[clang] [Clang][Solaris] Support --ld-path in Solaris driver (PR #163000)
Daniel Levin via cfe-commits
cfe-commits at lists.llvm.org
Tue Nov 11 06:51:06 PST 2025
https://github.com/daniel-levin updated https://github.com/llvm/llvm-project/pull/163000
>From dd443a162de6f14f923d67efbb4a082840ad3e08 Mon Sep 17 00:00:00 2001
From: Daniel Levin <daniellevin2607 at gmail.com>
Date: Wed, 22 Oct 2025 14:31:04 +0000
Subject: [PATCH] [Clang] [Driver] Support --ld-path flag on Illumos/Solaris
---
clang/include/clang/Driver/ToolChain.h | 2 +
clang/lib/Driver/ToolChains/CommonArgs.cpp | 8 +-
clang/lib/Driver/ToolChains/Solaris.cpp | 110 ++++++++++++++-------
clang/lib/Driver/ToolChains/Solaris.h | 25 ++++-
clang/test/Driver/solaris-ld.c | 37 +++++++
5 files changed, 141 insertions(+), 41 deletions(-)
diff --git a/clang/include/clang/Driver/ToolChain.h b/clang/include/clang/Driver/ToolChain.h
index 1425714d34110..753742067fe8c 100644
--- a/clang/include/clang/Driver/ToolChain.h
+++ b/clang/include/clang/Driver/ToolChain.h
@@ -491,6 +491,8 @@ class ToolChain {
}
/// GetDefaultLinker - Get the default linker to use.
+ /// Note: this is distinct from the 'preferred' linker, which is optionally
+ /// set at compile time using CLANG_DEFAULT_LINKER.
virtual const char *getDefaultLinker() const { return "ld"; }
/// GetDefaultRuntimeLibType - Get the default runtime library variant to use.
diff --git a/clang/lib/Driver/ToolChains/CommonArgs.cpp b/clang/lib/Driver/ToolChains/CommonArgs.cpp
index 99400ac701fbe..036f8d4b59313 100644
--- a/clang/lib/Driver/ToolChains/CommonArgs.cpp
+++ b/clang/lib/Driver/ToolChains/CommonArgs.cpp
@@ -1485,11 +1485,11 @@ static void addSanitizerRuntime(const ToolChain &TC, const ArgList &Args,
static bool addSanitizerDynamicList(const ToolChain &TC, const ArgList &Args,
ArgStringList &CmdArgs,
StringRef Sanitizer) {
- bool LinkerIsGnuLd = solaris::isLinkerGnuLd(TC, Args);
+ bool LinkerIsSolarisLinkEditor = solaris::isLinkerSolarisLinkEditor(TC, Args);
// Solaris ld defaults to --export-dynamic behaviour but doesn't support
// the option, so don't try to pass it.
- if (TC.getTriple().isOSSolaris() && !LinkerIsGnuLd)
+ if (TC.getTriple().isOSSolaris() && LinkerIsSolarisLinkEditor)
return true;
SmallString<128> SanRT(TC.getCompilerRT(Args, Sanitizer));
if (llvm::sys::fs::exists(SanRT + ".syms")) {
@@ -1505,14 +1505,14 @@ void tools::addAsNeededOption(const ToolChain &TC,
bool as_needed) {
assert(!TC.getTriple().isOSAIX() &&
"AIX linker does not support any form of --as-needed option yet.");
- bool LinkerIsGnuLd = solaris::isLinkerGnuLd(TC, Args);
+ bool LinkerIsSolarisLinkEditor = solaris::isLinkerSolarisLinkEditor(TC, Args);
// While the Solaris 11.2 ld added --as-needed/--no-as-needed as aliases
// for the native forms -z ignore/-z record, they are missing in Illumos,
// so always use the native form.
// GNU ld doesn't support -z ignore/-z record, so don't use them even on
// Solaris.
- if (TC.getTriple().isOSSolaris() && !LinkerIsGnuLd) {
+ if (TC.getTriple().isOSSolaris() && LinkerIsSolarisLinkEditor) {
CmdArgs.push_back("-z");
CmdArgs.push_back(as_needed ? "ignore" : "record");
} else {
diff --git a/clang/lib/Driver/ToolChains/Solaris.cpp b/clang/lib/Driver/ToolChains/Solaris.cpp
index 02aa59817449d..7e727d816e560 100644
--- a/clang/lib/Driver/ToolChains/Solaris.cpp
+++ b/clang/lib/Driver/ToolChains/Solaris.cpp
@@ -36,11 +36,11 @@ void solaris::Assembler::ConstructJob(Compilation &C, const JobAction &JA,
gnutools::Assembler::ConstructJob(C, JA, Output, Inputs, Args, LinkingOutput);
}
-bool solaris::isLinkerGnuLd(const ToolChain &TC, const ArgList &Args) {
- // Only used if targetting Solaris.
