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Auto merge of rust-lang#134296 - matthiaskrgr:rollup-o0sxozj, r=matth…
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Rollup of 6 pull requests

Successful merges:

 - rust-lang#132150 (Fix powerpc64 big-endian FreeBSD ABI)
 - rust-lang#133942 (Clarify how to use `black_box()`)
 - rust-lang#134081 (Try to evaluate constants in legacy mangling)
 - rust-lang#134192 (Remove `Lexer`'s dependency on `Parser`.)
 - rust-lang#134208 (coverage: Tidy up creation of covmap and covfun records)
 - rust-lang#134211 (On Neutrino QNX, reduce the need to set archiver via environment variables)

r? `@ghost`
`@rustbot` modify labels: rollup
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bors committed Dec 14, 2024
2 parents f5079d0 + a942794 commit f1ec5d6
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Showing 20 changed files with 327 additions and 249 deletions.
67 changes: 32 additions & 35 deletions compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -75,10 +75,10 @@ pub(crate) fn finalize(cx: &CodegenCx<'_, '_>) {

// Encode all filenames referenced by coverage mappings in this CGU.
let filenames_buffer = global_file_table.make_filenames_buffer(tcx);

let filenames_size = filenames_buffer.len();
let filenames_val = cx.const_bytes(&filenames_buffer);
let filenames_ref = llvm_cov::hash_bytes(&filenames_buffer);
// The `llvm-cov` tool uses this hash to associate each covfun record with
// its corresponding filenames table, since the final binary will typically
// contain multiple covmap records from different compilation units.
let filenames_hash = llvm_cov::hash_bytes(&filenames_buffer);

let mut unused_function_names = Vec::new();

Expand All @@ -101,7 +101,7 @@ pub(crate) fn finalize(cx: &CodegenCx<'_, '_>) {
for covfun in &covfun_records {
unused_function_names.extend(covfun.mangled_function_name_if_unused());

covfun::generate_covfun_record(cx, filenames_ref, covfun)
covfun::generate_covfun_record(cx, filenames_hash, covfun)
}

// For unused functions, we need to take their mangled names and store them
Expand All @@ -126,7 +126,7 @@ pub(crate) fn finalize(cx: &CodegenCx<'_, '_>) {
// Generate the coverage map header, which contains the filenames used by
// this CGU's coverage mappings, and store it in a well-known global.
// (This is skipped if we returned early due to having no covfun records.)
generate_covmap_record(cx, covmap_version, filenames_size, filenames_val);
generate_covmap_record(cx, covmap_version, &filenames_buffer);
}

/// Maps "global" (per-CGU) file ID numbers to their underlying filenames.
Expand Down Expand Up @@ -225,38 +225,35 @@ fn span_file_name(tcx: TyCtxt<'_>, span: Span) -> Symbol {
/// Generates the contents of the covmap record for this CGU, which mostly
/// consists of a header and a list of filenames. The record is then stored
/// as a global variable in the `__llvm_covmap` section.
fn generate_covmap_record<'ll>(
cx: &CodegenCx<'ll, '_>,
version: u32,
filenames_size: usize,
filenames_val: &'ll llvm::Value,
) {
debug!("cov map: filenames_size = {}, 0-based version = {}", filenames_size, version);

// Create the coverage data header (Note, fields 0 and 2 are now always zero,
// as of `llvm::coverage::CovMapVersion::Version4`.)
let zero_was_n_records_val = cx.const_u32(0);
let filenames_size_val = cx.const_u32(filenames_size as u32);
let zero_was_coverage_size_val = cx.const_u32(0);
let version_val = cx.const_u32(version);
let cov_data_header_val = cx.const_struct(
&[zero_was_n_records_val, filenames_size_val, zero_was_coverage_size_val, version_val],
/*packed=*/ false,
fn generate_covmap_record<'ll>(cx: &CodegenCx<'ll, '_>, version: u32, filenames_buffer: &[u8]) {
// A covmap record consists of four target-endian u32 values, followed by
// the encoded filenames table. Two of the header fields are unused in
// modern versions of the LLVM coverage mapping format, and are always 0.
// <https://llvm.org/docs/CoverageMappingFormat.html#llvm-ir-representation>
// See also `src/llvm-project/clang/lib/CodeGen/CoverageMappingGen.cpp`.
let covmap_header = cx.const_struct(
&[
cx.const_u32(0), // (unused)
cx.const_u32(filenames_buffer.len() as u32),
cx.const_u32(0), // (unused)
cx.const_u32(version),
],
/* packed */ false,
);

