No need to default offset since we always override it.

Author: Mukund Lakshman

src/librustdoc/externalfiles.rs

@@ -46,7 +46,7 @@ impl ExternalHtml {
                 error_codes: codes,
                 edition,
                 playground,
-                heading_level: 0
+                heading_level: 1
             }
             .into_string()
         );
@@ -62,7 +62,7 @@ impl ExternalHtml {
                 error_codes: codes,
                 edition,
                 playground,
-                heading_level: 0
+                heading_level: 1
             }
             .into_string()
         );

src/librustdoc/html/markdown.rs

@@ -19,7 +19,7 @@
 //!     error_codes: ErrorCodes::Yes,
 //!     edition: Edition::Edition2015,
 //!     playground: &None,
-//!     heading_level: 0
+//!     heading_level: 1
 //! };
 //! let html = md.into_string();
 //! // ... something using html
@@ -544,7 +544,7 @@ impl<'a, 'b, 'ids, I: Iterator<Item = SpannedEvent<'a>>> Iterator
                 self.buf.push_front((Event::Html(format!("{} ", sec).into()), 0..0));
             }
 
-            let level = std::cmp::min(level + self.level + 1, MAX_HEADER_LEVEL);
+            let level = std::cmp::min(level + self.level, MAX_HEADER_LEVEL);
             self.buf.push_back((Event::Html(format!("</a></h{}>", level).into()), 0..0));
 
             let start_tags = format!(

src/librustdoc/html/markdown/tests.rs

@@ -154,7 +154,7 @@ fn test_header() {
             error_codes: ErrorCodes::Yes,
             edition: DEFAULT_EDITION,
             playground: &None,
-            heading_level: 0,
+            heading_level: 1,
         }
         .into_string();
         assert_eq!(output, expect, "original: {}", input);
@@ -196,7 +196,7 @@ fn test_header_ids_multiple_blocks() {
             error_codes: ErrorCodes::Yes,
             edition: DEFAULT_EDITION,
             playground: &None,
-            heading_level: 0,
+            heading_level: 1,
         }
         .into_string();
         assert_eq!(output, expect, "original: {}", input);

src/librustdoc/html/render/mod.rs

@@ -470,11 +470,7 @@ fn settings(root_path: &str, suffix: &str, themes: &[StylePath]) -> Result<Strin
     ))
 }
 
-fn document(w: &mut Buffer, cx: &Context<'_>, item: &clean::Item, parent: Option<&clean::Item>) {
-    document_at_level(w, cx, item, parent, 0)
-}
-
-fn document_at_level(
+fn document(
     w: &mut Buffer,
     cx: &Context<'_>,
     item: &clean::Item,
@@ -1344,7 +1340,7 @@ fn render_impl(
                         // because impls can't have a stability.
                         if item.doc_value().is_some() {
                             document_item_info(&mut info_buffer, cx, it, Some(parent));
-                            document_full(&mut doc_buffer, item, cx, 3);
+                            document_full(&mut doc_buffer, item, cx, 4);
                             short_documented = false;
                         } else {
                             // In case the item isn't documented,
@@ -1362,7 +1358,7 @@ fn render_impl(
                 } else {
                     document_item_info(&mut info_buffer, cx, item, Some(parent));
                     if rendering_params.show_def_docs {
-                        document_full(&mut doc_buffer, item, cx, 3);
+                        document_full(&mut doc_buffer, item, cx, 4);
                         short_documented = false;
                     }
                 }
@@ -1603,7 +1599,7 @@ fn render_impl(
                     error_codes: cx.shared.codes,
                     edition: cx.shared.edition(),
                     playground: &cx.shared.playground,
-                    heading_level: 0
+                    heading_level: 1
                 }
                 .into_string()
             );

src/librustdoc/html/render/print_item.rs

@@ -16,10 +16,10 @@ use rustc_span::symbol::{kw, sym, Symbol};
 use rustc_target::abi::{Layout, Primitive, TagEncoding, Variants};
 
