Merge pull request #244 from rust-lang/feature/unwinding

Implement unwinding

Author: antoyo

.github/workflows/ci.yml

@@ -19,9 +19,9 @@ jobs:
       fail-fast: false
       matrix:
         libgccjit_version:
-          - { gcc: "libgccjit.so", extra: "", artifacts_branch: "master" }
-          - { gcc: "libgccjit_without_int128.so", extra: "", artifacts_branch: "master-without-128bit-integers" }
-          - { gcc: "libgccjit12.so", extra: "--no-default-features", artifacts_branch: "gcc12" }
+          - { gcc: "libgccjit.so", extra: "", env_extra: "", artifacts_branch: "master" }
+          - { gcc: "libgccjit_without_int128.so", extra: "", env_extra: "", artifacts_branch: "master-without-128bit-integers" }
+          - { gcc: "libgccjit12.so", extra: "--no-default-features", env_extra: "TEST_FLAGS='-Cpanic=abort -Zpanic-abort-tests'", artifacts_branch: "gcc12" }
         commands: [
           "--mini-tests",
           "--std-tests",
@@ -120,8 +120,8 @@ jobs:
     - name: Build
       run: |
         ./prepare_build.sh
-        ./build.sh ${{ matrix.libgccjit_version.extra }}
-        cargo test ${{ matrix.libgccjit_version.extra }}
+        ${{ matrix.libgccjit_version.env_extra }} ./build.sh ${{ matrix.libgccjit_version.extra }}
+        ${{ matrix.libgccjit_version.env_extra }} cargo test ${{ matrix.libgccjit_version.extra }}
         ./clean_all.sh
 
     - name: Prepare dependencies
@@ -143,7 +143,7 @@ jobs:
 
     - name: Run tests
       run: |
-        ./test.sh --release --clean --build-sysroot ${{ matrix.commands }} ${{ matrix.libgccjit_version.extra }}
+        ${{ matrix.libgccjit_version.env_extra }} ./test.sh --release --clean --build-sysroot ${{ matrix.commands }} ${{ matrix.libgccjit_version.extra }}
 
