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rust-timerrust-timer
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Unrolled build for #142934
Rollup merge of #142934 - nnethercote:tweak-macro-stats, r=petrochenkov Tweak `-Zmacro-stats` measurement. It currently reports net size, i.e. size(output) - size(input). After some use I think this is sub-optimal, and it's better to just report size(output). Because for derive macros the input size is always 1, and for attribute macros it's almost always 1. r? ```@petrochenkov```
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‎compiler/rustc_expand/src/stats.rs‎

Lines changed: 10 additions & 18 deletions
Original file line numberDiff line numberDiff line change
@@ -15,15 +15,11 @@ pub struct MacroStat {
1515
/// Number of uses of the macro.
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pub uses: usize,
1717

18-
/// Net increase in number of lines of code (when pretty-printed), i.e.
19-
/// `lines(output) - lines(invocation)`. Can be negative because a macro
20-
/// output may be smaller than the invocation.
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pub lines: isize,
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23-
/// Net increase in number of lines of code (when pretty-printed), i.e.
24-
/// `bytes(output) - bytes(invocation)`. Can be negative because a macro
25-
/// output may be smaller than the invocation.
26-
pub bytes: isize,
18+
/// Number of lines of code (when pretty-printed).
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pub lines: usize,
20+
21+
/// Number of bytes of code (when pretty-printed).
22+
pub bytes: usize,
2723
}
2824

2925
pub(crate) fn elems_to_string<T>(elems: &SmallVec<[T; 1]>, f: impl Fn(&T) -> String) -> String {
@@ -131,16 +127,12 @@ pub(crate) fn update_macro_stats(
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input: &str,
132128
fragment: &AstFragment,
133129
) {
134-
fn lines_and_bytes(s: &str) -> (usize, usize) {
135-
(s.trim_end().split('\n').count(), s.len())
136-
}
137-
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// Measure the size of the output by pretty-printing it and counting
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// the lines and bytes.
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let name = Symbol::intern(&pprust::path_to_string(path));
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let output = fragment.to_string();
142-
let (in_l, in_b) = lines_and_bytes(input);
143-
let (out_l, out_b) = lines_and_bytes(&output);
134+
let num_lines = output.trim_end().split('\n').count();
135+
let num_bytes = output.len();
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145137
// This code is useful for debugging `-Zmacro-stats`. For every
146138
// invocation it prints the full input and output.
@@ -157,7 +149,7 @@ pub(crate) fn update_macro_stats(
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{name}: [{crate_name}] ({fragment_kind:?}) {span}\n\
158150
-------------------------------\n\
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{input}\n\
160-
-- ({in_l} lines, {in_b} bytes) --> ({out_l} lines, {out_b} bytes) --\n\
152+
-- {num_lines} lines, {num_bytes} bytes --\n\
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{output}\n\
162154
"
163155
);
@@ -166,6 +158,6 @@ pub(crate) fn update_macro_stats(
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// The recorded size is the difference between the input and the output.
167159
let entry = ecx.macro_stats.entry((name, macro_kind)).or_insert(MacroStat::default());
168160
entry.uses += 1;
169-
entry.lines += out_l as isize - in_l as isize;
170-
entry.bytes += out_b as isize - in_b as isize;
161+
entry.lines += num_lines;
162+
entry.bytes += num_bytes;
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}

‎compiler/rustc_interface/src/passes.rs‎

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -355,9 +355,9 @@ fn print_macro_stats(ecx: &ExtCtxt<'_>) {
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"{prefix} {:<name_w$}{:>uses_w$}{:>lines_w$}{:>avg_lines_w$}{:>bytes_w$}{:>avg_bytes_w$}",
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name,
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thousands::usize_with_underscores(uses),
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thousands::isize_with_underscores(lines),
358+
thousands::usize_with_underscores(lines),
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thousands::f64p1_with_underscores(avg_lines),
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thousands::isize_with_underscores(bytes),
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thousands::usize_with_underscores(bytes),
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thousands::f64p1_with_underscores(avg_bytes),
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);
363363
}

