Add prefix to every line of `-Zhir-stats` output.

This is based on `-Zprint-type-sizes` which does the same thing. It
makes the output provenance clearer, and helps with post-processing.
E.g. if you have `-Zhir-stats` output from numerous compiler invocations
you can now easily extract the pre-expansion stats separately from the
post-expansion stats.

3 files changed, 164 insertions, 165 deletions

diff --git a/compiler/rustc_interface/src/passes.rs b/compiler/rustc_interface/src/passes.rs
index 66c6a229b89..1d083f3ec80 100644
--- a/compiler/rustc_interface/src/passes.rs
+++ b/compiler/rustc_interface/src/passes.rs
@@ -69,7 +69,7 @@ pub fn parse<'a>(sess: &'a Session, input: &Input) -> PResult<'a, ast::Crate> {
     }
 
     if sess.opts.unstable_opts.hir_stats {
-        hir_stats::print_ast_stats(&krate, "PRE EXPANSION AST STATS");
+        hir_stats::print_ast_stats(&krate, "PRE EXPANSION AST STATS", "ast-stats-1");
     }
 
     Ok(krate)
@@ -416,7 +416,7 @@ pub fn configure_and_expand(
     }
 
     if sess.opts.unstable_opts.hir_stats {
-        hir_stats::print_ast_stats(&krate, "POST EXPANSION AST STATS");
+        hir_stats::print_ast_stats(&krate, "POST EXPANSION AST STATS", "ast-stats-2");
     }
 
     resolver.resolve_crate(&krate);
diff --git a/compiler/rustc_passes/src/hir_stats.rs b/compiler/rustc_passes/src/hir_stats.rs
index 399d00b403a..859f22a799f 100644
--- a/compiler/rustc_passes/src/hir_stats.rs
+++ b/compiler/rustc_passes/src/hir_stats.rs
@@ -74,16 +74,16 @@ pub fn print_hir_stats(tcx: TyCtxt<'_>) {
     };
     tcx.hir().walk_toplevel_module(&mut collector);
     tcx.hir().walk_attributes(&mut collector);
-    collector.print("HIR STATS");
+    collector.print("HIR STATS", "hir-stats");
 }
 
-pub fn print_ast_stats(krate: &ast::Crate, title: &str) {
+pub fn print_ast_stats(krate: &ast::Crate, title: &str, prefix: &str) {
     use rustc_ast::visit::Visitor;
 
     let mut collector =
         StatCollector { krate: None, nodes: FxHashMap::default(), seen: FxHashSet::default() };
     collector.visit_crate(krate);
-    collector.print(title);
+    collector.print(title, prefix);
 }
 
 impl<'k> StatCollector<'k> {
@@ -119,23 +119,26 @@ impl<'k> StatCollector<'k> {
         }
     }
 
-    fn print(&self, title: &str) {
+    fn print(&self, title: &str, prefix: &str) {
         let mut nodes: Vec<_> = self.nodes.iter().collect();
         nodes.sort_by_key(|&(_, ref node)| node.stats.count * node.stats.size);
 
         let total_size = nodes.iter().map(|(_, node)| node.stats.count * node.stats.size).sum();
 
-        eprintln!("\n{}\n", title);
-
-        eprintln!("{:<18}{:>18}{:>14}{:>14}", "Name", "Accumulated Size", "Count", "Item Size");
-        eprintln!("----------------------------------------------------------------");
+        eprintln!("{} {}", prefix, title);
+        eprintln!(
+            "{} {:<18}{:>18}{:>14}{:>14}",
+            prefix, "Name", "Accumulated Size", "Count", "Item Size"
+        );
+        eprintln!("{} ----------------------------------------------------------------", prefix);
 
         let percent = |m, n| (m * 100) as f64 / n as f64;
 
         for (label, node) in nodes {
             let size = node.stats.count * node.stats.size;
             eprintln!(
-                "{:<18}{:>10} ({:4.1}%){:>14}{:>14}",
+                "{} {:<18}{:>10} ({:4.1}%){:>14}{:>14}",
+                prefix,
                 label,
                 to_readable_str(size),
                 percent(size, total_size),
@@ -149,7 +152,8 @@ impl<'k> StatCollector<'k> {
                 for (label, subnode) in subnodes {
                     let size = subnode.count * subnode.size;
                     eprintln!(
-                        "- {:<18}{:>10} ({:4.1}%){:>14}",
+                        "{} - {:<18}{:>10} ({:4.1}%){:>14}",
+                        prefix,
                         label,
                         to_readable_str(size),
                         percent(size, total_size),
@@ -158,8 +162,9 @@ impl<'k> StatCollector<'k> {
                 }
             }
         }
-        eprintln!("----------------------------------------------------------------");
-        eprintln!("{:<18}{:>10}\n", "Total", to_readable_str(total_size));
+        eprintln!("{} ----------------------------------------------------------------", prefix);
+        eprintln!("{} {:<18}{:>10}", prefix, "Total", to_readable_str(total_size));
+        eprintln!("{}", prefix);
     }
 }
 
