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[Driver] Fix link order of BareMetal toolchain object #132806

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merged 1 commit into from
Jun 17, 2025
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[Driver] Fix link order of BareMetal toolchain object #132806

merged 1 commit into from
Jun 17, 2025
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@quic-garvgupt quic-garvgupt commented Mar 24, 2025 •
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The linker job in BareMetal toolchain object will be used by GNU ld and lld both.
However, gnuld process the arguments in the order in which they appear on command
line, whereas there is no such restriction with lld.

The previous order was:
LibraryPaths -> Libraries -> LTOOptions -> LinkerInputs
The new order is:
LibraryPaths -> LTOOptions -> LinkerInputs -> Libraries

LTO options need to be added before adding any linker inputs because file format
after compile stage during LTO is bitcode which gnuld natively cannot process.
Hence will need to pass appropriate plugins before adding any bitcode file on the
command line.

Object files that are getting linked need to be passed before processing any
libraries so that gnuld can appropriately do symbol resolution for the symbols
for which no definition is provided through user code.

Similar link order is also followed by other linker jobs for gnuld such as in
gnutools::Linker in Gnu.cpp

This is the 3rd patch in the series of patches of merging RISCVToolchain into
BareMetal toolchain object.

RFC:
https://discourse.llvm.org/t/merging-riscvtoolchain-and-baremetal-toolchains/75524

This was referenced Mar 24, 2025
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@quic-garvgupt quic-garvgupt marked this pull request as ready for review March 24, 2025 18:53
@llvmbot llvmbot added clang Clang issues not falling into any other category clang:driver 'clang' and 'clang++' user-facing binaries. Not 'clang-cl' labels Mar 24, 2025
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llvmbot commented Mar 24, 2025 •
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@llvm/pr-subscribers-clang-driver

@llvm/pr-subscribers-clang

Author: Garvit Gupta (quic-garvgupt)

Changes

The linker job in BareMetal toolchain object will be used by gnuld and lld both.
However, gnuld process the arguments in the order in which they appear on command
line, whereas there is no such restriction with lld.

The previous order was:
LibraryPaths -> Libraries -> LTOOptions -> LinkerInputs
The new iorder is:
LibraryPaths -> LTOOptions -> LinkerInputs -> Libraries

LTO options need to be added before adding any linker inputs because file format
after compile stage during LTO is bitcode which gnuld natively cannot process.
Hence iwill need to pass appropriate plugins before adding any bitcode file on the
command line.

Object files that are getting linked need to be passed before processing any
libraries so that gnuld can appropriately do symbol resolution for the symbols
for which no definition is provided through user code.

Similar link order is also followed by other linker jobs for gnuld such as in
gnutools::Linker in Gnu.cpp

This is the 3rd patch in the series of patches of merging RISCVToolchain into
BareMetal toolchain object.

RFC:
https://discourse.llvm.org/t/merging-riscvtoolchain-and-baremetal-toolchains/75524

Patch is 42.29 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/132806.diff

8 Files Affected:

  • (modified) clang/lib/Driver/ToolChains/BareMetal.cpp (+16-16)
  • (modified) clang/test/Driver/aarch64-toolchain-extra.c (+1-1)
  • (modified) clang/test/Driver/aarch64-toolchain.c (+12-12)
  • (modified) clang/test/Driver/arm-toolchain-extra.c (+1-1)
  • (modified) clang/test/Driver/arm-toolchain.c (+12-12)
  • (modified) clang/test/Driver/baremetal-multilib.yaml (+2-1)
  • (modified) clang/test/Driver/baremetal-sysroot.cpp (+5-3)
  • (modified) clang/test/Driver/baremetal.cpp (+51-31)
diff --git a/clang/lib/Driver/ToolChains/BareMetal.cpp b/clang/lib/Driver/ToolChains/BareMetal.cpp
index 7ec6d86d998a4..919fc6fe71178 100644
--- a/clang/lib/Driver/ToolChains/BareMetal.cpp
+++ b/clang/lib/Driver/ToolChains/BareMetal.cpp
@@ -529,8 +529,6 @@ void baremetal::Linker::ConstructJob(Compilation &C, const JobAction &JA,
   const llvm::Triple::ArchType Arch = TC.getArch();
   const llvm::Triple &Triple = getToolChain().getEffectiveTriple();
 
-  AddLinkerInputs(TC, Inputs, Args, CmdArgs, JA);
-
   CmdArgs.push_back("-Bstatic");
 
   if (TC.getTriple().isRISCV() && Args.hasArg(options::OPT_mno_relax))
@@ -576,6 +574,22 @@ void baremetal::Linker::ConstructJob(Compilation &C, const JobAction &JA,
   for (const auto &LibPath : TC.getLibraryPaths())
     CmdArgs.push_back(Args.MakeArgString(llvm::Twine("-L", LibPath)));
 
+  if (D.isUsingLTO()) {
+    assert(!Inputs.empty() && "Must have at least one input.");
+    // Find the first filename InputInfo object.
+    auto Input = llvm::find_if(
+        Inputs, [](const InputInfo &II) -> bool { return II.isFilename(); });
+    if (Input == Inputs.end())
+      // For a very rare case, all of the inputs to the linker are
+      // InputArg. If that happens, just use the first InputInfo.
+      Input = Inputs.begin();
+
+    addLTOOptions(TC, Args, CmdArgs, Output, *Input,
+                  D.getLTOMode() == LTOK_Thin);
+  }
+
+  AddLinkerInputs(TC, Inputs, Args, CmdArgs, JA);
+
   if (TC.ShouldLinkCXXStdlib(Args)) {
     bool OnlyLibstdcxxStatic = Args.hasArg(options::OPT_static_libstdcxx) &&
                                !Args.hasArg(options::OPT_static);
@@ -596,20 +610,6 @@ void baremetal::Linker::ConstructJob(Compilation &C, const JobAction &JA,
     CmdArgs.push_back("--end-group");
   }
 