- const Arg *A = Args.getLastArg(options::OPT_fuse_ld_EQ);
- StringRef UseLinker = A ? A->getValue() : TC.getDriver().getPreferredLinker();
- return UseLinker == "bfd" || UseLinker == "gld";
+bool solaris::isLinkerSolarisLinkEditor(const ToolChain &TC,
+ const ArgList &Args) {
+ auto Determination =
+ solaris::LinkerDetermination::make(TC, Args, /* EmitDiagnostics */ false);
+ return Determination.IsSolarisLd;
}
static bool getPIE(const ArgList &Args, const ToolChain &TC) {
@@ -52,30 +52,11 @@ static bool getPIE(const ArgList &Args, const ToolChain &TC) {
TC.isPIEDefault(Args));
}
-// FIXME: Need to handle PreferredLinker here?
std::string solaris::Linker::getLinkerPath(const ArgList &Args) const {
- const ToolChain &ToolChain = getToolChain();
- if (const Arg *A = Args.getLastArg(options::OPT_fuse_ld_EQ)) {
- StringRef UseLinker = A->getValue();
- if (!UseLinker.empty()) {
- if (llvm::sys::path::is_absolute(UseLinker) &&
- llvm::sys::fs::can_execute(UseLinker))
- return std::string(UseLinker);
-
- // Accept 'bfd' and 'gld' as aliases for the GNU linker.
- if (UseLinker == "bfd" || UseLinker == "gld")
- // FIXME: Could also use /usr/bin/gld here.
- return "/usr/gnu/bin/ld";
-
- // Accept 'ld' as alias for the default linker
- if (UseLinker != "ld")
- ToolChain.getDriver().Diag(diag::err_drv_invalid_linker_name)
- << A->getAsString(Args);
- }
- }
+ auto Determination =
+ solaris::LinkerDetermination::make(getToolChain(), Args, true);
- // getDefaultLinker() always returns an absolute path.
- return ToolChain.getDefaultLinker();
+ return Determination.Linker;
}
void solaris::Linker::ConstructJob(Compilation &C, const JobAction &JA,
@@ -87,11 +68,11 @@ void solaris::Linker::ConstructJob(Compilation &C, const JobAction &JA,
const Driver &D = ToolChain.getDriver();
const llvm::Triple::ArchType Arch = ToolChain.getArch();
const bool IsPIE = getPIE(Args, ToolChain);
- const bool LinkerIsGnuLd = isLinkerGnuLd(ToolChain, Args);
+ const bool LinkerIsSolarisLd = isLinkerSolarisLinkEditor(ToolChain, Args);
ArgStringList CmdArgs;
// Demangle C++ names in errors. GNU ld already defaults to --demangle.
- if (!LinkerIsGnuLd)
+ if (LinkerIsSolarisLd)
CmdArgs.push_back("-C");
if (!Args.hasArg(options::OPT_nostdlib, options::OPT_shared,
@@ -101,7 +82,7 @@ void solaris::Linker::ConstructJob(Compilation &C, const JobAction &JA,
}
if (IsPIE) {
- if (LinkerIsGnuLd) {
+ if (!LinkerIsSolarisLd) {
CmdArgs.push_back("-pie");
} else {
CmdArgs.push_back("-z");
@@ -122,7 +103,7 @@ void solaris::Linker::ConstructJob(Compilation &C, const JobAction &JA,
Args.ClaimAllArgs(options::OPT_pthreads);
}
- if (LinkerIsGnuLd) {
+ if (!LinkerIsSolarisLd) {
// Set the correct linker emulation for 32- and 64-bit Solaris.
switch (Arch) {
case llvm::Triple::x86:
@@ -256,7 +237,7 @@ void solaris::Linker::ConstructJob(Compilation &C, const JobAction &JA,
if (Arch == llvm::Triple::x86_64 &&
(SA.needsAsanRt() || SA.needsStatsRt() ||
(SA.needsUbsanRt() && !SA.requiresMinimalRuntime())) &&
- !LinkerIsGnuLd) {
+ LinkerIsSolarisLd) {
CmdArgs.push_back("-z");
CmdArgs.push_back("relax=transtls");
}
@@ -344,10 +325,10 @@ SanitizerMask Solaris::getSupportedSanitizers() const {
}
const char *Solaris::getDefaultLinker() const {
- // FIXME: Only handle Solaris ld and GNU ld here.
