Auto merge of #73779 - Manishearth:rollup-lwqd9jm, r=Manishearth

Rollup of 12 pull requests

Successful merges:

 - #72771 (Warn if linking to a private item)
 - #72937 (Fortanix SGX target libunwind build process changes)
 - #73485 (Perform obligation deduplication to avoid buggy `ExistentialMismatch`)
 - #73529 (Add liballoc impl SpecFromElem for i8)
 - #73579 (add missing doc links)
 - #73627 (Shortcuts for min/max on double-ended BTreeMap/BTreeSet iterators)
 - #73691 (Bootstrap: detect Windows based on sys.platform)
 - #73694 (Document the Self keyword)
 - #73718 (Document the super keyword)
 - #73728 (Document some invariants correctly/more)
 - #73738 (Remove irrelevant comment)
 - #73765 (Remove blank line)

Failed merges:

r? @ghost

src/bootstrap/bootstrap.py

@@ -184,6 +184,7 @@ def default_build_triple():
     ostype = require(["uname", "-s"], exit=required)
     cputype = require(['uname', '-m'], exit=required)
 
+    # If we do not have `uname`, assume Windows.
     if ostype is None or cputype is None:
         return 'x86_64-pc-windows-msvc'
 
@@ -236,6 +237,11 @@ def default_build_triple():
         if ostype.endswith('WOW64'):
             cputype = 'x86_64'
         ostype = 'pc-windows-gnu'
+    elif sys.platform == 'win32':
+        # Some Windows platforms might have a `uname` command that returns a
+        # non-standard string (e.g. gnuwin32 tools returns `windows32`). In
+        # these cases, fall back to using sys.platform.
+        return 'x86_64-pc-windows-msvc'
     else:
         err = "unknown OS type: {}".format(ostype)
         sys.exit(err)

src/bootstrap/compile.rs

@@ -131,26 +131,13 @@ fn copy_third_party_objects(
     compiler: &Compiler,
     target: Interned<String>,
 ) -> Vec<(PathBuf, DependencyType)> {
-    let libdir = builder.sysroot_libdir(*compiler, target);
     let mut target_deps = vec![];
 
-    // Copies libunwind.a compiled to be linked with x86_64-fortanix-unknown-sgx.
-    //
-    // This target needs to be linked to Fortanix's port of llvm's libunwind.
-    // libunwind requires support for rwlock and printing to stderr,
-    // which is provided by std for this target.
+    // FIXME: remove this in 2021
     if target == "x86_64-fortanix-unknown-sgx" {
-        let src_path_env = "X86_FORTANIX_SGX_LIBS";
-        let src =
-            env::var(src_path_env).unwrap_or_else(|_| panic!("{} not found in env", src_path_env));
-        copy_and_stamp(
-            builder,
-            &*libdir,
-            Path::new(&src),
-            "libunwind.a",
-            &mut target_deps,
-            DependencyType::Target,
-        );
+        if env::var_os("X86_FORTANIX_SGX_LIBS").is_some() {
+            builder.info("Warning: X86_FORTANIX_SGX_LIBS environment variable is ignored, libunwind is now compiled as part of rustbuild");
+        }
     }
 
     if builder.config.sanitizers && compiler.stage != 0 {

src/ci/docker/dist-various-2/Dockerfile

@@ -71,9 +71,7 @@ RUN /tmp/build-solaris-toolchain.sh sparcv9 sparcv9 solaris-sparc
 COPY dist-various-2/build-x86_64-fortanix-unknown-sgx-toolchain.sh /tmp/
 COPY dist-various-2/x86_64-fortanix-unknown-sgx-clang-wrap.sh /usr/bin/x86_64-fortanix-unknown-sgx-clang-11
 RUN ln -s /usr/bin/x86_64-fortanix-unknown-sgx-clang-11 /usr/bin/x86_64-fortanix-unknown-sgx-clang++-11
-# We pass the commit id of the port of LLVM's libunwind to the build script.
-# Any update to the commit id here, should cause the container image to be re-built from this point on.
-RUN /tmp/build-x86_64-fortanix-unknown-sgx-toolchain.sh "800f95131fe6acd20b96b6f4723ca3c820f3d379"
+RUN /tmp/build-x86_64-fortanix-unknown-sgx-toolchain.sh
 