diff --git a/src/test/ui/stats/hir-stats.stderr b/src/test/ui/stats/hir-stats.stderr
index eb828bb9a2c..13cb140246f 100644
--- a/src/test/ui/stats/hir-stats.stderr
+++ b/src/test/ui/stats/hir-stats.stderr
@@ -1,151 +1,145 @@
-
-PRE EXPANSION AST STATS
-
-Name                Accumulated Size         Count     Item Size
-----------------------------------------------------------------
-ExprField                 48 ( 0.6%)             1            48
-Crate                     56 ( 0.7%)             1            56
-Attribute                 64 ( 0.8%)             2            32
-- Normal                    32 ( 0.4%)             1
-- DocComment                32 ( 0.4%)             1
-GenericArgs               64 ( 0.8%)             1            64
-- AngleBracketed            64 ( 0.8%)             1
-Local                     72 ( 0.9%)             1            72
-WherePredicate            72 ( 0.9%)             1            72
-- BoundPredicate            72 ( 0.9%)             1
-Arm                       96 ( 1.1%)             2            48
-ForeignItem               96 ( 1.1%)             1            96
-- Fn                        96 ( 1.1%)             1
-FieldDef                 160 ( 1.9%)             2            80
-Stmt                     160 ( 1.9%)             5            32
-- Local                     32 ( 0.4%)             1
-- MacCall                   32 ( 0.4%)             1
-- Expr                      96 ( 1.1%)             3
-Param                    160 ( 1.9%)             4            40
-FnDecl                   200 ( 2.4%)             5            40
-Variant                  240 ( 2.8%)             2           120
-Block                    288 ( 3.4%)             6            48
-GenericBound             352 ( 4.2%)             4            88
-- Trait                    352 ( 4.2%)             4
-AssocItem                416 ( 4.9%)             4           104
-- TyAlias                  208 ( 2.5%)             2
-- Fn                       208 ( 2.5%)             2
-GenericParam             520 ( 6.1%)             5           104
-PathSegment              720 ( 8.5%)            30            24
-Expr                     832 ( 9.8%)             8           104
-- Path                     104 ( 1.2%)             1
-- Match                    104 ( 1.2%)             1
-- Struct                   104 ( 1.2%)             1
-- Lit                      208 ( 2.5%)             2
-- Block                    312 ( 3.7%)             3
-Pat                      840 ( 9.9%)             7           120
-- Struct                   120 ( 1.4%)             1
-- Wild                     120 ( 1.4%)             1
-- Ident                    600 ( 7.1%)             5
-Ty                     1_344 (15.9%)            14            96
-- Rptr                      96 ( 1.1%)             1
-- Ptr                       96 ( 1.1%)             1
-- ImplicitSelf             192 ( 2.3%)             2
-- Path                     960 (11.4%)            10
-Item                   1_656 (19.6%)             9           184
-- Trait                    184 ( 2.2%)             1
-- Enum                     184 ( 2.2%)             1
-- ForeignMod               184 ( 2.2%)             1
-- Impl                     184 ( 2.2%)             1
-- Fn                       368 ( 4.4%)             2
-- Use                      552 ( 6.5%)             3
-----------------------------------------------------------------
-Total                  8_456
-
-
-POST EXPANSION AST STATS
-
-Name                Accumulated Size         Count     Item Size
-----------------------------------------------------------------
-ExprField                 48 ( 0.5%)             1            48
-Crate                     56 ( 0.6%)             1            56
-GenericArgs               64 ( 0.7%)             1            64
-- AngleBracketed            64 ( 0.7%)             1
-Local                     72 ( 0.8%)             1            72
-WherePredicate            72 ( 0.8%)             1            72
-- BoundPredicate            72 ( 0.8%)             1
-Arm                       96 ( 1.0%)             2            48
-ForeignItem               96 ( 1.0%)             1            96
-- Fn                        96 ( 1.0%)             1
-InlineAsm                120 ( 1.3%)             1           120
-Attribute                128 ( 1.4%)             4            32
-- DocComment                32 ( 0.3%)             1
-- Normal                    96 ( 1.0%)             3
-FieldDef                 160 ( 1.7%)             2            80
-Stmt                     160 ( 1.7%)             5            32
