From 45f5f8ec45da02700d77569b0ea470ae0fb430b0 Mon Sep 17 00:00:00 2001
From: Patrick Walton <pcwalton@mimiga.net>
Date: Wed, 12 Sep 2012 17:59:29 -0700
Subject: [PATCH] libcore: Add some visitor-based logging functionality

---
 src/libcore/core.rc   |   4 +-
 src/libcore/repr.rs   | 575 ++++++++++++++++++++++++++++++++++++++++++
 src/libcore/to_str.rs |   6 +
 3 files changed, 583 insertions(+), 2 deletions(-)
 create mode 100644 src/libcore/repr.rs

diff --git a/src/libcore/core.rc b/src/libcore/core.rc
index 84ea2fe4477f..d6091801da45 100644
--- a/src/libcore/core.rc
+++ b/src/libcore/core.rc
@@ -61,6 +61,7 @@ export mutable;
 export flate;
 export unit;
 export uniq;
+export repr;
 
 // NDM seems to be necessary for resolve to work
 export option_iter;
@@ -224,10 +225,9 @@ mod rand;
 mod run;
 mod sys;
 mod unsafe;
-
 mod mutable;
-
 mod flate;
+mod repr;
 
 // Modules supporting compiler-generated code
 // Exported but not part of the public interface
diff --git a/src/libcore/repr.rs b/src/libcore/repr.rs
new file mode 100644
index 000000000000..f052016ed6c9
--- /dev/null
+++ b/src/libcore/repr.rs
@@ -0,0 +1,575 @@
+use dvec::DVec;
+use io::{Writer, WriterUtil};
+use libc::c_void;
+use sys::TypeDesc;
+use to_str::ToStr;
+use unsafe::transmute;
+use intrinsic::{TyDesc, TyVisitor};
+
+/// Helpers
+
+/// Helper function for alignment calculation.
+#[inline(always)]
+fn align(size: uint, align: uint) -> uint {
+    ((size + align) - 1) & !(align - 1)
+}
+
+struct VecRepr {
+    box_header: (uint, uint, uint, uint),
+    mut fill: uint,
+    mut alloc: uint,
+    data: u8
+}
+
+struct BoxRepr {
+    ref_count: uint,
+    type_desc: *TyDesc,
+    prev: *BoxRepr,
+    next: *BoxRepr,
+    data: u8
+}
+
+trait EscapedCharWriter {
+    fn write_escaped_char(ch: char);
+}
+
+impl Writer : EscapedCharWriter {
+    fn write_escaped_char(ch: char) {
+        match ch {
+            '\t' => self.write_str("\\t"),
+            '\r' => self.write_str("\\r"),
+            '\n' => self.write_str("\\n"),
+            '\\' => self.write_str("\\\\"),
+            '\'' => self.write_str("\\'"),
+            '"' => self.write_str("\\\""),
+            '\x20'..'\x7e' => self.write_char(ch),
+            _ => {
+                // XXX: This is inefficient because it requires a malloc.
+                self.write_str(char::escape_unicode(ch))
+            }
+        }
+    }
+}
+
+/// Representations
+
+trait Repr {
+    fn write_repr(writer: @Writer);
+}
+
+impl () : Repr {
+    fn write_repr(writer: @Writer) { writer.write_str("()"); }
+}
+
+impl bool : Repr {
+    fn write_repr(writer: @Writer) {
+        writer.write_str(if self { "true" } else { "false" })
+    }
+}
+
+impl int : Repr {
+    fn write_repr(writer: @Writer) { writer.write_int(self); }
+}
+impl i8 : Repr {
+    fn write_repr(writer: @Writer) { writer.write_int(self as int); }
+}
+impl i16 : Repr {
+    fn write_repr(writer: @Writer) { writer.write_int(self as int); }
+}
+impl i32 : Repr {
+    fn write_repr(writer: @Writer) { writer.write_int(self as int); }
+}
+impl i64 : Repr {
+    // XXX: This can lose precision.