 use super::{
-    collect_paths_for_type, document, document_at_level, ensure_trailing_slash, item_ty_to_strs,
-    notable_traits_decl, render_assoc_item, render_assoc_items, render_attributes_in_code,
-    render_attributes_in_pre, render_impl, render_stability_since_raw, write_srclink,
-    AssocItemLink, Context, ImplRenderingParameters,
+    collect_paths_for_type, document, ensure_trailing_slash, item_ty_to_strs, notable_traits_decl,
+    render_assoc_item, render_assoc_items, render_attributes_in_code, render_attributes_in_pre,
+    render_impl, render_stability_since_raw, write_srclink, AssocItemLink, Context,
+    ImplRenderingParameters,
 };
 use crate::clean::{self, GetDefId};
 use crate::formats::item_type::ItemType;
@@ -173,7 +173,7 @@ fn toggle_close(w: &mut Buffer) {
 }
 
 fn item_module(w: &mut Buffer, cx: &Context<'_>, item: &clean::Item, items: &[clean::Item]) {
-    document(w, cx, item, None);
+    document(w, cx, item, None, 1);
 
     let mut indices = (0..items.len()).filter(|i| !items[*i].is_stripped()).collect::<Vec<usize>>();
 
@@ -485,7 +485,7 @@ fn item_function(w: &mut Buffer, cx: &Context<'_>, it: &clean::Item, f: &clean::
             notable_traits = notable_traits_decl(&f.decl, cx),
         );
     });
-    document(w, cx, it, None)
+    document(w, cx, it, None, 1)
 }
 
 fn item_trait(w: &mut Buffer, cx: &Context<'_>, it: &clean::Item, t: &clean::Trait) {
@@ -608,7 +608,7 @@ fn item_trait(w: &mut Buffer, cx: &Context<'_>, it: &clean::Item, t: &clean::Tra
     });
 
     // Trait documentation
-    document(w, cx, it, None);
+    document(w, cx, it, None, 1);
 
     fn write_small_section_header(w: &mut Buffer, id: &str, title: &str, extra_content: &str) {
         write!(
@@ -626,7 +626,7 @@ fn item_trait(w: &mut Buffer, cx: &Context<'_>, it: &clean::Item, t: &clean::Tra
         let item_type = m.type_();
         let id = cx.derive_id(format!("{}.{}", item_type, name));
         let mut content = Buffer::empty_from(w);
-        document_at_level(&mut content, cx, m, Some(t), 3);
+        document(&mut content, cx, m, Some(t), 4);
         let toggled = !content.is_empty();
         if toggled {
             write!(w, "<details class=\"rustdoc-toggle\" open><summary>");
@@ -840,7 +840,7 @@ fn item_trait_alias(w: &mut Buffer, cx: &Context<'_>, it: &clean::Item, t: &clea
         );
     });
 
-    document(w, cx, it, None);
+    document(w, cx, it, None, 1);
 
     // Render any items associated directly to this alias, as otherwise they
     // won't be visible anywhere in the docs. It would be nice to also show
@@ -862,7 +862,7 @@ fn item_opaque_ty(w: &mut Buffer, cx: &Context<'_>, it: &clean::Item, t: &clean:
         );
     });
 
-    document(w, cx, it, None);
+    document(w, cx, it, None, 1);
 
     // Render any items associated directly to this alias, as otherwise they
     // won't be visible anywhere in the docs. It would be nice to also show
@@ -893,7 +893,7 @@ fn item_typedef(
         );
     });
 
-    document(w, cx, it, None);
+    document(w, cx, it, None, 1);
 
     let def_id = it.def_id.expect_def_id();
     // Render any items associated directly to this alias, as otherwise they
@@ -911,7 +911,7 @@ fn item_union(w: &mut Buffer, cx: &Context<'_>, it: &clean::Item, s: &clean::Uni
         });
     });
 
-    document(w, cx, it, None);
+    document(w, cx, it, None, 1);
 
     let mut fields = s
         .fields
@@ -944,7 +944,7 @@ fn item_union(w: &mut Buffer, cx: &Context<'_>, it: &clean::Item, s: &clean::Uni
             if let Some(stability_class) = field.stability_class(cx.tcx()) {
                 write!(w, "<span class=\"stab {stab}\"></span>", stab = stability_class);
             }
-            document(w, cx, field, Some(it));
+            document(w, cx, field, Some(it), 1);
         }
     }
     let def_id = it.def_id.expect_def_id();
@@ -1026,7 +1026,7 @@ fn item_enum(w: &mut Buffer, cx: &Context<'_>, it: &clean::Item, e: &clean::Enum
         });
     });
 
