auto merge of #9613 : jld/rust/enum-discrim-size.r0, r=alexcrichton

Allows an enum with a discriminant to use any of the primitive integer types to store it.  By default the smallest usable type is chosen, but this can be overridden with an attribute: `#[repr(int)]` etc., or `#[repr(C)]` to match the target's C ABI for the equivalent C enum.

Also adds a lint pass for using non-FFI safe enums in extern declarations, checks that specified discriminants can be stored in the specified type if any, and fixes assorted code that was assuming int.

Author: bors

mk/tests.mk

@@ -465,6 +465,17 @@ $(foreach host,$(CFG_HOST_TRIPLES), \
       $(eval $(call DEF_TEST_CRATE_RULES,$(stage),$(target),$(host),$(crate))) \
      ))))))
 
+# FIXME (#10104): Raise the stack size to work around rustpkg bypassing
+# the code in rustc that would take care of it.
+define DEF_RUSTPKG_STACK_FIX
+$$(call TEST_OK_FILE,$(1),$(2),$(3),rustpkg): export RUST_MIN_STACK=8000000
+endef
+
+$(foreach host,$(CFG_HOST_TRIPLES), \
+ $(foreach target,$(CFG_TARGET_TRIPLES), \
+  $(foreach stage,$(STAGES), \
+   $(eval $(call DEF_RUSTPKG_STACK_FIX,$(stage),$(target),$(host))))))
+
 
 ######################################################################
 # Rules for the compiletest tests (rpass, rfail, etc.)

src/compiletest/runtest.rs

@@ -281,7 +281,7 @@ fn run_debuginfo_test(config: &config, props: &TestProps, testfile: &Path) {
     };
     let config = &mut config;
     let cmds = props.debugger_cmds.connect("\n");
-    let check_lines = props.check_lines.clone();
+    let check_lines = &props.check_lines;
 
     // compile test file (it shoud have 'compile-flags:-g' in the header)
     let mut ProcRes = compile_test(config, props, testfile);
@@ -315,11 +315,34 @@ fn run_debuginfo_test(config: &config, props: &TestProps, testfile: &Path) {
 
     let num_check_lines = check_lines.len();
     if num_check_lines > 0 {
+        // Allow check lines to leave parts unspecified (e.g., uninitialized
+        // bits in the wrong case of an enum) with the notation "[...]".
+        let check_fragments: ~[~[&str]] = check_lines.map(|s| s.split_str_iter("[...]").collect());
         // check if each line in props.check_lines appears in the
         // output (in order)
         let mut i = 0u;
         for line in ProcRes.stdout.line_iter() {
-            if check_lines[i].trim() == line.trim() {
+            let mut rest = line.trim();
+            let mut first = true;
+            let mut failed = false;
+            for &frag in check_fragments[i].iter() {
+                let found = if first {
+                    if rest.starts_with(frag) { Some(0) } else { None }
+                } else {
+                    rest.find_str(frag)
+                };
+                match found {
+                    None => {
+                        failed = true;
+                        break;
+                    }
+                    Some(i) => {
+                        rest = rest.slice_from(i + frag.len());
+                    }
+                }
+                first = false;
+            }
+            if !failed && rest.len() == 0 {
                 i += 1u;
             }
             if i == num_check_lines {

src/libextra/enum_set.rs

@@ -140,6 +140,7 @@ mod test {
     use enum_set::*;
 
     #[deriving(Eq)]
+    #[repr(uint)]
     enum Foo {
         A, B, C
     }

src/librustc/lib/llvm.rs

@@ -147,6 +147,7 @@ pub static Vector: TypeKind    = 13;
 pub static Metadata: TypeKind  = 14;
 pub static X86_MMX: TypeKind   = 15;
 
+#[repr(C)]
 pub enum AtomicBinOp {
     Xchg = 0,
     Add  = 1,
@@ -161,6 +162,7 @@ pub enum AtomicBinOp {
     UMin = 10,
 }
 
+#[repr(C)]
 pub enum AtomicOrdering {
     NotAtomic = 0,
     Unordered = 1,
@@ -173,6 +175,7 @@ pub enum AtomicOrdering {
 }
 
 // Consts for the LLVMCodeGenFileType type (in include/llvm/c/TargetMachine.h)
+#[repr(C)]
 pub enum FileType {
     AssemblyFile = 0,
     ObjectFile = 1
@@ -194,20 +197,23 @@ pub enum AsmDialect {
 }
 
 #[deriving(Eq)]
+#[repr(C)]
 pub enum CodeGenOptLevel {
     CodeGenLevelNone = 0,
     CodeGenLevelLess = 1,
     CodeGenLevelDefault = 2,
     CodeGenLevelAggressive = 3,
 }
 
+#[repr(C)]
 pub enum RelocMode {
     RelocDefault = 0,
     RelocStatic = 1,
     RelocPIC = 2,
     RelocDynamicNoPic = 3,
 }
 
+#[repr(C)]
 pub enum CodeGenModel {
     CodeModelDefault = 0,
     CodeModelJITDefault = 1,

src/librustc/metadata/common.rs

@@ -112,6 +112,7 @@ pub static tag_items_data_item_reexport_name: uint = 0x4f;
 
 // used to encode crate_ctxt side tables
 #[deriving(Eq)]
+#[repr(uint)]
 pub enum astencode_tag { // Reserves 0x50 -- 0x6f
     tag_ast = 0x50,
 
@@ -143,7 +144,7 @@ impl astencode_tag {
     pub fn from_uint(value : uint) -> Option<astencode_tag> {
         let is_a_tag = first_astencode_tag <= value && value <= last_astencode_tag;
         if !is_a_tag { None } else {
-            Some(unsafe { cast::transmute(value as int) })
+            Some(unsafe { cast::transmute(value) })
         }
     }
 }

src/librustc/metadata/encoder.rs

@@ -989,6 +989,7 @@ fn encode_info_for_item(ecx: &EncodeContext,
         encode_family(ebml_w, 't');
         encode_bounds_and_type(ebml_w, ecx, &lookup_item_type(tcx, def_id));
         encode_name(ecx, ebml_w, item.ident);
+        encode_attributes(ebml_w, item.attrs);
         for v in (*enum_definition).variants.iter() {
             encode_variant_id(ebml_w, local_def(v.node.id));
         }

src/librustc/middle/lint.rs

@@ -34,6 +34,7 @@
 //! Context itself, span_lint should be used instead of add_lint.
 
 use driver::session;
+use middle::trans::adt; // for `adt::is_ffi_safe`
 use middle::ty;
 use middle::pat_util;
 use metadata::csearch;
@@ -627,6 +628,14 @@ fn check_item_ctypes(cx: &Context, it: &ast::item) {
                                 "found rust type `uint` in foreign module, while \
                                 libc::c_uint or libc::c_ulong should be used");
                     }
+                    ast::DefTy(def_id) => {
+                        if !adt::is_ffi_safe(cx.tcx, def_id) {
+                            cx.span_lint(ctypes, ty.span,
+                                         "found enum type without foreign-function-safe \
+                                          representation annotation in foreign module");
+                            // NOTE this message could be more helpful
+                        }
+                    }
                     _ => ()
                 }
             }