stage2: pass most test cases under InternPool

All but 2 test cases now pass (tested on x86_64 Linux, native only). The
remaining two signify an issue requiring a larger refactor, which I will
do in a separate commit.

Notable changes:
* Fix uninitialized memory when allocating objects from free lists
* Implement TypedValue printing for pointers
* Fix some TypedValue printing logic
* Work around non-existence of InternPool.remove implementation

5 files changed, 214 insertions, 38 deletions

diff --git a/src/InternPool.zig b/src/InternPool.zig
index 0363003b36..a46f765ad5 100644
--- a/src/InternPool.zig
+++ b/src/InternPool.zig
@@ -400,14 +400,21 @@ pub const Key = union(enum) {
         /// integer tag type of the enum.
         pub fn tagValueIndex(self: EnumType, ip: *const InternPool, tag_val: Index) ?u32 {
             assert(tag_val != .none);
+            // TODO: we should probably decide a single interface for this function, but currently
+            // it's being called with both tag values and underlying ints. Fix this!
+            const int_tag_val = switch (ip.indexToKey(tag_val)) {
+                .enum_tag => |enum_tag| enum_tag.int,
+                .int => tag_val,
+                else => unreachable,
+            };
             if (self.values_map.unwrap()) |values_map| {
                 const map = &ip.maps.items[@enumToInt(values_map)];
                 const adapter: Index.Adapter = .{ .indexes = self.values };
-                const field_index = map.getIndexAdapted(tag_val, adapter) orelse return null;
+                const field_index = map.getIndexAdapted(int_tag_val, adapter) orelse return null;
                 return @intCast(u32, field_index);
             }
-            // Auto-numbered enum. Convert `tag_val` to field index.
-            switch (ip.indexToKey(tag_val).int.storage) {
+            // Auto-numbered enum. Convert `int_tag_val` to field index.
+            switch (ip.indexToKey(int_tag_val).int.storage) {
                 .u64 => |x| {
                     if (x >= self.names.len) return null;
                     return @intCast(u32, x);
@@ -4261,12 +4268,8 @@ fn addMap(ip: *InternPool, gpa: Allocator) Allocator.Error!MapIndex {
 
 /// This operation only happens under compile error conditions.
 /// Leak the index until the next garbage collection.
-pub fn remove(ip: *InternPool, index: Index) void {
-    _ = ip;
-    _ = index;
-    @setCold(true);
-    @panic("TODO this is a bit problematic to implement, could we maybe just never support a remove() operation on InternPool?");
-}
+/// TODO: this is a bit problematic to implement, can we get away without it?
+pub const remove = @compileError("InternPool.remove is not currently a supported operation; put a TODO there instead");
 
 fn addInt(ip: *InternPool, gpa: Allocator, ty: Index, tag: Tag, limbs: []const Limb) !void {
     const limbs_len = @intCast(u32, limbs.len);
@@ -5161,7 +5164,10 @@ pub fn createStruct(
     gpa: Allocator,
     initialization: Module.Struct,
 ) Allocator.Error!Module.Struct.Index {
-    if (ip.structs_free_list.popOrNull()) |index| return index;
+    if (ip.structs_free_list.popOrNull()) |index| {
+        ip.allocated_structs.at(@enumToInt(index)).* = initialization;
+        return index;
+    }
     const ptr = try ip.allocated_structs.addOne(gpa);
     ptr.* = initialization;
     return @intToEnum(Module.Struct.Index, ip.allocated_structs.len - 1);
@@ -5180,7 +5186,10 @@ pub fn createUnion(
     gpa: Allocator,
     initialization: Module.Union,
 ) Allocator.Error!Module.Union.Index {
-    if (ip.unions_free_list.popOrNull()) |index| return index;
+    if (ip.unions_free_list.popOrNull()) |index| {
+        ip.allocated_unions.at(@enumToInt(index)).* = initialization;
+        return index;
+    }
     const ptr = try ip.allocated_unions.addOne(gpa);
     ptr.* = initialization;
     return @intToEnum(Module.Union.Index, ip.allocated_unions.len - 1);
@@ -5199,7 +5208,10 @@ pub fn createFunc(
     gpa: Allocator,
     initialization: Module.Fn,
 ) Allocator.Error!Module.Fn.Index {
-    if (ip.funcs_free_list.popOrNull()) |index| return index;
+    if (ip.funcs_free_list.popOrNull()) |index| {
+        ip.allocated_funcs.at(@enumToInt(index)).* = initialization;
+        return index;
+    }
     const ptr = try ip.allocated_funcs.addOne(gpa);
     ptr.* = initialization;
     return @intToEnum(Module.Fn.Index, ip.allocated_funcs.len - 1);
@@ -5218,7 +5230,10 @@ pub fn createInferredErrorSet(
     gpa: Allocator,
     initialization: Module.Fn.InferredErrorSet,
 ) Allocator.Error!Module.Fn.InferredErrorSet.Index {
-    if (ip.inferred_error_sets_free_list.popOrNull()) |index| return index;
+    if (ip.inferred_error_sets_free_list.popOrNull()) |index| {
+        ip.allocated_inferred_error_sets.at(@enumToInt(index)).* = initialization;
+        return index;
+    }
     const ptr = try ip.allocated_inferred_error_sets.addOne(gpa);
     ptr.* = initialization;
     return @intToEnum(Module.Fn.InferredErrorSet.Index, ip.allocated_inferred_error_sets.len - 1);
diff --git a/src/Module.zig b/src/Module.zig
index c1d6b8157a..cb3e8884e3 100644
--- a/src/Module.zig
+++ b/src/Module.zig
@@ -4374,7 +4374,8 @@ pub fn semaFile(mod: *Module, file: *File) SemaError!void {
         .index = struct_index.toOptional(),
         .namespace = new_namespace_index.toOptional(),
     } });
-    errdefer mod.intern_pool.remove(struct_ty);
+    // TODO: figure out InternPool removals for incremental compilation
+    //errdefer mod.intern_pool.remove(struct_ty);
 
