[flang-commits] [flang] [flang][Driver] Add support for -mllvm -print-pipeline-passes (PR #106141)

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llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-flang-driver

Author: Tarun Prabhu (tarunprabhu)

<details>
<summary>Changes</summary>

The behavior deliberately mimics that of clang.

---
Full diff: https://github.com/llvm/llvm-project/pull/106141.diff


2 Files Affected:

- (modified) flang/lib/Frontend/FrontendActions.cpp (+16) 
- (added) flang/test/Driver/print-pipeline-passes.f90 (+10) 


``````````diff
diff --git a/flang/lib/Frontend/FrontendActions.cpp b/flang/lib/Frontend/FrontendActions.cpp
index 5c86bd947ce73f..012649b2ba16bd 100644
--- a/flang/lib/Frontend/FrontendActions.cpp
+++ b/flang/lib/Frontend/FrontendActions.cpp
@@ -79,6 +79,10 @@
 
 #include "flang/Tools/CLOptions.inc"
 
+namespace llvm {
+extern cl::opt<bool> PrintPipelinePasses;
+} // namespace llvm
+
 using namespace Fortran::frontend;
 
 // Declare plugin extension function declarations.
@@ -1015,6 +1019,18 @@ void CodeGenAction::runOptimizationPipeline(llvm::raw_pwrite_stream &os) {
   else if (action == BackendActionTy::Backend_EmitLL)
     mpm.addPass(llvm::PrintModulePass(os));
 
+  // Print a textual, '-passes=' compatible, representation of pipeline if
+  // requested. In this case, don't run the passes. This mimics the behavior of
+  // clang.
+  if (llvm::PrintPipelinePasses) {
+    mpm.printPipeline(llvm::outs(), [&pic](llvm::StringRef className) {
+      auto passName = pic.getPassNameForClassName(className);
+      return passName.empty() ? className : passName;
+    });
+    llvm::outs() << "\n";
+    return;
+  }
+
   // Run the passes.
   mpm.run(*llvmModule, mam);
 }
diff --git a/flang/test/Driver/print-pipeline-passes.f90 b/flang/test/Driver/print-pipeline-passes.f90
new file mode 100644
index 00000000000000..4b413cbc07b691
--- /dev/null
+++ b/flang/test/Driver/print-pipeline-passes.f90
@@ -0,0 +1,10 @@
+! Test that -print-pipeline-passes works in flang
+
+! RUN: %flang_fc1 -triple x86_64-unknown-linux-gnu -emit-llvm-bc -o /dev/null -mllvm -print-pipeline-passes -O0 %s 2>&1 | FileCheck %s
+
+! Don't try to check all passes, just a few to make sure that something is
+! actually printed.
+! CHECK: always-inline
+! CHECK-SAME: annotation-remarks
+
+end program

``````````

</details>


https://github.com/llvm/llvm-project/pull/106141