[clang] 065cd64 - [clang-repl] Teach clang-repl how to load PCHs (reprise) (#157359)
via cfe-commits
cfe-commits at lists.llvm.org
Tue Sep 30 03:59:01 PDT 2025
Author: Jeaye Wilkerson
Date: 2025-09-30T13:58:57+03:00
New Revision: 065cd64af3166da430bd03067514f9c9ac09e8e1
URL: https://github.com/llvm/llvm-project/commit/065cd64af3166da430bd03067514f9c9ac09e8e1
DIFF: https://github.com/llvm/llvm-project/commit/065cd64af3166da430bd03067514f9c9ac09e8e1.diff
LOG: [clang-repl] Teach clang-repl how to load PCHs (reprise) (#157359)
This is an updated version of @vgvassilev's PR from last year here:
https://github.com/llvm/llvm-project/pull/94166
In short, it includes:
1. The fix for a blocking issue where `clang::Interpreter` (and thus
`clang-repl`) cannot resolve symbols defined in a PCH
2. A test to prove this is working
3. A new hidden flag for `clang-repl` so that `llvm-lit` can match the
host JIT triple between the PCH and `clang-repl`; previously, they may
differ in some cases
4. Everything based on the latest LLVM main
Shout out to @kylc for finding a logic issue which had us stumped for a
while (and securing the
[bounty](https://github.com/jank-lang/jank/issues/446)).
---------
Co-authored-by: Vassil Vassilev <v.g.vassilev at gmail.com>
Co-authored-by: Kyle Cesare <kcesare at gmail.com>
Added:
clang/test/Interpreter/execute-pch.cpp
Modified:
clang/include/clang/CodeGen/ModuleBuilder.h
clang/lib/CodeGen/BackendConsumer.h
clang/lib/CodeGen/CodeGenAction.cpp
clang/lib/CodeGen/ModuleBuilder.cpp
clang/lib/Interpreter/IncrementalAction.cpp
clang/lib/Interpreter/IncrementalParser.cpp
clang/lib/Interpreter/Interpreter.cpp
clang/test/lit.cfg.py
clang/tools/clang-repl/ClangRepl.cpp
Removed:
################################################################################
diff --git a/clang/include/clang/CodeGen/ModuleBuilder.h b/clang/include/clang/CodeGen/ModuleBuilder.h
index 59b9840d02e08..f1b8229edd362 100644
--- a/clang/include/clang/CodeGen/ModuleBuilder.h
+++ b/clang/include/clang/CodeGen/ModuleBuilder.h
@@ -52,6 +52,12 @@ namespace CodeGen {
class CodeGenerator : public ASTConsumer {
virtual void anchor();
+protected:
+ /// True if we've finished generating IR. This prevents us from generating
+ /// additional LLVM IR after emitting output in HandleTranslationUnit. This
+ /// can happen when Clang plugins trigger additional AST deserialization.
+ bool IRGenFinished = false;
+
public:
/// Return an opaque reference to the CodeGenModule object, which can
/// be used in various secondary APIs. It is valid as long as the
diff --git a/clang/lib/CodeGen/BackendConsumer.h b/clang/lib/CodeGen/BackendConsumer.h
index ad3adfca36785..b7bbb81074836 100644
--- a/clang/lib/CodeGen/BackendConsumer.h
+++ b/clang/lib/CodeGen/BackendConsumer.h
@@ -40,11 +40,6 @@ class BackendConsumer : public ASTConsumer {
llvm::Timer LLVMIRGeneration;
unsigned LLVMIRGenerationRefCount = 0;
- /// True if we've finished generating IR. This prevents us from generating
- /// additional LLVM IR after emitting output in HandleTranslationUnit. This
- /// can happen when Clang plugins trigger additional AST deserialization.
- bool IRGenFinished = false;
-
bool TimerIsEnabled = false;
BackendAction Action;
diff --git a/clang/lib/CodeGen/CodeGenAction.cpp b/clang/lib/CodeGen/CodeGenAction.cpp
index 9286f1f25c6cc..60d6b7fa009e7 100644
--- a/clang/lib/CodeGen/CodeGenAction.cpp
+++ b/clang/lib/CodeGen/CodeGenAction.cpp
@@ -190,9 +190,7 @@ void BackendConsumer::HandleInlineFunctionDefinition(FunctionDecl *D) {
}
void BackendConsumer::HandleInterestingDecl(DeclGroupRef D) {
- // Ignore interesting decls from the AST reader after IRGen is finished.
- if (!IRGenFinished)
- HandleTopLevelDecl(D);
+ HandleTopLevelDecl(D);
}
// Links each entry in LinkModules into our module. Returns true on error.