   duplicates:
     runs-on: ubuntu-latest

Cargo.lock

@@ -162,8 +162,26 @@ To print a debug representation of a tree:
 debug_tree(expr);
 ```
 
+(defined in print-tree.h)
+
+To print a debug reprensentation of a gimple struct:
+
+```c
+debug_gimple_stmt(gimple_struct)
+```
+
 To get the `rustc` command to run in `gdb`, add the `--verbose` flag to `cargo build`.
 
+To have the correct file paths in `gdb` instead of `/usr/src/debug/gcc/libstdc++-v3/libsupc++/eh_personality.cc`, TODO
+
+Maybe by calling the following at the beginning of gdb:
+
+```
+set substitute-path /usr/src/debug/gcc /path/to/gcc-repo/gcc
+```
+
+TODO: but that's not what I remember I was doing.
+
 ### How to use a custom-build rustc
 
  * Build the stage2 compiler (`rustup toolchain link debug-current build/x86_64-unknown-linux-gnu/stage2`).

Readme.md

@@ -16,7 +16,7 @@ rm Cargo.lock test_target/Cargo.lock 2>/dev/null || true
 rm -r sysroot/ 2>/dev/null || true
 
 # Build libs
-export RUSTFLAGS="$RUSTFLAGS -Z force-unstable-if-unmarked -Cpanic=abort"
+export RUSTFLAGS="$RUSTFLAGS -Z force-unstable-if-unmarked"
 if [[ "$1" == "--release" ]]; then
     sysroot_channel='release'
     RUSTFLAGS="$RUSTFLAGS -Zmir-opt-level=3" cargo build --target $TARGET_TRIPLE --release

build_sysroot/build_sysroot.sh

@@ -38,7 +38,7 @@ if [[ "$HOST_TRIPLE" != "$TARGET_TRIPLE" ]]; then
    fi
 fi
 
-export RUSTFLAGS="$CG_RUSTFLAGS $linker -Cpanic=abort -Csymbol-mangling-version=v0 -Cdebuginfo=2 -Clto=off -Zpanic-abort-tests -Zcodegen-backend=$(pwd)/target/${CHANNEL:-debug}/librustc_codegen_gcc.$dylib_ext --sysroot $(pwd)/build_sysroot/sysroot"
+export RUSTFLAGS="$CG_RUSTFLAGS $linker -Csymbol-mangling-version=v0 -Cdebuginfo=2 -Clto=off -Zcodegen-backend=$(pwd)/target/${CHANNEL:-debug}/librustc_codegen_gcc.$dylib_ext --sysroot $(pwd)/build_sysroot/sysroot $TEST_FLAGS"
 
 # FIXME(antoyo): remove once the atomic shim is gone
 if [[ `uname` == 'Darwin' ]]; then

config.sh

@@ -1,4 +1,4 @@
-#![feature(start, box_syntax, core_intrinsics, alloc_error_handler)]
+#![feature(start, box_syntax, core_intrinsics, alloc_error_handler, lang_items)]
 #![no_std]
 
 extern crate alloc;
@@ -26,6 +26,16 @@ fn alloc_error_handler(_: alloc::alloc::Layout) -> ! {
     core::intrinsics::abort();
 }
 
+#[lang = "eh_personality"]
+fn eh_personality() -> ! {
+    loop {}
+}
+
+#[no_mangle]
+unsafe extern "C" fn _Unwind_Resume() {
+    core::intrinsics::unreachable();
+}
+
 #[start]
 fn main(_argc: isize, _argv: *const *const u8) -> isize {
     let world: Box<&str> = box "Hello World!\0";

example/alloc_example.rs

@@ -41,3 +41,29 @@ src/test/ui/sse2.rs
 src/test/ui/statics/issue-91050-1.rs
 src/test/ui/statics/issue-91050-2.rs
 src/test/ui/target-feature/missing-plusminus.rs
+src/test/ui/asm/x86_64/may_unwind.rs
+src/test/ui/backtrace.rs
+src/test/ui/catch-unwind-bang.rs
+src/test/ui/cfg/cfg-panic-abort.rs
+src/test/ui/drop/dynamic-drop-async.rs
+src/test/ui/drop/repeat-drop.rs
+src/test/ui/fmt/format-args-capture.rs
+src/test/ui/generator/panic-drops-resume.rs
+src/test/ui/generator/panic-drops.rs
+src/test/ui/generator/panic-safe.rs
+src/test/ui/intrinsics/panic-uninitialized-zeroed.rs
+src/test/ui/issues/issue-14875.rs
+src/test/ui/issues/issue-29948.rs
+src/test/ui/issues/issue-43853.rs
+src/test/ui/iterators/iter-sum-overflow-debug.rs
+src/test/ui/iterators/iter-sum-overflow-overflow-checks.rs
+src/test/ui/mir/mir_calls_to_shims.rs
+src/test/ui/mir/mir_drop_order.rs
+src/test/ui/mir/mir_let_chains_drop_order.rs
+src/test/ui/oom_unwind.rs
+src/test/ui/panic-runtime/abort-link-to-unwinding-crates.rs
+src/test/ui/panic-runtime/abort.rs
+src/test/ui/panic-runtime/link-to-abort.rs