‎src/doc/unstable-book/src/compiler-flags/macro-stats.md‎

Lines changed: 3 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -10,12 +10,12 @@ generated code is normally invisible to the programmer.
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This flag helps identify such cases. When enabled, the compiler measures the
1212
effect on code size of all used macros and prints a table summarizing that
13-
effect. For each distinct macro, it counts how many times it is used, and the
14-
net effect on code size (in terms of lines of code, and bytes of code). The
13+
effect. For each distinct macro, it counts how many times it is used, and how
14+
much code it produces when expanded (in lines of code, and bytes of code). The
1515
code size evaluation uses the compiler's internal pretty-printing, and so will
1616
be independent of the formatting in the original code.
1717

18-
Note that the net effect of a macro may be negative. E.g. the `cfg!` and
18+
Note that the output size of a macro may be zero. E.g. the `cfg!` and
1919
`#[test]` macros often strip out code.
2020

2121
If a macro is identified as causing a large increase in code size, it is worth

‎tests/ui/stats/macro-stats.stderr‎

Lines changed: 20 additions & 20 deletions
Original file line numberDiff line numberDiff line change
@@ -2,25 +2,25 @@ macro-stats ====================================================================
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macro-stats MACRO EXPANSION STATS: macro_stats
33
macro-stats Macro Name Uses Lines Avg Lines Bytes Avg Bytes
44
macro-stats -----------------------------------------------------------------------------------
5-
macro-stats #[derive(Clone)] 8 56 7.0 1_660 207.5
6-
macro-stats #[derive(PartialOrd)] 1 16 16.0 654 654.0
7-
macro-stats #[derive(Hash)] 2 15 7.5 547 273.5
8-
macro-stats #[derive(Ord)] 1 14 14.0 489 489.0
9-
macro-stats q! 1 24 24.0 435 435.0
10-
macro-stats #[derive(Default)] 2 14 7.0 367 183.5
11-
macro-stats #[derive(Eq)] 1 10 10.0 312 312.0
12-
macro-stats #[derive(Debug)] 1 7 7.0 261 261.0
13-
macro-stats #[derive(PartialEq)] 1 8 8.0 247 247.0
14-
macro-stats #[derive(Copy)] 1 1 1.0 46 46.0
15-
macro-stats p! 1 2 2.0 28 28.0
16-
macro-stats trait_impl_tys! 1 1 1.0 11 11.0
17-
macro-stats foreign_item! 1 0 0.0 6 6.0
18-
macro-stats impl_const! 1 0 0.0 4 4.0
19-
macro-stats trait_tys! 1 1 1.0 3 3.0
20-
macro-stats u32! 1 0 0.0 -3 -3.0
21-
macro-stats none! 1 0 0.0 -3 -3.0
22-
macro-stats n99! 2 0 0.0 -8 -4.0
5+
macro-stats #[derive(Clone)] 8 64 8.0 1_788 223.5
6+
macro-stats #[derive(PartialOrd)] 1 17 17.0 675 675.0
7+
macro-stats #[derive(Hash)] 2 17 8.5 577 288.5
8+
macro-stats q! 1 26 26.0 519 519.0
9+
macro-stats #[derive(Ord)] 1 15 15.0 503 503.0
10+
macro-stats #[derive(Default)] 2 16 8.0 403 201.5
11+
macro-stats #[derive(Eq)] 1 11 11.0 325 325.0
12+
macro-stats #[derive(Debug)] 1 8 8.0 277 277.0
13+
macro-stats #[derive(PartialEq)] 1 9 9.0 267 267.0
14+
macro-stats #[derive(Copy)] 1 2 2.0 61 61.0
15+
macro-stats p! 1 3 3.0 32 32.0
16+
macro-stats trait_impl_tys! 1 2 2.0 28 28.0
17+
macro-stats foreign_item! 1 1 1.0 21 21.0
2318
macro-stats this_is_a_really_really_long_macro_name!
24-
macro-stats 1 0 0.0 -30 -30.0
25-
macro-stats #[test] 1 -6 -6.0 -158 -158.0
19+
macro-stats 1 1 1.0 18 18.0
20+
macro-stats impl_const! 1 1 1.0 17 17.0
21+
macro-stats trait_tys! 1 2 2.0 15 15.0
22+
macro-stats n99! 2 2 1.0 4 2.0
23+
macro-stats none! 1 1 1.0 4 4.0
24+
macro-stats u32! 1 1 1.0 3 3.0
25+
macro-stats #[test] 1 1 1.0 0 0.0
2626
macro-stats ===================================================================================

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