Merge pull request #6 from sunfishcode/index-fix

Merge the index-fix branch

lib/execute/src/lib.rs

@@ -8,6 +8,7 @@ extern crate region;
 extern crate wasmstandalone_runtime;
 
 use cretonne_codegen::isa::TargetIsa;
+use cretonne_codegen::binemit::Reloc;
 use std::mem::transmute;
 use region::Protection;
 use region::protect;
@@ -41,11 +42,22 @@ fn relocate(compilation: &mut Compilation, relocations: &wasmstandalone_runtime:
         for ref r in function_relocs {
             let target_func_address: isize = compilation.functions[r.func_index].as_ptr() as isize;
             let body = &mut compilation.functions[i];
-            unsafe {
-                let reloc_address = body.as_mut_ptr().offset(r.offset as isize + 4) as isize;
+            match r.reloc {
+                Reloc::Abs8 => unsafe {
+                    let reloc_address = body.as_mut_ptr().offset(r.offset as isize) as i64;
+                    let reloc_addend = r.addend as i64;
+                    let reloc_abs = target_func_address as i64 + reloc_addend;
+                    write_unaligned(reloc_address as *mut i64, reloc_abs);
+                },
+                Reloc::X86PCRel4 => unsafe {
+                    let reloc_address = body.as_mut_ptr().offset(r.offset as isize) as isize;
                     let reloc_addend = r.addend as isize;
-                let reloc_delta_i32 = (target_func_address - reloc_address + reloc_addend) as i32;
+                    // TODO: Handle overflow.
+                    let reloc_delta_i32 = (target_func_address - reloc_address + reloc_addend) as
+                        i32;
                     write_unaligned(reloc_address as *mut i32, reloc_delta_i32);
+                },
+                _ => panic!("unsupported reloc kind"),
             }
         }
     }
@@ -72,7 +84,9 @@ pub fn execute(
     let start_index = compilation.module.start_func.ok_or_else(|| {
         String::from("No start function defined, aborting execution")
     })?;
-    let code_buf = &compilation.functions[start_index];
+    // TODO: Put all the function bodies into a page-aligned memory region, and
+    // then make them ReadExecute rather than ReadWriteExecute.
+    for code_buf in &compilation.functions {
         match unsafe {
             protect(
                 code_buf.as_ptr(),
@@ -88,6 +102,9 @@ pub fn execute(
                 ))
             }
         }
+    }
+
+    let code_buf = &compilation.functions[start_index];
 
     let vmctx = make_vmctx(instance);
 

lib/runtime/src/lib.rs

@@ -569,7 +569,8 @@ impl<'data, 'module> ModuleTranslation<'data, 'module> {
     ) -> Result<(Compilation<'module>, Relocations), String> {
         let mut functions = Vec::new();
         let mut relocations = Vec::new();
-        for (func_index, input) in self.lazy.function_body_inputs.iter().enumerate() {
+        for (i, input) in self.lazy.function_body_inputs.iter().enumerate() {
+            let func_index = i + self.module.imported_funcs.len();
             let mut context = cretonne_codegen::Context::new();
             context.func.name = get_func_name(func_index);
             context.func.signature = self.module.signatures[self.module.functions[func_index]]