refactors sus_panic and sus_unreachable (#470)

These macros have been changed to functions, which will provide better
ergonomics for C++. Care was taken to ensure that calls to `sus::panic`
weren't substantially worse than expanding `sus_panic`. In addition,
`sus_panic_with_message` was refactored into `sus::panic`.

The same logic was applied to refactoring `sus_unreachable`, although
the assembly wasn't inspected.

---------

Co-authored-by: Dana Jansens <[email protected]>

Author: cjdb

STYLE.md

@@ -7,7 +7,7 @@ footguns, crashes, bugs, and UB.
 1. All methods are `constexpr` unless they must call a non-`constexpr` function,
    or they expose floating point NaNs (since constexpr NaNs change their bit
    values).
-    * Consider `sus_panic()`/`sus_check()` as constexpr for these purposes, they will
+    * Consider `sus::panic()`/`sus_check()` as constexpr for these purposes, they will
       correctly prevent compiling if the condition fails.
 1. If you override on `const&`, then explicitly provide or delete the `&&`
    override.
@@ -71,7 +71,7 @@ footguns, crashes, bugs, and UB.
    `operator==(Option, Option)` and `operator==(Option<T>, Option<U>)` look redundant
    but they are not, as the former allows conversions to Option for the rhs to happen
    while the latter does not (it would have to deduce `U` and fails).
-  
+
 ## Containers that hold references
 
 Container types that hold references require extra care in a number of ways. To
@@ -87,13 +87,13 @@ properly build such a container type (e.g. `Option` and `Tuple`):
     from an rvalue is okay, but when holding a value, giving a reference to it from an
     rvalue is not.
   * Use `static_assert(SafelyConstructibleFromReference<ToType, FromReferenceType&&>)`
-    in places that store the reference to ensure a reference to a temporary does not 
+    in places that store the reference to ensure a reference to a temporary does not
     get created due to an implicit conversion. The `FromReferenceType&&` here is should
     be the input type as it's written in the function parameters.
   * If a ctor type deduction guide is provided, the deduction should strip qualifiers
     and references with `std::remove_cvref_t` on the deduced type arguments.
   * Consider providing a construction marker type such as `some() -> SomeMarker` which
-    captures the parameters as references and lazily constructs the final type. This 
+    captures the parameters as references and lazily constructs the final type. This
     allows reference types to be preserved through to the construction of the
     container without requiring the full type defn to be written every time.
     * Notably, this is omitted for `Choice`, which needs to be reasonably used behind

subdoc/lib/friendly_names.h

@@ -67,7 +67,7 @@ inline std::string friendly_record_type_name(RecordType t,
     case RecordType::Struct: return capitalize ? "Struct" : "struct";
     case RecordType::Union: return capitalize ? "Union" : "union";
   }
-  sus_unreachable_unchecked(unsafe_fn);
+  sus::unreachable_unchecked(unsafe_fn);
 }
 
 }  // namespace subdoc

subdoc/lib/gen/files.h

@@ -101,7 +101,7 @@ inline std::filesystem::path construct_html_namespace_file_path(
         return fmt::format("namespace.{}",
                            namespace_path[0u].as<Namespace::Tag::Named>());
     }
-    sus_unreachable();
+    sus::unreachable();
   }();
 
   fname << name;
@@ -316,7 +316,7 @@ inline Option<std::string> construct_html_url_for_alias(
               // aliases.
               break;
           }
-          sus_unreachable();
+          sus::unreachable();
         });
       }
       case AliasTarget::Tag::AliasOfConcept: {
@@ -330,11 +330,11 @@ inline Option<std::string> construct_html_url_for_alias(
           }
           case ConceptRefOrName::Tag::Name: return sus::none();
         }
-        sus_unreachable();
+        sus::unreachable();
       }
       case AliasTarget::Tag::AliasOfMethod: {
         // TODO: Link to method.
-        sus_unreachable();
+        sus::unreachable();
       }
       case AliasTarget::Tag::AliasOfFunction: {
         const LinkedFunction& fun =
@@ -347,11 +347,11 @@ inline Option<std::string> construct_html_url_for_alias(
           }
           case FunctionRefOrName::Tag::Name: return sus::none();
         }
-        sus_unreachable();
+        sus::unreachable();
       }
       case AliasTarget::Tag::AliasOfEnumConstant: {
         // TODO: Link to constant.
-        sus_unreachable();
+        sus::unreachable();
       }
       case AliasTarget::Tag::AliasOfVariable: {
         const LinkedVariable& var =
@@ -364,10 +364,10 @@ inline Option<std::string> construct_html_url_for_alias(
           }
           case VariableRefOrName::Tag::Name: return sus::none();
         }
-        sus_unreachable();
+        sus::unreachable();
       }
     }
-    sus_unreachable();
+    sus::unreachable();
   } else {
     // TODO: Link to the alias' page.
     return sus::some("TODO");

