codegen: Use target pointer size consistently for layout calculations

.travis.yml

@@ -10,29 +10,33 @@ env:
   global:
     - CARGO_TARGET_DIR=/tmp/bindgen
   matrix:
-    - LLVM_VERSION="3.8.1" BINDGEN_JOB="test"         BINDGEN_PROFILE=
-    - LLVM_VERSION="3.8.1" BINDGEN_JOB="test"         BINDGEN_PROFILE="--release"
-    - LLVM_VERSION="3.8.1" BINDGEN_JOB="integration"  BINDGEN_PROFILE=
-    - LLVM_VERSION="3.8.1" BINDGEN_JOB="integration"  BINDGEN_PROFILE="--release"
-    - LLVM_VERSION="3.9.0" BINDGEN_JOB="test"         BINDGEN_PROFILE=
-    - LLVM_VERSION="3.9.0" BINDGEN_JOB="test"         BINDGEN_PROFILE="--release"
-    - LLVM_VERSION="3.9.0" BINDGEN_JOB="integration"  BINDGEN_PROFILE=
-    - LLVM_VERSION="3.9.0" BINDGEN_JOB="integration"  BINDGEN_PROFILE="--release"
-    - LLVM_VERSION="4.0.0" BINDGEN_JOB="test"         BINDGEN_PROFILE=
-    - LLVM_VERSION="4.0.0" BINDGEN_JOB="test"         BINDGEN_PROFILE="--release"
-    - LLVM_VERSION="4.0.0" BINDGEN_JOB="test"         BINDGEN_PROFILE=            BINDGEN_FEATURES="testing_only_extra_assertions"
-    - LLVM_VERSION="4.0.0" BINDGEN_JOB="test"         BINDGEN_PROFILE="--release" BINDGEN_FEATURES="testing_only_extra_assertions"
-    - LLVM_VERSION="4.0.0" BINDGEN_JOB="integration"  BINDGEN_PROFILE=
-    - LLVM_VERSION="4.0.0" BINDGEN_JOB="integration"  BINDGEN_PROFILE="--release"
-    - LLVM_VERSION="4.0.0" BINDGEN_JOB="expectations" BINDGEN_PROFILE=
-    - LLVM_VERSION="4.0.0" BINDGEN_JOB="expectations" BINDGEN_PROFILE="--release"
-    - LLVM_VERSION="4.0.0" BINDGEN_JOB="misc"
-    - LLVM_VERSION="4.0.0" BINDGEN_JOB="quickchecking"
+    - LLVM_VERSION="3.8" BINDGEN_JOB="test"         BINDGEN_PROFILE=
+    - LLVM_VERSION="3.8" BINDGEN_JOB="test"         BINDGEN_PROFILE="--release"
+    - LLVM_VERSION="3.8" BINDGEN_JOB="integration"  BINDGEN_PROFILE=
+    - LLVM_VERSION="3.8" BINDGEN_JOB="integration"  BINDGEN_PROFILE="--release"
+    - LLVM_VERSION="3.9" BINDGEN_JOB="test"         BINDGEN_PROFILE=
+    - LLVM_VERSION="3.9" BINDGEN_JOB="test"         BINDGEN_PROFILE="--release"
+    - LLVM_VERSION="3.9" BINDGEN_JOB="integration"  BINDGEN_PROFILE=
+    - LLVM_VERSION="3.9" BINDGEN_JOB="integration"  BINDGEN_PROFILE="--release"
+    - LLVM_VERSION="4.0" BINDGEN_JOB="test"         BINDGEN_PROFILE=
+    - LLVM_VERSION="4.0" BINDGEN_JOB="test"         BINDGEN_PROFILE="--release"
+    - LLVM_VERSION="4.0" BINDGEN_JOB="integration"  BINDGEN_PROFILE=
+    - LLVM_VERSION="4.0" BINDGEN_JOB="integration"  BINDGEN_PROFILE="--release"
+    - LLVM_VERSION="5.0" BINDGEN_JOB="test"         BINDGEN_PROFILE=
+    - LLVM_VERSION="5.0" BINDGEN_JOB="test"         BINDGEN_PROFILE="--release"
+    - LLVM_VERSION="5.0" BINDGEN_JOB="test"         BINDGEN_PROFILE=            BINDGEN_FEATURES="testing_only_extra_assertions"
+    - LLVM_VERSION="5.0" BINDGEN_JOB="test"         BINDGEN_PROFILE="--release" BINDGEN_FEATURES="testing_only_extra_assertions"
+    - LLVM_VERSION="5.0" BINDGEN_JOB="integration"  BINDGEN_PROFILE=
+    - LLVM_VERSION="5.0" BINDGEN_JOB="integration"  BINDGEN_PROFILE="--release"
+    - LLVM_VERSION="5.0" BINDGEN_JOB="expectations" BINDGEN_PROFILE=
+    - LLVM_VERSION="5.0" BINDGEN_JOB="expectations" BINDGEN_PROFILE="--release"
+    - LLVM_VERSION="5.0" BINDGEN_JOB="misc"
+    - LLVM_VERSION="5.0" BINDGEN_JOB="quickchecking"
 
