[llvm] [llvm-extract] support unnamed bbs. (PR #135140)

[Allin Lee via llvm-commits]

https://github.com/AllinLeeYL updated https://github.com/llvm/llvm-project/pull/135140

>From 39c85fcb47ac8c6a2515373d906de42ed5d76fe4 Mon Sep 17 00:00:00 2001
From: Yilin Li <allinleeme at gmail.com>
Date: Thu, 10 Apr 2025 13:48:02 +0800
Subject: [PATCH] [llvm-extract] support unnamed bbs.

---
 llvm/include/llvm/IR/Value.h                  |  2 --
 llvm/lib/IR/Value.cpp                         |  2 --
 .../tools/llvm-extract/extract-unnamed-bb.ll  | 28 +++++++++++++++++++
 llvm/tools/llvm-extract/llvm-extract.cpp      |  7 +++--
 4 files changed, 33 insertions(+), 6 deletions(-)
 create mode 100644 llvm/test/tools/llvm-extract/extract-unnamed-bb.ll

diff --git a/llvm/include/llvm/IR/Value.h b/llvm/include/llvm/IR/Value.h
index cfed12e2f5f8d..bf1de7eef9932 100644
--- a/llvm/include/llvm/IR/Value.h
+++ b/llvm/include/llvm/IR/Value.h
@@ -290,9 +290,7 @@ class Value {
   /// \note It is an error to call V->takeName(V).
   void takeName(Value *V);
 
-#ifndef NDEBUG
   std::string getNameOrAsOperand() const;
-#endif
 
   /// Change all uses of this to point to a new Value.
   ///
diff --git a/llvm/lib/IR/Value.cpp b/llvm/lib/IR/Value.cpp
index 0eaf75b7bfaec..aa97b70f21aeb 100644
--- a/llvm/lib/IR/Value.cpp
+++ b/llvm/lib/IR/Value.cpp
@@ -441,7 +441,6 @@ void Value::takeName(Value *V) {
     ST->reinsertValue(this);
 }
 
-#ifndef NDEBUG
 std::string Value::getNameOrAsOperand() const {
   if (!getName().empty())
     return std::string(getName());
@@ -451,7 +450,6 @@ std::string Value::getNameOrAsOperand() const {
   printAsOperand(OS, false);
   return OS.str();
 }
-#endif
 
 void Value::assertModuleIsMaterializedImpl() const {
 #ifndef NDEBUG
diff --git a/llvm/test/tools/llvm-extract/extract-unnamed-bb.ll b/llvm/test/tools/llvm-extract/extract-unnamed-bb.ll
new file mode 100644
index 0000000000000..bb82cfdee57d9
--- /dev/null
+++ b/llvm/test/tools/llvm-extract/extract-unnamed-bb.ll
@@ -0,0 +1,28 @@
+; RUN: llvm-extract -S --bb "_Z6kernelv.extracted:%5" < %s | FileCheck %s
+
+; CHECK: define dso_local void @_Z6kernelv.extracted.extracted(i64 %0, i64 %1) {
+
+; CHECK       2:
+; CHECK:        %3 = add nuw nsw i64 %0, 1
+; CHECK-NEXT:   %4 = sub nuw nsw i64 %3, %1
+; CHECK-NEXT:   br label %.exitStub
+
+define dso_local void @_Z6kernelv.extracted(i64 %0, ptr %.out) #0 {
+newFuncRoot:
+  br label %1
+
+1:
+  %2 = phi i64 [ 0, %newFuncRoot ], [ %3, %1 ]
+  %3 = add nuw nsw i64 %2, 1
+  %4 = icmp eq i64 %2, %3
+  br i1 %4, label %5, label %1
+
+5:
+  %6 = add nuw nsw i64 %0, 1
+  %7 = sub nuw nsw i64 %6, %3
+  br label %8
+
+8:
+  %9 = add nuw i64 %0, 2
+  ret void
+}
diff --git a/llvm/tools/llvm-extract/llvm-extract.cpp b/llvm/tools/llvm-extract/llvm-extract.cpp
index 648060acb392c..69636ca018dcb 100644
--- a/llvm/tools/llvm-extract/llvm-extract.cpp
+++ b/llvm/tools/llvm-extract/llvm-extract.cpp
@@ -90,10 +90,13 @@ static cl::list<std::string> ExtractBlocks(
         "Each pair will create a function.\n"
         "If multiple basic blocks are specified in one pair,\n"
         "the first block in the sequence should dominate the rest.\n"
+        "If an unnamed basic block is to be extracted,\n"
+        "'%' should be added before the basic block variable names.\n"
         "eg:\n"
         "  --bb=f:bb1;bb2 will extract one function with both bb1 and bb2;\n"
         "  --bb=f:bb1 --bb=f:bb2 will extract two functions, one with bb1, one "
-        "with bb2."),
+        "with bb2.\n"
+        "  --bb=f:%1 will extract one function with basic block 1;"),
     cl::value_desc("function:bb1[;bb2...]"), cl::cat(ExtractCat));
 
 // ExtractAlias - The alias to extract from the module.
@@ -356,7 +359,7 @@ int main(int argc, char **argv) {
         // The function has been materialized, so add its matching basic blocks
         // to the block extractor list, or fail if a name is not found.
         auto Res = llvm::find_if(*P.first, [&](const BasicBlock &BB) {
-          return BB.getName() == BBName;
+          return BB.getNameOrAsOperand() == BBName;
         });
         if (Res == P.first->end()) {
           errs() << argv[0] << ": function " << P.first->getName()