Merge #1162 #1167 #1168 #1170

1162: CI: catch malformed test cases r=philberty a=liushuyu

- catch malformed test cases and use GitHub Actions' annotation feature to mark the failures

1167: Fix nullptr when resolving the root of a path expression r=philberty a=philberty

When we resolve paths we don't have a _type_, in this scenario there is a
bug in our resolution of this generic function so this means the root_tyty
is nullptr but the offset is non zero so we return nullptr.

Addresses #1132

This test case no longer ICE's but still fails. I have a fix in progress for this

```rust
mod mem {
    extern "rust-intrinsic" {
        fn transmute<U, V>(_: U) -> V;
    }
}

pub trait Hasher {
    fn write(&mut self, bytes: &[u8]);
    fn write_u16(&mut self, i: u16) {
        self.write(&mem::transmute::<_, [u8; 2]>(i))
    }
}

pub struct SipHasher;

impl Hasher for SipHasher {
    #[inline]
    fn write(&mut self, msg: &[u8]) {}
}

```

1168: ast: resolve: Move ResolveItem into its own source file r=CohenArthur a=CohenArthur

Since we need to add new functions to resolve visibilities, we might as well refactor this file before hand :) 

1170: Implement macro expansion in `IfExpr`, `IfExprConseqElse`, `IfExprConseqIf`, `IfExprConseqIfLet`. r=CohenArthur a=antego

Addresses #1141. Following up on #1161.

This change adds support for the macros inside the `if` condition expressions.

Things to note:
1. Judging by my research, the `IfExprConseqIfLet` isn't used. The parser treats the syntax `let var = if ...` as a `let` expression followed by `if` expression:
![Screen Shot 2022-04-26 at 9 47 29 am](https://user-images.githubusercontent.com/1451467/165258060-6a42f918-2585-4aef-9da5-9d60d69ca248.png)
2. I didn't add the macro expansion to the `IfLetExpr...` family of expressions because I wasn't able to write a test case reproducing the missing macro expansion. I've tried the following code
```rust
fn main() -> i32 {
    let mut res = 0;

    enum E {
        X(u8),
        Y(u8),
        Z(u8),
    }
    let v = E::Y(12);
    if let E::Y(n) = v {
        res = 1;
    }

    0
}
```
which caused the compiler error
```
FAIL: rust/compile/macro43.rs (internal compiler error: in append_reference_for_def, at rust/resolve/rust-name-resolver.h:227)
```



Co-authored-by: liushuyu <liushuyu011@gmail.com>
Co-authored-by: Philip Herron <philip.herron@embecosm.com>
Co-authored-by: Arthur Cohen <arthur.cohen@embecosm.com>
Co-authored-by: antego <antego@users.noreply.github.com>

Author: 5 people

.github/emit_test_errors.pl

@@ -0,0 +1,25 @@
+#!/bin/perl -n
+
+sub analyze_errors() {
+    /^(FAIL|ERROR|XPASS):\s([^:\s]+):?\s+(.+)/;
+
+    my $type     = $1;
+    my $filename = $2;
+    my $message  = $3;
+    my $line;
+
+    if ( !$type ) { return; }
+
+    if ( $message =~ /(at line (\d+))?.+(test for \w+, line (\d+))/g ) {
+        $line = $2 || $4;
+    }
+
+    my $command = "::error file=gcc/testsuite/$filename";
+    if ($line) {
+        $command = "$command,line=$line";
+    }
+
+    print "$command,title=Test failure ($type)::$message\n";
+}
+
+analyze_errors();

