lots of miscellaneous things all in one big commit

 * add `@compileLog(...)` builtin function
   - Helps debug code running at compile time
   - See #240
 * fix crash when there is an error on the start value of a slice
 * add implicit cast from int and float types to int and float
   literals if the value is known at compile time
 * make array concatenation work with slices in addition to
   arrays and c string literals
 * fix compile error message for something not having field access
 * fix crash when `@setDebugSafety()` was called from a
   function being evaluated at compile-time
 * fix compile-time evaluation of overflow math builtins.
 * avoid debug safety panic handler in builtin.o and compiler_rt.o
   since we use no debug safety in these modules anyway
 * add compiler_rt functions for division on ARM
   - Closes #254
 * move default panic handler to std.debug so users can
   call it manually
 * std.io.printf supports a width in the format specifier

3 files changed, 34 insertions, 4 deletions

diff --git a/test/cases/enum_with_members.zig b/test/cases/enum_with_members.zig
index b338b9b014..5abb297674 100644
--- a/test/cases/enum_with_members.zig
+++ b/test/cases/enum_with_members.zig
@@ -8,8 +8,8 @@ const ET = enum {
 
     pub fn print(a: &const ET, buf: []u8) -> %usize {
         return switch (*a) {
-            ET.SINT => |x| { io.bufPrintInt(buf, x, 10, false) },
-            ET.UINT => |x| { io.bufPrintInt(buf, x, 10, false) },
+            ET.SINT => |x| { io.bufPrintInt(buf, x, 10, false, 0) },
+            ET.UINT => |x| { io.bufPrintInt(buf, x, 10, false, 0) },
         }
     }
 };
diff --git a/test/cases/eval.zig b/test/cases/eval.zig
index 9f3b1d2fcd..027bb643b6 100644
--- a/test/cases/eval.zig
+++ b/test/cases/eval.zig
@@ -251,3 +251,15 @@ fn comptimeIterateOverFnPtrList() {
     assert(performFn('o', 0) == 1);
     assert(performFn('w', 99) == 99);
 }
+
+fn evalSetDebugSafetyAtCompileTime() {
+    @setFnTest(this);
+
+    const result = comptime fnWithSetDebugSafety();
+    assert(result == 1234);
+}
+
+fn fnWithSetDebugSafety() -> i32{
+    @setDebugSafety(this, true);
+    return 1234;
+}
diff --git a/test/run_tests.cpp b/test/run_tests.cpp
index 01d16a2543..828f3469bf 100644
--- a/test/run_tests.cpp
+++ b/test/run_tests.cpp
@@ -1015,8 +1015,9 @@ const x = foo();
 
     add_compile_fail_case("array concatenation with wrong type", R"SOURCE(
 const src = "aoeu";
-const a = src[0...] ++ "foo";
-    )SOURCE", 1, ".tmp_source.zig:3:14: error: expected array or C string literal, found '[]u8'");
+const derp = usize(1234);
+const a = derp ++ "foo";
+    )SOURCE", 1, ".tmp_source.zig:4:11: error: expected array or C string literal, found 'usize'");
 
     add_compile_fail_case("non compile time array concatenation", R"SOURCE(
 fn f(s: [10]u8) -> []u8 {
@@ -1632,6 +1633,23 @@ const some_data: [100]u8 = {
 };
     )SOURCE", 1, ".tmp_source.zig:3:32: error: alignment value must be power of 2");
 
+    add_compile_fail_case("compile log", R"SOURCE(
+fn foo() {
+    comptime bar(12, "hi");
+}
+fn bar(a: i32, b: []const u8) {
+    @compileLog("begin");
+    @compileLog("a", a, "b", b);
+    @compileLog("end");
+}
+    )SOURCE", 6,
+        ".tmp_source.zig:6:5: error: found compile log statement",
+        ".tmp_source.zig:3:17: note: called from here",
+        ".tmp_source.zig:7:5: error: found compile log statement",
+        ".tmp_source.zig:3:17: note: called from here",
+        ".tmp_source.zig:8:5: error: found compile log statement",
+        ".tmp_source.zig:3:17: note: called from here");
+
 }
 
 //////////////////////////////////////////////////////////////////////////////