[lld] 0a470a9 - [ELF] --package-metadata: support %[0-9a-fA-F][0-9a-fA-F]
via llvm-commits
llvm-commits at lists.llvm.org
Mon Feb 10 09:21:36 PST 2025
Author: Fangrui Song
Date: 2025-02-10T09:21:31-08:00
New Revision: 0a470a926481d370251731cb2dd897531756335f
URL: https://github.com/llvm/llvm-project/commit/0a470a926481d370251731cb2dd897531756335f
DIFF: https://github.com/llvm/llvm-project/commit/0a470a926481d370251731cb2dd897531756335f.diff
LOG: [ELF] --package-metadata: support %[0-9a-fA-F][0-9a-fA-F]
(This application-specific option is probably not appropriate as a
linker option (.o file offers more flexibility and decouples JSON
verification from linkers). However, the option has gained some traction
in Linux distributions, with support in GNU ld, gold, and mold.)
GNU ld has supported percent-encoded bytes and extensions like
`%[comma]` since November 2024. mold supports just percent-encoded
bytes. To prepare for potential adoption by Ubuntu, let's support
percent-encoded bytes.
Link: https://sourceware.org/bugzilla/show_bug.cgi?id=32003
Link: https://bugs.launchpad.net/ubuntu/+source/dpkg/+bug/2071468
Pull Request: https://github.com/llvm/llvm-project/pull/126396
Added:
Modified:
lld/ELF/Config.h
lld/ELF/Driver.cpp
lld/ELF/Options.td
lld/docs/ld.lld.1
lld/test/ELF/package-metadata.s
Removed:
################################################################################
diff --git a/lld/ELF/Config.h b/lld/ELF/Config.h
index 3cdb400e423fd95..f132b11b20c631e 100644
--- a/lld/ELF/Config.h
+++ b/lld/ELF/Config.h
@@ -411,7 +411,7 @@ struct Config {
StringRef thinLTOJobs;
unsigned timeTraceGranularity;
int32_t splitStackAdjustSize;
- StringRef packageMetadata;
+ SmallVector<uint8_t, 0> packageMetadata;
// The following config options do not directly correspond to any
// particular command line options.
diff --git a/lld/ELF/Driver.cpp b/lld/ELF/Driver.cpp
index 3d6e022a89e5f68..7d14180a4992622 100644
--- a/lld/ELF/Driver.cpp
+++ b/lld/ELF/Driver.cpp
@@ -816,6 +816,26 @@ static ICFLevel getICF(opt::InputArgList &args) {
return ICFLevel::All;
}
+static void parsePackageMetadata(Ctx &ctx, const opt::Arg &arg) {
+ unsigned c0, c1;
+ SmallVector<uint8_t, 0> decoded;
+ StringRef s = arg.getValue();
+ for (size_t i = 0, e = s.size(); i != e; ++i) {
+ if (s[i] != '%') {
+ decoded.push_back(s[i]);
+ } else if (i + 2 < e && (c1 = hexDigitValue(s[i + 1])) != -1u &&
+ (c0 = hexDigitValue(s[i + 2])) != -1u) {
+ decoded.push_back(uint8_t(c1 * 16 + c0));
+ i += 2;
+ } else {
+ ErrAlways(ctx) << arg.getSpelling() << ": invalid % escape at byte " << i
+ << "; supports only %[0-9a-fA-F][0-9a-fA-F]";
+ return;
+ }
+ }
+ ctx.arg.packageMetadata = std::move(decoded);
+}
+
static StripPolicy getStrip(Ctx &ctx, opt::InputArgList &args) {
if (args.hasArg(OPT_relocatable))
return StripPolicy::None;
@@ -1425,7 +1445,8 @@ static void readConfigs(Ctx &ctx, opt::InputArgList &args) {
ctx.arg.optimize = args::getInteger(args, OPT_O, 1);
ctx.arg.orphanHandling = getOrphanHandling(ctx, args);
ctx.arg.outputFile = args.getLastArgValue(OPT_o);
