Auto merge of #4082 - Manishearth:macro-check-split, r=oli-obk

Make most macro checks also check for desugarings

We should audit the macro checks one by one and re-add `in_macro`. I suspect it's applicable to most of them.

fixes #4081

clippy_lints/src/assertions_on_constants.rs

@@ -5,7 +5,7 @@ use rustc::{declare_lint_pass, declare_tool_lint};
 use syntax_pos::Span;
 
 use crate::consts::{constant, Constant};
-use crate::utils::{in_macro, is_direct_expn_of, span_help_and_lint};
+use crate::utils::{in_macro_or_desugar, is_direct_expn_of, span_help_and_lint};
 
 declare_clippy_lint! {
     /// **What it does:** Checks for `assert!(true)` and `assert!(false)` calls.
@@ -34,16 +34,16 @@ declare_lint_pass!(AssertionsOnConstants => [ASSERTIONS_ON_CONSTANTS]);
 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for AssertionsOnConstants {
     fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, e: &'tcx Expr) {
         let mut is_debug_assert = false;
-        let debug_assert_not_in_macro = |span: Span| {
+        let debug_assert_not_in_macro_or_desugar = |span: Span| {
             is_debug_assert = true;
             // Check that `debug_assert!` itself is not inside a macro
-            !in_macro(span)
+            !in_macro_or_desugar(span)
         };
         if_chain! {
             if let Some(assert_span) = is_direct_expn_of(e.span, "assert");
-            if !in_macro(assert_span)
+            if !in_macro_or_desugar(assert_span)
                 || is_direct_expn_of(assert_span, "debug_assert")
-                    .map_or(false, debug_assert_not_in_macro);
+                    .map_or(false, debug_assert_not_in_macro_or_desugar);
             if let ExprKind::Unary(_, ref lit) = e.node;
             if let Some(bool_const) = constant(cx, cx.tables, lit);
             then {

clippy_lints/src/attrs.rs

@@ -2,7 +2,7 @@
 
 use crate::reexport::*;
 use crate::utils::{
-    in_macro, is_present_in_source, last_line_of_span, paths, snippet_opt, span_lint, span_lint_and_sugg,
+    in_macro_or_desugar, is_present_in_source, last_line_of_span, paths, snippet_opt, span_lint, span_lint_and_sugg,
     span_lint_and_then, without_block_comments,
 };
 use if_chain::if_chain;
@@ -408,7 +408,7 @@ fn is_relevant_expr(cx: &LateContext<'_, '_>, tables: &ty::TypeckTables<'_>, exp
 }
 
 fn check_attrs(cx: &LateContext<'_, '_>, span: Span, name: Name, attrs: &[Attribute]) {
-    if in_macro(span) {
+    if in_macro_or_desugar(span) {
         return;
     }
 

clippy_lints/src/block_in_if_condition.rs

@@ -54,7 +54,7 @@ impl<'a, 'tcx: 'a> Visitor<'tcx> for ExVisitor<'a, 'tcx> {
         if let ExprKind::Closure(_, _, eid, _, _) = expr.node {
             let body = self.cx.tcx.hir().body(eid);
             let ex = &body.value;
-            if matches!(ex.node, ExprKind::Block(_, _)) && !in_macro(body.value.span) {
+            if matches!(ex.node, ExprKind::Block(_, _)) && !in_macro_or_desugar(body.value.span) {
                 self.found_block = Some(ex);
                 return;
             }
@@ -79,7 +79,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for BlockInIfCondition {
                         if let Some(ex) = &block.expr {
                             // don't dig into the expression here, just suggest that they remove
                             // the block
-                            if in_macro(expr.span) || differing_macro_contexts(expr.span, ex.span) {
+                            if in_macro_or_desugar(expr.span) || differing_macro_contexts(expr.span, ex.span) {
                                 return;
                             }
                             span_help_and_lint(
@@ -96,7 +96,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for BlockInIfCondition {
                         }
                     } else {
                         let span = block.expr.as_ref().map_or_else(|| block.stmts[0].span, |e| e.span);
-                        if in_macro(span) || differing_macro_contexts(expr.span, span) {
+                        if in_macro_or_desugar(span) || differing_macro_contexts(expr.span, span) {
                             return;
                         }
                         // move block higher