@@ -243,8 +241,6 @@ void BackendConsumer::HandleTranslationUnit(ASTContext &C) {
if (TimerIsEnabled && !--LLVMIRGenerationRefCount)
LLVMIRGeneration.yieldTo(CI.getFrontendTimer());
-
- IRGenFinished = true;
}
// Silently ignore if we weren't initialized for some reason.
diff --git a/clang/lib/CodeGen/ModuleBuilder.cpp b/clang/lib/CodeGen/ModuleBuilder.cpp
index 8c1fee8c974f1..96f3f6221e20f 100644
--- a/clang/lib/CodeGen/ModuleBuilder.cpp
+++ b/clang/lib/CodeGen/ModuleBuilder.cpp
@@ -138,6 +138,8 @@ namespace {
assert(!M && "Replacing existing Module?");
M.reset(new llvm::Module(ExpandModuleName(ModuleName, CodeGenOpts), C));
+ IRGenFinished = false;
+
std::unique_ptr<CodeGenModule> OldBuilder = std::move(Builder);
Initialize(*Ctx);
@@ -179,6 +181,10 @@ namespace {
}
bool HandleTopLevelDecl(DeclGroupRef DG) override {
+ // Ignore interesting decls from the AST reader after IRGen is finished.
+ if (IRGenFinished)
+ return true; // We can't CodeGen more but pass to other consumers.
+
// FIXME: Why not return false and abort parsing?
if (Diags.hasUnrecoverableErrorOccurred())
return true;
@@ -292,8 +298,9 @@ namespace {
if (Builder)
Builder->clear();
M.reset();
- return;
}
+
+ IRGenFinished = true;
}
void AssignInheritanceModel(CXXRecordDecl *RD) override {
diff --git a/clang/lib/Interpreter/IncrementalAction.cpp b/clang/lib/Interpreter/IncrementalAction.cpp
index 4d1bc4c59e851..3d489fce54bc6 100644
--- a/clang/lib/Interpreter/IncrementalAction.cpp
+++ b/clang/lib/Interpreter/IncrementalAction.cpp
@@ -106,7 +106,8 @@ std::unique_ptr<llvm::Module> IncrementalAction::GenModule() {
// around we created an empty module to make CodeGen happy. We should make
// sure it always stays empty.
assert(((!CachedInCodeGenModule ||
- !CI.getPreprocessorOpts().Includes.empty()) ||
+ !CI.getPreprocessorOpts().Includes.empty() ||
+ !CI.getPreprocessorOpts().ImplicitPCHInclude.empty()) ||
(CachedInCodeGenModule->empty() &&
CachedInCodeGenModule->global_empty() &&
CachedInCodeGenModule->alias_empty() &&
diff --git a/clang/lib/Interpreter/IncrementalParser.cpp b/clang/lib/Interpreter/IncrementalParser.cpp
index 32d1663fbe1a9..bf08911e23533 100644
--- a/clang/lib/Interpreter/IncrementalParser.cpp
+++ b/clang/lib/Interpreter/IncrementalParser.cpp
@@ -37,6 +37,10 @@ IncrementalParser::IncrementalParser(CompilerInstance &Instance,
llvm::ErrorAsOutParameter EAO(&Err);
Consumer = &S.getASTConsumer();
P.reset(new Parser(S.getPreprocessor(), S, /*SkipBodies=*/false));
+
+ if (ExternalASTSource *External = S.getASTContext().getExternalSource())
+ External->StartTranslationUnit(Consumer);
+
P->Initialize();
}
diff --git a/clang/lib/Interpreter/Interpreter.cpp b/clang/lib/Interpreter/Interpreter.cpp
index 9cc1c450b7650..b05cb5a0f1dbe 100644
--- a/clang/lib/Interpreter/Interpreter.cpp
+++ b/clang/lib/Interpreter/Interpreter.cpp
@@ -278,9 +278,10 @@ Interpreter::Interpreter(std::unique_ptr<CompilerInstance> Instance,
if (Act->getCodeGen()) {
Act->CacheCodeGenModule();
- // The initial PTU is filled by `-include` or by CUDA includes
- // automatically.
- if (!CI->getPreprocessorOpts().Includes.empty()) {
+ // The initial PTU is filled by `-include`/`-include-pch` or by CUDA
+ // includes automatically.