- ctx.arg.packageMetadata = args.getLastArgValue(OPT_package_metadata);
+ if (auto *arg = args.getLastArg(OPT_package_metadata))
+ parsePackageMetadata(ctx, *arg);
ctx.arg.pie = args.hasFlag(OPT_pie, OPT_no_pie, false);
ctx.arg.printIcfSections =
args.hasFlag(OPT_print_icf_sections, OPT_no_print_icf_sections, false);
diff --git a/lld/ELF/Options.td b/lld/ELF/Options.td
index 80032490da0de4b..b3b12a064687580 100644
--- a/lld/ELF/Options.td
+++ b/lld/ELF/Options.td
@@ -578,7 +578,7 @@ def z: JoinedOrSeparate<["-"], "z">, MetaVarName<"<option>">,
def visual_studio_diagnostics_format : FF<"vs-diagnostics">,
HelpText<"Format diagnostics for Visual Studio compatibility">;
-def package_metadata: JJ<"package-metadata=">, HelpText<"Emit package metadata note">;
+def package_metadata: JJ<"package-metadata=">, HelpText<"Emit a percent-encoded string to the .note.package section">;
// Aliases
def: Separate<["-"], "dT">, Alias<default_script>, HelpText<"Alias for --default-script">;
diff --git a/lld/docs/ld.lld.1 b/lld/docs/ld.lld.1
index b28c6082f68b091..b5c1816ce6e5fde 100644
--- a/lld/docs/ld.lld.1
+++ b/lld/docs/ld.lld.1
@@ -493,6 +493,10 @@ If
.Fl -use-android-relr-tags
is specified, use SHT_ANDROID_RELR instead of SHT_RELR.
.Pp
+.It Fl -package-metadata
+Emit a percent-encoded string to the
+.Cm .note.package
+section. For example, %25 decodes to a single %.
.It Fl -pic-veneer
Always generate position independent thunks.
.It Fl -pie , Fl -pic-executable
diff --git a/lld/test/ELF/package-metadata.s b/lld/test/ELF/package-metadata.s
index 29df499d7e98d29..a70a8940d7c68bb 100644
--- a/lld/test/ELF/package-metadata.s
+++ b/lld/test/ELF/package-metadata.s
@@ -1,12 +1,15 @@
# REQUIRES: x86
+# 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-mc -filetype=obj -triple=x86_64 %s -o %t.o
+# RUN: ld.lld a.o --package-metadata='{}'
+# RUN: llvm-readelf -n a.out | FileCheck %s --check-prefixes=NOTE,FIRST
-# RUN: ld.lld %t.o -o %t --package-metadata='{}'
-# RUN: llvm-readelf -n %t | FileCheck %s --check-prefixes=NOTE,FIRST
+# RUN: ld.lld a.o --package-metadata='{"abc":123}'
+# RUN: llvm-readelf -n a.out | FileCheck %s --check-prefixes=NOTE,SECOND
-# RUN: ld.lld %t.o -o %t --package-metadata='{"abc":123}'
-# RUN: llvm-readelf -n %t | FileCheck %s --check-prefixes=NOTE,SECOND
+# RUN: ld.lld a.o --package-metadata='%7b%22abc%22:123%7D'
+# RUN: llvm-readelf -n a.out | FileCheck %s --check-prefixes=NOTE,SECOND
# NOTE: .note.package
# NOTE-NEXT: Owner
@@ -14,6 +17,13 @@
# FIRST-NEXT: description data: 7b 7d 00
# SECOND-NEXT: description data: 7b 22 61 62 63 22 3a 31 32 33 7d 00
+# RUN: not ld.lld a.o --package-metadata='%7b%' 2>&1 | FileCheck %s --check-prefix=ERR
+# RUN: not ld.lld a.o --package-metadata='%7b%7' 2>&1 | FileCheck %s --check-prefix=ERR
+# RUN: not ld.lld a.o --package-metadata='%7b%7g' 2>&1 | FileCheck %s --check-prefix=ERR
+
+# ERR: error: --package-metadata=: invalid % escape at byte 3; supports only %[0-9a-fA-F][0-9a-fA-F]
+
+#--- a.s
.globl _start
_start:
ret
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