 matrix:
   fast_finish: true
   allow_failures:
-    - env: LLVM_VERSION=4.0.0 BINDGEN_JOB=rustfmt
+    - env: LLVM_VERSION=5.0 BINDGEN_JOB=rustfmt
 
 cache:
   directories:

Cargo.toml

@@ -47,7 +47,7 @@ cexpr = "0.2"
 cfg-if = "0.1.0"
 # This kinda sucks: https://github.com/rust-lang/cargo/issues/1982
 clap = "2"
-clang-sys = { version = "0.22.0", features = ["runtime", "clang_3_9"] }
+clang-sys = { version = "0.22.0", features = ["runtime", "clang_6_0"] }
 lazy_static = "1"
 peeking_take_while = "0.1.2"
 quote = "0.3.15"
@@ -71,6 +71,7 @@ static = []
 # on bindgen!
 testing_only_docs = []
 testing_only_extra_assertions = []
+testing_only_libclang_5 = []
 testing_only_libclang_4 = []
 testing_only_libclang_3_9 = []
 testing_only_libclang_3_8 = []

appveyor.yml

@@ -8,12 +8,18 @@ environment:
   - TARGET: gnu
     LLVM_VERSION: 4.0.0-1
     BINDGEN_FEATURES: testing_only_libclang_4
+  - TARGET: msvc
+    LLVM_VERSION: 5.0.0-1
+    BINDGEN_FEATURES: testing_only_libclang_5
   - TARGET: msvc
     LLVM_VERSION: 3.9.0
     BINDGEN_FEATURES: testing_only_libclang_3_9
   - TARGET: msvc
     LLVM_VERSION: 4.0.0
     BINDGEN_FEATURES: testing_only_libclang_4
+  - TARGET: msvc
+    LLVM_VERSION: 5.0.0
+    BINDGEN_FEATURES: testing_only_libclang_5
 
 configuration:
 - stable

bindgen-integration/Cargo.toml

@@ -11,6 +11,7 @@ bindgen = { path = ".." }
 gcc = "0.3"
 
 [features]
+testing_only_libclang_5 = ["bindgen/testing_only_libclang_5"]
 testing_only_libclang_4 = ["bindgen/testing_only_libclang_4"]
 testing_only_libclang_3_9 = ["bindgen/testing_only_libclang_3_9"]
 testing_only_libclang_3_8 = ["bindgen/testing_only_libclang_3_8"]

ci/before_install.sh

@@ -6,31 +6,55 @@ if [ "${TRAVIS_OS_NAME}" == "osx" ]; then
     rvm get head || true
 fi
 
-function llvm_download_if_needed() {
-    export LLVM_VERSION_TRIPLE="${LLVM_VERSION}"
-    export LLVM=clang+llvm-${LLVM_VERSION_TRIPLE}-x86_64-$1
-
-    local llvm_build_dir="$HOME/.llvm-builds/${LLVM}"
-
-    if [ -d "${llvm_build_dir}" ]; then
-        echo "Using cached LLVM build for ${LLVM} in ${llvm_build_dir}";
+function llvm_linux_target_triple() {
+    if [ "$1" == "5.0" ]; then
+        echo "linux-x86_64-ubuntu14.04"
     else
-        wget http://llvm.org/releases/${LLVM_VERSION_TRIPLE}/${LLVM}.tar.xz
-        mkdir -p "${llvm_build_dir}"
-        tar -xf ${LLVM}.tar.xz -C "${llvm_build_dir}" --strip-components=1
+        echo "x86_64-linux-gnu-ubuntu-14.04"
     fi
+}
 
