[lld] 39c20a6 - [ELF] Add --remap-inputs= and --remap-inputs-file=
Fangrui Song via llvm-commits
llvm-commits at lists.llvm.org
Wed Apr 26 13:19:00 PDT 2023
Author: Fangrui Song
Date: 2023-04-26T13:18:55-07:00
New Revision: 39c20a63b150053fcee5928be7ea1b3b0a51c9d4
URL: https://github.com/llvm/llvm-project/commit/39c20a63b150053fcee5928be7ea1b3b0a51c9d4
DIFF: https://github.com/llvm/llvm-project/commit/39c20a63b150053fcee5928be7ea1b3b0a51c9d4.diff
LOG: [ELF] Add --remap-inputs= and --remap-inputs-file=
--remap-inputs-file= can be specified multiple times, each naming a
remap file that contains `from-glob=to-file` lines or `#`-led comments.
('=' is used a separator a la -fdebug-prefix-map=)
--remap-inputs-file= can be used to:
* replace an input file. E.g. `"*/libz.so=exp/libz.so"` can replace a resolved
`-lz` without updating the input file list or (if used) a response file.
When debugging an application where a bug is isolated to one single
input file, this option gives a convenient way to test fixes.
* remove an input file with `/dev/null` (changed to `NUL` on Windows), e.g.
`"a.o=/dev/null"`. A build system may add unneeded dependencies.
This option gives a convenient way to test the result removing some inputs.
`--remap-inputs=a.o=aa.o` can be specified to provide one pattern without using
an extra file.
(bash/zsh process substitution is handy for specifying a pattern without using
a remap file, e.g. `--remap-inputs-file=<(printf 'a.o=aa.o')`, but it may be
unavailable in some systems. An extra file can be inconvenient for a build
system.)
Exact patterns are tested before wildcard patterns. In case of a tie, the first
patterns wins. This is an implementation detail that users should not rely on.
Co-authored-by: Marco Elver <elver at google.com>
Link: https://discourse.llvm.org/t/rfc-support-exclude-inputs/70070
Reviewed By: melver, peter.smith
Differential Revision: https://reviews.llvm.org/D148859
Added:
lld/test/ELF/remap-inputs.test
Modified:
lld/ELF/Config.h
lld/ELF/Driver.cpp
lld/ELF/DriverUtils.cpp
lld/ELF/InputFiles.cpp
lld/ELF/Options.td
lld/docs/ReleaseNotes.rst
lld/docs/ld.lld.1
Removed:
################################################################################
diff --git a/lld/ELF/Config.h b/lld/ELF/Config.h
index c446508dfa2f0..9c9a49d9f20ed 100644
--- a/lld/ELF/Config.h
+++ b/lld/ELF/Config.h
@@ -407,6 +407,12 @@ struct Config {
bool androidMemtagStack;
unsigned threadCount;
+
+ // If an input file equals a key, remap it to the value.
+ llvm::DenseMap<llvm::StringRef, llvm::StringRef> remapInputs;
+ // If an input file matches a wildcard pattern, remap it to the value.
+ llvm::SmallVector<std::pair<llvm::GlobPattern, llvm::StringRef>, 0>
+ remapInputsWildcards;
};
struct ConfigWrapper {
Config c;
diff --git a/lld/ELF/Driver.cpp b/lld/ELF/Driver.cpp
index 79f16a281df9b..f235ffcbb9559 100644
--- a/lld/ELF/Driver.cpp
+++ b/lld/ELF/Driver.cpp
@@ -1077,6 +1077,25 @@ static bool isValidReportString(StringRef arg) {
return arg == "none" || arg == "warning" || arg == "error";
}
+// Process a remap pattern 'from-glob=to-file'.
+static bool remapInputs(StringRef line, const Twine &location) {
+ SmallVector<StringRef, 0> fields;
+ line.split(fields, '=');
+ if (fields.size() != 2 || fields[1].empty()) {
+ error(location + ": parse error, not 'from-glob=to-file'");
+ return true;
+ }
+ if (!hasWildcard(fields[0]))
+ config->remapInputs[fields[0]] = fields[1];
+ else if (Expected<GlobPattern> pat = GlobPattern::create(fields[0]))
+ config->remapInputsWildcards.emplace_back(std::move(*pat), fields[1]);
+ else {
+ error(location + ": " + toString(pat.takeError()));
+ return true;
+ }
+ return false;
+}
+
// Initializes Config members by the command line options.
static void readConfigs(opt::InputArgList &args) {
errorHandler().verbose = args.hasArg(OPT_verbose);
@@ -1335,6 +1354,21 @@ static void readConfigs(opt::InputArgList &args) {
config->optEL = true;
}
+ for (opt::Arg *arg : args.filtered(OPT_remap_inputs)) {
+ StringRef value(arg->getValue());
+ remapInputs(value, arg->getSpelling());
+ }
+ for (opt::Arg *arg : args.filtered(OPT_remap_inputs_file)) {
+ StringRef filename(arg->getValue());
+ std::optional<MemoryBufferRef> buffer = readFile(filename);
+ if (!buffer)
+ continue;
+ // Parse 'from-glob=to-file' lines, ignoring #-led comments.