     new_namespace.ty = struct_ty.toType();
     file.root_decl = new_decl_index.toOptional();
@@ -5682,7 +5683,10 @@ fn markOutdatedDecl(mod: *Module, decl_index: Decl.Index) !void {
 }
 
 pub fn createNamespace(mod: *Module, initialization: Namespace) !Namespace.Index {
-    if (mod.namespaces_free_list.popOrNull()) |index| return index;
+    if (mod.namespaces_free_list.popOrNull()) |index| {
+        mod.allocated_namespaces.at(@enumToInt(index)).* = initialization;
+        return index;
+    }
     const ptr = try mod.allocated_namespaces.addOne(mod.gpa);
     ptr.* = initialization;
     return @intToEnum(Namespace.Index, mod.allocated_namespaces.len - 1);
diff --git a/src/Sema.zig b/src/Sema.zig
index be354ff350..715c63c77c 100644
--- a/src/Sema.zig
+++ b/src/Sema.zig
@@ -2801,7 +2801,8 @@ fn zirStructDecl(
         .index = struct_index.toOptional(),
         .namespace = new_namespace_index.toOptional(),
     } });
-    errdefer mod.intern_pool.remove(struct_ty);
+    // TODO: figure out InternPool removals for incremental compilation
+    //errdefer mod.intern_pool.remove(struct_ty);
 
     new_decl.val = struct_ty.toValue();
     new_namespace.ty = struct_ty.toType();
@@ -3012,7 +3013,8 @@ fn zirEnumDecl(
         else
             .explicit,
     });
-    errdefer if (!done) mod.intern_pool.remove(incomplete_enum.index);
+    // TODO: figure out InternPool removals for incremental compilation
+    //errdefer if (!done) mod.intern_pool.remove(incomplete_enum.index);
 
     new_decl.val = incomplete_enum.index.toValue();
     new_namespace.ty = incomplete_enum.index.toType();
@@ -3260,7 +3262,8 @@ fn zirUnionDecl(
             .ReleaseFast, .ReleaseSmall => .none,
         },
     } });
-    errdefer mod.intern_pool.remove(union_ty);
+    // TODO: figure out InternPool removals for incremental compilation
+    //errdefer mod.intern_pool.remove(union_ty);
 
     new_decl.val = union_ty.toValue();
     new_namespace.ty = union_ty.toType();
@@ -3321,7 +3324,8 @@ fn zirOpaqueDecl(
         .decl = new_decl_index,
         .namespace = new_namespace_index,
     } });
-    errdefer mod.intern_pool.remove(opaque_ty);
+    // TODO: figure out InternPool removals for incremental compilation
+    //errdefer mod.intern_pool.remove(opaque_ty);
 
     new_decl.val = opaque_ty.toValue();
     new_namespace.ty = opaque_ty.toType();
@@ -19424,7 +19428,10 @@ fn zirReify(
             }, name_strategy, "enum", inst);
             const new_decl = mod.declPtr(new_decl_index);
             new_decl.owns_tv = true;
-            errdefer mod.abortAnonDecl(new_decl_index);
+            errdefer {
+                new_decl.has_tv = false; // namespace and val were destroyed by later errdefers
+                mod.abortAnonDecl(new_decl_index);
+            }
 
