Add some switches helpful for debugging:

-print-before=<Pass Name>

Dump IR before running pass <Pass Name>.

-print-before-all

Dump IR before running each pass.

-print-after-all

Dump IR after running each pass.

These are helpful when tracking down a miscompilation.  It is easy to
get IR dumps and do diffs on them, etc.

To make this work well, add a new getPrinterPass API to Pass so that
each kind of pass (ModulePass, FunctionPass, etc.) can create a Pass
suitable for dumping out the kind of object the Pass works on.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100143 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 66 insertions, 34 deletions

diff --git a/lib/CodeGen/MachineFunction.cpp b/lib/CodeGen/MachineFunction.cpp
index f6cc71f3a4..3a7de300c1 100644
--- a/lib/CodeGen/MachineFunction.cpp
+++ b/lib/CodeGen/MachineFunction.cpp
@@ -39,40 +39,6 @@
 #include "llvm/Support/raw_ostream.h"
 using namespace llvm;
 
-namespace {
-  struct Printer : public MachineFunctionPass {
-    static char ID;
-
-    raw_ostream &OS;
-    const std::string Banner;
-
-    Printer(raw_ostream &os, const std::string &banner) 
-      : MachineFunctionPass(&ID), OS(os), Banner(banner) {}
-
-    const char *getPassName() const { return "MachineFunction Printer"; }
-
-    virtual void getAnalysisUsage(AnalysisUsage &AU) const {
-      AU.setPreservesAll();
-      MachineFunctionPass::getAnalysisUsage(AU);
-    }
-
-    bool runOnMachineFunction(MachineFunction &MF) {
-      OS << "# " << Banner << ":\n";
-      MF.print(OS);
-      return false;
-    }
-  };
-  char Printer::ID = 0;
-}
-
-/// Returns a newly-created MachineFunction Printer pass. The default banner is
-/// empty.
-///
-FunctionPass *llvm::createMachineFunctionPrinterPass(raw_ostream &OS,
-                                                     const std::string &Banner){
-  return new Printer(OS, Banner);
-}
-
 //===----------------------------------------------------------------------===//
 // MachineFunction implementation
 //===----------------------------------------------------------------------===//
diff --git a/lib/CodeGen/MachineFunctionPass.cpp b/lib/CodeGen/MachineFunctionPass.cpp
index 2f8d4c9e7a..e5a491270a 100644
--- a/lib/CodeGen/MachineFunctionPass.cpp
+++ b/lib/CodeGen/MachineFunctionPass.cpp
@@ -15,8 +15,14 @@
 #include "llvm/Analysis/AliasAnalysis.h"
 #include "llvm/CodeGen/MachineFunctionAnalysis.h"
 #include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/Passes.h"
 using namespace llvm;
 
+Pass *MachineFunctionPass::createPrinterPass(raw_ostream &O,
+                                             const std::string &Banner) const {
+  return createMachineFunctionPrinterPass(O, Banner);
+}
+
 bool MachineFunctionPass::runOnFunction(Function &F) {
   // Do not codegen any 'available_externally' functions at all, they have
   // definitions outside the translation unit.
diff --git a/lib/CodeGen/MachineFunctionPrinterPass.cpp b/lib/CodeGen/MachineFunctionPrinterPass.cpp
new file mode 100644
index 0000000000..547c4febc8
--- /dev/null
+++ b/lib/CodeGen/MachineFunctionPrinterPass.cpp
@@ -0,0 +1,60 @@
+//===-- MachineFunctionPrinterPass.cpp ------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// MachineFunctionPrinterPass implementation.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/CodeGen/Passes.h"
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace llvm;
+
+namespace {
+/// MachineFunctionPrinterPass - This is a pass to dump the IR of a
+/// MachineFunction.
+///
+struct MachineFunctionPrinterPass : public MachineFunctionPass {
+  static char ID;
+
+  raw_ostream &OS;
+  const std::string Banner;
+
+  MachineFunctionPrinterPass(raw_ostream &os, const std::string &banner) 
+      : MachineFunctionPass(&ID), OS(os), Banner(banner) {}
+
+  const char *getPassName() const { return "MachineFunction Printer"; }
+
+  virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+    AU.setPreservesAll();
+    MachineFunctionPass::getAnalysisUsage(AU);
+  }
+
+  bool runOnMachineFunction(MachineFunction &MF) {
+    OS << "# " << Banner << ":\n";
+    MF.print(OS);
+    return false;
+  }
+};
+
+char MachineFunctionPrinterPass::ID = 0;
+}
+
+namespace llvm {
+/// Returns a newly-created MachineFunction Printer pass. The
+/// default banner is empty.
+///
+MachineFunctionPass *createMachineFunctionPrinterPass(raw_ostream &OS,
+                                                      const std::string &Banner){
+  return new MachineFunctionPrinterPass(OS, Banner);
+}
+
+}