[Clang-Repl] Add custom function as lambda in launchExecutor and fetch PID of launched executor

[kr-2003]

[EDITED on 9 Jul 2025]
This PR introduces:

1. Custom lambda function in launchExecutor.
2. Fetching PID of the launched out-of-process(OOP) JIT executor.

This PR introduces:

1. Pipe based redirection for stdin, stdout and stderr for out-of-process(OOP) JIT execution.
2. Fetching PID of the launched out-of-process(OOP) JIT executor.

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Author: Abhinav Kumar (kr-2003)

Changes

This PR introduces:

1. Pipe based redirection for stdin, stdout and stderr for out-of-process(OOP) JIT execution.
2. Fetching PID of the launched out-of-process(OOP) JIT executor.

---

Full diff: https://github.com/llvm/llvm-project/pull/147478.diff

2 Files Affected:

• (modified) clang/include/clang/Interpreter/RemoteJITUtils.h (+12-1)
• (modified) clang/lib/Interpreter/RemoteJITUtils.cpp (+33-1)

diff --git a/clang/include/clang/Interpreter/RemoteJITUtils.h b/clang/include/clang/Interpreter/RemoteJITUtils.h index 8705a3b1f669d..8fc520380dbb5 100644 --- a/clang/include/clang/Interpreter/RemoteJITUtils.h +++ b/clang/include/clang/Interpreter/RemoteJITUtils.h @@ -23,10 +23,13 @@ #include <cstdint> #include <memory> #include <string> +#include <unistd.h> llvm::Expected<std::unique_ptr<llvm::orc::SimpleRemoteEPC>> launchExecutor(llvm::StringRef ExecutablePath, bool UseSharedMemory, - llvm::StringRef SlabAllocateSizeString); + llvm::StringRef SlabAllocateSizeString, + int stdin_fd = STDIN_FILENO, int stdout_fd = STDOUT_FILENO, + int stderr_fd = STDERR_FILENO); /// Create a JITLinkExecutor that connects to the given network address /// through a TCP socket. A valid NetworkAddress provides hostname and port, @@ -35,4 +38,12 @@ llvm::Expected<std::unique_ptr<llvm::orc::SimpleRemoteEPC>> connectTCPSocket(llvm::StringRef NetworkAddress, bool UseSharedMemory, llvm::StringRef SlabAllocateSizeString); + +/// Returns PID of last launched executor. +pid_t getLastLaunchedExecutorPID(); + +/// Returns PID of nth launched executor. +/// 1-based indexing. +pid_t getNthLaunchedExecutorPID(int n); + #endif // LLVM_CLANG_INTERPRETER_REMOTEJITUTILS_H diff --git a/clang/lib/Interpreter/RemoteJITUtils.cpp b/clang/lib/Interpreter/RemoteJITUtils.cpp index c0e663b764785..1b414dcd5ec25 100644 --- a/clang/lib/Interpreter/RemoteJITUtils.cpp +++ b/clang/lib/Interpreter/RemoteJITUtils.cpp @@ -33,6 +33,8 @@ using namespace llvm; using namespace llvm::orc; +static std::vector<pid_t> LaunchedExecutorPID; + Expected<uint64_t> getSlabAllocSize(StringRef SizeString) { SizeString = SizeString.trim(); @@ -91,7 +93,8 @@ createSharedMemoryManager(SimpleRemoteEPC &SREPC, Expected<std::unique_ptr<SimpleRemoteEPC>> launchExecutor(StringRef ExecutablePath, bool UseSharedMemory, - llvm::StringRef SlabAllocateSizeString) { + llvm::StringRef SlabAllocateSizeString, int stdin_fd, + int stdout_fd, int stderr_fd) { #ifndef LLVM_ON_UNIX // FIXME: Add support for Windows. return make_error<StringError>("-" + ExecutablePath + @@ -134,6 +137,23 @@ launchExecutor(StringRef ExecutablePath, bool UseSharedMemory, close(ToExecutor[WriteEnd]); close(FromExecutor[ReadEnd]); + if (stdin_fd != STDIN_FILENO) { + dup2(stdin_fd, STDIN_FILENO); + close(stdin_fd); + } + + if (stdout_fd != STDOUT_FILENO) { + dup2(stdout_fd, STDOUT_FILENO); + close(stdout_fd); + setvbuf(stdout, NULL, _IONBF, 0); + } + + if (stderr_fd != STDERR_FILENO) { + dup2(stderr_fd, STDERR_FILENO); + close(stderr_fd); + setvbuf(stderr, NULL, _IONBF, 0); + } + // Execute the child process. std::unique_ptr<char[]> ExecutorPath, FDSpecifier; { @@ -155,6 +175,8 @@ launchExecutor(StringRef ExecutablePath, bool UseSharedMemory, << ExecutorPath.get() << "\"\n"; exit(1); } + } else { + LaunchedExecutorPID.push_back(ChildPID); } // else we're the parent... @@ -265,3 +287,13 @@ connectTCPSocket(StringRef NetworkAddress, bool UseSharedMemory, std::move(S), *SockFD, *SockFD); #endif } + +pid_t getLastLaunchedExecutorPID() {  + if(!LaunchedExecutorPID.size()) return -1; + return LaunchedExecutorPID.back();  +} + +pid_t getNthLaunchedExecutorPID(int n) {  + if (n - 1 < 0 || n - 1 >= static_cast<int>(LaunchedExecutorPID.size())) return -1; + return LaunchedExecutorPID.at(n - 1);  +} 

[github-actions]

✅ With the latest revision this PR passed the C/C++ code formatter.

[vgvassilev]

We will probably need a test in clang/unittest/Interpreter

[kr-2003]

We will probably need a test in clang/unittest/Interpreter

Ok. So, replicating clang-repl's way of creating interpreter when out-of-process should work, right?

[Vipul-Cariappa]

LGTM!
Please address the comments I have left.
I guess, you can remove the [wip] and draft status.

[anutosh491]

Looks okay to me, let's see what other reviewers have to say.

[vgvassilev]

LGTM!

[anutosh491]

LGTM. Thanks !