Use `-cfg-func-name` value as filter for `-view-cfg`, etc.

[fodinabor]

Summary

Currently the value is only used when calling F->viewCFG() which is missing out on its potential and usefulness.
So I added the check to the printer passes as well.

[MaskRay]

Test?

[fodinabor]

Add test for the filtering with -dot-cfg and -dot-cfg-only. As far as I see it, the view variant is not really testable. Happy to be proved wrong, though. :)

[fodinabor]

clang-format file

[fodinabor]

Also, would it make sense to un-hide and document the flag now, given it actually is useful now?

[MaskRay]

In D102011#2744949, @fodinabor wrote:

Also, would it make sense to un-hide and document the flag now, given it actually is useful now?

You may document the effect of -cfg-func-name in docs/Passes.rst

llvm/test/Other/cfg-printer-filter.ll

1

The most common style is ; RUN

Add a comment, e.g. ;; Both f and func are dumped because their names contain the pattern f` as a substring.`

4

It will be robust to rm -f %t.other.dot first before testing this.

A stale (e.g. when testing the feature) %t.other.dot file could cause the test to fail.

11

Delete

40

Delete trailing blank lines

[fodinabor]

Incorporate review of the test and document the behavior in Passes.rst.

[fodinabor]

Ping.

[fodinabor]

Ping.

[MaskRay]

Thanks!

llvm/lib/Analysis/CFGPrinter.cpp

 namespace {
 struct CFGViewerLegacyPass : public FunctionPass {
   static char ID; // Pass identifcation, replacement for typeid
   CFGViewerLegacyPass() : FunctionPass(ID) {
     initializeCFGViewerLegacyPassPass(*PassRegistry::getPassRegistry());
   }
 
   bool runOnFunction(Function &F) override {
+    if (!CFGFuncName.empty() && !F.getName().contains(CFGFuncName))
+      return false;
     auto *BPI = &getAnalysis<BranchProbabilityInfoWrapperPass>().getBPI();
     auto *BFI = &getAnalysis<BlockFrequencyInfoWrapperPass>().getBFI();
     viewCFG(F, BFI, BPI, getMaxFreq(F, BFI));
     return false;
   }
 
   void print(raw_ostream &OS, const Module * = nullptr) const override {}
 
   void getAnalysisUsage(AnalysisUsage &AU) const override {
     FunctionPass::getAnalysisUsage(AU);
     AU.addRequired<BlockFrequencyInfoWrapperPass>();
     AU.addRequired<BranchProbabilityInfoWrapperPass>();
     AU.setPreservesAll();
   }
 };
-}
+} // namespace
 
 char CFGViewerLegacyPass::ID = 0;
 INITIALIZE_PASS(CFGViewerLegacyPass, "view-cfg", "View CFG of function", false,
                 true)
 
 PreservedAnalyses CFGViewerPass::run(Function &F, FunctionAnalysisManager &AM) {
+  if (!CFGFuncName.empty() && !F.getName().contains(CFGFuncName))
+    return PreservedAnalyses::all();
   auto *BFI = &AM.getResult<BlockFrequencyAnalysis>(F);
   auto *BPI = &AM.getResult<BranchProbabilityAnalysis>(F);
   viewCFG(F, BFI, BPI, getMaxFreq(F, BFI));
   return PreservedAnalyses::all();
 }
 
 namespace {
 struct CFGOnlyViewerLegacyPass : public FunctionPass {
   static char ID; // Pass identifcation, replacement for typeid
   CFGOnlyViewerLegacyPass() : FunctionPass(ID) {
     initializeCFGOnlyViewerLegacyPassPass(*PassRegistry::getPassRegistry());
   }
 
   bool runOnFunction(Function &F) override {
+    if (!CFGFuncName.empty() && !F.getName().contains(CFGFuncName))
+      return false;
     auto *BPI = &getAnalysis<BranchProbabilityInfoWrapperPass>().getBPI();
     auto *BFI = &getAnalysis<BlockFrequencyInfoWrapperPass>().getBFI();
     viewCFG(F, BFI, BPI, getMaxFreq(F, BFI), /*CFGOnly=*/true);
     return false;
   }
 
   void print(raw_ostream &OS, const Module * = nullptr) const override {}
 
   void getAnalysisUsage(AnalysisUsage &AU) const override {
     FunctionPass::getAnalysisUsage(AU);
     AU.addRequired<BlockFrequencyInfoWrapperPass>();
     AU.addRequired<BranchProbabilityInfoWrapperPass>();
     AU.setPreservesAll();
   }
 };
-}
+} // namespace
 
 char CFGOnlyViewerLegacyPass::ID = 0;
 INITIALIZE_PASS(CFGOnlyViewerLegacyPass, "view-cfg-only",
                 "View CFG of function (with no function bodies)", false, true)
 