             // Define our empty enum decl
             const fields_len = @intCast(u32, try sema.usizeCast(block, src, fields_val.sliceLen(mod)));
@@ -19439,7 +19446,8 @@ fn zirReify(
                     .explicit,
                 .tag_ty = int_tag_ty.toIntern(),
             });
-            errdefer ip.remove(incomplete_enum.index);
+            // TODO: figure out InternPool removals for incremental compilation
+            //errdefer ip.remove(incomplete_enum.index);
 
             new_decl.val = incomplete_enum.index.toValue();
 
@@ -19514,7 +19522,10 @@ fn zirReify(
             }, name_strategy, "opaque", inst);
             const new_decl = mod.declPtr(new_decl_index);
             new_decl.owns_tv = true;
-            errdefer mod.abortAnonDecl(new_decl_index);
+            errdefer {
+                new_decl.has_tv = false; // namespace and val were destroyed by later errdefers
+                mod.abortAnonDecl(new_decl_index);
+            }
 
             const new_namespace_index = try mod.createNamespace(.{
                 .parent = block.namespace.toOptional(),
@@ -19528,7 +19539,8 @@ fn zirReify(
                 .decl = new_decl_index,
                 .namespace = new_namespace_index,
             } });
-            errdefer ip.remove(opaque_ty);
+            // TODO: figure out InternPool removals for incremental compilation
+            //errdefer ip.remove(opaque_ty);
 
             new_decl.val = opaque_ty.toValue();
             new_namespace.ty = opaque_ty.toType();
@@ -19568,7 +19580,10 @@ fn zirReify(
             }, name_strategy, "union", inst);
             const new_decl = mod.declPtr(new_decl_index);
             new_decl.owns_tv = true;
-            errdefer mod.abortAnonDecl(new_decl_index);
+            errdefer {
+                new_decl.has_tv = false; // namespace and val were destroyed by later errdefers
+                mod.abortAnonDecl(new_decl_index);
+            }
 
             const new_namespace_index = try mod.createNamespace(.{
                 .parent = block.namespace.toOptional(),
@@ -19601,7 +19616,8 @@ fn zirReify(
                     .ReleaseFast, .ReleaseSmall => .none,
                 },
             } });
-            errdefer ip.remove(union_ty);
+            // TODO: figure out InternPool removals for incremental compilation
+            //errdefer ip.remove(union_ty);
 
             new_decl.val = union_ty.toValue();
             new_namespace.ty = union_ty.toType();
@@ -19865,7 +19881,10 @@ fn reifyStruct(
     }, name_strategy, "struct", inst);
     const new_decl = mod.declPtr(new_decl_index);
     new_decl.owns_tv = true;
-    errdefer mod.abortAnonDecl(new_decl_index);
+    errdefer {
+        new_decl.has_tv = false; // namespace and val were destroyed by later errdefers
+        mod.abortAnonDecl(new_decl_index);
+    }
 
     const new_namespace_index = try mod.createNamespace(.{
         .parent = block.namespace.toOptional(),
@@ -19892,7 +19911,8 @@ fn reifyStruct(
         .index = struct_index.toOptional(),
         .namespace = new_namespace_index.toOptional(),
     } });
-    errdefer ip.remove(struct_ty);
+    // TODO: figure out InternPool removals for incremental compilation
+    //errdefer ip.remove(struct_ty);
 
     new_decl.val = struct_ty.toValue();
     new_namespace.ty = struct_ty.toType();
@@ -27515,8 +27535,8 @@ fn coerceInMemoryAllowedFns(
                 if (rt != .ok) {
                     return InMemoryCoercionResult{ .fn_return_type = .{
                         .child = try rt.dupe(sema.arena),
-                        .actual = dest_return_type,
-                        .wanted = src_return_type,
+                        .actual = src_return_type,
+                        .wanted = dest_return_type,
                     } };
                 }
             },
@@ -29505,7 +29525,8 @@ fn coerceTupleToStruct(
         .ty = struct_ty.toIntern(),
         .storage = .{ .elems = field_vals },
     } });
-    errdefer ip.remove(struct_val);
+    // TODO: figure out InternPool removals for incremental compilation
+    //errdefer ip.remove(struct_val);
 
     return sema.addConstant(struct_ty, struct_val.toValue());
 }
@@ -34666,14 +34687,14 @@ fn floatToIntScalar(
     var big_int = try float128IntPartToBigInt(sema.arena, float);
     defer big_int.deinit();
 