.github/workflows/ccpp.yml

@@ -77,9 +77,10 @@ jobs:
     - name: Check regressions
       run: |
            cd gccrs-build; \
-           if grep -e "unexpected" -e "unresolved" gcc/testsuite/rust/rust.sum;\
+           if grep -e "unexpected" -e "unresolved" -e "ERROR:" gcc/testsuite/rust/rust.sum;\
            then \
-              echo "some tests are not correct"; \
+              echo "::error title=Regression test failed::some tests are not correct"; \
+              perl -n ../.github/emit_test_errors.pl < gcc/testsuite/rust/rust.sum; \
               exit 1; \
             else \
               exit 0; \
@@ -142,9 +143,9 @@ jobs:
     - name: Check regressions
       run: |
            cd gccrs-build; \
-           if grep -e "unexpected" -e "unresolved" gcc/testsuite/rust/rust.sum;\
+           if grep -e "unexpected" -e "unresolved" -e "ERROR:" gcc/testsuite/rust/rust.sum;\
            then \
-              echo "some tests are not correct"; \
+              echo "::error title=Regression test failed::some tests are not correct"; \
               exit 1; \
             else \
               exit 0; \
@@ -196,9 +197,9 @@ jobs:
     - name: Check regressions
       run: |
            cd gccrs-build; \
-           if grep -e "unexpected" -e "unresolved" gcc/testsuite/rust/rust.sum;\
+           if grep -e "unexpected" -e "unresolved" -e "ERROR:" gcc/testsuite/rust/rust.sum;\
            then \
-              echo "some tests are not correct"; \
+              echo "::error title=Regression test failed::some tests are not correct"; \
               exit 1; \
             else \
               exit 0; \

gcc/rust/Make-lang.in

@@ -87,6 +87,7 @@ GRS_OBJS = \
     rust/rust-ast-lower-pattern.o \
     rust/rust-name-resolver.o \
     rust/rust-ast-resolve.o \
+    rust/rust-ast-resolve-item.o \
     rust/rust-ast-resolve-pattern.o \
     rust/rust-ast-resolve-expr.o \
     rust/rust-ast-resolve-type.o \

gcc/rust/expand/rust-attribute-visitor.cc

@@ -1630,6 +1630,9 @@ AttrVisitor::visit (AST::IfExpr &expr)
   // can't strip condition expr itself, but can strip sub-expressions
   auto &condition_expr = expr.get_condition_expr ();
   condition_expr->accept_vis (*this);
+  auto cond_fragment = expander.take_expanded_fragment (*this);
+  if (cond_fragment.should_expand ())
+    condition_expr = cond_fragment.take_expression_fragment ();
   if (condition_expr->is_marked_for_strip ())
     rust_error_at (condition_expr->get_locus (),
 		   "cannot strip expression in this position - outer "
@@ -1657,6 +1660,9 @@ AttrVisitor::visit (AST::IfExprConseqElse &expr)
   // can't strip condition expr itself, but can strip sub-expressions
   auto &condition_expr = expr.get_condition_expr ();
   condition_expr->accept_vis (*this);
+  auto cond_fragment = expander.take_expanded_fragment (*this);
+  if (cond_fragment.should_expand ())
+    condition_expr = cond_fragment.take_expression_fragment ();
   if (condition_expr->is_marked_for_strip ())
     rust_error_at (condition_expr->get_locus (),
 		   "cannot strip expression in this position - outer "
@@ -1692,6 +1698,9 @@ AttrVisitor::visit (AST::IfExprConseqIf &expr)
   // can't strip condition expr itself, but can strip sub-expressions
   auto &condition_expr = expr.get_condition_expr ();
   condition_expr->accept_vis (*this);
+  auto cond_fragment = expander.take_expanded_fragment (*this);
+  if (cond_fragment.should_expand ())
+    condition_expr = cond_fragment.take_expression_fragment ();
   if (condition_expr->is_marked_for_strip ())
     rust_error_at (condition_expr->get_locus (),
 		   "cannot strip expression in this position - outer "
@@ -1727,6 +1736,9 @@ AttrVisitor::visit (AST::IfExprConseqIfLet &expr)
   // can't strip condition expr itself, but can strip sub-expressions
   auto &condition_expr = expr.get_condition_expr ();
   condition_expr->accept_vis (*this);
+  auto cond_fragment = expander.take_expanded_fragment (*this);
+  if (cond_fragment.should_expand ())
+    condition_expr = cond_fragment.take_expression_fragment ();
   if (condition_expr->is_marked_for_strip ())
     rust_error_at (condition_expr->get_locus (),
 		   "cannot strip expression in this position - outer "