-  if (D.isUsingLTO()) {
-    assert(!Inputs.empty() && "Must have at least one input.");
-    // Find the first filename InputInfo object.
-    auto Input = llvm::find_if(
-        Inputs, [](const InputInfo &II) -> bool { return II.isFilename(); });
-    if (Input == Inputs.end())
-      // For a very rare case, all of the inputs to the linker are
-      // InputArg. If that happens, just use the first InputInfo.
-      Input = Inputs.begin();
-
-    addLTOOptions(TC, Args, CmdArgs, Output, *Input,
-                  D.getLTOMode() == LTOK_Thin);
-  }
-
   if ((TC.hasValidGCCInstallation() || hasGCCToolChainAlongSideClang(D)) &&
       WantCRTs)
     CmdArgs.push_back(Args.MakeArgString(TC.GetFilePath(crtend)));
diff --git a/clang/test/Driver/aarch64-toolchain-extra.c b/clang/test/Driver/aarch64-toolchain-extra.c
index 2a930e35acd45..a0b5f2902962f 100644
--- a/clang/test/Driver/aarch64-toolchain-extra.c
+++ b/clang/test/Driver/aarch64-toolchain-extra.c
@@ -31,5 +31,5 @@
 // C-AARCH64-BAREMETAL-NOGCC: "{{.*}}/aarch64-nogcc/bin/../aarch64-none-elf/lib/crt0.o"
 // C-AARCH64-BAREMETAL-NOGCC: "{{.*}}/aarch64-nogcc/{{.*}}/aarch64-none-elf/lib/crtbegin.o"
 // C-AARCH64-BAREMETAL-NOGCC: "{{.*}}/aarch64-nogcc/bin/../aarch64-none-elf/lib"
-// C-AARCH64-BAREMETAL-NOGCC: "--start-group" "-lgcc" "--as-needed" "-lgcc_s" "--no-as-needed" "-lc" "-lgloss" "--end-group"
+// C-AARCH64-BAREMETAL-NOGCC: "{{.*}}.o" "--start-group" "-lgcc" "--as-needed" "-lgcc_s" "--no-as-needed" "-lc" "-lgloss" "--end-group"
 // C-AARCH64-BAREMETAL-NOGCC: "{{.*}}/aarch64-nogcc/{{.*}}/aarch64-none-elf/lib/crtend.o"
diff --git a/clang/test/Driver/aarch64-toolchain.c b/clang/test/Driver/aarch64-toolchain.c
index 5371577267d0d..d45be9a6ee649 100644
--- a/clang/test/Driver/aarch64-toolchain.c
+++ b/clang/test/Driver/aarch64-toolchain.c
@@ -17,12 +17,12 @@
 // C-AARCH64-BAREMETAL: "-isysroot" "{{.*}}Inputs/basic_aarch64_gcc_tree/aarch64-none-elf"
 // C-AARCH64-BAREMETAL: "-internal-isystem" "{{.*}}Inputs/basic_aarch64_gcc_tree/aarch64-none-elf/include"
 // C-AARCH64-BAREMETAL: "{{.*}}/Inputs/basic_aarch64_gcc_tree/lib/gcc/aarch64-none-elf/8.2.1/../../../../bin/aarch64-none-elf-ld"
-// C-AARCH64-BAREMETAL: "{{.*}}.o" "-Bstatic" "-EL"
+// C-AARCH64-BAREMETAL: "-Bstatic" "-EL"
 // C-AARCH64-BAREMETAL: "{{.*}}/Inputs/basic_aarch64_gcc_tree/aarch64-none-elf/lib/crt0.o"
 // C-AARCH64-BAREMETAL: "{{.*}}/Inputs/basic_aarch64_gcc_tree/lib/gcc/aarch64-none-elf/8.2.1/crtbegin.o"
 // C-AARCH64-BAREMETAL: "-L{{.*}}/Inputs/basic_aarch64_gcc_tree/lib/gcc/aarch64-none-elf/8.2.1"
 // C-AARCH64-BAREMETAL: "-L{{.*}}/Inputs/basic_aarch64_gcc_tree/aarch64-none-elf/lib"
-// C-AARCH64-BAREMETAL: "--start-group" "-lgcc" "--as-needed" "-lgcc_s" "--no-as-needed" "-lc" "-lgloss" "--end-group"
+// C-AARCH64-BAREMETAL: "{{.*}}.o" "--start-group" "-lgcc" "--as-needed" "-lgcc_s" "--no-as-needed" "-lc" "-lgloss" "--end-group"
 // C-AARCH64-BAREMETAL: "{{.*}}/Inputs/basic_aarch64_gcc_tree/lib/gcc/aarch64-none-elf/8.2.1/crtend.o"
 
