Reland [clang-repl] Expose setter for triple in IncrementalCompilerBuilder (#84174)

With out-of-process execution the target triple can be different from
the one on the host. We need an interface to configure it.

Relanding this with cleanup-fixes in the unittest.

Author: weliveindetail

clang/include/clang/Interpreter/Interpreter.h

@@ -48,6 +48,8 @@ class IncrementalCompilerBuilder {
     UserArgs = Args;
   }
 
+  void SetTargetTriple(std::string TT) { TargetTriple = TT; }
+
   // General C++
   llvm::Expected<std::unique_ptr<CompilerInstance>> CreateCpp();
 
@@ -62,11 +64,12 @@ class IncrementalCompilerBuilder {
 
 private:
   static llvm::Expected<std::unique_ptr<CompilerInstance>>
-  create(std::vector<const char *> &ClangArgv);
+  create(std::string TT, std::vector<const char *> &ClangArgv);
 
   llvm::Expected<std::unique_ptr<CompilerInstance>> createCuda(bool device);
 
   std::vector<const char *> UserArgs;
+  std::optional<std::string> TargetTriple;
 
   llvm::StringRef OffloadArch;
   llvm::StringRef CudaSDKPath;

clang/lib/Interpreter/Interpreter.cpp

@@ -132,7 +132,8 @@ CreateCI(const llvm::opt::ArgStringList &Argv) {
 } // anonymous namespace
 
 llvm::Expected<std::unique_ptr<CompilerInstance>>
-IncrementalCompilerBuilder::create(std::vector<const char *> &ClangArgv) {
+IncrementalCompilerBuilder::create(std::string TT,
+                                   std::vector<const char *> &ClangArgv) {
 
   // If we don't know ClangArgv0 or the address of main() at this point, try
   // to guess it anyway (it's possible on some platforms).
@@ -162,8 +163,7 @@ IncrementalCompilerBuilder::create(std::vector<const char *> &ClangArgv) {
   TextDiagnosticBuffer *DiagsBuffer = new TextDiagnosticBuffer;
   DiagnosticsEngine Diags(DiagID, &*DiagOpts, DiagsBuffer);
 
-  driver::Driver Driver(/*MainBinaryName=*/ClangArgv[0],
-                        llvm::sys::getProcessTriple(), Diags);
+  driver::Driver Driver(/*MainBinaryName=*/ClangArgv[0], TT, Diags);
   Driver.setCheckInputsExist(false); // the input comes from mem buffers
   llvm::ArrayRef<const char *> RF = llvm::ArrayRef(ClangArgv);
   std::unique_ptr<driver::Compilation> Compilation(Driver.BuildCompilation(RF));
@@ -185,7 +185,8 @@ IncrementalCompilerBuilder::CreateCpp() {
   Argv.push_back("-xc++");
   Argv.insert(Argv.end(), UserArgs.begin(), UserArgs.end());
 
-  return IncrementalCompilerBuilder::create(Argv);
+  std::string TT = TargetTriple ? *TargetTriple : llvm::sys::getProcessTriple();
+  return IncrementalCompilerBuilder::create(TT, Argv);
 }
 
 llvm::Expected<std::unique_ptr<CompilerInstance>>
@@ -213,7 +214,8 @@ IncrementalCompilerBuilder::createCuda(bool device) {
 
   Argv.insert(Argv.end(), UserArgs.begin(), UserArgs.end());
 
-  return IncrementalCompilerBuilder::create(Argv);
+  std::string TT = TargetTriple ? *TargetTriple : llvm::sys::getProcessTriple();
+  return IncrementalCompilerBuilder::create(TT, Argv);
 }
 
 llvm::Expected<std::unique_ptr<CompilerInstance>>

clang/unittests/Interpreter/CMakeLists.txt

@@ -7,6 +7,7 @@ set(LLVM_LINK_COMPONENTS
   )
 
 add_clang_unittest(ClangReplInterpreterTests
+  IncrementalCompilerBuilderTest.cpp
   IncrementalProcessingTest.cpp
   InterpreterTest.cpp
   CodeCompletionTest.cpp

clang/unittests/Interpreter/IncrementalCompilerBuilderTest.cpp

@@ -0,0 +1,47 @@
+//=== unittests/Interpreter/IncrementalCompilerBuilderTest.cpp ------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Basic/TargetOptions.h"
+#include "clang/Frontend/CompilerInstance.h"
+#include "clang/Interpreter/Interpreter.h"
+#include "clang/Lex/PreprocessorOptions.h"
+#include "llvm/Support/Error.h"
+#include "gtest/gtest.h"
+
+using namespace llvm;
+using namespace clang;
+
+namespace {
+
+// Usually FrontendAction takes the raw pointers and wraps them back into
+// unique_ptrs in InitializeFileRemapping()
+static void cleanupRemappedFileBuffers(CompilerInstance &CI) {
+  for (const auto &RB : CI.getPreprocessorOpts().RemappedFileBuffers) {
+    delete RB.second;
+  }
+  CI.getPreprocessorOpts().clearRemappedFiles();
+}
+
+TEST(IncrementalCompilerBuilder, SetCompilerArgs) {
+  std::vector<const char *> ClangArgv = {"-Xclang", "-ast-dump-all"};
+  auto CB = clang::IncrementalCompilerBuilder();
+  CB.SetCompilerArgs(ClangArgv);
+  auto CI = cantFail(CB.CreateCpp());
+  EXPECT_TRUE(CI->getFrontendOpts().ASTDumpAll);
+  cleanupRemappedFileBuffers(*CI);
+}
+
+TEST(IncrementalCompilerBuilder, SetTargetTriple) {
+  auto CB = clang::IncrementalCompilerBuilder();
+  CB.SetTargetTriple("armv6-none-eabi");
+  auto CI = cantFail(CB.CreateCpp());
+  EXPECT_EQ(CI->getTargetOpts().Triple, "armv6-none-unknown-eabi");
+  cleanupRemappedFileBuffers(*CI);
+}
+
+} // end anonymous namespace