- return llvm::StringSwitch<const char *>(getDriver().getPreferredLinker())
- .Cases("bfd", "gld", "/usr/gnu/bin/ld")
- .Default("/usr/bin/ld");
+ // The default linker on Solaris is _always_ the Solaris Link Editor.
+ // Recall that the driver's _default_ linker is distinct from the compile-time
+ // _preferred_ linker setting CLANG_DEFAULT_LINKER, which may even be empty.
+ return "/usr/bin/ld";
}
Tool *Solaris::buildAssembler() const {
@@ -423,3 +404,60 @@ void Solaris::addLibStdCxxIncludePaths(
TripleStr, Multilib.includeSuffix(), DriverArgs,
CC1Args);
}
+
+solaris::LinkerDetermination
+solaris::LinkerDetermination::make(const ToolChain &TC, const ArgList &Args,
+ bool EmitDiagnostics) {
+ // First, check --ld-path, then -fuse-ld, then the compile-time
+ // preferred linker (CLANG_DEFAULT_LINKER), then finally fall back to the
+ // platform's default - the Solaris Link Editor. This behavior is consonant
+ // with the other platforms' drivers.
+
+ auto GuessIfSolarisLd = [](const std::string &s) -> bool {
+ return (s == "ld" || s == "/bin/ld" || s == "/usr/bin/ld");
+ };
+
+ if (const Arg *A = Args.getLastArg(options::OPT_ld_path_EQ)) {
+ StringRef UseLinker = A->getValue();
+ if (!UseLinker.empty()) {
+ auto LinkerPath = std::string(UseLinker);
+ if (llvm::sys::fs::can_execute(LinkerPath))
+ return solaris::LinkerDetermination(LinkerPath,
+ GuessIfSolarisLd(LinkerPath));
+ }
+ if (EmitDiagnostics)
+ TC.getDriver().Diag(diag::err_drv_invalid_linker_name)
+ << A->getAsString(Args);
+ } else if (const Arg *A = Args.getLastArg(options::OPT_fuse_ld_EQ)) {
+ StringRef UseLinker = A->getValue();
+ if (!UseLinker.empty()) {
+ if (llvm::sys::path::is_absolute(UseLinker) &&
+ llvm::sys::fs::can_execute(UseLinker)) {
+ auto LinkerPath = std::string(UseLinker);
+ return solaris::LinkerDetermination(LinkerPath,
+ GuessIfSolarisLd(LinkerPath));
+ }
+
+ // Accept 'bfd' and 'gld' as aliases for the GNU linker.
+ if (UseLinker == "bfd" || UseLinker == "gld")
+ return solaris::LinkerDetermination("/usr/gnu/bin/ld", false);
+
+ // Accept 'ld' as an alias for the default linker
+ if (UseLinker == "ld")
+ return solaris::LinkerDetermination("/usr/bin/ld", true);
+
+ if (EmitDiagnostics)
+ TC.getDriver().Diag(diag::err_drv_invalid_linker_name)
+ << A->getAsString(Args);
+ }
+ }
+
+ auto CompileTimePreferredLinker = TC.getDriver().getPreferredLinker();
+ if (!CompileTimePreferredLinker.empty()) {
+ auto LinkerPath = std::string(CompileTimePreferredLinker);
+ return solaris::LinkerDetermination(LinkerPath,
+ GuessIfSolarisLd(LinkerPath));
+ }
+
+ return solaris::LinkerDetermination(std::string("/usr/bin/ld"), true);
+}
diff --git a/clang/lib/Driver/ToolChains/Solaris.h b/clang/lib/Driver/ToolChains/Solaris.h
index 9ec83b773da44..394ba648b53f2 100644
--- a/clang/lib/Driver/ToolChains/Solaris.h
+++ b/clang/lib/Driver/ToolChains/Solaris.h
@@ -31,7 +31,8 @@ class LLVM_LIBRARY_VISIBILITY Assembler final : public gnutools::Assembler {
const char *LinkingOutput) const override;
};
-bool isLinkerGnuLd(const ToolChain &TC, const llvm::opt::ArgList &Args);
+bool isLinkerSolarisLinkEditor(const ToolChain &TC,
+ const llvm::opt::ArgList &Args);
class LLVM_LIBRARY_VISIBILITY Linker final : public Tool {
public:
@@ -46,6 +47,28 @@ class LLVM_LIBRARY_VISIBILITY Linker final : public Tool {
const llvm::opt::ArgList &TCArgs,
const char *LinkingOutput) const override;
};
+
+/// We use Solaris's built-in linker by default. It has a unique command line
+/// syntax and specific limitations. By contrast, other linkers such as lld,
+/// Mold, and Wild are compatible with GNU ld's command line syntax. Knowing
+/// _which_ linker to use is sufficient to determine the expectations of that
+/// linker. Rather than spread ad-hoc string comparisons all over the driver, we
+/// encapsulate the details of differences in the chosen linker here.