 // RUN: %clang -### %s -fuse-ld= \
@@ -34,12 +34,12 @@
 // C-AARCH64-BAREMETAL-NOSYSROOT: "-cc1" "-triple" "aarch64-unknown-none-elf"
 // C-AARCH64-BAREMETAL-NOSYSROOT: "-internal-isystem" "{{.*}}/Inputs/basic_aarch64_gcc_tree/lib/gcc/aarch64-none-elf/8.2.1/../../../../aarch64-none-elf/include"
 // C-AARCH64-BAREMETAL-NOSYSROOT: "{{.*}}/Inputs/basic_aarch64_gcc_tree/lib/gcc/aarch64-none-elf/8.2.1/../../../../bin/aarch64-none-elf-ld"
-// C-AARCH64-BAREMETAL-NOSYSROOT: "{{.*}}.o" "-Bstatic" "-EL"
+// C-AARCH64-BAREMETAL-NOSYSROOT: "-Bstatic" "-EL"
 // C-AARCH64-BAREMETAL-NOSYSROOT: "{{.*}}/Inputs/basic_aarch64_gcc_tree/lib/gcc/aarch64-none-elf/8.2.1/../../../../aarch64-none-elf/lib/crt0.o"
 // C-AARCH64-BAREMETAL-NOSYSROOT: "{{.*}}/Inputs/basic_aarch64_gcc_tree/lib/gcc/aarch64-none-elf/8.2.1/crtbegin.o"
 // C-AARCH64-BAREMETAL-NOSYSROOT: "-L{{.*}}/Inputs/basic_aarch64_gcc_tree/lib/gcc/aarch64-none-elf/8.2.1"
 // C-AARCH64-BAREMETAL-NOSYSROOT: "-L{{.*}}/Inputs/basic_aarch64_gcc_tree/lib/gcc/aarch64-none-elf/8.2.1/../../../../aarch64-none-elf/lib"
-// C-AARCH64-BAREMETAL-NOSYSROOT: "--start-group" "-lgcc" "--as-needed" "-lgcc_s" "--no-as-needed" "-lc" "-lgloss" "--end-group"
+// C-AARCH64-BAREMETAL-NOSYSROOT: "{{.*}}.o" "--start-group" "-lgcc" "--as-needed" "-lgcc_s" "--no-as-needed" "-lc" "-lgloss" "--end-group"
 // C-AARCH64-BAREMETAL-NOSYSROOT: "{{.*}}/Inputs/basic_aarch64_gcc_tree/lib/gcc/aarch64-none-elf/8.2.1/crtend.o"
 
 // RUN: %clangxx -### %s -fuse-ld= \
@@ -53,12 +53,12 @@
 // CXX-AARCH64-BAREMETAL: "-internal-isystem" "{{.*}}/Inputs/basic_aarch64_gcc_tree/aarch64-none-elf/include/c++/8.2.1"
 // CXX-AARCH64-BAREMETAL: "-internal-isystem" "{{.*}}/Inputs/basic_aarch64_gcc_tree/aarch64-none-elf/include"
 // CXX-AARCH64-BAREMETAL: "{{.*}}/Inputs/basic_aarch64_gcc_tree/lib/gcc/aarch64-none-elf/8.2.1/../../../../bin/aarch64-none-elf-ld"
-// CXX-AARCH64-BAREMETAL: "{{.*}}.o" "-Bstatic" "-EL"
+// CXX-AARCH64-BAREMETAL: "-Bstatic" "-EL"
 // CXX-AARCH64-BAREMETAL: "{{.*}}/Inputs/basic_aarch64_gcc_tree/aarch64-none-elf/lib/crt0.o"
 // CXX-AARCH64-BAREMETAL: "{{.*}}/Inputs/basic_aarch64_gcc_tree/lib/gcc/aarch64-none-elf/8.2.1/crtbegin.o"
 // CXX-AARCH64-BAREMETAL: "-L{{.*}}/Inputs/basic_aarch64_gcc_tree/lib/gcc/aarch64-none-elf/8.2.1"
 // CXX-AARCH64-BAREMETAL: "-L{{.*}}/Inputs/basic_aarch64_gcc_tree/aarch64-none-elf/lib"
-// CXX-AARCH64-BAREMETAL: "-lstdc++" "-lm" "--start-group" "-lgcc_s" "-lgcc" "-lc" "-lgloss" "--end-group"
+// CXX-AARCH64-BAREMETAL: "{{.*}}.o" "-lstdc++" "-lm" "--start-group" "-lgcc_s" "-lgcc" "-lc" "-lgloss" "--end-group"
 // CXX-AARCH64-BAREMETAL: "{{.*}}/Inputs/basic_aarch64_gcc_tree/lib/gcc/aarch64-none-elf/8.2.1/crtend.o"
 
 // RUN: %clangxx -### %s -fuse-ld= \
@@ -72,12 +72,12 @@
 // CXX-AARCH64-BAREMETAL-NOSYSROOT: "-internal-isystem" "{{.*}}/Inputs/basic_aarch64_gcc_tree/lib/gcc/aarch64-none-elf/8.2.1/../../../../aarch64-none-elf/include/c++/8.2.1"
 // CXX-AARCH64-BAREMETAL-NOSYSROOT: "-internal-isystem" "{{.*}}/Inputs/basic_aarch64_gcc_tree/lib/gcc/aarch64-none-elf/8.2.1/../../../../aarch64-none-elf/include"
 // CXX-AARCH64-BAREMETAL-NOSYSROOT: "{{.*}}/Inputs/basic_aarch64_gcc_tree/lib/gcc/aarch64-none-elf/8.2.1/../../../../bin/aarch64-none-elf-ld"
-// CXX-AARCH64-BAREMETAL-NOSYSROOT: "{{.*}}.o" "-Bstatic" "-EL"
+// CXX-AARCH64-BAREMETAL-NOSYSROOT: "-Bstatic" "-EL"
 // CXX-AARCH64-BAREMETAL-NOSYSROOT: "{{.*}}/Inputs/basic_aarch64_gcc_tree/lib/gcc/aarch64-none-elf/8.2.1/../../../../aarch64-none-elf/lib/crt0.o"
 // CXX-AARCH64-BAREMETAL-NOSYSROOT: "{{.*}}/Inputs/basic_aarch64_gcc_tree/lib/gcc/aarch64-none-elf/8.2.1/crtbegin.o"
 // CXX-AARCH64-BAREMETAL-NOSYSROOT: "-L{{.*}}/Inputs/basic_aarch64_gcc_tree/lib/gcc/aarch64-none-elf/8.2.1"
 // CXX-AARCH64-BAREMETAL-NOSYSROOT: "-L{{.*}}/Inputs/basic_aarch64_gcc_tree/lib/gcc/aarch64-none-elf/8.2.1/../../../../aarch64-none-elf/lib"
-// CXX-AARCH64-BAREMETAL-NOSYSROOT: "-lstdc++" "-lm" "--start-group" "-lgcc_s" "-lgcc" "-lc" "-lgloss" "--end-group"
+// CXX-AARCH64-BAREMETAL-NOSYSROOT: "{{.*}}.o" "-lstdc++" "-lm" "--start-group" "-lgcc_s" "-lgcc" "-lc" "-lgloss" "--end-group"
 // CXX-AARCH64-BAREMETAL-NOSYSROOT: "{{.*}}/Inputs/basic_aarch64_gcc_tree/lib/gcc/aarch64-none-elf/8.2.1/crtend.o"
 