-- Local                     32 ( 0.3%)             1
-- Semi                      32 ( 0.3%)             1
-- Expr                      96 ( 1.0%)             3
-Param                    160 ( 1.7%)             4            40
-FnDecl                   200 ( 2.2%)             5            40
-Variant                  240 ( 2.6%)             2           120
-Block                    288 ( 3.1%)             6            48
-GenericBound             352 ( 3.8%)             4            88
-- Trait                    352 ( 3.8%)             4
-AssocItem                416 ( 4.5%)             4           104
-- TyAlias                  208 ( 2.3%)             2
-- Fn                       208 ( 2.3%)             2
-GenericParam             520 ( 5.7%)             5           104
-PathSegment              792 ( 8.6%)            33            24
-Pat                      840 ( 9.1%)             7           120
-- Struct                   120 ( 1.3%)             1
-- Wild                     120 ( 1.3%)             1
-- Ident                    600 ( 6.5%)             5
-Expr                     936 (10.2%)             9           104
-- Path                     104 ( 1.1%)             1
-- Match                    104 ( 1.1%)             1
-- Struct                   104 ( 1.1%)             1
-- InlineAsm                104 ( 1.1%)             1
-- Lit                      208 ( 2.3%)             2
-- Block                    312 ( 3.4%)             3
-Ty                     1_344 (14.6%)            14            96
-- Rptr                      96 ( 1.0%)             1
-- Ptr                       96 ( 1.0%)             1
-- ImplicitSelf             192 ( 2.1%)             2
-- Path                     960 (10.5%)            10
-Item                   2_024 (22.0%)            11           184
-- Trait                    184 ( 2.0%)             1
-- Enum                     184 ( 2.0%)             1
-- ExternCrate              184 ( 2.0%)             1
-- ForeignMod               184 ( 2.0%)             1
-- Impl                     184 ( 2.0%)             1
-- Fn                       368 ( 4.0%)             2
-- Use                      736 ( 8.0%)             4
-----------------------------------------------------------------
-Total                  9_184
-
-
-HIR STATS
-
-Name                Accumulated Size         Count     Item Size
-----------------------------------------------------------------
-Param                     64 ( 0.7%)             2            32
-Local                     64 ( 0.7%)             1            64
-ForeignItem               72 ( 0.8%)             1            72
-FieldDef                  96 ( 1.0%)             2            48
-Arm                       96 ( 1.0%)             2            48
-Stmt                      96 ( 1.0%)             3            32
-FnDecl                   120 ( 1.3%)             3            40
-Attribute                128 ( 1.4%)             4            32
-Lifetime                 128 ( 1.4%)             4            32
-Variant                  160 ( 1.7%)             2            80
-ImplItem                 176 ( 1.9%)             2            88
-GenericBound             192 ( 2.1%)             4            48
-TraitItem                192 ( 2.1%)             2            96
-WherePredicate           216 ( 2.3%)             3            72
-Block                    288 ( 3.1%)             6            48
-QPath                    408 ( 4.4%)            17            24
-Pat                      440 ( 4.8%)             5            88
-Expr                     672 ( 7.3%)            12            56
-Item                     960 (10.4%)            12            80
-Ty                     1_152 (12.4%)            16            72
-Path                   1_296 (14.0%)            27            48
-PathSegment            2_240 (24.2%)            40            56
-----------------------------------------------------------------
-Total                  9_256
-
+ast-stats-1 PRE EXPANSION AST STATS
+ast-stats-1 Name                Accumulated Size         Count     Item Size
+ast-stats-1 ----------------------------------------------------------------
+ast-stats-1 ExprField                 48 ( 0.6%)             1            48
+ast-stats-1 Crate                     56 ( 0.7%)             1            56
+ast-stats-1 Attribute                 64 ( 0.8%)             2            32
+ast-stats-1 - Normal                    32 ( 0.4%)             1
+ast-stats-1 - DocComment                32 ( 0.4%)             1
+ast-stats-1 GenericArgs               64 ( 0.8%)             1            64
+ast-stats-1 - AngleBracketed            64 ( 0.8%)             1
