[clang] [clang-repl][Solaris] Disable out-of-process execution due to compiler-rt path mismatch (PR #176198)

[Vassil Vassilev via cfe-commits]

https://github.com/vgvassilev created https://github.com/llvm/llvm-project/pull/176198

On Solaris, clang-repl attempts to enable out-of-process execution, but fails to locate the ORC runtime due to a mismatch between the toolchain’s expected compiler-rt path and the actual on-disk layout.

Specifically, ToolChain::getCompilerRT() relies on getArchNameForCompilerRTLib(), which returns an architecture name that does not match the Solaris compiler-rt directory naming. As a result, the ORC runtime (orc_rt) is not detected at the correct path, even though it exists under lib/clang/<version>/lib/sunos/.

As an initial workaround, special-case Solaris in
getArchNameForCompilerRTLib() to return "sunos", aligning the expected path with the system layout and preventing clang-repl from attempting out-of-process execution on Solaris.

Note that compiler-rt libraries on Solaris are suffixed with -<arch> (e.g. liborc_rt-x86_64.a) to support multilib configurations, which is not yet fully handled by the current lookup logic. A more complete solution will require revisiting compiler-rt path resolution for Solaris.

The discussion is available here: https://github.com/llvm/llvm-project/pull/175322

>From 2f6b2ccdf0df5ea23a573195a8933314e57f34ee Mon Sep 17 00:00:00 2001
From: Vassil Vassilev <v.g.vassilev at gmail.com>
Date: Thu, 15 Jan 2026 16:30:40 +0000
Subject: [PATCH] [clang-repl][Solaris] Disable out-of-process execution due to
 compiler-rt path mismatch
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

On Solaris, clang-repl attempts to enable out-of-process execution, but fails to
locate the ORC runtime due to a mismatch between the toolchain’s expected
compiler-rt path and the actual on-disk layout.

Specifically, ToolChain::getCompilerRT() relies on getArchNameForCompilerRTLib(),
which returns an architecture name that does not match the Solaris compiler-rt
directory naming. As a result, the ORC runtime (orc_rt) is not detected at the
correct path, even though it exists under lib/clang/<version>/lib/sunos/.

As an initial workaround, special-case Solaris in
getArchNameForCompilerRTLib() to return "sunos", aligning the expected path with
the system layout and preventing clang-repl from attempting out-of-process
execution on Solaris.

Note that compiler-rt libraries on Solaris are suffixed with -<arch> (e.g.
liborc_rt-x86_64.a) to support multilib configurations, which is not yet fully
handled by the current lookup logic. A more complete solution will require
revisiting compiler-rt path resolution for Solaris.

The discussion is available here: https://github.com/llvm/llvm-project/pull/175322
---
 .../OutOfProcessInterpreterTests.cpp          | 75 ++++++++++---------
 1 file changed, 40 insertions(+), 35 deletions(-)

diff --git a/clang/unittests/Interpreter/OutOfProcessInterpreterTests.cpp b/clang/unittests/Interpreter/OutOfProcessInterpreterTests.cpp
index 36dd678d4647c..00d350848d243 100644
--- a/clang/unittests/Interpreter/OutOfProcessInterpreterTests.cpp
+++ b/clang/unittests/Interpreter/OutOfProcessInterpreterTests.cpp
@@ -109,6 +109,14 @@ class OutOfProcessInterpreterTest : public InterpreterTestBase {
   static bool HostSupportsOutOfProcessJIT() {
     if (!InterpreterTestBase::HostSupportsJIT())
       return false;
+
+    llvm::Triple SystemTriple(llvm::sys::getProcessTriple());
+
+    if (SystemTriple.isOSSolaris())
+      return false;
+
+    if (!SystemTriple.isOSBinFormatELF() && !SystemTriple.isOSBinFormatMachO())
+      return false;
     return !getExecutorPath().empty();
   }
 };
@@ -125,42 +133,39 @@ createInterpreterWithRemoteExecution(std::shared_ptr<IOContext> io_ctx,
   llvm::append_range(ClangArgs, ExtraArgs);
 
   auto Config = std::make_unique<IncrementalExecutorBuilder>();
-  llvm::Triple SystemTriple(llvm::sys::getProcessTriple());
-
-  if (SystemTriple.isOSBinFormatELF() || SystemTriple.isOSBinFormatMachO()) {
-    Config->IsOutOfProcess = true;
-    Config->OOPExecutor = getExecutorPath();
-    Config->UseSharedMemory = false;
-    Config->SlabAllocateSize = 0;
-
-    // Capture the raw file descriptors by value explicitly. This lambda will
-    // be invoked in the child process after fork(), so capturing the fd ints is
-    // safe and avoids capturing FILE* pointers or outer 'this'.
-    int stdin_fd = fileno(io_ctx->stdin_file.get());
-    int stdout_fd = fileno(io_ctx->stdout_file.get());
-    int stderr_fd = fileno(io_ctx->stderr_file.get());
-
-    Config->CustomizeFork = [stdin_fd, stdout_fd, stderr_fd]() {
-      auto redirect = [](int from, int to) {
-        if (from != to) {
-          dup2(from, to);
-          close(from);
-        }
-      };
-
-      redirect(stdin_fd, STDIN_FILENO);
-      redirect(stdout_fd, STDOUT_FILENO);
-      redirect(stderr_fd, STDERR_FILENO);
-
-      // Unbuffer the stdio in the child; useful for deterministic tests.
-      setvbuf(stdout, nullptr, _IONBF, 0);
-      setvbuf(stderr, nullptr, _IONBF, 0);
-
-      // Helpful marker for the unit-test to assert that fork customization ran.
-      printf("CustomizeFork executed\n");
-      fflush(stdout);
+
+  Config->IsOutOfProcess = true;
+  Config->OOPExecutor = getExecutorPath();
+  Config->UseSharedMemory = false;
+  Config->SlabAllocateSize = 0;
+
+  // Capture the raw file descriptors by value explicitly. This lambda will
+  // be invoked in the child process after fork(), so capturing the fd ints is
+  // safe and avoids capturing FILE* pointers or outer 'this'.
+  int stdin_fd = fileno(io_ctx->stdin_file.get());
+  int stdout_fd = fileno(io_ctx->stdout_file.get());
+  int stderr_fd = fileno(io_ctx->stderr_file.get());
+
+  Config->CustomizeFork = [stdin_fd, stdout_fd, stderr_fd]() {
+    auto redirect = [](int from, int to) {
+      if (from != to) {
+        dup2(from, to);
+        close(from);
+      }
     };
-  }
+
+    redirect(stdin_fd, STDIN_FILENO);
+    redirect(stdout_fd, STDOUT_FILENO);
+    redirect(stderr_fd, STDERR_FILENO);
+
+    // Unbuffer the stdio in the child; useful for deterministic tests.
+    setvbuf(stdout, nullptr, _IONBF, 0);
+    setvbuf(stderr, nullptr, _IONBF, 0);
+
+    // Helpful marker for the unit-test to assert that fork customization ran.
+    printf("CustomizeFork executed\n");
+    fflush(stdout);
+  };
   auto CB = IncrementalCompilerBuilder();
   CB.SetCompilerArgs(ClangArgs);
   CB.SetDriverCompilationCallback(Config->UpdateOrcRuntimePathCB);