 // RUN: %clangxx -### %s -fuse-ld= \
@@ -90,12 +90,12 @@
 // CXX-AARCH64-BAREMETAL-LIBCXX: "-internal-isystem" "{{.*}}/Inputs/basic_aarch64_gcc_tree/aarch64-none-elf/include/c++/v1"
 // CXX-AARCH64-BAREMETAL-LIBCXX: "-internal-isystem" "{{.*}}/Inputs/basic_aarch64_gcc_tree/aarch64-none-elf/include"
 // CXX-AARCH64-BAREMETAL-LIBCXX: "{{.*}}/Inputs/basic_aarch64_gcc_tree/lib/gcc/aarch64-none-elf/8.2.1/../../../../bin/aarch64-none-elf-ld
-// CXX-AARCH64-BAREMETAL-LIBCXX: "{{.*}}.o" "-Bstatic" "-EL"
+// CXX-AARCH64-BAREMETAL-LIBCXX: "-Bstatic" "-EL"
 // CXX-AARCH64-BAREMETAL-LIBCXX: "{{.*}}/Inputs/basic_aarch64_gcc_tree/aarch64-none-elf/lib/crt0.o"
 // CXX-AARCH64-BAREMETAL-LIBCXX: "{{.*}}/Inputs/basic_aarch64_gcc_tree/lib/gcc/aarch64-none-elf/8.2.1/crtbegin.o"
 // CXX-AARCH64-BAREMETAL-LIBCXX: "-L{{.*}}/Inputs/basic_aarch64_gcc_tree/lib/gcc/aarch64-none-elf/8.2.1"
 // CXX-AARCH64-BAREMETAL-LIBCXX: "-L{{.*}}/Inputs/basic_aarch64_gcc_tree/aarch64-none-elf/lib"
-// CXX-AARCH64-BAREMETAL-LIBCXX: "-lc++" "-lm" "--start-group" "-lgcc_s" "-lgcc" "-lc" "-lgloss" "--end-group"
+// CXX-AARCH64-BAREMETAL-LIBCXX: "{{.*}}.o" "-lc++" "-lm" "--start-group" "-lgcc_s" "-lgcc" "-lc" "-lgloss" "--end-group"
 // CXX-AARCH64-BAREMETAL-LIBCXX: "{{.*}}/Inputs/basic_aarch64_gcc_tree/lib/gcc/aarch64-none-elf/8.2.1/crtend.o"
 
 // RUN: %clangxx -### %s -fuse-ld= \
@@ -107,12 +107,12 @@
 // CXX-AARCH64-BAREMETAL-NOSYSROOT-LIBCXX: "-internal-isystem" "{{.*}}/Inputs/basic_aarch64_gcc_tree/lib/gcc/aarch64-none-elf/8.2.1/../../../../aarch64-none-elf/include/c++/v1"
 // CXX-AARCH64-BAREMETAL-NOSYSROOT-LIBCXX: "-internal-isystem" "{{.*}}/Inputs/basic_aarch64_gcc_tree/lib/gcc/aarch64-none-elf/8.2.1/../../../../aarch64-none-elf/include"
 // CXX-AARCH64-BAREMETAL-NOSYSROOT-LIBCXX: "{{.*}}/Inputs/basic_aarch64_gcc_tree/lib/gcc/aarch64-none-elf/8.2.1/../../../../bin/aarch64-none-elf-ld"
-// CXX-AARCH64-BAREMETAL-NOSYSROOT-LIBCXX: "{{.*}}.o" "-Bstatic" "-EL"
+// CXX-AARCH64-BAREMETAL-NOSYSROOT-LIBCXX: "-Bstatic" "-EL"
 // CXX-AARCH64-BAREMETAL-NOSYSROOT-LIBCXX: "{{.*}}/Inputs/basic_aarch64_gcc_tree/lib/gcc/aarch64-none-elf/8.2.1/../../../../aarch64-none-elf/lib/crt0.o"
 // CXX-AARCH64-BAREMETAL-NOSYSROOT-LIBCXX: "{{.*}}/Inputs/basic_aarch64_gcc_tree/lib/gcc/aarch64-none-elf/8.2.1/crtbegin.o"
 // CXX-AARCH64-BAREMETAL-NOSYSROOT-LIBCXX: "-L{{.*}}/Inputs/basic_aarch64_gcc_tree/lib/gcc/aarch64-none-elf/8.2.1"
 // CXX-AARCH64-BAREMETAL-NOSYSROOT-LIBCXX: "-L{{.*}}/Inputs/basic_aarch64_gcc_tree/lib/gcc/aarch64-none-elf/8.2.1/../../../../aarch64-none-elf/lib"
-// CXX-AARCH64-BAREMETAL-NOSYSROOT-LIBCXX: "-lc++" "-lm" "--start-group" "-lgcc_s" "-lgcc" "-lc" "-lgloss" "--end-group"
+// CXX-AARCH64-BAREMETAL-NOSYSROOT-LIBCXX: "{{.*}}.o" "-lc++" "-lm" "--start-group" "-lgcc_s" "-lgcc" "-lc" "-lgloss" "--end-group"
 // CXX-AARCH64-BAREMETAL-NOSYSROOT-LIBCXX: "{{.*}}/Inputs/basic_aarch64_gcc_tree/lib/gcc/aarch64-none-elf/8.2.1/crtend.o"
 