+    fn write_repr(writer: @Writer) { writer.write_int(self as int); }
+}
+
+impl uint : Repr {
+    fn write_repr(writer: @Writer) { writer.write_uint(self); }
+}
+impl u8 : Repr {
+    fn write_repr(writer: @Writer) { writer.write_uint(self as uint); }
+}
+impl u16 : Repr {
+    fn write_repr(writer: @Writer) { writer.write_uint(self as uint); }
+}
+impl u32 : Repr {
+    fn write_repr(writer: @Writer) { writer.write_uint(self as uint); }
+}
+impl u64 : Repr {
+    // XXX: This can lose precision.
+    fn write_repr(writer: @Writer) { writer.write_uint(self as uint); }
+}
+
+impl float : Repr {
+    // XXX: This mallocs.
+    fn write_repr(writer: @Writer) { writer.write_str(self.to_str()); }
+}
+impl f32 : Repr {
+    // XXX: This mallocs.
+    fn write_repr(writer: @Writer) { writer.write_str(self.to_str()); }
+}
+impl f64 : Repr {
+    // XXX: This mallocs.
+    fn write_repr(writer: @Writer) { writer.write_str(self.to_str()); }
+}
+
+impl char : Repr {
+    fn write_repr(writer: @Writer) { writer.write_char(self); }
+}
+
+/// XXX: This should not use a boxed writer!
+struct ReprPrinter {
+    mut ptr: *c_void,
+    writer: @Writer,    // XXX: This should not use a boxed trait.
+    mut skip: bool,
+    enum_stack: DVec<*c_void>
+}
+
+/// FIXME (issue #3462): This is horrible.
+struct ReprPrinterWrapper {
+    printer: @ReprPrinter
+}
+
+impl ReprPrinter {
+    #[inline(always)]
+    fn align(n: uint) {
+        unsafe {
+            self.ptr = transmute(align(self.ptr as uint, n));
+        }
+    }
+
+    #[inline(always)]
+    fn bump(n: uint) {
+        unsafe {
+            self.ptr = transmute(self.ptr as uint + n);
+        }
+    }
+
+    #[inline(always)]
+    fn log_simple<T:Repr>() -> bool {
+        unsafe {
+            self.align(sys::min_align_of::<T>());
+            let value_addr: &T = transmute(copy self.ptr);
+            (*value_addr).write_repr(self.writer);
+            self.bump(sys::size_of::<T>());
+            true
+        }
+    }
+}
+
+impl ReprPrinterWrapper {
+    fn visit_estr() -> bool {
+        unsafe {
+            self.printer.writer.write_char('"');
+            let vec_repr_ptr: **VecRepr = transmute(copy self.printer.ptr);
+            let vec_repr = *vec_repr_ptr;
+            let data_ptr = ptr::to_unsafe_ptr(&(*vec_repr).data);
+            let slice: &str = transmute((data_ptr, (*vec_repr).fill));
+            do str::chars_iter(slice) |ch| {
+                self.printer.writer.write_escaped_char(ch);
+            }
+            self.printer.writer.write_char('"');
+            let ptr_size = sys::size_of::<*c_void>();
+            self.printer.ptr = transmute(self.printer.ptr as uint + ptr_size);
+            true
+        }
+    }
+
+    fn visit_self_describing_heap_alloc(mtbl: uint) -> bool {
+        unsafe {
+            if mtbl != 1 { self.printer.writer.write_str("mut "); }
+            let box_ptr: **BoxRepr = transmute(copy self.printer.ptr);
+            let box = *box_ptr;
+            self.printer.ptr = transmute(&(*box).data);
+            intrinsic::visit_tydesc((*box).type_desc, self as @TyVisitor);
+            let box_size = sys::size_of::<*BoxRepr>();
+            self.printer.ptr = transmute(self.printer.ptr as uint + box_size);
+            true
+        }
+    }
+
+    fn visit_ptr_contents(mtbl: uint, inner: *TyDesc) -> bool {
+        unsafe {
+            if mtbl != 1 { self.printer.writer.write_str("mut "); }
+            let data_ptr: **c_void = transmute(copy self.printer.ptr);
+            if *data_ptr == ptr::null() {
+                self.printer.writer.write_str("null");