-    export LLVM_CONFIG_PATH="${llvm_build_dir}/bin/llvm-config"
-    if [ "${TRAVIS_OS_NAME}" == "osx" ]; then
-        cp "${llvm_build_dir}/lib/libclang.dylib" /usr/local/lib/libclang.dylib
+function llvm_version_triple() {
+    if [ "$1" == "3.5" ]; then
+        echo "3.5.2"
+    elif [ "$1" == "3.6" ]; then
+        echo "3.6.2"
+    elif [ "$1" == "3.7" ]; then
+        echo "3.7.1"
+    elif [ "$1" == "3.8" ]; then
+        echo "3.8.1"
+    elif [ "$1" == "3.9" ]; then
+        echo "3.9.0"
+    elif [ "$1" == "4.0" ]; then
+        echo "4.0.0"
+    elif [ "$1" == "5.0" ]; then
+        echo "5.0.0"
     fi
 }
 
+function llvm_download() {
+    export LLVM_VERSION_TRIPLE=`llvm_version_triple ${LLVM_VERSION}`
+    export LLVM=clang+llvm-${LLVM_VERSION_TRIPLE}-$1
+    export LLVM_DIRECTORY="$HOME/.llvm/${LLVM}"
+
+    if [ -d "${LLVM_DIRECTORY}" ]; then
+        echo "Using cached LLVM download for ${LLVM}..."
+    else
+        wget http://releases.llvm.org/${LLVM_VERSION_TRIPLE}/${LLVM}.tar.xz
+        mkdir -p "${LLVM_DIRECTORY}"
+        tar xf ${LLVM}.tar.xz -C "${LLVM_DIRECTORY}" --strip-components=1
+    fi
+
+    export LLVM_CONFIG_PATH="${LLVM_DIRECTORY}/bin/llvm-config"
+}
 
 if [ "${TRAVIS_OS_NAME}" == "linux" ]; then
-    llvm_download_if_needed linux-gnu-ubuntu-14.04
+    llvm_download `llvm_linux_target_triple ${LLVM_VERSION}`
+    export LD_LIBRARY_PATH="${LLVM_DIRECTORY}/lib":$LD_LIBRARY_PATH
 else
-    llvm_download_if_needed apple-darwin
+    llvm_download x86_64-apple-darwin
+    cp "${LLVM_DIRECTORY}/lib/libclang.dylib" /usr/local/lib/libclang.dylib
+    export DYLD_LIBRARY_PATH="${LLVM_DIRECTORY}/lib":$DYLD_LIBRARY_PATH
 fi
 
 popd

src/clang.rs

@@ -1812,3 +1812,35 @@ impl Drop for EvalResult {
         unsafe { clang_EvalResult_dispose(self.x) };
     }
 }
+
+/// Target information obtained from libclang.
+#[derive(Debug)]
+pub struct TargetInfo {
+    /// The target triple.
+    pub triple: String,
+    /// The width of the pointer _in bits_.
+    pub pointer_width: usize,
+}
+
+impl TargetInfo {
+    /// Tries to obtain target information from libclang.
+    pub fn new(tu: &TranslationUnit) -> Option<Self> {
+        if !clang_getTranslationUnitTargetInfo::is_loaded() {
+            return None;
+        }
+        let triple;
+        let pointer_width;
+        unsafe {
+            let ti = clang_getTranslationUnitTargetInfo(tu.x);
+            triple = cxstring_into_string(clang_TargetInfo_getTriple(ti));
+            pointer_width = clang_TargetInfo_getPointerWidth(ti);
+            clang_TargetInfo_dispose(ti);
+        }
+        assert!(pointer_width > 0);
+        assert_eq!(pointer_width % 8, 0);
+        Some(TargetInfo {
+            triple,
+            pointer_width: pointer_width as usize,
+        })
+    }
+}

src/codegen/mod.rs

@@ -45,7 +45,6 @@ use std::collections::{HashSet, VecDeque};
 use std::collections::hash_map::{Entry, HashMap};
 use std::fmt::Write;
 use std::iter;
-use std::mem;
 use std::ops;
 