+src/test/ui/rfc-2091-track-caller/std-panic-locations.rs
+src/test/ui/rfcs/rfc1857-drop-order.rs
+src/test/ui/unwind-no-uwtable.rs

failing-ui-tests.txt

@@ -22,3 +22,12 @@ src/test/ui/simd/intrinsic/inlining-issue67557.rs
 src/test/ui/simd/monomorphize-shuffle-index.rs
 src/test/ui/simd/shuffle.rs
 src/test/ui/simd/simd-bitmask.rs
+src/test/ui/binding/fn-arg-incomplete-pattern-drop-order.rs
+src/test/ui/drop/dynamic-drop.rs
+src/test/ui/generator/resume-after-return.rs
+src/test/ui/iterators/iter-step-overflow-debug.rs
+src/test/ui/macros/rfc-2011-nicer-assert-messages/all-expr-kinds.rs
+src/test/ui/numbers-arithmetic/next-power-of-two-overflow-debug.rs
+src/test/ui/panic-while-printing.rs
+src/test/ui/privacy/reachable-unnameable-items.rs
+src/test/ui/rfc-1937-termination-trait/termination-trait-in-test.rs

failing-ui-tests12.txt

@@ -352,8 +352,7 @@ impl<'a, 'gcc, 'tcx> AsmBuilderMethods<'tcx> for Builder<'a, 'gcc, 'tcx> {
                     inputs.push(AsmInOperand {
                         constraint: "X".into(),
                         rust_idx,
-                        val: self.cx.rvalue_as_function(get_fn(self.cx, instance))
-                            .get_address(None),
+                        val: get_fn(self.cx, instance).get_address(None),
                     });
                 }
 
@@ -739,7 +738,7 @@ impl<'gcc, 'tcx> AsmMethods<'tcx> for CodegenCx<'gcc, 'tcx> {
                         }
 
                         GlobalAsmOperandRef::SymFn { instance } => {
-                            let function = self.rvalue_as_function(get_fn(self, instance));
+                            let function = get_fn(self, instance);
                             self.add_used_function(function);
                             // TODO(@Amanieu): Additional mangling is needed on
                             // some targets to add a leading underscore (Mach-O)

src/asm.rs

@@ -87,6 +87,10 @@ pub fn compile_codegen_unit<'tcx>(tcx: TyCtxt<'tcx>, cgu_name: Symbol, supports_
         // Instantiate monomorphizations without filling out definitions yet...
         //let llvm_module = ModuleLlvm::new(tcx, &cgu_name.as_str());
         let context = Context::default();
+
+        context.add_command_line_option("-fexceptions");
+        context.add_driver_option("-fexceptions");
+
         // TODO(antoyo): only set on x86 platforms.
         context.add_command_line_option("-masm=intel");
         // TODO(antoyo): only add the following cli argument if the feature is supported.
@@ -146,7 +150,7 @@ pub fn compile_codegen_unit<'tcx>(tcx: TyCtxt<'tcx>, cgu_name: Symbol, supports_
             context.set_keep_intermediates(true);
         }
 
-        // TODO(bjorn3): Remove once unwinding is properly implemented
+        // NOTE: The codegen generates unrechable blocks.
         context.set_allow_unreachable_blocks(true);
 
         {

src/base.rs

@@ -372,10 +372,11 @@ impl<'tcx> FnAbiOfHelpers<'tcx> for Builder<'_, '_, 'tcx> {
     }
 }
 
-impl<'gcc, 'tcx> Deref for Builder<'_, 'gcc, 'tcx> {
+impl<'a, 'gcc, 'tcx> Deref for Builder<'a, 'gcc, 'tcx> {
     type Target = CodegenCx<'gcc, 'tcx>;
 
-    fn deref(&self) -> &Self::Target {
+    fn deref<'b>(&'b self) -> &'a Self::Target
+    {
         self.cx
     }
 }
@@ -393,7 +394,7 @@ impl<'gcc, 'tcx> BackendTypes for Builder<'_, 'gcc, 'tcx> {
 }
 
 impl<'a, 'gcc, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'gcc, 'tcx> {
-    fn build(cx: &'a CodegenCx<'gcc, 'tcx>, block: Block<'gcc>) -> Self {
+    fn build(cx: &'a CodegenCx<'gcc, 'tcx>, block: Block<'gcc>) -> Builder<'a, 'gcc, 'tcx> {
         Builder::with_cx(cx, block)
     }
 