 // RUN: %clang -### %s -fuse-ld= \
diff --git a/clang/test/Driver/arm-toolchain-extra.c b/clang/test/Driver/arm-toolchain-extra.c
index 2adf4ab698ba0..a04b41c13e95e 100644
--- a/clang/test/Driver/arm-toolchain-extra.c
+++ b/clang/test/Driver/arm-toolchain-extra.c
@@ -31,6 +31,6 @@
 // C-ARM-BAREMETAL-NOGCC: "{{.*}}/arm-nogcc/bin/../armv6m-none-eabi/lib/crt0.o"
 // C-ARM-BAREMETAL-NOGCC: "{{.*}}/arm-nogcc/{{.*}}/armv6m-none-eabi/lib/crtbegin.o"
 // C-ARM-BAREMETAL-NOGCC: "{{.*}}/arm-nogcc/bin/../armv6m-none-eabi/lib"
-// C-ARM-BAREMETAL-NOGCC: "--start-group" "-lgcc" "--as-needed" "-lgcc_s" "--no-as-needed" "-lc" "-lgloss" "--end-group"
+// C-ARM-BAREMETAL-NOGCC: "{{.*}}.o" "--start-group" "-lgcc" "--as-needed" "-lgcc_s" "--no-as-needed" "-lc" "-lgloss" "--end-group"
 // C-ARM-BAREMETAL-NOGCC: "{{.*}}/arm-nogcc/{{.*}}/armv6m-none-eabi/lib/crtend.o"
 
diff --git a/clang/test/Driver/arm-toolchain.c b/clang/test/Driver/arm-toolchain.c
index 6ee1b29497f97..d89f77b86c23b 100644
--- a/clang/test/Driver/arm-toolchain.c
+++ b/clang/test/Driver/arm-toolchain.c
@@ -17,12 +17,12 @@
 // C-ARM-BAREMETAL: "-isysroot" "{{.*}}Inputs/basic_arm_gcc_tree/armv6m-none-eabi"
 // C-ARM-BAREMETAL: "-internal-isystem" "{{.*}}Inputs/basic_arm_gcc_tree/armv6m-none-eabi/include"
 // C-ARM-BAREMETAL: "{{.*}}/Inputs/basic_arm_gcc_tree/lib/gcc/armv6m-none-eabi/8.2.1/../../../../bin/armv6m-none-eabi-ld"
-// C-ARM-BAREMETAL: "{{.*}}.o" "-Bstatic" "-EL"
+// C-ARM-BAREMETAL: "-Bstatic" "-EL"
 // C-ARM-BAREMETAL: "{{.*}}/Inputs/basic_arm_gcc_tree/armv6m-none-eabi/lib/crt0.o"
 // C-ARM-BAREMETAL: "{{.*}}/Inputs/basic_arm_gcc_tree/lib/gcc/armv6m-none-eabi/8.2.1/crtbegin.o"
 // C-ARM-BAREMETAL: "-L{{.*}}/Inputs/basic_arm_gcc_tree/lib/gcc/armv6m-none-eabi/8.2.1"
 // C-ARM-BAREMETAL: "-L{{.*}}/Inputs/basic_arm_gcc_tree/armv6m-none-eabi/lib"
-// C-ARM-BAREMETAL: "--start-group" "-lgcc" "--as-needed" "-lgcc_s" "--no-as-needed" "-lc" "-lgloss" "--end-group"
+// C-ARM-BAREMETAL: "{{.*}}.o" "--start-group" "-lgcc" "--as-needed" "-lgcc_s" "--no-as-needed" "-lc" "-lgloss" "--end-group"
 // C-ARM-BAREMETAL: "{{.*}}/Inputs/basic_arm_gcc_tree/lib/gcc/armv6m-none-eabi/8.2.1/crtend.o"
 