clippy_lints/src/booleans.rs

@@ -1,5 +1,6 @@
 use crate::utils::{
-    get_trait_def_id, implements_trait, in_macro, match_type, paths, snippet_opt, span_lint_and_then, SpanlessEq,
+    get_trait_def_id, implements_trait, in_macro, in_macro_or_desugar, match_type, paths, snippet_opt,
+    span_lint_and_then, SpanlessEq,
 };
 use rustc::hir::intravisit::*;
 use rustc::hir::*;
@@ -93,7 +94,7 @@ impl<'a, 'tcx, 'v> Hir2Qmm<'a, 'tcx, 'v> {
 
     fn run(&mut self, e: &'v Expr) -> Result<Bool, String> {
         // prevent folding of `cfg!` macros and the like
-        if !in_macro(e.span) {
+        if !in_macro_or_desugar(e.span) {
             match &e.node {
                 ExprKind::Unary(UnNot, inner) => return Ok(Bool::Not(box self.run(inner)?)),
                 ExprKind::Binary(binop, lhs, rhs) => match &binop.node {

clippy_lints/src/cognitive_complexity.rs

@@ -9,7 +9,7 @@ use rustc::{declare_tool_lint, impl_lint_pass};
 use syntax::ast::Attribute;
 use syntax::source_map::Span;
 
-use crate::utils::{in_macro, is_allowed, match_type, paths, span_help_and_lint, LimitStack};
+use crate::utils::{in_macro_or_desugar, is_allowed, match_type, paths, span_help_and_lint, LimitStack};
 
 declare_clippy_lint! {
     /// **What it does:** Checks for methods with high cognitive complexity.
@@ -42,7 +42,7 @@ impl_lint_pass!(CognitiveComplexity => [COGNITIVE_COMPLEXITY]);
 
 impl CognitiveComplexity {
     fn check<'a, 'tcx: 'a>(&mut self, cx: &'a LateContext<'a, 'tcx>, body: &'tcx Body, span: Span) {
-        if in_macro(span) {
+        if in_macro_or_desugar(span) {
             return;
         }
 

clippy_lints/src/collapsible_if.rs

@@ -18,7 +18,9 @@ use rustc::{declare_lint_pass, declare_tool_lint};
 use syntax::ast;
 
 use crate::utils::sugg::Sugg;
-use crate::utils::{in_macro, snippet_block, snippet_block_with_applicability, span_lint_and_sugg, span_lint_and_then};
+use crate::utils::{
+    in_macro_or_desugar, snippet_block, snippet_block_with_applicability, span_lint_and_sugg, span_lint_and_then,
+};
 use rustc_errors::Applicability;
 
 declare_clippy_lint! {
@@ -75,7 +77,7 @@ declare_lint_pass!(CollapsibleIf => [COLLAPSIBLE_IF]);
 
 impl EarlyLintPass for CollapsibleIf {
     fn check_expr(&mut self, cx: &EarlyContext<'_>, expr: &ast::Expr) {
-        if !in_macro(expr.span) {
+        if !in_macro_or_desugar(expr.span) {
             check_if(cx, expr)
         }
     }
@@ -110,7 +112,7 @@ fn check_collapsible_maybe_if_let(cx: &EarlyContext<'_>, else_: &ast::Expr) {
         if let ast::ExprKind::Block(ref block, _) = else_.node;
         if !block_starts_with_comment(cx, block);
         if let Some(else_) = expr_block(block);
-        if !in_macro(else_.span);
+        if !in_macro_or_desugar(else_.span);
         then {
             match else_.node {
                 ast::ExprKind::If(..) | ast::ExprKind::IfLet(..) => {

clippy_lints/src/const_static_lifetime.rs

@@ -1,4 +1,4 @@
-use crate::utils::{in_macro, snippet, span_lint_and_then};
+use crate::utils::{in_macro_or_desugar, snippet, span_lint_and_then};
 use rustc::lint::{EarlyContext, EarlyLintPass, LintArray, LintPass};
 use rustc::{declare_lint_pass, declare_tool_lint};
 use rustc_errors::Applicability;
@@ -81,7 +81,7 @@ impl StaticConst {
 