+            } else {
+                self.printer.ptr = *data_ptr;
+                intrinsic::visit_tydesc(inner, self as @TyVisitor);
+            }
+            let ptr_size = sys::size_of::<*c_void>();
+            self.printer.ptr = transmute(self.printer.ptr as uint + ptr_size);
+            true
+        }
+    }
+
+    fn visit_evec(mtbl: uint, inner: *TyDesc) -> bool {
+        unsafe {
+            self.printer.writer.write_char('[');
+            self.printer.align(sys::min_align_of::<*c_void>());
+            let vec_repr_ptr: **VecRepr = transmute(copy self.printer.ptr);
+            let old_ptr = self.printer.ptr as uint;
+            let vec_repr: *VecRepr = *vec_repr_ptr;
+            self.printer.ptr = transmute(&(*vec_repr).data);
+            let end_ptr: *c_void = transmute(self.printer.ptr as uint +
+                                             (*vec_repr).fill);
+            let sys_tydesc: *TypeDesc = transmute(copy inner);
+            let alignment = (*sys_tydesc).align;
+            let mut first = true;
+            loop {
+                self.printer.align(alignment);
+                if self.printer.ptr >= end_ptr { break; }
+                if first {
+                    self.printer.writer.write_char(' ');
+                    if mtbl != 1 { self.printer.writer.write_str("mut "); }
+                } else {
+                    self.printer.writer.write_str(", ");
+                }
+                intrinsic::visit_tydesc(inner, self as @TyVisitor);
+                first = false;
+            }
+            if !first {
+                self.printer.writer.write_char(' ');
+            } else if mtbl != 1 {
+                self.printer.writer.write_str("mut");
+            }
+            self.printer.writer.write_char(']');
+            self.printer.ptr = transmute(old_ptr + sys::size_of::<int>());
+            true
+        }
+    }
+}
+
+impl ReprPrinterWrapper : TyVisitor {
+    fn visit_bot() -> bool {
+        self.printer.bump(1);
+        self.printer.writer.write_str("fail");
+        true
+    }
+
+    fn visit_nil() -> bool { self.printer.log_simple::<()>() }
+    fn visit_bool() -> bool { self.printer.log_simple::<bool>() }
+
+    // Numbers
+
+    fn visit_int() -> bool { self.printer.log_simple::<int>() }
+    fn visit_i8() -> bool { self.printer.log_simple::<i8>() }
+    fn visit_i16() -> bool { self.printer.log_simple::<i16>() }
+    fn visit_i32() -> bool { self.printer.log_simple::<i32>() }
+    fn visit_i64() -> bool { self.printer.log_simple::<i64>() }
+
+    fn visit_uint() -> bool { self.printer.log_simple::<uint>() }
+    fn visit_u8() -> bool { self.printer.log_simple::<u8>() }
+    fn visit_u16() -> bool { self.printer.log_simple::<u16>() }
+    fn visit_u32() -> bool { self.printer.log_simple::<u32>() }
+    fn visit_u64() -> bool { self.printer.log_simple::<u64>() }
+
+    fn visit_float() -> bool { self.printer.log_simple::<float>() }
+    fn visit_f32() -> bool { self.printer.log_simple::<f32>() }
+    fn visit_f64() -> bool { self.printer.log_simple::<f64>() }
+
+    fn visit_char() -> bool { self.printer.log_simple::<char>() }
+    fn visit_str() -> bool { true }
+
+    // Strings
+
+    fn visit_estr_box() -> bool {
+        self.printer.writer.write_char('@');
+        self.visit_estr()
+    }
+    fn visit_estr_uniq() -> bool {
+        self.printer.writer.write_char('~');
+        self.visit_estr()
+    }
+    fn visit_estr_slice() -> bool {
+        unsafe {
+            self.printer.writer.write_char('"');
+            let slice_ptr: *&str = transmute(copy self.printer.ptr);