 // Name of type defined in constified enum module
@@ -1777,8 +1776,9 @@ impl CodeGenerator for CompInfo {
                     let align = layout.align;
 
                     let check_struct_align =
-                        if align > mem::size_of::<*mut ()>() {
-                            // FIXME when [RFC 1358](https://github.com/rust-lang/rust/issues/33626) ready
+                        if align > ctx.target_pointer_size() &&
+                            !ctx.options().rust_features().repr_align
+                        {
                             None
                         } else {
                             Some(quote! {
@@ -2720,9 +2720,8 @@ trait TryToOpaque {
 /// leverage the blanket impl for this trait.
 trait ToOpaque: TryToOpaque {
     fn get_layout(&self, ctx: &BindgenContext, extra: &Self::Extra) -> Layout {
-        self.try_get_layout(ctx, extra).unwrap_or_else(
-            |_| Layout::for_size(1),
-        )
+        self.try_get_layout(ctx, extra)
+            .unwrap_or_else(|_| Layout::for_size(ctx, 1))
     }
 
     fn to_opaque(

src/codegen/struct_layout.rs

@@ -8,7 +8,6 @@ use ir::layout::Layout;
 use ir::ty::{Type, TypeKind};
 use quote;
 use std::cmp;
-use std::mem;
 
 /// Trace the layout of struct.
 #[derive(Debug)]
@@ -101,7 +100,7 @@ impl<'a> StructLayoutTracker<'a> {
     pub fn saw_vtable(&mut self) {
         debug!("saw vtable for {}", self.name);
 
-        let ptr_size = mem::size_of::<*mut ()>();
+        let ptr_size = self.ctx.target_pointer_size();
         self.latest_offset += ptr_size;
         self.latest_field_layout = Some(Layout::new(ptr_size, ptr_size));
         self.max_field_align = ptr_size;
@@ -165,15 +164,13 @@ impl<'a> StructLayoutTracker<'a> {
             // can support.
             //
             // This means that the structs in the array are super-unsafe to
-            // access, since they won't be properly aligned, but *shrug*.
-            if let Some(layout) = self.ctx.resolve_type(inner).layout(
-                self.ctx,
-            )
-            {
-                if layout.align > mem::size_of::<*mut ()>() {
-                    field_layout.size = align_to(layout.size, layout.align) *
-                        len;
-                    field_layout.align = mem::size_of::<*mut ()>();
+            // access, since they won't be properly aligned, but there's not too
+            // much we can do about it.
+            if let Some(layout) = self.ctx.resolve_type(inner).layout(self.ctx) {
+                if layout.align > self.ctx.target_pointer_size() {
+                    field_layout.size =
+                        align_to(layout.size, layout.align) * len;
+                    field_layout.align = self.ctx.target_pointer_size();
                 }
             }
         }
@@ -193,7 +190,7 @@ impl<'a> StructLayoutTracker<'a> {
 
             // Otherwise the padding is useless.
             let need_padding = padding_bytes >= field_layout.align ||
-                field_layout.align > mem::size_of::<*mut ()>();
+                field_layout.align > self.ctx.target_pointer_size();
 
             self.latest_offset += padding_bytes;
 
@@ -215,7 +212,7 @@ impl<'a> StructLayoutTracker<'a> {
             if need_padding && padding_bytes != 0 {
                 Some(Layout::new(
                     padding_bytes,
-                    cmp::min(field_layout.align, mem::size_of::<*mut ()>()),
+                    cmp::min(field_layout.align, self.ctx.target_pointer_size())
                 ))
             } else {
                 None
@@ -267,15 +264,15 @@ impl<'a> StructLayoutTracker<'a> {
                  (self.last_field_was_bitfield &&
                       padding_bytes >=
                           self.latest_field_layout.unwrap().align) ||
-                 layout.align > mem::size_of::<*mut ()>())
+                 layout.align > self.ctx.target_pointer_size())
         {
             let layout = if self.is_packed {
                 Layout::new(padding_bytes, 1)
             } else if self.last_field_was_bitfield ||
-                       layout.align > mem::size_of::<*mut ()>()
+                       layout.align > self.ctx.target_pointer_size()
             {
                 // We've already given up on alignment here.
-                Layout::for_size(padding_bytes)
+                Layout::for_size(self.ctx, padding_bytes)
             } else {
                 Layout::new(padding_bytes, layout.align)
             };
@@ -289,8 +286,18 @@ impl<'a> StructLayoutTracker<'a> {
     }
 
     pub fn requires_explicit_align(&self, layout: Layout) -> bool {
-        self.max_field_align < layout.align &&
-            layout.align <= mem::size_of::<*mut ()>()
+        if self.max_field_align >= layout.align {
+            return false;
+        }
+        // At this point we require explicit alignment, but we may not be able
+        // to generate the right bits, let's double check.
+        if self.ctx.options().rust_features().repr_align {
+            return true;
+        }
+
+        // We can only generate up-to a word of alignment unless we support
+        // repr(align).
+        layout.align <= self.ctx.target_pointer_size()
     }
 
     fn padding_bytes(&self, layout: Layout) -> usize {