+ast-stats-1 Local                     72 ( 0.9%)             1            72
+ast-stats-1 WherePredicate            72 ( 0.9%)             1            72
+ast-stats-1 - BoundPredicate            72 ( 0.9%)             1
+ast-stats-1 Arm                       96 ( 1.1%)             2            48
+ast-stats-1 ForeignItem               96 ( 1.1%)             1            96
+ast-stats-1 - Fn                        96 ( 1.1%)             1
+ast-stats-1 FieldDef                 160 ( 1.9%)             2            80
+ast-stats-1 Stmt                     160 ( 1.9%)             5            32
+ast-stats-1 - Local                     32 ( 0.4%)             1
+ast-stats-1 - MacCall                   32 ( 0.4%)             1
+ast-stats-1 - Expr                      96 ( 1.1%)             3
+ast-stats-1 Param                    160 ( 1.9%)             4            40
+ast-stats-1 FnDecl                   200 ( 2.4%)             5            40
+ast-stats-1 Variant                  240 ( 2.8%)             2           120
+ast-stats-1 Block                    288 ( 3.4%)             6            48
+ast-stats-1 GenericBound             352 ( 4.2%)             4            88
+ast-stats-1 - Trait                    352 ( 4.2%)             4
+ast-stats-1 AssocItem                416 ( 4.9%)             4           104
+ast-stats-1 - TyAlias                  208 ( 2.5%)             2
+ast-stats-1 - Fn                       208 ( 2.5%)             2
+ast-stats-1 GenericParam             520 ( 6.1%)             5           104
+ast-stats-1 PathSegment              720 ( 8.5%)            30            24
+ast-stats-1 Expr                     832 ( 9.8%)             8           104
+ast-stats-1 - Path                     104 ( 1.2%)             1
+ast-stats-1 - Match                    104 ( 1.2%)             1
+ast-stats-1 - Struct                   104 ( 1.2%)             1
+ast-stats-1 - Lit                      208 ( 2.5%)             2
+ast-stats-1 - Block                    312 ( 3.7%)             3
+ast-stats-1 Pat                      840 ( 9.9%)             7           120
+ast-stats-1 - Struct                   120 ( 1.4%)             1
+ast-stats-1 - Wild                     120 ( 1.4%)             1
+ast-stats-1 - Ident                    600 ( 7.1%)             5
+ast-stats-1 Ty                     1_344 (15.9%)            14            96
+ast-stats-1 - Rptr                      96 ( 1.1%)             1
+ast-stats-1 - Ptr                       96 ( 1.1%)             1
+ast-stats-1 - ImplicitSelf             192 ( 2.3%)             2
+ast-stats-1 - Path                     960 (11.4%)            10
+ast-stats-1 Item                   1_656 (19.6%)             9           184
+ast-stats-1 - Trait                    184 ( 2.2%)             1
+ast-stats-1 - Enum                     184 ( 2.2%)             1
+ast-stats-1 - ForeignMod               184 ( 2.2%)             1
+ast-stats-1 - Impl                     184 ( 2.2%)             1
+ast-stats-1 - Fn                       368 ( 4.4%)             2
+ast-stats-1 - Use                      552 ( 6.5%)             3
+ast-stats-1 ----------------------------------------------------------------
+ast-stats-1 Total                  8_456
+ast-stats-1
+ast-stats-2 POST EXPANSION AST STATS
+ast-stats-2 Name                Accumulated Size         Count     Item Size
+ast-stats-2 ----------------------------------------------------------------
+ast-stats-2 ExprField                 48 ( 0.5%)             1            48
+ast-stats-2 Crate                     56 ( 0.6%)             1            56
+ast-stats-2 GenericArgs               64 ( 0.7%)             1            64
+ast-stats-2 - AngleBracketed            64 ( 0.7%)             1
+ast-stats-2 Local                     72 ( 0.8%)             1            72
+ast-stats-2 WherePredicate            72 ( 0.8%)             1            72
+ast-stats-2 - BoundPredicate            72 ( 0.8%)             1
+ast-stats-2 Arm                       96 ( 1.0%)             2            48
+ast-stats-2 ForeignItem               96 ( 1.0%)             1            96
+ast-stats-2 - Fn                        96 ( 1.0%)             1
+ast-stats-2 InlineAsm                120 ( 1.3%)             1           120
+ast-stats-2 Attribute                128 ( 1.4%)             4            32
+ast-stats-2 - DocComment                32 ( 0.3%)             1
+ast-stats-2 - Normal                    96 ( 1.0%)             3
+ast-stats-2 FieldDef                 160 ( 1.7%)             2            80
+ast-stats-2 Stmt                     160 ( 1.7%)             5            32
+ast-stats-2 - Local                     32 ( 0.3%)             1