@@ -450,8 +451,36 @@ impl<'a, 'gcc, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'gcc, 'tcx> {
         self.block.end_with_switch(None, value, default_block, &gcc_cases);
     }
 
+    #[cfg(feature="master")]
+    fn invoke(&mut self, typ: Type<'gcc>, func: RValue<'gcc>, args: &[RValue<'gcc>], then: Block<'gcc>, catch: Block<'gcc>, _funclet: Option<&Funclet>) -> RValue<'gcc> {
+        let try_block = self.current_func().new_block("try");
+
+        let current_block = self.block.clone();
+        self.block = try_block;
+        let call = self.call(typ, func, args, None); // TODO(antoyo): use funclet here?
+        self.block = current_block;
+
+        let return_value = self.current_func()
+            .new_local(None, call.get_type(), "invokeResult");
+
+        try_block.add_assignment(None, return_value, call);
+
+        try_block.end_with_jump(None, then);
+
+        if self.cleanup_blocks.borrow().contains(&catch) {
+            self.block.add_try_finally(None, try_block, catch);
+        }
+        else {
+            self.block.add_try_catch(None, try_block, catch);
+        }
+
+        self.block.end_with_jump(None, then);
+
+        return_value.to_rvalue()
+    }
+
+    #[cfg(not(feature="master"))]
     fn invoke(&mut self, typ: Type<'gcc>, func: RValue<'gcc>, args: &[RValue<'gcc>], then: Block<'gcc>, catch: Block<'gcc>, _funclet: Option<&Funclet>) -> RValue<'gcc> {
-        // TODO(bjorn3): Properly implement unwinding.
         let call_site = self.call(typ, func, args, None);
         let condition = self.context.new_rvalue_from_int(self.bool_type, 1);
         self.llbb().end_with_conditional(None, condition, then, catch);
@@ -1161,22 +1190,61 @@ impl<'a, 'gcc, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'gcc, 'tcx> {
     }
 
     fn set_personality_fn(&mut self, _personality: RValue<'gcc>) {
-        // TODO(antoyo)
+        #[cfg(feature="master")]
+        {
+            let personality = self.rvalue_as_function(_personality);
+            self.current_func().set_personality_function(personality);
+        }
     }
 
+    #[cfg(feature="master")]
+    fn cleanup_landing_pad(&mut self, _ty: Type<'gcc>, pers_fn: RValue<'gcc>) -> RValue<'gcc> {
+        self.set_personality_fn(pers_fn);
+
+        // NOTE: insert the current block in a variable so that a later call to invoke knows to
+        // generate a try/finally instead of a try/catch for this block.
+        self.cleanup_blocks.borrow_mut().insert(self.block);
+
+        let eh_pointer_builtin = self.cx.context.get_target_builtin_function("__builtin_eh_pointer");
+        let zero = self.cx.context.new_rvalue_zero(self.int_type);
+        let ptr = self.cx.context.new_call(None, eh_pointer_builtin, &[zero]);
+
+        let field1_type = self.u8_type.make_pointer();
+        let field1 = self.context.new_field(None, field1_type, "landing_pad_field_1");
+        let field2 = self.context.new_field(None, self.i32_type, "landing_pad_field_2");
+        let struct_type = self.context.new_struct_type(None, "landing_pad", &[field1, field2]);
+        let value = self.current_func().new_local(None, struct_type.as_type(), "landing_pad");
+        let ptr = self.cx.context.new_cast(None, ptr, field1_type);
+        self.block.add_assignment(None, value.access_field(None, field1), ptr);
+        self.block.add_assignment(None, value.access_field(None, field2), zero); // TODO: set the proper value here (the type of exception?).
+
+        value.to_rvalue()
+    }
+
+    #[cfg(not(feature="master"))]
     fn cleanup_landing_pad(&mut self, _ty: Type<'gcc>, _pers_fn: RValue<'gcc>) -> RValue<'gcc> {
         let field1 = self.context.new_field(None, self.u8_type.make_pointer(), "landing_pad_field_1");