// Create the complete LLVM coverage data value to add to the LLVM IR
let covmap_data =
cx.const_struct(&[cov_data_header_val, filenames_val], /*packed=*/ false);

let llglobal = llvm::add_global(cx.llmod, cx.val_ty(covmap_data), &llvm_cov::covmap_var_name());
llvm::set_initializer(llglobal, covmap_data);
llvm::set_global_constant(llglobal, true);
llvm::set_linkage(llglobal, llvm::Linkage::PrivateLinkage);
llvm::set_section(llglobal, &llvm_cov::covmap_section_name(cx.llmod));
let covmap_record = cx
.const_struct(&[covmap_header, cx.const_bytes(filenames_buffer)], /* packed */ false);

let covmap_global =
llvm::add_global(cx.llmod, cx.val_ty(covmap_record), &llvm_cov::covmap_var_name());
llvm::set_initializer(covmap_global, covmap_record);
llvm::set_global_constant(covmap_global, true);
llvm::set_linkage(covmap_global, llvm::Linkage::PrivateLinkage);
llvm::set_section(covmap_global, &llvm_cov::covmap_section_name(cx.llmod));
// LLVM's coverage mapping format specifies 8-byte alignment for items in this section.
// <https://llvm.org/docs/CoverageMappingFormat.html>
llvm::set_alignment(llglobal, Align::EIGHT);
cx.add_used_global(llglobal);
llvm::set_alignment(covmap_global, Align::EIGHT);

cx.add_used_global(covmap_global);
}

/// Each CGU will normally only emit coverage metadata for the functions that it actually generates.
Expand Down
59 changes: 29 additions & 30 deletions compiler/rustc_codegen_llvm/src/coverageinfo/mapgen/covfun.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -136,7 +136,7 @@ fn fill_region_tables<'tcx>(
/// as a global variable in the `__llvm_covfun` section.
pub(crate) fn generate_covfun_record<'tcx>(
cx: &CodegenCx<'_, 'tcx>,
filenames_ref: u64,
filenames_hash: u64,
covfun: &CovfunRecord<'tcx>,
) {
let &CovfunRecord {
Expand All @@ -155,46 +155,45 @@ pub(crate) fn generate_covfun_record<'tcx>(
regions,
);

// Concatenate the encoded coverage mappings
let coverage_mapping_size = coverage_mapping_buffer.len();
let coverage_mapping_val = cx.const_bytes(&coverage_mapping_buffer);

// A covfun record consists of four target-endian integers, followed by the
// encoded mapping data in bytes. Note that the length field is 32 bits.
// <https://llvm.org/docs/CoverageMappingFormat.html#llvm-ir-representation>
// See also `src/llvm-project/clang/lib/CodeGen/CoverageMappingGen.cpp` and
// `COVMAP_V3` in `src/llvm-project/llvm/include/llvm/ProfileData/InstrProfData.inc`.
let func_name_hash = llvm_cov::hash_bytes(mangled_function_name.as_bytes());
let func_name_hash_val = cx.const_u64(func_name_hash);
let coverage_mapping_size_val = cx.const_u32(coverage_mapping_size as u32);
let source_hash_val = cx.const_u64(source_hash);
let filenames_ref_val = cx.const_u64(filenames_ref);
let func_record_val = cx.const_struct(
let covfun_record = cx.const_struct(
&[
func_name_hash_val,
coverage_mapping_size_val,
source_hash_val,
filenames_ref_val,
coverage_mapping_val,
cx.const_u64(func_name_hash),
cx.const_u32(coverage_mapping_buffer.len() as u32),
cx.const_u64(source_hash),
cx.const_u64(filenames_hash),
cx.const_bytes(&coverage_mapping_buffer),
],
/*packed=*/ true,
// This struct needs to be packed, so that the 32-bit length field
// doesn't have unexpected padding.
true,
);