-    const result = try mod.intValue_big(int_ty, big_int.toConst());
+    const cti_result = try mod.intValue_big(Type.comptime_int, big_int.toConst());
 
-    if (!(try sema.intFitsInType(result, int_ty, null))) {
+    if (!(try sema.intFitsInType(cti_result, int_ty, null))) {
         return sema.fail(block, src, "float value '{}' cannot be stored in integer type '{}'", .{
             val.fmtValue(float_ty, sema.mod), int_ty.fmt(sema.mod),
         });
     }
-    return result;
+    return mod.getCoerced(cti_result, int_ty);
 }
 
 /// Asserts the value is an integer, and the destination type is ComptimeInt or Int.
diff --git a/src/TypedValue.zig b/src/TypedValue.zig
index 0d771aa184..723207eeff 100644
--- a/src/TypedValue.zig
+++ b/src/TypedValue.zig
@@ -203,7 +203,7 @@ pub fn print(
             .extern_func => |extern_func| return writer.print("(extern function '{s}')", .{
                 mod.intern_pool.stringToSlice(mod.declPtr(extern_func.decl).name),
             }),
-            .func => |func| return writer.print("(function '{d}')", .{
+            .func => |func| return writer.print("(function '{s}')", .{
                 mod.intern_pool.stringToSlice(mod.declPtr(mod.funcPtr(func.index).owner_decl).name),
             }),
             .int => |int| switch (int.storage) {
@@ -234,7 +234,12 @@ pub fn print(
                 if (level == 0) {
                     return writer.writeAll("(enum)");
                 }
-
+                const enum_type = mod.intern_pool.indexToKey(ty.toIntern()).enum_type;
+                if (enum_type.tagValueIndex(&mod.intern_pool, val.toIntern())) |tag_index| {
+                    const tag_name = mod.intern_pool.stringToSlice(enum_type.names[tag_index]);
+                    try writer.print(".{}", .{std.zig.fmtId(tag_name)});
+                    return;
+                }
                 try writer.writeAll("@intToEnum(");
                 try print(.{
                     .ty = Type.type,
@@ -250,9 +255,129 @@ pub fn print(
             },
             .empty_enum_value => return writer.writeAll("(empty enum value)"),
             .float => |float| switch (float.storage) {
-                inline else => |x| return writer.print("{}", .{x}),
+                inline else => |x| return writer.print("{d}", .{@floatCast(f64, x)}),
+            },
+            .ptr => |ptr| {
+                if (ptr.addr == .int) {
+                    const i = mod.intern_pool.indexToKey(ptr.addr.int).int;
+                    switch (i.storage) {
+                        inline else => |addr| return writer.print("{x:0>8}", .{addr}),
+                    }
+                }
+
+                const ptr_ty = mod.intern_pool.indexToKey(ty.toIntern()).ptr_type;
+                if (ptr_ty.flags.size == .Slice) {
+                    if (level == 0) {
+                        return writer.writeAll(".{ ... }");
+                    }
+                    const elem_ty = ptr_ty.child.toType();
+                    const len = ptr.len.toValue().toUnsignedInt(mod);
+                    if (elem_ty.eql(Type.u8, mod)) str: {
+                        const max_len = @min(len, max_string_len);
+                        var buf: [max_string_len]u8 = undefined;
+                        for (buf[0..max_len], 0..) |*c, i| {
+                            const elem = try val.elemValue(mod, i);
+                            if (elem.isUndef(mod)) break :str;
+                            c.* = @intCast(u8, elem.toUnsignedInt(mod));
+                        }
+                        const truncated = if (len > max_string_len) " (truncated)" else "";
+                        return writer.print("\"{}{s}\"", .{ std.zig.fmtEscapes(buf[0..max_len]), truncated });
+                    }
+                    try writer.writeAll(".{ ");
+                    const max_len = @min(len, max_aggregate_items);
+                    for (0..max_len) |i| {
+                        if (i != 0) try writer.writeAll(", ");
+                        try print(.{
+                            .ty = elem_ty,
+                            .val = try val.elemValue(mod, i),
+                        }, writer, level - 1, mod);
+                    }
+                    if (len > max_aggregate_items) {
+                        try writer.writeAll(", ...");
+                    }
+                    return writer.writeAll(" }");
+                }
+
+                switch (ptr.addr) {
+                    .decl => |decl_index| {
+                        const decl = mod.declPtr(decl_index);
+                        if (level == 0) return writer.print("(decl '{s}')", .{mod.intern_pool.stringToSlice(decl.name)});
+                        return print(.{
+                            .ty = decl.ty,
+                            .val = decl.val,
+                        }, writer, level - 1, mod);
+                    },
+                    .mut_decl => |mut_decl| {
+                        const decl = mod.declPtr(mut_decl.decl);
+                        if (level == 0) return writer.print("(mut decl '{s}')", .{mod.intern_pool.stringToSlice(decl.name)});
+                        return print(.{