-    document(w, cx, it, None);
+    document(w, cx, it, None, 1);
 
     if !e.variants.is_empty() {
         write!(
@@ -1055,7 +1055,7 @@ fn item_enum(w: &mut Buffer, cx: &Context<'_>, it: &clean::Item, e: &clean::Enum
             w.write_str("</code>");
             render_stability_since(w, variant, it, cx.tcx());
             w.write_str("</div>");
-            document(w, cx, variant, Some(it));
+            document(w, cx, variant, Some(it), 1);
             document_non_exhaustive(w, variant);
 
             use crate::clean::Variant;
@@ -1095,7 +1095,7 @@ fn item_enum(w: &mut Buffer, cx: &Context<'_>, it: &clean::Item, e: &clean::Enum
                                 f = field.name.as_ref().unwrap(),
                                 t = ty.print(cx)
                             );
-                            document(w, cx, field, Some(variant));
+                            document(w, cx, field, Some(variant), 1);
                         }
                         _ => unreachable!(),
                     }
@@ -1122,7 +1122,7 @@ fn item_macro(w: &mut Buffer, cx: &Context<'_>, it: &clean::Item, t: &clean::Mac
             None,
         );
     });
-    document(w, cx, it, None)
+    document(w, cx, it, None, 1)
 }
 
 fn item_proc_macro(w: &mut Buffer, cx: &Context<'_>, it: &clean::Item, m: &clean::ProcMacro) {
@@ -1152,11 +1152,11 @@ fn item_proc_macro(w: &mut Buffer, cx: &Context<'_>, it: &clean::Item, m: &clean
             });
         }
     }
-    document(w, cx, it, None)
+    document(w, cx, it, None, 1)
 }
 
 fn item_primitive(w: &mut Buffer, cx: &Context<'_>, it: &clean::Item) {
-    document(w, cx, it, None);
+    document(w, cx, it, None, 1);
     render_assoc_items(w, cx, it, it.def_id.expect_def_id(), AssocItemRender::All)
 }
 
@@ -1195,7 +1195,7 @@ fn item_constant(w: &mut Buffer, cx: &Context<'_>, it: &clean::Item, c: &clean::
         }
     });
 
-    document(w, cx, it, None)
+    document(w, cx, it, None, 1)
 }
 
 fn item_struct(w: &mut Buffer, cx: &Context<'_>, it: &clean::Item, s: &clean::Struct) {
@@ -1206,7 +1206,7 @@ fn item_struct(w: &mut Buffer, cx: &Context<'_>, it: &clean::Item, s: &clean::St
         });
     });
 
-    document(w, cx, it, None);
+    document(w, cx, it, None, 1);
 
     let mut fields = s
         .fields
@@ -1242,7 +1242,7 @@ fn item_struct(w: &mut Buffer, cx: &Context<'_>, it: &clean::Item, s: &clean::St
                     name = field_name,
                     ty = ty.print(cx)
                 );
-                document(w, cx, field, Some(it));
+                document(w, cx, field, Some(it), 1);
             }
         }
     }
@@ -1263,7 +1263,7 @@ fn item_static(w: &mut Buffer, cx: &Context<'_>, it: &clean::Item, s: &clean::St
             typ = s.type_.print(cx)
         );
     });
-    document(w, cx, it, None)
+    document(w, cx, it, None, 1)
 }
 
 fn item_foreign_type(w: &mut Buffer, cx: &Context<'_>, it: &clean::Item) {
@@ -1278,13 +1278,13 @@ fn item_foreign_type(w: &mut Buffer, cx: &Context<'_>, it: &clean::Item) {
         );
     });
 
-    document(w, cx, it, None);
+    document(w, cx, it, None, 1);
 
     render_assoc_items(w, cx, it, it.def_id.expect_def_id(), AssocItemRender::All)
 }
 
 fn item_keyword(w: &mut Buffer, cx: &Context<'_>, it: &clean::Item) {
-    document(w, cx, it, None)
+    document(w, cx, it, None, 1)
 }
 
 /// Compare two strings treating multi-digit numbers as single units (i.e. natural sort order).

src/tools/error_index_generator/main.rs

@@ -126,7 +126,7 @@ impl Formatter for HTMLFormatter {
                         error_codes: ErrorCodes::Yes,
                         edition: DEFAULT_EDITION,
                         playground: &Some(playground),
-                        heading_level: 0
+                        heading_level: 1
                     }
                     .into_string()
                 )?