+            let slice = *slice_ptr;
+            do str::chars_iter(slice) |ch| {
+                self.printer.writer.write_escaped_char(ch);
+            }
+            self.printer.writer.write_char('"');
+            let slice_sz = sys::size_of::<(*char,uint)>();
+            self.printer.ptr = transmute(self.printer.ptr as uint + slice_sz);
+            true
+        }
+    }
+    fn visit_estr_fixed(_n: uint, _sz: uint, _align: uint) -> bool { true }
+
+    // Pointers
+
+    fn visit_box(mtbl: uint, _inner: *TyDesc) -> bool {
+        self.printer.writer.write_char('@');
+        self.visit_self_describing_heap_alloc(mtbl)
+    }
+    fn visit_uniq(mtbl: uint, _inner: *TyDesc) -> bool {
+        self.printer.writer.write_char('~');
+        self.visit_self_describing_heap_alloc(mtbl)
+    }
+    fn visit_ptr(mtbl: uint, inner: *TyDesc) -> bool {
+        self.printer.writer.write_char('*');
+        self.visit_ptr_contents(mtbl, inner)
+    }
+    fn visit_rptr(mtbl: uint, inner: *TyDesc) -> bool {
+        self.printer.writer.write_char('&');
+        self.visit_ptr_contents(mtbl, inner)
+    }
+
+    // Vectors
+
+    fn visit_vec(_mtbl: uint, _inner: *TyDesc) -> bool { true }
+    fn visit_unboxed_vec(_mtbl: uint, _inner: *TyDesc) -> bool { true }
+    fn visit_evec_box(mtbl: uint, inner: *TyDesc) -> bool {
+        self.printer.writer.write_char('@');
+        self.visit_evec(mtbl, inner)
+    }
+    fn visit_evec_uniq(mtbl: uint, inner: *TyDesc) -> bool {
+        self.printer.writer.write_char('~');
+        self.visit_evec(mtbl, inner)
+    }
+    fn visit_evec_slice(mtbl: uint, inner: *TyDesc) -> bool {
+        unsafe {
+            self.printer.writer.write_str("&[");
+            self.printer.align(sys::min_align_of::<(*c_void,uint)>());
+            let slice_ptr: *(*c_void,uint) = transmute(copy self.printer.ptr);
+            let (data, fill) = *slice_ptr;
+            self.printer.ptr = data;
+            let end_ptr: *c_void = transmute(self.printer.ptr as uint + fill);
+            let sys_tydesc: *TypeDesc = transmute(copy inner);
+            let alignment = (*sys_tydesc).align;
+            let mut first = true;
+            loop {
+                self.printer.align(alignment);
+                if self.printer.ptr >= end_ptr { break; }
+                if first {
+                    self.printer.writer.write_char(' ');
+                    if mtbl != 1 { self.printer.writer.write_str("mut "); }
+                } else {
+                    self.printer.writer.write_str(", ");
+                }
+                intrinsic::visit_tydesc(inner, self as @TyVisitor);
+                first = false;
+            }
+            if !first {
+                self.printer.writer.write_char(' ');
+            } else if mtbl != 1 {
+                self.printer.writer.write_str("mut");
+            }
+            self.printer.writer.write_char(']');
+            let slice_size = sys::size_of::<(uint, *c_void)>();
+            self.printer.ptr = transmute(slice_ptr as uint + slice_size);
+            true
+        }
+    }
+    fn visit_evec_fixed(n: uint, sz: uint, align: uint, mtbl: uint,
+                        inner: *TyDesc) -> bool {
+        unsafe {
+            self.printer.writer.write_char('[');
+            self.printer.align(align);
+            let end_ptr: *c_void = transmute(self.printer.ptr as uint + sz);
+            for uint::range(0, n) |i| {
+                self.printer.align(align);
+                if i == 0 {
+                    self.printer.writer.write_char(' ');
+                    if mtbl != 1 { self.printer.writer.write_str("mut "); }