 // RUN: %clang -### %s -fuse-ld= \
@@ -34,12 +34,12 @@
 // C-ARM-BAREMETAL-NOSYSROOT: "-cc1" "-triple" "thumbv6m-unknown-none-eabi"
 // C-ARM-BAREMETAL-NOSYSROOT: "-internal-isystem" "{{.*}}/Inputs/basic_arm_gcc_tree/lib/gcc/armv6m-none-eabi/8.2.1/../../../../armv6m-none-eabi/include"
 // C-ARM-BAREMETAL-NOSYSROOT: "{{.*}}/Inputs/basic_arm_gcc_tree/lib/gcc/armv6m-none-eabi/8.2.1/../../../../bin/armv6m-none-eabi-ld"
-// C-ARM-BAREMETAL-NOSYSROOT: "{{.*}}.o" "-Bstatic" "-EL"
+// C-ARM-BAREMETAL-NOSYSROOT: "-Bstatic" "-EL"
 // C-ARM-BAREMETAL-NOSYSROOT: "{{.*}}/Inputs/basic_arm_gcc_tree/lib/gcc/armv6m-none-eabi/8.2.1/../../../../armv6m-none-eabi/lib/crt0.o"
 // C-ARM-BAREMETAL-NOSYSROOT: "{{.*}}/Inputs/basic_arm_gcc_tree/lib/gcc/armv6m-none-eabi/8.2.1/crtbegin.o"
 // C-ARM-BAREMETAL-NOSYSROOT: "-L{{.*}}/Inputs/basic_arm_gcc_tree/lib/gcc/armv6m-none-eabi/8.2.1"
 // C-ARM-BAREMETAL-NOSYSROOT: "-L{{.*}}/Inputs/basic_arm_gcc_tree/lib/gcc/armv6m-none-eabi/8.2.1/../../../../armv6m-none-eabi/lib"
-// C-ARM-BAREMETAL-NOSYSROOT: "--start-group" "-lgcc" "--as-needed" "-lgcc_s" "--no-as-needed" "-lc" "-lgloss" "--end-group"
+// C-ARM-BAREMETAL-NOSYSROOT: "{{.*}}.o" "--start-group" "-lgcc" "--as-needed" "-lgcc_s" "--no-as-needed" "-lc" "-lgloss" "--end-group"
 // C-ARM-BAREMETAL-NOSYSROOT: "{{.*}}/Inputs/basic_arm_gcc_tree/lib/gcc/armv6m-none-eabi/8.2.1/crtend.o"
 
 // RUN: %clangxx -### %s -fuse-ld= \
@@ -54,12 +54,12 @@
 // CXX-ARM-BAREMETAL: "-internal-isystem" "{{.*}}/Inputs/basic_arm_gcc_tree/armv6m-none-eabi/include/c++/8.2.1"
 // CXX-ARM-BAREMETAL: "-internal-isystem" "{{.*}}/Inputs/basic_arm_gcc_tree/armv6m-none-eabi/include"
 // CXX-ARM-BAREMETAL: "{{.*}}/Inputs/basic_arm_gcc_tree/lib/gcc/armv6m-none-eabi/8.2.1/../../../../bin/armv6m-none-eabi-ld"
-// CXX-ARM-BAREMETAL: "{{.*}}.o" "-Bstatic" "-EL"
+// CXX-ARM-BAREMETAL: "-Bstatic" "-EL"
 // CXX-ARM-BAREMETAL: "{{.*}}/Inputs/basic_arm_gcc_tree/armv6m-none-eabi/lib/crt0.o"
 // CXX-ARM-BAREMETAL: "{{.*}}/Inputs/basic_arm_gcc_tree/lib/gcc/armv6m-none-eabi/8.2.1/crtbegin.o"
 // CXX-ARM-BAREMETAL: "-L{{.*}}/Inputs/basic_arm_gcc_tree/lib/gcc/armv6m-none-eabi/8.2.1"
 // CXX-ARM-BAREMETAL: "-L{{.*}}/Inputs/basic_arm_gcc_tree/armv6m-none-eabi/lib"
-// CXX-ARM-BAREMETAL: "-lstdc++" "-lm" "--start-group" "-lgcc_s" "-lgcc" "-lc" "-lgloss" "--end-group"
+// CXX-ARM-BAREMETAL: "{{.*}}.o" "-lstdc++" "-lm" "--start-group" "-lgcc_s" "-lgcc" "-lc" "-lgloss" "--end-group"
 // CXX-ARM-BAREMETAL: "{{.*}}/Inputs/basic_arm_gcc_tree/lib/gcc/armv6m-none-eabi/8.2.1/crtend.o"
 
 
@@ -74,12 +74,12 @@
 // CXX-ARM-BAREMETAL-NOSYSROOT: "-internal-isystem" "{{.*}}/Inputs/basic_arm_gcc_tree/lib/gcc/armv6m-none-eabi/8.2.1/../../../../armv6m-none-eabi/include/c++/8.2.1"
 // CXX-ARM-BAREMETAL-NOSYSROOT: "-internal-isystem" "{{.*}}/Inputs/basic_arm_gcc_tree/lib/gcc/armv6m-none-eabi/8.2.1/../../../../armv6m-none-eabi/include"
 // CXX-ARM-BAREMETAL-NOSYSROOT: "{{.*}}/Inputs/basic_arm_gcc_tree/lib/gcc/armv6m-none-eabi/8.2.1/../../../../bin/armv6m-none-eabi-ld"
-// CXX-ARM-BAREMETAL-NOSYSROOT: "{{.*}}.o" "-Bstatic" "-EL"
+// CXX-ARM-BAREMETAL-NOSYSROOT: "-Bstatic" "-EL"
 // CXX-ARM-BAREMETAL-NOSYSROOT: "{{.*}}/Inputs/basic_arm_gcc_tree/lib/gcc/armv6m-none-eabi/8.2.1/../../../../armv6m-none-eabi/lib/crt0.o"
 // CXX-ARM-BAREMETAL-NOSYSROOT: "{{.*}}/Inputs/basic_arm_gcc_tree/lib/gcc/armv6m-none-eabi/8.2.1/crtbegin.o"
 // CXX-ARM-BAREMETAL-NOSYSROOT: "-L{{.*}}/Inputs/basic_arm_gcc_tree/lib/gcc/armv6m-none-eabi/8.2.1"
 // CXX-ARM-BAREMETAL-NOSYSROOT: "-L{{.*}}/Inputs/basic_arm_gcc_tree/lib/gcc/armv6m-none-eabi/8.2.1/../../../../armv6m-none-eabi/lib"
-// CXX-ARM-BAREMETAL-NOSYSROOT: "-lstdc++" "-lm" "--start-group" "-lgcc_s" "-lgcc" "-lc" "-lgloss" "--end-group"
+// CXX-ARM-BAREMETAL-NOSYSROOT: "{{.*}}.o" "-lstdc++" "-lm" "--start-group" "-lgcc_s" "-lgcc" "-lc" "-lgloss" "--end-group"
 // CXX-ARM-BAREMETAL-NOSYSROOT: "{{.*}}/Inputs/basic_arm_gcc_tree/lib/gcc/armv6m-none-eabi/8.2.1/crtend.o"
 