 COPY dist-various-2/build-wasi-toolchain.sh /tmp/
 RUN /tmp/build-wasi-toolchain.sh
@@ -105,8 +103,6 @@ ENV TARGETS=$TARGETS,nvptx64-nvidia-cuda
 ENV TARGETS=$TARGETS,armv7-unknown-linux-gnueabi
 ENV TARGETS=$TARGETS,armv7-unknown-linux-musleabi
 
-ENV X86_FORTANIX_SGX_LIBS="/x86_64-fortanix-unknown-sgx/lib/"
-
 # As per https://bugs.launchpad.net/ubuntu/+source/gcc-defaults/+bug/1300211
 # we need asm in the search path for gcc-7 (for gnux32) but not in the search path of the
 # cross compilers.

src/ci/docker/dist-various-2/build-x86_64-fortanix-unknown-sgx-toolchain.sh

@@ -3,14 +3,7 @@
 set -eu
 source shared.sh
 
-if [ -z "$1" ]; then
-    echo "Usage: ${0} <commit_id>"
-    exit -1
-fi
-
 target="x86_64-fortanix-unknown-sgx"
-url="https://github.com/fortanix/llvm-project/archive/${1}.tar.gz"
-repo_name="llvm-project"
 
 install_prereq() {
     curl https://apt.llvm.org/llvm-snapshot.gpg.key|apt-key add -
@@ -24,39 +17,4 @@ install_prereq() {
             clang-11
 }
 
-build_unwind() {
-    set -x
-    dir_name="${target}_temp"
-    rm -rf ${dir_name}
-    mkdir -p ${dir_name}
-    pushd ${dir_name}
-
-    # Clone Fortanix's fork of llvm-project which has a port of libunwind
-    fetch_github_commit_archive "$repo_name" "$url"
-    cd "${repo_name}/libunwind"
-
-    # Build libunwind
-    mkdir -p build
-    cd build
-    target_CC="CC_${target//-/_}"
-    target_CXX="CXX_${target//-/_}"
-    target_CFLAGS="CFLAGS_${target//-/_}"
-    target_CXXFLAGS="CXXFLAGS_${target//-/_}"
-    cmake -DCMAKE_BUILD_TYPE="RELEASE" -DRUST_SGX=1 -G "Unix Makefiles" \
-        -DCMAKE_C_COMPILER="${!target_CC}" -DCMAKE_CXX_COMPILER="${!target_CXX}" \
-        -DCMAKE_C_FLAGS="${!target_CFLAGS}" -DCMAKE_CXX_FLAGS="${!target_CXXFLAGS}" \
-        -DCMAKE_C_COMPILER_TARGET=$target -DCMAKE_CXX_COMPILER_TARGET=$target \
-        -DLLVM_ENABLE_WARNINGS=1 -DLIBUNWIND_ENABLE_WERROR=1 -DLIBUNWIND_ENABLE_PEDANTIC=0 \
-        -DLLVM_PATH=../../llvm/ ../
-    make unwind_static
-    install -D "lib/libunwind.a" "/${target}/lib/libunwind.a"
-
-    popd
-    rm -rf ${dir_name}
-
-    { set +x; } 2>/dev/null
-}
-
-set -x
 hide_output install_prereq
-build_unwind

src/liballoc/collections/btree/map.rs

@@ -1396,6 +1396,14 @@ impl<'a, K: 'a, V: 'a> Iterator for Iter<'a, K, V> {
     fn last(mut self) -> Option<(&'a K, &'a V)> {
         self.next_back()
     }
+
+    fn min(mut self) -> Option<(&'a K, &'a V)> {
+        self.next()
+    }
+
+    fn max(mut self) -> Option<(&'a K, &'a V)> {
+        self.next_back()
+    }
 }
 
 #[stable(feature = "fused", since = "1.26.0")]
@@ -1458,6 +1466,14 @@ impl<'a, K: 'a, V: 'a> Iterator for IterMut<'a, K, V> {
     fn last(mut self) -> Option<(&'a K, &'a mut V)> {
         self.next_back()
     }
+
+    fn min(mut self) -> Option<(&'a K, &'a mut V)> {
+        self.next()
+    }
+
+    fn max(mut self) -> Option<(&'a K, &'a mut V)> {
+        self.next_back()
+    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -1595,6 +1611,14 @@ impl<'a, K, V> Iterator for Keys<'a, K, V> {
     fn last(mut self) -> Option<&'a K> {
         self.next_back()
     }
+
+    fn min(mut self) -> Option<&'a K> {
+        self.next()
+    }
+
+    fn max(mut self) -> Option<&'a K> {
+        self.next_back()
+    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -1768,6 +1792,14 @@ impl<'a, K, V> Iterator for Range<'a, K, V> {
     fn last(mut self) -> Option<(&'a K, &'a V)> {
         self.next_back()
     }
+
+    fn min(mut self) -> Option<(&'a K, &'a V)> {
+        self.next()
+    }
+
+    fn max(mut self) -> Option<(&'a K, &'a V)> {
+        self.next_back()
+    }
 }
 