 impl EarlyLintPass for StaticConst {
     fn check_item(&mut self, cx: &EarlyContext<'_>, item: &Item) {
-        if !in_macro(item.span) {
+        if !in_macro_or_desugar(item.span) {
             // Match only constants...
             if let ItemKind::Const(ref var_type, _) = item.node {
                 self.visit_type(var_type, cx);

clippy_lints/src/copies.rs

@@ -1,4 +1,4 @@
-use crate::utils::{get_parent_expr, higher, in_macro, snippet, span_lint_and_then, span_note_and_lint};
+use crate::utils::{get_parent_expr, higher, in_macro_or_desugar, snippet, span_lint_and_then, span_note_and_lint};
 use crate::utils::{SpanlessEq, SpanlessHash};
 use rustc::hir::*;
 use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
@@ -107,7 +107,7 @@ declare_lint_pass!(CopyAndPaste => [IFS_SAME_COND, IF_SAME_THEN_ELSE, MATCH_SAME
 
 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for CopyAndPaste {
     fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) {
-        if !in_macro(expr.span) {
+        if !in_macro_or_desugar(expr.span) {
             // skip ifs directly in else, it will be checked in the parent if
             if let Some(expr) = get_parent_expr(cx, expr) {
                 if let Some((_, _, Some(ref else_expr))) = higher::if_block(&expr) {

clippy_lints/src/double_parens.rs

@@ -1,4 +1,4 @@
-use crate::utils::{in_macro, span_lint};
+use crate::utils::{in_macro_or_desugar, span_lint};
 use rustc::lint::{EarlyContext, EarlyLintPass, LintArray, LintPass};
 use rustc::{declare_lint_pass, declare_tool_lint};
 use syntax::ast::*;
@@ -26,7 +26,7 @@ declare_lint_pass!(DoubleParens => [DOUBLE_PARENS]);
 
 impl EarlyLintPass for DoubleParens {
     fn check_expr(&mut self, cx: &EarlyContext<'_>, expr: &Expr) {
-        if in_macro(expr.span) {
+        if in_macro_or_desugar(expr.span) {
             return;
         }
 

clippy_lints/src/enum_variants.rs

@@ -1,6 +1,6 @@
 //! lint on enum variants that are prefixed or suffixed by the same characters
 
-use crate::utils::{camel_case, in_macro, is_present_in_source};
+use crate::utils::{camel_case, in_macro_or_desugar, is_present_in_source};
 use crate::utils::{span_help_and_lint, span_lint};
 use rustc::lint::{EarlyContext, EarlyLintPass, Lint, LintArray, LintPass};
 use rustc::{declare_tool_lint, impl_lint_pass};
@@ -244,7 +244,7 @@ impl EarlyLintPass for EnumVariantNames {
         let item_name = item.ident.as_str();
         let item_name_chars = item_name.chars().count();
         let item_camel = to_camel_case(&item_name);
-        if !in_macro(item.span) && is_present_in_source(cx, item.span) {
+        if !in_macro_or_desugar(item.span) && is_present_in_source(cx, item.span) {
             if let Some(&(ref mod_name, ref mod_camel)) = self.modules.last() {
                 // constants don't have surrounding modules
                 if !mod_camel.is_empty() {

clippy_lints/src/eq_op.rs

@@ -1,5 +1,5 @@
 use crate::utils::{
-    implements_trait, in_macro, is_copy, multispan_sugg, snippet, span_lint, span_lint_and_then, SpanlessEq,
+    implements_trait, in_macro_or_desugar, is_copy, multispan_sugg, snippet, span_lint, span_lint_and_then, SpanlessEq,
 };
 use rustc::hir::*;
 use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
@@ -52,7 +52,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for EqOp {
     #[allow(clippy::similar_names, clippy::too_many_lines)]
     fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, e: &'tcx Expr) {
         if let ExprKind::Binary(op, ref left, ref right) = e.node {
-            if in_macro(e.span) {
+            if in_macro_or_desugar(e.span) {
                 return;
             }
             if is_valid_operator(op) && SpanlessEq::new(cx).ignore_fn().eq_expr(left, right) {

clippy_lints/src/erasing_op.rs

@@ -4,7 +4,7 @@ use rustc::{declare_lint_pass, declare_tool_lint};
 use syntax::source_map::Span;
 
 use crate::consts::{constant_simple, Constant};
-use crate::utils::{in_macro, span_lint};
+use crate::utils::{in_macro_or_desugar, span_lint};
 
 declare_clippy_lint! {
     /// **What it does:** Checks for erasing operations, e.g., `x * 0`.
@@ -31,7 +31,7 @@ declare_lint_pass!(ErasingOp => [ERASING_OP]);
 