 // RUN: %clangxx -### %s -fuse-ld= \
@@ -92,12 +92,12 @@
 // CXX-ARM-BAREMETAL-LIBCXX: "-internal-isystem" "{{.*}}/Inputs/basic_arm_gcc_tree/armv6m-none-eabi/include/c++/v1"
 // CXX-ARM-BAREMETAL-LIBCXX: "-internal-isystem" "{{.*}}/Inputs/basic_arm_gcc_tree/armv6m-none-eabi/include"
 // CXX-ARM-BAREMETAL-LIBCXX: "{{.*}}/Inputs/basic_arm_gcc_tree/lib/gcc/armv6m-none-eabi/8.2.1/../../../../bin/armv6m-none-eabi-ld"
-// CXX-ARM-BAREMETAL-LIBCXX: "{{.*}}.o" "-Bstatic" "-EL"
+// CXX-ARM-BAREMETAL-LIBCXX: "-Bstatic" "-EL"
 // CXX-ARM-BAREMETAL-LIBCXX: "{{.*}}/Inputs/basic_arm_gcc_tree/armv6m-none-eabi/lib/crt0.o"
 // CXX-ARM-BAREMETAL-LIBCXX: "{{.*}}/Inputs/basic_arm_gcc_tree/lib/gcc/armv6m-none-eabi/8.2.1/crtbegin.o"
 // CXX-ARM-BAREMETAL-LIBCXX: "-L{{.*}}/Inputs/basic_arm_gcc_tree/lib/gcc/armv6m-none-eabi/8.2.1"
 // CXX-ARM-BAREMETAL-LIBCXX: "-L{{.*}}/Inputs/basic_arm_gcc_tree/armv6m-none-eabi/lib"
-// CXX-ARM-BAREMETAL-LIBCXX: "-lc++" "-lm" "--start-group" "-lgcc_s" "-lgcc" "-lc" "-lgloss" "--end-group"
+// CXX-ARM-BAREMETAL-LIBCXX: "{{.*}}.o" "-lc++" "-lm" "--start-group" "-lgcc_s" "-lgcc" "-lc" "-lgloss" "--end-group"
 // CXX-ARM-BAREMETAL-LIBCXX: "{{.*}}/Inputs/basic_arm_gcc_tree/lib/gcc/armv6m-none-eabi/8.2.1/crtend.o"
 
 // RUN: %clangxx -### %s -fuse-ld= \
@@ -109,12 +109,12 @@
 // CXX-ARM-BAREMETAL-NOSYSROOT-LIBCXX: "-internal-isystem" "{{.*}}/Inputs/basic_arm_gcc_tree/lib/gcc/armv6m-none-eabi/8.2.1/../../../../armv6m-none-eabi/include/c++/v1"
 // CXX-ARM-BAREMETAL-NOSYSROOT-LIBCXX: "-internal-isystem" "{{.*}}/Inputs/basic_arm_gcc_tree/lib/gcc/armv6m-none-eabi/8.2.1/../../../../armv6m-none-eabi/include"
 // CXX-ARM-BAREMETAL-NOSYSROOT-LIBCXX: "{{.*}}/Inputs/basic_arm_gcc_tree/lib/gcc/armv6m-none-eabi/8.2.1/../../../../bin/armv6m-none-eabi-ld"
-// CXX-ARM-BAREMETAL-NOSYSROOT-LIBCXX: "{{.*}}.o" "-Bstatic" "-EL"
+// CXX-ARM-BAREMETAL-NOSYSROOT-LIBCXX: "-Bstatic" "-EL"
 // CXX-ARM-BAREMETAL-NOSYSROOT-LIBCXX: "{{.*}}/Inputs/basic_arm_gcc_tree/lib/gcc/armv6m-none-eabi/8.2.1/../../../../armv6m-none-eabi/lib/crt0.o"
 // CXX-ARM-BAREMETAL-NOSYSROOT-LIBCXX: "{{.*}}/Inputs/basic_arm_gcc_tree/lib/gcc/armv6m-none-eabi/8.2.1/crtbegin.o"
 // CXX-ARM-BAREMETAL-NOSYSROOT-LIBCXX: "-L{{.*}}/Inputs/basic_arm_gcc_tree/lib/gcc/armv6m-none-eabi/8.2.1"
 // CXX-ARM-BAREMETAL-NOSYSROOT-LIBCXX: "-L{{.*}}/Inputs/basic_arm_gcc_tree/lib/gcc/armv6m-none-eabi/8.2.1/../....
[truncated]

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MaskRay commented Mar 25, 2025

The linker job in BareMetal toolchain object will be used by gnuld and lld both.

GNU ld instead of gnuld.

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Base automatically changed from users/quic-garvgupt/linker_job to main June 17, 2025 17:19
@quic-garvgupt
[Driver] Fix link order of BareMetal toolchain object
fa8aad1 
The linker job in BareMetal toolchain object will be used by gnuld and lld both.
However, gnuld process the arguments in the order in which they appear on command
line, whereas there is no such restriction with lld.