         let field2 = self.context.new_field(None, self.i32_type, "landing_pad_field_1");
         let struct_type = self.context.new_struct_type(None, "landing_pad", &[field1, field2]);
         self.current_func().new_local(None, struct_type.as_type(), "landing_pad")
             .to_rvalue()
-        // TODO(antoyo): Properly implement unwinding.
-        // the above is just to make the compilation work as it seems
-        // rustc_codegen_ssa now calls the unwinding builder methods even on panic=abort.
     }
 
+    #[cfg(feature="master")]
+    fn resume(&mut self, exn: RValue<'gcc>) {
+        // TODO: check if this is normal that we need to dereference the value.
+        // NOTE: the type is wrong, so in order to get a pointer for parameter, cast it to a
+        // pointer of pointer that is later dereferenced.
+        let exn_type = exn.get_type().make_pointer();
+        let exn = self.context.new_cast(None, exn, exn_type);
+        let exn = exn.dereference(None).to_rvalue();
+        let unwind_resume = self.context.get_target_builtin_function("__builtin_unwind_resume");
+        self.llbb().add_eval(None, self.context.new_call(None, unwind_resume, &[exn]));
+        self.unreachable();
+    }
+
+    #[cfg(not(feature="master"))]
     fn resume(&mut self, _exn: RValue<'gcc>) {
-        // TODO(bjorn3): Properly implement unwinding.
         self.unreachable();
     }
 

src/builder.rs

@@ -1,11 +1,9 @@
 #[cfg(feature="master")]
 use gccjit::{FnAttribute, Visibility};
-use gccjit::{FunctionType, RValue};
-use rustc_codegen_ssa::traits::BaseTypeMethods;
+use gccjit::{FunctionType, Function};
 use rustc_middle::ty::{self, Instance, TypeVisitable};
 use rustc_middle::ty::layout::{FnAbiOf, HasTyCtxt};
 
-use crate::abi::FnAbiGccExt;
 use crate::attributes;
 use crate::context::CodegenCx;
 
@@ -16,22 +14,26 @@ use crate::context::CodegenCx;
 ///
 /// - `cx`: the crate context
 /// - `instance`: the instance to be instantiated
-pub fn get_fn<'gcc, 'tcx>(cx: &CodegenCx<'gcc, 'tcx>, instance: Instance<'tcx>) -> RValue<'gcc> {
+pub fn get_fn<'gcc, 'tcx>(cx: &CodegenCx<'gcc, 'tcx>, instance: Instance<'tcx>) -> Function<'gcc> {
     let tcx = cx.tcx();
 
     assert!(!instance.substs.needs_infer());
     assert!(!instance.substs.has_escaping_bound_vars());
 
+    let sym = tcx.symbol_name(instance).name;
+
     if let Some(&func) = cx.function_instances.borrow().get(&instance) {
         return func;
     }
 
-    let sym = tcx.symbol_name(instance).name;
-
     let fn_abi = cx.fn_abi_of_instance(instance, ty::List::empty());
 
     let func =
-        if let Some(func) = cx.get_declared_value(&sym) {
+        if let Some(_func) = cx.get_declared_value(&sym) {
+            // FIXME: we never reach this because get_declared_value only returns global variables
+            // and here we try to get a function.
+            unreachable!();
+            /*
             // Create a fn pointer with the new signature.
             let ptrty = fn_abi.ptr_to_gcc_type(cx);
 
@@ -64,7 +66,7 @@ pub fn get_fn<'gcc, 'tcx>(cx: &CodegenCx<'gcc, 'tcx>, instance: Instance<'tcx>)
             }
             else {
                 func
-            }
+            }*/
         }
         else {
             cx.linkage.set(FunctionType::Extern);
@@ -163,8 +165,7 @@ pub fn get_fn<'gcc, 'tcx>(cx: &CodegenCx<'gcc, 'tcx>, instance: Instance<'tcx>)
                 }
             }
 
-            // FIXME(antoyo): this is a wrong cast. That requires changing the compiler API.
-            unsafe { std::mem::transmute(func) }
+            func
         };
 
     cx.function_instances.borrow_mut().insert(instance, func);