+ for (auto [lineno, line] : llvm::enumerate(args::getLines(*buffer)))
+ if (remapInputs(line, filename + ":" + Twine(lineno + 1)))
+ break;
+ }
+
for (opt::Arg *arg : args.filtered(OPT_shuffle_sections)) {
constexpr StringRef errPrefix = "--shuffle-sections=: ";
std::pair<StringRef, StringRef> kv = StringRef(arg->getValue()).split('=');
diff --git a/lld/ELF/DriverUtils.cpp b/lld/ELF/DriverUtils.cpp
index 254f4b7224628..50e9f509bcb47 100644
--- a/lld/ELF/DriverUtils.cpp
+++ b/lld/ELF/DriverUtils.cpp
@@ -192,6 +192,7 @@ std::string elf::createResponseFile(const opt::InputArgList &args) {
case OPT_export_dynamic_symbol_list:
case OPT_just_symbols:
case OPT_library_path:
+ case OPT_remap_inputs_file:
case OPT_retain_symbols_file:
case OPT_rpath:
case OPT_script:
diff --git a/lld/ELF/InputFiles.cpp b/lld/ELF/InputFiles.cpp
index b7686e8e3ba99..b8291fb4307bc 100644
--- a/lld/ELF/InputFiles.cpp
+++ b/lld/ELF/InputFiles.cpp
@@ -195,6 +195,29 @@ std::optional<MemoryBufferRef> elf::readFile(StringRef path) {
if (!config->chroot.empty() && path.startswith("/"))
path = saver().save(config->chroot + path);
+ bool remapped = false;
+ auto it = config->remapInputs.find(path);
+ if (it != config->remapInputs.end()) {
+ path = it->second;
+ remapped = true;
+ } else {
+ for (const auto &[pat, toFile] : config->remapInputsWildcards) {
+ if (pat.match(path)) {
+ path = toFile;
+ remapped = true;
+ break;
+ }
+ }
+ }
+ if (remapped) {
+ // Use /dev/null to indicate an input file that should be ignored. Change
+ // the path to NUL on Windows.
+#ifdef _WIN32
+ if (path == "/dev/null")
+ path = "NUL";
+#endif
+ }
+
log(path);
config->dependencyFiles.insert(llvm::CachedHashString(path));
diff --git a/lld/ELF/Options.td b/lld/ELF/Options.td
index 5b3d9f6c40dee..8f2a440fd67a2 100644
--- a/lld/ELF/Options.td
+++ b/lld/ELF/Options.td
@@ -359,6 +359,14 @@ defm relax_gp: BB<"relax-gp",
"Enable global pointer relaxation",
"Disable global pointer relaxation (default)">;
+defm remap_inputs: EEq<"remap-inputs",
+ "Remap input files matching <from-glob> to <to-file>">,
+ MetaVarName<"<from-glob>=<to-file>">;
+
+def remap_inputs_file: JJ<"remap-inputs-file=">,
+ HelpText<"Each line contains 'from-glob=to-file'. An input file matching <from-glob> is remapped to <to-file>">,
+ MetaVarName<"<file>">;
+
defm reproduce:
EEq<"reproduce",
"Write tar file containing inputs and command to reproduce link">;
diff --git a/lld/docs/ReleaseNotes.rst b/lld/docs/ReleaseNotes.rst
index 50c556bb8b311..393b3f7d848de 100644
--- a/lld/docs/ReleaseNotes.rst
+++ b/lld/docs/ReleaseNotes.rst
@@ -26,6 +26,9 @@ Non-comprehensive list of changes in this release
ELF Improvements
----------------
+* ``--remap-inputs=`` and ``--remap-inputs-file=`` are added to remap input files.
+ (`D148859 <https://reviews.llvm.org/D148859>`_)
+
Breaking changes
----------------
diff --git a/lld/docs/ld.lld.1 b/lld/docs/ld.lld.1
index d97cd26a6378b..e3db3a20678d9 100644
--- a/lld/docs/ld.lld.1
+++ b/lld/docs/ld.lld.1
@@ -497,6 +497,21 @@ Restore the states saved by
Enable global pointer relaxation for RISC-V.