// Choose a variable name to hold this function's covfun data.
// Functions that are used have a suffix ("u") to distinguish them from
// unused copies of the same function (from different CGUs), so that if a
// linker sees both it won't discard the used copy's data.
let func_record_var_name =
CString::new(format!("__covrec_{:X}{}", func_name_hash, if is_used { "u" } else { "" }))
.unwrap();
debug!("function record var name: {:?}", func_record_var_name);

let llglobal = llvm::add_global(cx.llmod, cx.val_ty(func_record_val), &func_record_var_name);
llvm::set_initializer(llglobal, func_record_val);
llvm::set_global_constant(llglobal, true);
llvm::set_linkage(llglobal, llvm::Linkage::LinkOnceODRLinkage);
llvm::set_visibility(llglobal, llvm::Visibility::Hidden);
llvm::set_section(llglobal, cx.covfun_section_name());
let u = if is_used { "u" } else { "" };
let covfun_var_name = CString::new(format!("__covrec_{func_name_hash:X}{u}")).unwrap();
debug!("function record var name: {covfun_var_name:?}");

let covfun_global = llvm::add_global(cx.llmod, cx.val_ty(covfun_record), &covfun_var_name);
llvm::set_initializer(covfun_global, covfun_record);
llvm::set_global_constant(covfun_global, true);
llvm::set_linkage(covfun_global, llvm::Linkage::LinkOnceODRLinkage);
llvm::set_visibility(covfun_global, llvm::Visibility::Hidden);
llvm::set_section(covfun_global, cx.covfun_section_name());
// LLVM's coverage mapping format specifies 8-byte alignment for items in this section.
// <https://llvm.org/docs/CoverageMappingFormat.html>
llvm::set_alignment(llglobal, Align::EIGHT);
llvm::set_alignment(covfun_global, Align::EIGHT);
if cx.target_spec().supports_comdat() {
llvm::set_comdat(cx.llmod, llglobal, &func_record_var_name);
llvm::set_comdat(cx.llmod, covfun_global, &covfun_var_name);
}
cx.add_used_global(llglobal);

cx.add_used_global(covfun_global);
}
40 changes: 23 additions & 17 deletions compiler/rustc_parse/src/lexer/mod.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -69,24 +69,30 @@ pub(crate) fn lex_token_trees<'psess, 'src>(
token: Token::dummy(),
diag_info: TokenTreeDiagInfo::default(),
};
let (_open_spacing, stream, res) = lexer.lex_token_trees(/* is_delimited */ false);
let unmatched_delims = lexer.diag_info.unmatched_delims;

if res.is_ok() && unmatched_delims.is_empty() {
Ok(stream)
} else {
// Return error if there are unmatched delimiters or unclosed delimiters.
// We emit delimiter mismatch errors first, then emit the unclosing delimiter mismatch
// because the delimiter mismatch is more likely to be the root cause of error
let mut buffer: Vec<_> = unmatched_delims
.into_iter()
.filter_map(|unmatched_delim| make_unclosed_delims_error(unmatched_delim, psess))
.collect();
if let Err(errs) = res {
// Add unclosing delimiter or diff marker errors
buffer.extend(errs);
let res = lexer.lex_token_trees(/* is_delimited */ false);

let mut unmatched_delims: Vec<_> = lexer
.diag_info
.unmatched_delims
.into_iter()
.filter_map(|unmatched_delim| make_unclosed_delims_error(unmatched_delim, psess))
.collect();

match res {
Ok((_open_spacing, stream)) => {
if unmatched_delims.is_empty() {
Ok(stream)
} else {
// Return error if there are unmatched delimiters or unclosed delimiters.
Err(unmatched_delims)
}
}
Err(errs) => {
// We emit delimiter mismatch errors first, then emit the unclosing delimiter mismatch
// because the delimiter mismatch is more likely to be the root cause of error
unmatched_delims.extend(errs);
Err(unmatched_delims)
}
Err(buffer)
}
}

Expand Down
94 changes: 14 additions & 80 deletions compiler/rustc_parse/src/lexer/tokentrees.rs
View file
Original file line number Diff line number Diff line change
@@ -1,20 +1,18 @@
use rustc_ast::token::{self, Delimiter, Token};
use rustc_ast::tokenstream::{DelimSpacing, DelimSpan, Spacing, TokenStream, TokenTree};
use rustc_ast_pretty::pprust::token_to_string;
use rustc_errors::{Applicability, Diag};
use rustc_span::symbol::kw;
use rustc_errors::Diag;

use super::diagnostics::{report_suspicious_mismatch_block, same_indentation_level};
use super::{Lexer, UnmatchedDelim};
use crate::Parser;

impl<'psess, 'src> Lexer<'psess, 'src> {
// Lex into a token stream. The `Spacing` in the result is that of the
// opening delimiter.
pub(super) fn lex_token_trees(
&mut self,
is_delimited: bool,
) -> (Spacing, TokenStream, Result<(), Vec<Diag<'psess>>>) {
) -> Result<(Spacing, TokenStream), Vec<Diag<'psess>>> {
// Move past the opening delimiter.
let open_spacing = self.bump_minimal();

