inspect_with_uninit_and_ptr_outside_interpreter(
+ offset..offset + ptr_size.bytes()asusize,
+);
+read_target_uint(endianness, bytes).unwrap()
+};
+assert_eq!(addend,0);
+ init_array.push(instance);
+}
+ _ => throw_ub_format!(".init_array.* member is not a function pointer"),
+}
+}
+}
+
+Ok(init_array)
+}
+
 /// Lookup the body of a function that has `link_name` as the symbol name.
 fnlookup_exported_symbol(
 &mutself,