+ if (!CI->getPreprocessorOpts().Includes.empty() ||
+ !CI->getPreprocessorOpts().ImplicitPCHInclude.empty()) {
// We can't really directly pass the CachedInCodeGenModule to the Jit
// because it will steal it, causing dangling references as explained in
// Interpreter::Execute
diff --git a/clang/test/Interpreter/execute-pch.cpp b/clang/test/Interpreter/execute-pch.cpp
new file mode 100644
index 0000000000000..8041ee6ac966d
--- /dev/null
+++ b/clang/test/Interpreter/execute-pch.cpp
@@ -0,0 +1,23 @@
+// REQUIRES: host-supports-jit
+// UNSUPPORTED: system-aix
+//
+// RUN: rm -rf %t
+// RUN: mkdir -p %t
+// RUN: split-file %s %t
+//
+// RUN: %clang -fmax-type-align=16 -Xclang -fdeprecated-macro -fno-stack-protector -Xclang -fwrapv -Xclang -fblocks -Xclang -fskip-odr-check-in-gmf -fexceptions -fcxx-exceptions -fgnuc-version=0 -target %host-jit-triple -Xclang -fblocks -Xclang -fmax-type-align=8 -Xclang -fincremental-extensions -Xclang -emit-pch -x c++-header -o %t/include.pch %t/include.hpp
+//
+// RUN: cat %t/main.cpp \
+// RUN: | clang-repl -Xcc -fgnuc-version=0 -Xcc -fno-stack-protector -Xcc -fwrapv -Xcc -fblocks -Xcc -fskip-odr-check-in-gmf -Xcc -fmax-type-align=8 -Xcc -include-pch -Xcc %t/include.pch \
+// RUN: | FileCheck %s
+
+//--- include.hpp
+
+int f_pch() { return 5; }
+
+//--- main.cpp
+
+extern "C" int printf(const char *, ...);
+printf("f_pch = %d\n", f_pch());
+
+// CHECK: f_pch = 5
diff --git a/clang/test/lit.cfg.py b/clang/test/lit.cfg.py
index 4a5d9e582b54c..64e2bbad8f3b2 100644
--- a/clang/test/lit.cfg.py
+++ b/clang/test/lit.cfg.py
@@ -140,7 +140,8 @@ def have_host_out_of_process_jit_feature_support():
return False
-def have_host_jit_feature_support(feature_name):
+
+def run_clang_repl(args):
clang_repl_exe = lit.util.which("clang-repl", config.clang_tools_dir)
if not clang_repl_exe:
@@ -148,7 +149,7 @@ def have_host_jit_feature_support(feature_name):
try:
clang_repl_cmd = subprocess.Popen(
- [clang_repl_exe, "--host-supports-" + feature_name], stdout=subprocess.PIPE
+ [clang_repl_exe, args], stdout=subprocess.PIPE
)
except OSError:
print("could not exec clang-repl")
@@ -157,7 +158,11 @@ def have_host_jit_feature_support(feature_name):
clang_repl_out = clang_repl_cmd.stdout.read().decode("ascii")
clang_repl_cmd.wait()
- return "true" in clang_repl_out
+ return clang_repl_out
+
+
+def have_host_jit_feature_support(feature_name):
+ return "true" in run_clang_repl("--host-supports-" + feature_name)
def have_host_clang_repl_cuda():
clang_repl_exe = lit.util.which('clang-repl', config.clang_tools_dir)
@@ -191,6 +196,8 @@ def have_host_clang_repl_cuda():
if have_host_clang_repl_cuda():
config.available_features.add('host-supports-cuda')
+ hosttriple = run_clang_repl("--host-jit-triple")
+ config.substitutions.append(("%host-jit-triple", hosttriple.strip()))
if have_host_out_of_process_jit_feature_support():
config.available_features.add("host-supports-out-of-process-jit")
diff --git a/clang/tools/clang-repl/ClangRepl.cpp b/clang/tools/clang-repl/ClangRepl.cpp
index 1d508816d7047..c7879422cd7df 100644
--- a/clang/tools/clang-repl/ClangRepl.cpp
+++ b/clang/tools/clang-repl/ClangRepl.cpp
@@ -85,6 +85,8 @@ static llvm::cl::list<std::string>
llvm::cl::CommaSeparated);
static llvm::cl::opt<bool> OptHostSupportsJit("host-supports-jit",
llvm::cl::Hidden);
+static llvm::cl::opt<bool> OptHostJitTriple("host-jit-triple",
+ llvm::cl::Hidden);
static llvm::cl::list<std::string> OptInputs(llvm::cl::Positional,
llvm::cl::desc("[code to run]"));
@@ -279,6 +281,11 @@ int main(int argc, const char **argv) {
llvm::outs() << "false\n";
}
return 0;
+ } else if (OptHostJitTriple) {
+ auto J = ExitOnErr(llvm::orc::LLJITBuilder().create());
+ auto T = J->getTargetTriple();
+ llvm::outs() << T.normalize() << '\n';
+ return 0;
}
clang::IncrementalCompilerBuilder CB;
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