subdoc/lib/gen/generate.h

@@ -70,7 +70,7 @@ struct sus::error::ErrorImpl<subdoc::gen::GenerateError> {
         return fmt::format("parsing doc comment markdown");
       }
     }
-    sus_unreachable();
+    sus::unreachable();
   }
   static Option<const sus::error::DynError&> source(
       const GenerateError& e) noexcept {
@@ -88,6 +88,6 @@ struct sus::error::ErrorImpl<subdoc::gen::GenerateError> {
         return sus::some(*p);
       }
     }
-    sus_unreachable();
+    sus::unreachable();
   }
 };

subdoc/lib/gen/generate_alias.cc

@@ -77,7 +77,7 @@ sus::Result<MarkdownToHtml, MarkdownToHtmlError> get_alias_comment(
       }
       case AliasTarget::Tag::AliasOfMethod: {
         // TODO: Link to method.
-        sus_unreachable();
+        sus::unreachable();
       }
       case AliasTarget::Tag::AliasOfFunction: {
         const LinkedFunction& fun =
@@ -94,7 +94,7 @@ sus::Result<MarkdownToHtml, MarkdownToHtmlError> get_alias_comment(
       }
       case AliasTarget::Tag::AliasOfEnumConstant: {
         // TODO: Link to constant.
-        sus_unreachable();
+        sus::unreachable();
       }
       case AliasTarget::Tag::AliasOfVariable: {
         const LinkedVariable& var =

subdoc/lib/gen/generate_concept.cc

@@ -77,7 +77,7 @@ void generate_concept_overview(HtmlWriter::OpenDiv& record_div,
               break;  // Macro can't be an ancesor of a concept.
             case CppPathConcept: return "concept-name";
           }
-          sus_unreachable();
+          sus::unreachable();
         }());
         ancestor_anchor.add_href(e.link_href);
         ancestor_anchor.write_text(e.name);

subdoc/lib/gen/generate_cpp_path.cc

@@ -41,7 +41,7 @@ Vec<CppPathElement> generate_with_ancestors(
                   return std::string("(anonymous)");
                 case Namespace::Tag::Named: return sus::clone(ancestor.name);
               }
-              sus_unreachable();
+              sus::unreachable();
             }(),
         .link_href = construct_html_url_for_namespace(ancestor),
         .type =
@@ -51,7 +51,7 @@ Vec<CppPathElement> generate_with_ancestors(
                 case Namespace::Tag::Anonymous: return CppPathNamespace;
                 case Namespace::Tag::Named: return CppPathNamespace;
               }
-              sus_unreachable();
+              sus::unreachable();
             }(),
         .search_weight = 1_f32,
     });

subdoc/lib/gen/generate_function.cc

@@ -321,7 +321,7 @@ sus::Result<void, MarkdownToHtmlError> generate_function(
             case CppPathConcept:
               break;  // Concept can't be an ancestor of a function.
           }
-          sus_unreachable();
+          sus::unreachable();
         }());
         ancestor_anchor.add_href(e.link_href);
         ancestor_anchor.write_text(e.name);

subdoc/lib/gen/generate_macro.cc

@@ -145,7 +145,7 @@ sus::Result<void, MarkdownToHtmlError> generate_macro(
             case CppPathProject: return "project-name";
             case CppPathMacro: return "macro-name";
             default:
-              sus_unreachable();  // Macros are only in the global namespace.
+              sus::unreachable();  // Macros are only in the global namespace.
           }
         }());
         ancestor_anchor.add_href(e.link_href);

subdoc/lib/gen/generate_namespace.cc

@@ -196,7 +196,7 @@ void generate_namespace_overview(HtmlWriter::OpenDiv& namespace_div,
             case CppPathConcept:
               break;  // Concept can't be an ancestor of a namespace.
           }
-          sus_unreachable();
+          sus::unreachable();
         }());
         ancestor_anchor.add_href(e.link_href);
         ancestor_anchor.write_text(e.name);
@@ -615,7 +615,7 @@ sus::Result<void, MarkdownToHtmlError> generate_namespace(
           json.add_string("split_name", split_for_search(options.project_name));
           break;
         }
-        case Namespace::Tag::Anonymous: sus_unreachable();
+        case Namespace::Tag::Anonymous: sus::unreachable();
         case Namespace::Tag::Named: {
           json.add_string("type", "namespace");
           json.add_string("name", element.name);