 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for ErasingOp {
     fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, e: &'tcx Expr) {
-        if in_macro(e.span) {
+        if in_macro_or_desugar(e.span) {
             return;
         }
         if let ExprKind::Binary(ref cmp, ref left, ref right) = e.node {

clippy_lints/src/format.rs

@@ -1,6 +1,7 @@
 use crate::utils::paths;
 use crate::utils::{
-    in_macro, is_expn_of, last_path_segment, match_type, resolve_node, snippet, span_lint_and_then, walk_ptrs_ty,
+    in_macro_or_desugar, is_expn_of, last_path_segment, match_type, resolve_node, snippet, span_lint_and_then,
+    walk_ptrs_ty,
 };
 use if_chain::if_chain;
 use rustc::hir::*;
@@ -38,7 +39,7 @@ declare_lint_pass!(UselessFormat => [USELESS_FORMAT]);
 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for UselessFormat {
     fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) {
         if let Some(span) = is_expn_of(expr.span, "format") {
-            if in_macro(span) {
+            if in_macro_or_desugar(span) {
                 return;
             }
             match expr.node {

clippy_lints/src/formatting.rs

@@ -1,4 +1,4 @@
-use crate::utils::{differing_macro_contexts, in_macro, snippet_opt, span_note_and_lint};
+use crate::utils::{differing_macro_contexts, in_macro_or_desugar, snippet_opt, span_note_and_lint};
 use if_chain::if_chain;
 use rustc::lint::{in_external_macro, EarlyContext, EarlyLintPass, LintArray, LintPass};
 use rustc::{declare_lint_pass, declare_tool_lint};
@@ -108,7 +108,7 @@ impl EarlyLintPass for Formatting {
 /// Implementation of the `SUSPICIOUS_ASSIGNMENT_FORMATTING` lint.
 fn check_assign(cx: &EarlyContext<'_>, expr: &ast::Expr) {
     if let ast::ExprKind::Assign(ref lhs, ref rhs) = expr.node {
-        if !differing_macro_contexts(lhs.span, rhs.span) && !in_macro(lhs.span) {
+        if !differing_macro_contexts(lhs.span, rhs.span) && !in_macro_or_desugar(lhs.span) {
             let eq_span = lhs.span.between(rhs.span);
             if let ast::ExprKind::Unary(op, ref sub_rhs) = rhs.node {
                 if let Some(eq_snippet) = snippet_opt(cx, eq_span) {
@@ -140,7 +140,7 @@ fn check_else(cx: &EarlyContext<'_>, expr: &ast::Expr) {
         if let Some((then, &Some(ref else_))) = unsugar_if(expr);
         if is_block(else_) || unsugar_if(else_).is_some();
         if !differing_macro_contexts(then.span, else_.span);
-        if !in_macro(then.span) && !in_external_macro(cx.sess, expr.span);
+        if !in_macro_or_desugar(then.span) && !in_external_macro(cx.sess, expr.span);
 
         // workaround for rust-lang/rust#43081
         if expr.span.lo().0 != 0 && expr.span.hi().0 != 0;
@@ -206,7 +206,7 @@ fn check_array(cx: &EarlyContext<'_>, expr: &ast::Expr) {
 
 fn check_missing_else(cx: &EarlyContext<'_>, first: &ast::Expr, second: &ast::Expr) {
     if !differing_macro_contexts(first.span, second.span)
-        && !in_macro(first.span)
+        && !in_macro_or_desugar(first.span)
         && unsugar_if(first).is_some()
         && (is_block(second) || unsugar_if(second).is_some())
     {

clippy_lints/src/identity_conversion.rs

@@ -1,4 +1,6 @@
-use crate::utils::{in_macro, match_trait_method, same_tys, snippet, snippet_with_macro_callsite, span_lint_and_then};
+use crate::utils::{
+    in_macro_or_desugar, match_trait_method, same_tys, snippet, snippet_with_macro_callsite, span_lint_and_then,
+};
 use crate::utils::{paths, resolve_node};
 use rustc::hir::*;
 use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
@@ -31,7 +33,7 @@ impl_lint_pass!(IdentityConversion => [IDENTITY_CONVERSION]);
 