+ast-stats-2 - Semi                      32 ( 0.3%)             1
+ast-stats-2 - Expr                      96 ( 1.0%)             3
+ast-stats-2 Param                    160 ( 1.7%)             4            40
+ast-stats-2 FnDecl                   200 ( 2.2%)             5            40
+ast-stats-2 Variant                  240 ( 2.6%)             2           120
+ast-stats-2 Block                    288 ( 3.1%)             6            48
+ast-stats-2 GenericBound             352 ( 3.8%)             4            88
+ast-stats-2 - Trait                    352 ( 3.8%)             4
+ast-stats-2 AssocItem                416 ( 4.5%)             4           104
+ast-stats-2 - TyAlias                  208 ( 2.3%)             2
+ast-stats-2 - Fn                       208 ( 2.3%)             2
+ast-stats-2 GenericParam             520 ( 5.7%)             5           104
+ast-stats-2 PathSegment              792 ( 8.6%)            33            24
+ast-stats-2 Pat                      840 ( 9.1%)             7           120
+ast-stats-2 - Struct                   120 ( 1.3%)             1
+ast-stats-2 - Wild                     120 ( 1.3%)             1
+ast-stats-2 - Ident                    600 ( 6.5%)             5
+ast-stats-2 Expr                     936 (10.2%)             9           104
+ast-stats-2 - Path                     104 ( 1.1%)             1
+ast-stats-2 - Match                    104 ( 1.1%)             1
+ast-stats-2 - Struct                   104 ( 1.1%)             1
+ast-stats-2 - InlineAsm                104 ( 1.1%)             1
+ast-stats-2 - Lit                      208 ( 2.3%)             2
+ast-stats-2 - Block                    312 ( 3.4%)             3
+ast-stats-2 Ty                     1_344 (14.6%)            14            96
+ast-stats-2 - Rptr                      96 ( 1.0%)             1
+ast-stats-2 - Ptr                       96 ( 1.0%)             1
+ast-stats-2 - ImplicitSelf             192 ( 2.1%)             2
+ast-stats-2 - Path                     960 (10.5%)            10
+ast-stats-2 Item                   2_024 (22.0%)            11           184
+ast-stats-2 - Trait                    184 ( 2.0%)             1
+ast-stats-2 - Enum                     184 ( 2.0%)             1
+ast-stats-2 - ExternCrate              184 ( 2.0%)             1
+ast-stats-2 - ForeignMod               184 ( 2.0%)             1
+ast-stats-2 - Impl                     184 ( 2.0%)             1
+ast-stats-2 - Fn                       368 ( 4.0%)             2
+ast-stats-2 - Use                      736 ( 8.0%)             4
+ast-stats-2 ----------------------------------------------------------------
+ast-stats-2 Total                  9_184
+ast-stats-2
+hir-stats HIR STATS
+hir-stats Name                Accumulated Size         Count     Item Size
+hir-stats ----------------------------------------------------------------
+hir-stats Param                     64 ( 0.7%)             2            32
+hir-stats Local                     64 ( 0.7%)             1            64
+hir-stats ForeignItem               72 ( 0.8%)             1            72
+hir-stats FieldDef                  96 ( 1.0%)             2            48
+hir-stats Arm                       96 ( 1.0%)             2            48
+hir-stats Stmt                      96 ( 1.0%)             3            32
+hir-stats FnDecl                   120 ( 1.3%)             3            40
+hir-stats Attribute                128 ( 1.4%)             4            32
+hir-stats Lifetime                 128 ( 1.4%)             4            32
+hir-stats Variant                  160 ( 1.7%)             2            80
+hir-stats ImplItem                 176 ( 1.9%)             2            88
+hir-stats GenericBound             192 ( 2.1%)             4            48
+hir-stats TraitItem                192 ( 2.1%)             2            96
+hir-stats WherePredicate           216 ( 2.3%)             3            72
+hir-stats Block                    288 ( 3.1%)             6            48
+hir-stats QPath                    408 ( 4.4%)            17            24
+hir-stats Pat                      440 ( 4.8%)             5            88
+hir-stats Expr                     672 ( 7.3%)            12            56
+hir-stats Item                     960 (10.4%)            12            80
+hir-stats Ty                     1_152 (12.4%)            16            72
+hir-stats Path                   1_296 (14.0%)            27            48
+hir-stats PathSegment            2_240 (24.2%)            40            56
+hir-stats ----------------------------------------------------------------
+hir-stats Total                  9_256
+hir-stats