 #[stable(feature = "map_values_mut", since = "1.10.0")]
@@ -1853,6 +1885,14 @@ impl<'a, K, V> Iterator for RangeMut<'a, K, V> {
     fn last(mut self) -> Option<(&'a K, &'a mut V)> {
         self.next_back()
     }
+
+    fn min(mut self) -> Option<(&'a K, &'a mut V)> {
+        self.next()
+    }
+
+    fn max(mut self) -> Option<(&'a K, &'a mut V)> {
+        self.next_back()
+    }
 }
 
 impl<'a, K, V> RangeMut<'a, K, V> {

src/liballoc/collections/btree/set.rs

@@ -1291,12 +1291,22 @@ impl<'a, T> Iterator for Iter<'a, T> {
     fn next(&mut self) -> Option<&'a T> {
         self.iter.next()
     }
+
     fn size_hint(&self) -> (usize, Option<usize>) {
         self.iter.size_hint()
     }
+
     fn last(mut self) -> Option<&'a T> {
         self.next_back()
     }
+
+    fn min(mut self) -> Option<&'a T> {
+        self.next()
+    }
+
+    fn max(mut self) -> Option<&'a T> {
+        self.next_back()
+    }
 }
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<'a, T> DoubleEndedIterator for Iter<'a, T> {
@@ -1321,6 +1331,7 @@ impl<T> Iterator for IntoIter<T> {
     fn next(&mut self) -> Option<T> {
         self.iter.next().map(|(k, _)| k)
     }
+
     fn size_hint(&self) -> (usize, Option<usize>) {
         self.iter.size_hint()
     }
@@ -1359,6 +1370,14 @@ impl<'a, T> Iterator for Range<'a, T> {
     fn last(mut self) -> Option<&'a T> {
         self.next_back()
     }
+
+    fn min(mut self) -> Option<&'a T> {
+        self.next()
+    }
+
+    fn max(mut self) -> Option<&'a T> {
+        self.next_back()
+    }
 }
 
 #[stable(feature = "btree_range", since = "1.17.0")]
@@ -1429,6 +1448,10 @@ impl<'a, T: Ord> Iterator for Difference<'a, T> {
         };
         (self_len.saturating_sub(other_len), Some(self_len))
     }
+
+    fn min(mut self) -> Option<&'a T> {
+        self.next()
+    }
 }
 
 #[stable(feature = "fused", since = "1.26.0")]
@@ -1460,6 +1483,10 @@ impl<'a, T: Ord> Iterator for SymmetricDifference<'a, T> {
         // the number of elements to less than half the range of usize.
         (0, Some(a_len + b_len))
     }
+
+    fn min(mut self) -> Option<&'a T> {
+        self.next()
+    }
 }
 
 #[stable(feature = "fused", since = "1.26.0")]
@@ -1516,6 +1543,10 @@ impl<'a, T: Ord> Iterator for Intersection<'a, T> {
             IntersectionInner::Answer(Some(_)) => (1, Some(1)),
         }
     }
+
+    fn min(mut self) -> Option<&'a T> {
+        self.next()
+    }
 }
 
 #[stable(feature = "fused", since = "1.26.0")]
@@ -1541,6 +1572,10 @@ impl<'a, T: Ord> Iterator for Union<'a, T> {
         // No checked_add - see SymmetricDifference::size_hint.
         (max(a_len, b_len), Some(a_len + b_len))
     }
+
+    fn min(mut self) -> Option<&'a T> {
+        self.next()
+    }
 }
 
 #[stable(feature = "fused", since = "1.26.0")]

src/liballoc/raw_vec/tests.rs

@@ -12,7 +12,6 @@ fn allocator_param() {
     //
     // Instead, this just checks that the `RawVec` methods do at
     // least go through the Allocator API when it reserves
-
     // storage.
 
