From fd36daf55d7f9e8ab412fcbf0441658a8d8be727 Mon Sep 17 00:00:00 2001
From: Dmitry Vyukov <dvyukov@google.com>
Date: Thu, 5 Feb 2026 13:59:08 +0100
Subject: tools/clang: compile clang tools into the binary

Compiled clang tools into Go binaries using cgo.
This significantly simplifies building and deployment.
This also enables unit testing of clang tools.
Now raw go test for clang tools will build them, run,
and verify output.

Each clang tool is still started as a subprocess.
I've experimented with running them in-process,
but this makes stdout/stderr interception extremly complicated,
and it seems that clang tools still use unsynchronized global state,
which breaks when invoked multiple times.
Subprocesses also make it safer in the face of potential memory leaks,
or memory corruptions in clang tools.

Fixes #6645
---
 tools/clang/declextract/declextract.cpp | 32 ++++++++++++++++++++++++++------
 1 file changed, 26 insertions(+), 6 deletions(-)

(limited to 'tools/clang/declextract/declextract.cpp')

diff --git a/tools/clang/declextract/declextract.cpp b/tools/clang/declextract/declextract.cpp
index d7230a578..620c81f17 100644
--- a/tools/clang/declextract/declextract.cpp
+++ b/tools/clang/declextract/declextract.cpp
@@ -21,6 +21,7 @@
 #include "clang/Basic/LLVM.h"
 #include "clang/Basic/SourceManager.h"
 #include "clang/Basic/TypeTraits.h"
+#include "clang/Basic/Version.h"
 #include "clang/Frontend/CompilerInstance.h"
 #include "clang/Tooling/CommonOptionsParser.h"
 #include "clang/Tooling/Tooling.h"
@@ -297,7 +298,12 @@ FieldType Extractor::extractRecord(QualType QT, const RecordType* Typ, const std
       IsAnonymous = true;
     }
     FieldType FieldType = genType(F->getType(), BackupFieldName);
-    int BitWidth = F->isBitField() ? F->getBitWidthValue() : 0;
+    int BitWidth = F->isBitField() ? F->getBitWidthValue(
+#if CLANG_VERSION_MAJOR == 19
+                                         *Context
+#endif
+                                         )
+                                   : 0;
     int CountedBy = F->getType()->isCountAttributedType()
                         ? llvm::dyn_cast<FieldDecl>(
                               F->getType()->getAs<CountAttributedType>()->getCountExpr()->getReferencedDeclOfCallee())
@@ -338,9 +344,16 @@ std::string Extractor::extractEnum(QualType QT, const EnumDecl* Decl) {
   if (Name.empty()) {
     // This is an unnamed enum declared with a typedef:
     //   typedef enum {...} enum_name;
-    auto Typedef = dyn_cast<TypedefType>(QT.getTypePtr());
-    if (Typedef)
-      Name = Typedef->getDecl()->getNameAsString();
+    auto Elaborated = dyn_cast<ElaboratedType>(QT.getTypePtr());
+    if (Elaborated) {
+      auto Typedef = dyn_cast<TypedefType>(Elaborated->getNamedType().getTypePtr());
+      if (Typedef)
+        Name = Typedef->getDecl()->getNameAsString();
+    }
+    // This is the code we will need for one of future versions (past 21).
+    // auto Typedef = dyn_cast<TypedefType>(QT.getTypePtr());
+    // if (Typedef)
+    //   Name = Typedef->getDecl()->getNameAsString();
     if (Name.empty()) {
       QT.dump();
       llvm::report_fatal_error("enum with empty name");
@@ -993,8 +1006,8 @@ void Extractor::extractIoctl(const Expr* Cmd, const ConstDesc& Const) {
   });
 }
 
-int main(int argc, const char** argv) {
-  llvm::cl::OptionCategory Options("syz-declextract options");
+static int Main(int argc, const char** argv) {
+  llvm::cl::OptionCategory Options("declextract options");
   auto OptionsParser = tooling::CommonOptionsParser::create(argc, argv, Options);
   if (!OptionsParser) {
     llvm::errs() << OptionsParser.takeError();
@@ -1005,5 +1018,12 @@ int main(int argc, const char** argv) {
   if (Tool.run(tooling::newFrontendActionFactory(&Ex, &Ex).get()))
     return 1;
   Ex.print();
+  fflush(stdout);
   return 0;
 }
+
+__attribute__((constructor(1000))) static void ctor(int argc, const char** argv) {
+  const char* run = getenv("SYZ_RUN_CLANGTOOL");
+  if (run && !strcmp(run, "declextract"))
+    exit(Main(argc, argv));
+}
-- 
cgit mrf-deployment