+                } else {
+                    self.printer.writer.write_str(", ");
+                }
+                intrinsic::visit_tydesc(inner, self as @TyVisitor);
+            }
+            if n > 0 {
+                self.printer.writer.write_char(' ');
+            } else if mtbl != 1 {
+                self.printer.writer.write_str("mut");
+            }
+            self.printer.writer.write_char(']');
+            self.printer.ptr = end_ptr;
+            true
+        }
+    }
+
+    // Records
+
+    fn visit_enter_rec(_n_fields: uint, _sz: uint, align: uint) -> bool {
+        self.printer.writer.write_char('{');
+        self.printer.align(align);
+        true
+    }
+    fn visit_rec_field(i: uint, name: &str, mtbl: uint, inner: *TyDesc) ->
+                       bool {
+        if i != 0 {
+            self.printer.writer.write_str(", ");
+        } else {
+            self.printer.writer.write_char(' ');
+        }
+        if mtbl != 1 { self.printer.writer.write_str("mut "); }
+        self.printer.writer.write_str(name);
+        self.printer.writer.write_str(": ");
+        intrinsic::visit_tydesc(inner, self as @TyVisitor);
+        true
+    }
+    fn visit_leave_rec(n_fields: uint, _sz: uint, _align: uint) -> bool {
+        if n_fields > 0 { self.printer.writer.write_char(' '); }
+        self.printer.writer.write_char('}');
+        true
+    }
+
+    // Structs
+
+    fn visit_enter_class(_n_fields: uint, _sz: uint, align: uint) -> bool {
+        self.printer.writer.write_char('{');
+        self.printer.align(align);
+        true
+    }
+    fn visit_class_field(i: uint, name: &str, mtbl: uint, inner: *TyDesc) ->
+                         bool {
+        if i != 0 {
+            self.printer.writer.write_str(", ");
+        } else {
+            self.printer.writer.write_char(' ');
+        }
+        if mtbl != 1 { self.printer.writer.write_str("mut "); }
+        self.printer.writer.write_str(name);
+        self.printer.writer.write_str(": ");
+        intrinsic::visit_tydesc(inner, self as @TyVisitor);
+        true
+    }
+    fn visit_leave_class(n_fields: uint, _sz: uint, _align: uint) -> bool {
+        if n_fields > 0 { self.printer.writer.write_char(' '); }
+        self.printer.writer.write_char('}');
+        true
+    }
+
+    // Tuples
+
+    fn visit_enter_tup(_n_fields: uint, _sz: uint, align: uint) -> bool {
+        self.printer.writer.write_char('(');
+        self.printer.align(align);
+        true
+    }
+    fn visit_tup_field(i: uint, inner: *TyDesc) -> bool {
+        if i != 0 { self.printer.writer.write_str(", "); }
+        intrinsic::visit_tydesc(inner, self as @TyVisitor);
+        true
+    }
+    fn visit_leave_tup(_n_fields: uint, _sz: uint, _align: uint) -> bool {
+        self.printer.writer.write_char(')');
+        true
+    }
+
+    // Enums
+
+    fn visit_enter_enum(_n_variants: uint, sz: uint, align: uint) -> bool {
+        unsafe {
+            self.printer.align(align);
+
+            // Write in the location of the end of this enum.
+            let new_pos = self.printer.ptr as uint + sz;
+            self.printer.enum_stack.push(transmute(new_pos));
+
+            true
+        }
+    }
+
+    fn visit_enter_enum_variant(_variant: uint,
+                                disr_val: int,
+                                _n_fields: uint,
+                                name: &str) -> bool {
+        unsafe {
+            let disr_ptr = self.printer.ptr as *int;
+            if *disr_ptr == disr_val {
+                self.printer.skip = false;  // Don't skip this variant.