+                            .ty = decl.ty,
+                            .val = decl.val,
+                        }, writer, level - 1, mod);
+                    },
+                    .comptime_field => |field_val_ip| {
+                        return print(.{
+                            .ty = mod.intern_pool.typeOf(field_val_ip).toType(),
+                            .val = field_val_ip.toValue(),
+                        }, writer, level - 1, mod);
+                    },
+                    .int => unreachable,
+                    .eu_payload => |eu_ip| {
+                        try writer.writeAll("(payload of ");
+                        try print(.{
+                            .ty = mod.intern_pool.typeOf(eu_ip).toType(),
+                            .val = eu_ip.toValue(),
+                        }, writer, level - 1, mod);
+                        try writer.writeAll(")");
+                    },
+                    .opt_payload => |opt_ip| {
+                        try print(.{
+                            .ty = mod.intern_pool.typeOf(opt_ip).toType(),
+                            .val = opt_ip.toValue(),
+                        }, writer, level - 1, mod);
+                        try writer.writeAll(".?");
+                    },
+                    .elem => |elem| {
+                        try print(.{
+                            .ty = mod.intern_pool.typeOf(elem.base).toType(),
+                            .val = elem.base.toValue(),
+                        }, writer, level - 1, mod);
+                        try writer.print("[{}]", .{elem.index});
+                    },
+                    .field => |field| {
+                        const container_ty = mod.intern_pool.typeOf(field.base).toType();
+                        try print(.{
+                            .ty = container_ty,
+                            .val = field.base.toValue(),
+                        }, writer, level - 1, mod);
+
+                        switch (container_ty.zigTypeTag(mod)) {
+                            .Struct => {
+                                if (container_ty.isTuple(mod)) {
+                                    try writer.print("[{d}]", .{field.index});
+                                }
+                                const field_name_ip = container_ty.structFieldName(field.index, mod);
+                                const field_name = mod.intern_pool.stringToSlice(field_name_ip);
+                                try writer.print(".{}", .{std.zig.fmtId(field_name)});
+                            },
+                            .Union => {
+                                const field_name_ip = container_ty.unionFields(mod).keys()[field.index];
+                                const field_name = mod.intern_pool.stringToSlice(field_name_ip);
+                                try writer.print(".{}", .{std.zig.fmtId(field_name)});
+                            },
+                            .Pointer => {
+                                std.debug.assert(container_ty.isSlice(mod));
+                                try writer.writeAll(switch (field.index) {
+                                    Value.slice_ptr_index => ".ptr",
+                                    Value.slice_len_index => ".len",
+                                    else => unreachable,
+                                });
+                            },
+                            else => unreachable,
+                        }
+                    },
+                }
             },
-            .ptr => return writer.writeAll("(ptr)"),
             .opt => |opt| switch (opt.val) {
                 .none => return writer.writeAll("null"),
                 else => |payload| {
@@ -261,7 +386,15 @@ pub fn print(
                 },
             },
             .aggregate => |aggregate| switch (aggregate.storage) {
-                .bytes => |bytes| return writer.print("\"{}\"", .{std.zig.fmtEscapes(bytes)}),
+                .bytes => |bytes| {
+                    // Strip the 0 sentinel off of strings before printing
+                    const zero_sent = blk: {
+                        const sent = ty.sentinel(mod) orelse break :blk false;
+                        break :blk sent.eql(Value.zero_u8, Type.u8, mod);
+                    };
+                    const str = if (zero_sent) bytes[0..bytes.len - 1] else bytes;
+                    return writer.print("\"{}\"", .{std.zig.fmtEscapes(str)});
+                },
                 .elems, .repeated_elem => return printAggregate(ty, val, writer, level, mod),
             },
             .un => |un| {
diff --git a/src/type.zig b/src/type.zig
index d9ae710b2d..a6997bc590 100644
--- a/src/type.zig
+++ b/src/type.zig
@@ -345,6 +345,9 @@ pub const Type = struct {
                 }
             },
             .anon_struct_type => |anon_struct| {
+                if (anon_struct.types.len == 0) {
+                    return writer.writeAll("@TypeOf(.{})");
+                }
                 try writer.writeAll("struct{");
                 for (anon_struct.types, anon_struct.values, 0..) |field_ty, val, i| {
                     if (i != 0) try writer.writeAll(", ");