 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for IdentityConversion {
     fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, e: &'tcx Expr) {
-        if in_macro(e.span) {
+        if in_macro_or_desugar(e.span) {
             return;
         }
 

clippy_lints/src/identity_op.rs

@@ -5,7 +5,7 @@ use rustc::{declare_lint_pass, declare_tool_lint};
 use syntax::source_map::Span;
 
 use crate::consts::{constant_simple, Constant};
-use crate::utils::{clip, in_macro, snippet, span_lint, unsext};
+use crate::utils::{clip, in_macro_or_desugar, snippet, span_lint, unsext};
 
 declare_clippy_lint! {
     /// **What it does:** Checks for identity operations, e.g., `x + 0`.
@@ -28,7 +28,7 @@ declare_lint_pass!(IdentityOp => [IDENTITY_OP]);
 
 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for IdentityOp {
     fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, e: &'tcx Expr) {
-        if in_macro(e.span) {
+        if in_macro_or_desugar(e.span) {
             return;
         }
         if let ExprKind::Binary(ref cmp, ref left, ref right) = e.node {

clippy_lints/src/implicit_return.rs

@@ -1,4 +1,4 @@
-use crate::utils::{in_macro, is_expn_of, snippet_opt, span_lint_and_then};
+use crate::utils::{in_macro_or_desugar, is_expn_of, snippet_opt, span_lint_and_then};
 use rustc::hir::{intravisit::FnKind, Body, ExprKind, FnDecl, HirId, MatchSource};
 use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
 use rustc::{declare_lint_pass, declare_tool_lint};
@@ -118,7 +118,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for ImplicitReturn {
 
         // checking return type through MIR, HIR is not able to determine inferred closure return types
         // make sure it's not a macro
-        if !mir.return_ty().is_unit() && !in_macro(span) {
+        if !mir.return_ty().is_unit() && !in_macro_or_desugar(span) {
             Self::expr_match(cx, &body.value);
         }
     }

clippy_lints/src/items_after_statements.rs

@@ -1,6 +1,6 @@
 //! lint when items are used after statements
 
-use crate::utils::{in_macro, span_lint};
+use crate::utils::{in_macro_or_desugar, span_lint};
 use matches::matches;
 use rustc::lint::{EarlyContext, EarlyLintPass, LintArray, LintPass};
 use rustc::{declare_lint_pass, declare_tool_lint};
@@ -38,7 +38,7 @@ declare_lint_pass!(ItemsAfterStatements => [ITEMS_AFTER_STATEMENTS]);
 
 impl EarlyLintPass for ItemsAfterStatements {
     fn check_block(&mut self, cx: &EarlyContext<'_>, item: &Block) {
-        if in_macro(item.span) {
+        if in_macro_or_desugar(item.span) {
             return;
         }
 
@@ -52,7 +52,7 @@ impl EarlyLintPass for ItemsAfterStatements {
         // lint on all further items
         for stmt in stmts {
             if let StmtKind::Item(ref it) = *stmt {
-                if in_macro(it.span) {
+                if in_macro_or_desugar(it.span) {
                     return;
                 }
                 if let ItemKind::MacroDef(..) = it.node {

clippy_lints/src/len_zero.rs

@@ -1,4 +1,6 @@
-use crate::utils::{get_item_name, in_macro, snippet_with_applicability, span_lint, span_lint_and_sugg, walk_ptrs_ty};
+use crate::utils::{
+    get_item_name, in_macro_or_desugar, snippet_with_applicability, span_lint, span_lint_and_sugg, walk_ptrs_ty,
+};
 use rustc::hir::def_id::DefId;
 use rustc::hir::*;
 use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
@@ -73,7 +75,7 @@ declare_lint_pass!(LenZero => [LEN_ZERO, LEN_WITHOUT_IS_EMPTY]);
 
 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for LenZero {
     fn check_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx Item) {
-        if in_macro(item.span) {
+        if in_macro_or_desugar(item.span) {
             return;
         }
 
@@ -85,7 +87,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for LenZero {
     }
 
     fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) {
-        if in_macro(expr.span) {
+        if in_macro_or_desugar(expr.span) {
             return;
         }