.It Fl -relocatable , Fl r
Create relocatable object file.
+.It Fl -remap-inputs Ns = Ns Ar from-glob=to-file
+Input files matching
+.Cm from-glob
+are mapped to
+.Cm to-file.
+Use
+.Cm /dev/null
+to ignore an input file.
+.It Fl -remap-inputs-file Ns = Ns Ar file
+Remap input files based on patterns in
+.Ar file .
+Each line in the remap file is of the format
+.Cm from-glob=to-file
+or a comment starting with
+.Cm # .
.It Fl -reproduce Ns = Ns Ar path
Write a tar file to
.Ar path,
diff --git a/lld/test/ELF/remap-inputs.test b/lld/test/ELF/remap-inputs.test
new file mode 100644
index 0000000000000..8a2d2e9891064
--- /dev/null
+++ b/lld/test/ELF/remap-inputs.test
@@ -0,0 +1,85 @@
+# REQUIRES: x86
+## --remap-inputs and --remap-inputs-file= remap input files.
+
+# RUN: rm -rf %t && split-file %s %t && cd %t
+# RUN: llvm-mc -filetype=obj -triple=x86_64 a.s -o a.o
+# RUN: llvm-as b.ll -o b.o
+# RUN: llvm-mc -filetype=obj -triple=x86_64 c.s -o c.o && llvm-ar rc c.a c.o
+# RUN: llvm-mc -filetype=obj -triple=x86_64 d.s -o d.o && ld.lld -shared -soname=d d.o -o d.so
+# RUN: ld.lld --remap-inputs-file=1.map --remap-inputs-file=2.map --remap-inputs='d*.so=d.so' --reproduce=repro.tar aa.o bb.bc cc.a dd.so empty -o out
+# RUN: tar tf repro.tar | FileCheck %s --check-prefix=REPRO
+
+# REPRO: 1.map
+# REPRO-NEXT: 2.map
+# REPRO-NEXT: a.o
+# REPRO-NEXT: b.o
+# REPRO-NEXT: c.a
+# REPRO-NEXT: d.so
+
+## --remap-inputs can also be specified multiple times.
+# RUN: ld.lld --remap-inputs 'aa.o=a.o' --remap-inputs='d[d].so=d.so' aa.o b.o c.a d.so -o /dev/null
+
+## A multiple-to-one pattern may easily cause issues. Users should be careful.
+# RUN: not ld.lld --remap-inputs-file=3.map aa.o bb.bc -o /dev/null 2>&1 | \
+# RUN: FileCheck %s --check-prefix=DUPLICATE --implicit-check-not=error:
+# DUPLICATE: error: duplicate symbol: _start
+
+# RUN: not ld.lld --remap-inputs-file=err1.map aa.o bb.bc -o /dev/null 2>&1 | \
+# RUN: FileCheck %s --check-prefix=ERR1 --implicit-check-not=error:
+# ERR1: error: err1.map:2: parse error, not 'from-glob=to-file'
+# ERR1-NEXT: error: cannot open bb.bc: {{.*}}
+
+# RUN: not ld.lld --remap-inputs-file=err2.map aa.o -o /dev/null 2>&1 | \
+# RUN: FileCheck %s --check-prefix=ERR2 --implicit-check-not=error:
+# ERR2: error: err2.map:1: invalid glob pattern: aa.[o
+# ERR2-NEXT: error: cannot open aa.o: {{.*}}
+
+# RUN: not ld.lld --remap-inputs=aa.o aa.o -o /dev/null 2>&1 | \
+# RUN: FileCheck %s --check-prefix=ERR3 --implicit-check-not=error:
+# RUN: not ld.lld --remap-inputs=aa.o= aa.o -o /dev/null 2>&1 | \
+# RUN: FileCheck %s --check-prefix=ERR3 --implicit-check-not=error:
+# ERR3: error: --remap-inputs: parse error, not 'from-glob=to-file'
+# ERR3-NEXT: error: cannot open aa.o: {{.*}}
+
+#--- a.s
+.globl _start
+_start:
+ call b
+ call c
+ call d
+
+#--- b.ll
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+define void @b() {
+ ret void
+}
+
+#--- c.s
+.globl c
+c:
+
+#--- d.s
+.globl d
+d:
+
+#--- 1.map
+aa.o=a.o
+b?.[b]c=b.o
+
+#--- 2.map
+cc.a=c.a
+## Use /dev/null to indicate an input file which should be ignored.
+empty=/dev/null
+
+#--- 3.map
+*=a.o
+
+#--- err1.map
+aa.o=a.o
+bb.bc
+cc.a
+
+#--- err2.map
+aa.[o=a.o
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