The previous order was:
LibraryPaths -> Libraries -> LTOOptions -> LinkerInputs
The new iorder is:
LibraryPaths -> LTOOptions -> LinkerInputs -> Libraries

LTO options need to be added before adding any linker inputs because file format
after compile stage during LTO is bitcode which gnuld natively cannot process.
Hence iwill need to pass appropriate plugins before adding any bitcode file on the
command line.

Object files that are getting linked need to be passed before processing any
libraries so that gnuld can appropriately do symbol resolution for the symbols
for which no definition is provided through user code.

Similar link order is also followed by other linker jobs for gnuld such as in
gnutools::Linker in Gnu.cpp

This is the 3rd patch in the series of patches of merging RISCVToolchain into
BareMetal toolchain object.

RFC:
https://discourse.llvm.org/t/merging-riscvtoolchain-and-baremetal-toolchains/75524

Change-Id: I0e68e403c08b5687cc3346e833981f7b9f3819c4
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@quic-garvgupt quic-garvgupt merged commit 31523de into main Jun 17, 2025
7 checks passed
@quic-garvgupt quic-garvgupt deleted the users/quic-garvgupt/link_order branch June 17, 2025 18:13
@mysterymath mysterymath mentioned this pull request Jun 17, 2025
Merged
mysterymath added a commit that referenced this pull request Jun 17, 2025
@mysterymath
Revert stack "[Driver] Add support for GCC installation detection in … (
ecfb8fe 
#144603)

…Baremetal toolchain (#121829)"

This reverts the following stack of commits, due to them breaking the
Fuchsia toolchain and corresponding LLVM buildbot.

Revert "[Driver] Fix Arm/AArch64 Link Argument tests (#144582)" This
reverts commit a79186c.

Revert "[Driver] Add option to force undefined symbols during linking in
BareMetal toolchain object. (#132807)" This reverts commit
9cb7545.

Revert "[Driver] Fix link order of BareMetal toolchain object (#132806)"
This reverts commit 31523de.

Revert "[Driver] Add support for crtbegin.o, crtend.o and libgloss lib
to BareMetal toolchain object (#121830)" This reverts commit
ec230aa.

Revert "[Driver] Add support for GCC installation detection in Baremetal
toolchain (#121829)" This reverts commit
eb31c42.
mysterymath added a commit to mysterymath/llvm-project that referenced this pull request Jun 17, 2025
@mysterymath
Revert stack "[Driver] Add support for GCC installation detection in …
73be680 
…Baremetal toolchain (llvm#121829)"

This reverts the following stack of commits, due to them breaking the
Fuchsia toolchain and corresponding LLVM buildbot.

Revert "[Driver] Fix Arm/AArch64 Link Argument tests (llvm#144582)"
This reverts commit a79186c.

Revert "[Driver] Add option to force undefined symbols during linking in BareMetal toolchain object. (llvm#132807)"
This reverts commit 9cb7545.

Revert "[Driver] Fix link order of BareMetal toolchain object (llvm#132806)"
This reverts commit 31523de.

Revert "[Driver] Add support for crtbegin.o, crtend.o and libgloss lib to BareMetal toolchain object (llvm#121830)"
This reverts commit ec230aa.

Revert "[Driver] Add support for GCC installation detection in Baremetal toolchain (llvm#121829)"
This reverts commit eb31c42.
fschlimb pushed a commit to fschlimb/llvm-project that referenced this pull request Jun 18, 2025
@quic-garvgupt @fschlimb
[Driver] Fix link order of BareMetal toolchain object (llvm#132806)
d93e6f5 
The linker job in BareMetal toolchain object will be used by GNU ld and
lld both.
However, gnuld process the arguments in the order in which they appear
on command
line, whereas there is no such restriction with lld.

The previous order was:
LibraryPaths -> Libraries -> LTOOptions -> LinkerInputs
The new order is:
LibraryPaths -> LTOOptions -> LinkerInputs -> Libraries

LTO options need to be added before adding any linker inputs because
file format
after compile stage during LTO is bitcode which gnuld natively cannot
process.
Hence will need to pass appropriate plugins before adding any bitcode
file on the
command line.

Object files that are getting linked need to be passed before processing
any
libraries so that gnuld can appropriately do symbol resolution for the
symbols
for which no definition is provided through user code.

Similar link order is also followed by other linker jobs for gnuld such
as in
gnutools::Linker in Gnu.cpp

This is the 3rd patch in the series of patches of merging RISCVToolchain
into
BareMetal toolchain object.

RFC:

https://discourse.llvm.org/t/merging-riscvtoolchain-and-baremetal-toolchains/75524
fschlimb pushed a commit to fschlimb/llvm-project that referenced this pull request Jun 18, 2025
@mysterymath @fschlimb
Revert stack "[Driver] Add support for GCC installation detection in … (
44ea7c3 
llvm#144603)

…Baremetal toolchain (llvm#121829)"

This reverts the following stack of commits, due to them breaking the
Fuchsia toolchain and corresponding LLVM buildbot.

Revert "[Driver] Fix Arm/AArch64 Link Argument tests (llvm#144582)" This
reverts commit a79186c.

Revert "[Driver] Add option to force undefined symbols during linking in
BareMetal toolchain object. (llvm#132807)" This reverts commit
9cb7545.

Revert "[Driver] Fix link order of BareMetal toolchain object (llvm#132806)"
This reverts commit 31523de.

Revert "[Driver] Add support for crtbegin.o, crtend.o and libgloss lib
to BareMetal toolchain object (llvm#121830)" This reverts commit
ec230aa.

Revert "[Driver] Add support for GCC installation detection in Baremetal
toolchain (llvm#121829)" This reverts commit
eb31c42.
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