Expand All @@ -27,25 +25,25 @@ impl<'psess, 'src> Lexer<'psess, 'src> {
debug_assert!(!matches!(delim, Delimiter::Invisible(_)));
buf.push(match self.lex_token_tree_open_delim(delim) {
Ok(val) => val,
Err(errs) => return (open_spacing, TokenStream::new(buf), Err(errs)),
Err(errs) => return Err(errs),
})
}
token::CloseDelim(delim) => {
// Invisible delimiters cannot occur here because `TokenTreesReader` parses
// code directly from strings, with no macro expansion involved.
debug_assert!(!matches!(delim, Delimiter::Invisible(_)));
return (
open_spacing,
TokenStream::new(buf),
if is_delimited { Ok(()) } else { Err(vec![self.close_delim_err(delim)]) },
);
return if is_delimited {
Ok((open_spacing, TokenStream::new(buf)))
} else {
Err(vec![self.close_delim_err(delim)])
};
}
token::Eof => {
return (
open_spacing,
TokenStream::new(buf),
if is_delimited { Err(vec![self.eof_err()]) } else { Ok(()) },
);
return if is_delimited {
Err(vec![self.eof_err()])
} else {
Ok((open_spacing, TokenStream::new(buf)))
};
}
_ => {
// Get the next normal token.
Expand Down Expand Up @@ -107,10 +105,7 @@ impl<'psess, 'src> Lexer<'psess, 'src> {
// Lex the token trees within the delimiters.
// We stop at any delimiter so we can try to recover if the user
// uses an incorrect delimiter.
let (open_spacing, tts, res) = self.lex_token_trees(/* is_delimited */ true);
if let Err(errs) = res {
return Err(self.unclosed_delim_err(tts, errs));
}
let (open_spacing, tts) = self.lex_token_trees(/* is_delimited */ true)?;

// Expand to cover the entire delimited token tree.
let delim_span = DelimSpan::from_pair(pre_span, self.token.span);
Expand Down Expand Up @@ -247,67 +242,6 @@ impl<'psess, 'src> Lexer<'psess, 'src> {
this_spacing
}

fn unclosed_delim_err(
&mut self,
tts: TokenStream,
mut errs: Vec<Diag<'psess>>,
) -> Vec<Diag<'psess>> {
// If there are unclosed delims, see if there are diff markers and if so, point them
// out instead of complaining about the unclosed delims.
let mut parser = Parser::new(self.psess, tts, None);
let mut diff_errs = vec![];
// Suggest removing a `{` we think appears in an `if`/`while` condition.
// We want to suggest removing a `{` only if we think we're in an `if`/`while` condition,
// but we have no way of tracking this in the lexer itself, so we piggyback on the parser.
let mut in_cond = false;
while parser.token != token::Eof {
if let Err(diff_err) = parser.err_vcs_conflict_marker() {
diff_errs.push(diff_err);
} else if parser.is_keyword_ahead(0, &[kw::If, kw::While]) {
in_cond = true;
} else if matches!(
parser.token.kind,
token::CloseDelim(Delimiter::Brace) | token::FatArrow
) {
// End of the `if`/`while` body, or the end of a `match` guard.
in_cond = false;
} else if in_cond && parser.token == token::OpenDelim(Delimiter::Brace) {
// Store the `&&` and `let` to use their spans later when creating the diagnostic
let maybe_andand = parser.look_ahead(1, |t| t.clone());
let maybe_let = parser.look_ahead(2, |t| t.clone());
if maybe_andand == token::OpenDelim(Delimiter::Brace) {
// This might be the beginning of the `if`/`while` body (i.e., the end of the
// condition).
in_cond = false;
} else if maybe_andand == token::AndAnd && maybe_let.is_keyword(kw::Let) {
let mut err = parser.dcx().struct_span_err(
parser.token.span,
"found a `{` in the middle of a let-chain",
);
err.span_suggestion(
parser.token.span,
"consider removing this brace to parse the `let` as part of the same chain",
"",
Applicability::MachineApplicable,
);
err.span_label(
maybe_andand.span.to(maybe_let.span),
"you might have meant to continue the let-chain here",
);
errs.push(err);
}
}
parser.bump();
}
if !diff_errs.is_empty() {
for err in errs {
err.cancel();
}
return diff_errs;
}
errs
}

fn close_delim_err(&mut self, delim: Delimiter) -> Diag<'psess> {
// An unexpected closing delimiter (i.e., there is no matching opening delimiter).
let token_str = token_to_string(&self.token);
Expand Down
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