     // A dumb allocator that consumes a fixed amount of fuel

src/liballoc/tests/btree/map.rs

@@ -309,6 +309,41 @@ fn test_iter_mixed() {
     test(size, map.into_iter());
 }
 
+#[test]
+fn test_iter_min_max() {
+    let mut a = BTreeMap::new();
+    assert_eq!(a.iter().min(), None);
+    assert_eq!(a.iter().max(), None);
+    assert_eq!(a.iter_mut().min(), None);
+    assert_eq!(a.iter_mut().max(), None);
+    assert_eq!(a.range(..).min(), None);
+    assert_eq!(a.range(..).max(), None);
+    assert_eq!(a.range_mut(..).min(), None);
+    assert_eq!(a.range_mut(..).max(), None);
+    assert_eq!(a.keys().min(), None);
+    assert_eq!(a.keys().max(), None);
+    assert_eq!(a.values().min(), None);
+    assert_eq!(a.values().max(), None);
+    assert_eq!(a.values_mut().min(), None);
+    assert_eq!(a.values_mut().max(), None);
+    a.insert(1, 42);
+    a.insert(2, 24);
+    assert_eq!(a.iter().min(), Some((&1, &42)));
+    assert_eq!(a.iter().max(), Some((&2, &24)));
+    assert_eq!(a.iter_mut().min(), Some((&1, &mut 42)));
+    assert_eq!(a.iter_mut().max(), Some((&2, &mut 24)));
+    assert_eq!(a.range(..).min(), Some((&1, &42)));
+    assert_eq!(a.range(..).max(), Some((&2, &24)));
+    assert_eq!(a.range_mut(..).min(), Some((&1, &mut 42)));
+    assert_eq!(a.range_mut(..).max(), Some((&2, &mut 24)));
+    assert_eq!(a.keys().min(), Some(&1));
+    assert_eq!(a.keys().max(), Some(&2));
+    assert_eq!(a.values().min(), Some(&24));
+    assert_eq!(a.values().max(), Some(&42));
+    assert_eq!(a.values_mut().min(), Some(&mut 24));
+    assert_eq!(a.values_mut().max(), Some(&mut 42));
+}
+
 fn range_keys(map: &BTreeMap<i32, i32>, range: impl RangeBounds<i32>) -> Vec<i32> {
     map.range(range)
         .map(|(&k, &v)| {

src/liballoc/tests/btree/set.rs

@@ -33,6 +33,37 @@ fn test_hash() {
     assert_eq!(hash(&x), hash(&y));
 }
 
+#[test]
+fn test_iter_min_max() {
+    let mut a = BTreeSet::new();
+    assert_eq!(a.iter().min(), None);
+    assert_eq!(a.iter().max(), None);
+    assert_eq!(a.range(..).min(), None);
+    assert_eq!(a.range(..).max(), None);
+    assert_eq!(a.difference(&BTreeSet::new()).min(), None);
+    assert_eq!(a.difference(&BTreeSet::new()).max(), None);
+    assert_eq!(a.intersection(&a).min(), None);
+    assert_eq!(a.intersection(&a).max(), None);
+    assert_eq!(a.symmetric_difference(&BTreeSet::new()).min(), None);
+    assert_eq!(a.symmetric_difference(&BTreeSet::new()).max(), None);
+    assert_eq!(a.union(&a).min(), None);
+    assert_eq!(a.union(&a).max(), None);
+    a.insert(1);
+    a.insert(2);
+    assert_eq!(a.iter().min(), Some(&1));
+    assert_eq!(a.iter().max(), Some(&2));
+    assert_eq!(a.range(..).min(), Some(&1));
+    assert_eq!(a.range(..).max(), Some(&2));
+    assert_eq!(a.difference(&BTreeSet::new()).min(), Some(&1));
+    assert_eq!(a.difference(&BTreeSet::new()).max(), Some(&2));
+    assert_eq!(a.intersection(&a).min(), Some(&1));
+    assert_eq!(a.intersection(&a).max(), Some(&2));
+    assert_eq!(a.symmetric_difference(&BTreeSet::new()).min(), Some(&1));
+    assert_eq!(a.symmetric_difference(&BTreeSet::new()).max(), Some(&2));
+    assert_eq!(a.union(&a).min(), Some(&1));
+    assert_eq!(a.union(&a).max(), Some(&2));
+}
+
 fn check<F>(a: &[i32], b: &[i32], expected: &[i32], f: F)
 where
     F: FnOnce(&BTreeSet<i32>, &BTreeSet<i32>, &mut dyn FnMut(&i32) -> bool) -> bool,