+                self.printer.writer.write_str(name);
+                self.printer.bump(sys::size_of::<int>());
+            } else {
+                self.printer.skip = true;   // Skip this variant.
+            }
+            true
+        }
+    }
+
+    fn visit_enum_variant_field(i: uint, inner: *TyDesc) -> bool {
+        if !self.printer.skip {
+            if i == 0 {
+                self.printer.writer.write_char('(');
+            } else {
+                self.printer.writer.write_str(", ");
+            }
+
+            intrinsic::visit_tydesc(inner, self as @TyVisitor);
+        }
+        true
+    }
+
+    fn visit_leave_enum_variant(_variant: uint,
+                                _disr_val: int,
+                                n_fields: uint,
+                                _name: &str) -> bool {
+        if !self.printer.skip && n_fields > 1 {
+            self.printer.writer.write_char(')');
+        }
+        true
+    }
+
+    fn visit_leave_enum(_n_variants: uint, _sz: uint, _align: uint) -> bool {
+        self.printer.ptr = self.printer.enum_stack.pop();
+        true
+    }
+
+    // Functions
+
+    fn visit_enter_fn(_purity: uint, proto: uint,
+                      _n_inputs: uint, _retstyle: uint) -> bool {
+        self.printer.align(sys::min_align_of::<(uint,uint)>());
+        match proto {
+            2u => self.printer.writer.write_char('~'),
+            3u => self.printer.writer.write_char('@'),
+            4u => self.printer.writer.write_char('&'),
+            _ => {}
+        }
+        self.printer.writer.write_str("fn");
+        true
+    }
+
+    fn visit_fn_input(_i: uint, _mode: uint, _inner: *TyDesc) -> bool { true }
+    fn visit_fn_output(_retstyle: uint, _inner: *TyDesc) -> bool { true }
+    fn visit_leave_fn(_purity: uint, _proto: uint,
+                      _n_inputs: uint, _retstyle: uint) -> bool { true }
+
+    // Others
+
+    fn visit_trait() -> bool { self.printer.writer.write_str("@trait"); true }
+    fn visit_var() -> bool { true }
+    fn visit_var_integral() -> bool { true }
+    fn visit_param(_i: uint) -> bool { true }
+    fn visit_self() -> bool { true }
+    fn visit_type() -> bool { true }
+    fn visit_opaque_box() -> bool {
+        self.printer.writer.write_char('@');
+        self.visit_self_describing_heap_alloc(1)
+    }
+    fn visit_constr(_inner: *TyDesc) -> bool { true }
+    fn visit_closure_ptr(_ck: uint) -> bool { true }
+}
+
+pub fn write_repr<T>(writer: @Writer, object: &T) {
+    unsafe {
+        let ptr = ptr::to_unsafe_ptr(object) as *c_void;
+        let tydesc = sys::get_type_desc::<T>();
+        let tydesc = unsafe::transmute(tydesc);
+
+        let repr_printer = @ReprPrinter {
+            ptr: ptr,
+            writer: writer,
+            skip: false,
+            enum_stack: DVec()
+        };
+
+        let wrapper = ReprPrinterWrapper { printer: repr_printer };
+        intrinsic::visit_tydesc(tydesc, wrapper as @TyVisitor);
+    }
+}
+
diff --git a/src/libcore/to_str.rs b/src/libcore/to_str.rs
index b0caf894dfc7..358ad0e281fe 100644
--- a/src/libcore/to_str.rs
+++ b/src/libcore/to_str.rs
@@ -37,6 +37,12 @@ impl u64: ToStr {
 impl float: ToStr {
     fn to_str() -> ~str { float::to_str(self, 4u) }
 }
+impl f32: ToStr {
+    fn to_str() -> ~str { float::to_str(self as float, 4u) }
+}
+impl f64: ToStr {
+    fn to_str() -> ~str { float::to_str(self as float, 4u) }
+}
 impl bool: ToStr {
     fn to_str() -> ~str { bool::to_str(self) }
 }