+class LinkerDetermination final {
+ LinkerDetermination(std::string Linker, bool IsSolarisLd)
+ : Linker(Linker), IsSolarisLd(IsSolarisLd) {}
+
+public:
+ std::string Linker;
+ bool IsSolarisLd;
+
+ /// Choose the correct linker based on arguments and compile-time options
+ /// recorded in the ToolChain.
+ static LinkerDetermination make(const ToolChain &TC,
+ const llvm::opt::ArgList &Args,
+ bool EmitDiagnostics);
+};
+
} // end namespace solaris
} // end namespace tools
diff --git a/clang/test/Driver/solaris-ld.c b/clang/test/Driver/solaris-ld.c
index 5940ee2add769..b0434bb128118 100644
--- a/clang/test/Driver/solaris-ld.c
+++ b/clang/test/Driver/solaris-ld.c
@@ -275,3 +275,40 @@
// CHECK-CRTFASTMATH-X64: "-isysroot" "[[SYSROOT:[^"]+]]"
// CHECK-CRTFASTMATH-X64: "[[SYSROOT]]/usr/gcc/4.9/lib/gcc/i386-pc-solaris2.11/4.9.4/amd64{{/|\\\\}}crtfastmath.o"
// CHECK-NOCRTFASTMATH-X64-NOT: crtfastmath.o
+
+// Check --ld-path flag with GNU ld
+// RUN: test -f /usr/gnu/bin/ld && %clang --ld-path=/usr/gnu/bin/ld -### %s \
+// RUN: -rtlib=platform --unwindlib=platform \
+// RUN: --sysroot=%S/Inputs/solaris_x86_tree 2>&1 \
+// RUN: | FileCheck --check-prefix=CHECK-GNU-LD %s
+// CHECK-GNU-LD: /usr/gnu/bin/ld
+// CHECK-GNU-LD-NOT: "-C"
+
+// Check --ld-path flag with system linker
+// RUN: %clang --ld-path=/bin/ld -### %s \
+// RUN: -rtlib=platform --unwindlib=platform \
+// RUN: --sysroot=%S/Inputs/solaris_x86_tree 2>&1 \
+// RUN: | FileCheck --check-prefix=CHECK-SYSLINKER %s
+// CHECK-SYSLINKER: /bin/ld
+// CHECK-SYSLINKER: "-C"
+// CHECK-SYSLINKER-NOT: /usr/gnu/bin/ld
+
+// Check --ld-path flag with empty args errors out
+// RUN: not %clang --ld-path= -### %s \
+// RUN: -rtlib=platform --unwindlib=platform \
+// RUN: --sysroot=%S/Inputs/solaris_x86_tree 2>&1 \
+// RUN: | FileCheck --check-prefix=NOT_EXIST %s
+// NOT_EXIST: error: invalid linker name in argument '--ld-path='
+
+// Check --ld-path flag with non-existent linker errors out
+// RUN: not %clang --ld-path=bogus-nonsense -### %s \
+// RUN: -rtlib=platform --unwindlib=platform \
+// RUN: --sysroot=%S/Inputs/solaris_x86_tree 2>&1 \
+// RUN: | FileCheck --check-prefix=NOT_EXIST_BOGUS %s
+// NOT_EXIST_BOGUS: error: invalid linker name in argument '--ld-path=bogus-nonsense'
+
+// Check --ld-path flag takes precedence over -fuse-ld
+// RUN: %clang --ld-path=/bin/ld -fuse-ld=bfd -### %s \
+// RUN: -rtlib=platform --unwindlib=platform \
+// RUN: --sysroot=%S/Inputs/solaris_x86_tree 2>&1 \
+// RUN: | FileCheck --check-prefix=CHECK-SYSLINKER %s
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