 PreservedAnalyses CFGOnlyViewerPass::run(Function &F,
                                          FunctionAnalysisManager &AM) {
+  if (!CFGFuncName.empty() && !F.getName().contains(CFGFuncName))
+    return PreservedAnalyses::all();
   auto *BFI = &AM.getResult<BlockFrequencyAnalysis>(F);
   auto *BPI = &AM.getResult<BranchProbabilityAnalysis>(F);
   viewCFG(F, BFI, BPI, getMaxFreq(F, BFI), /*CFGOnly=*/true);
   return PreservedAnalyses::all();
 }
 
 namespace {
 struct CFGPrinterLegacyPass : public FunctionPass {
   static char ID; // Pass identification, replacement for typeid
   CFGPrinterLegacyPass() : FunctionPass(ID) {
     initializeCFGPrinterLegacyPassPass(*PassRegistry::getPassRegistry());
   }
 
   bool runOnFunction(Function &F) override {
+    if (!CFGFuncName.empty() && !F.getName().contains(CFGFuncName))
+      return false;
     auto *BPI = &getAnalysis<BranchProbabilityInfoWrapperPass>().getBPI();
     auto *BFI = &getAnalysis<BlockFrequencyInfoWrapperPass>().getBFI();
     writeCFGToDotFile(F, BFI, BPI, getMaxFreq(F, BFI));
     return false;
   }
 
   void print(raw_ostream &OS, const Module * = nullptr) const override {}
 
   void getAnalysisUsage(AnalysisUsage &AU) const override {
     FunctionPass::getAnalysisUsage(AU);
     AU.addRequired<BlockFrequencyInfoWrapperPass>();
     AU.addRequired<BranchProbabilityInfoWrapperPass>();
     AU.setPreservesAll();
   }
 };
-}
+} // namespace
 
 char CFGPrinterLegacyPass::ID = 0;
 INITIALIZE_PASS(CFGPrinterLegacyPass, "dot-cfg",
                 "Print CFG of function to 'dot' file", false, true)
 
 PreservedAnalyses CFGPrinterPass::run(Function &F,
                                       FunctionAnalysisManager &AM) {
+  if (!CFGFuncName.empty() && !F.getName().contains(CFGFuncName))
+    return PreservedAnalyses::all();
   auto *BFI = &AM.getResult<BlockFrequencyAnalysis>(F);
   auto *BPI = &AM.getResult<BranchProbabilityAnalysis>(F);
   writeCFGToDotFile(F, BFI, BPI, getMaxFreq(F, BFI));
   return PreservedAnalyses::all();
 }
 
 namespace {
 struct CFGOnlyPrinterLegacyPass : public FunctionPass {
   static char ID; // Pass identification, replacement for typeid
   CFGOnlyPrinterLegacyPass() : FunctionPass(ID) {
     initializeCFGOnlyPrinterLegacyPassPass(*PassRegistry::getPassRegistry());
   }
 
   bool runOnFunction(Function &F) override {
+    if (!CFGFuncName.empty() && !F.getName().contains(CFGFuncName))
+      return false;
     auto *BPI = &getAnalysis<BranchProbabilityInfoWrapperPass>().getBPI();
     auto *BFI = &getAnalysis<BlockFrequencyInfoWrapperPass>().getBFI();
     writeCFGToDotFile(F, BFI, BPI, getMaxFreq(F, BFI), /*CFGOnly=*/true);
     return false;
   }
   void print(raw_ostream &OS, const Module * = nullptr) const override {}
 
   void getAnalysisUsage(AnalysisUsage &AU) const override {
     FunctionPass::getAnalysisUsage(AU);
     AU.addRequired<BlockFrequencyInfoWrapperPass>();
     AU.addRequired<BranchProbabilityInfoWrapperPass>();
     AU.setPreservesAll();
   }
 };
-}
+} // namespace
 
 char CFGOnlyPrinterLegacyPass::ID = 0;
 INITIALIZE_PASS(CFGOnlyPrinterLegacyPass, "dot-cfg-only",
                 "Print CFG of function to 'dot' file (with no function bodies)",
                 false, true)
 
 PreservedAnalyses CFGOnlyPrinterPass::run(Function &F,
                                           FunctionAnalysisManager &AM) {
+  if (!CFGFuncName.empty() && !F.getName().contains(CFGFuncName))
+    return PreservedAnalyses::all();
   auto *BFI = &AM.getResult<BlockFrequencyAnalysis>(F);
   auto *BPI = &AM.getResult<BranchProbabilityAnalysis>(F);
   writeCFGToDotFile(F, BFI, BPI, getMaxFreq(F, BFI), /*CFGOnly=*/true);
   return PreservedAnalyses::all();
 }
 
 /// viewCFG - This function is meant for use from the debugger.  You can just
 /// say 'call F->viewCFG()' and a ghostview window should pop up from the

llvm/test/Other/cfg-printer-filter.ll

+;RUN: opt < %s -dot-cfg -cfg-dot-filename-prefix=%t -cfg-func-name=f 2>/dev/null
+;RUN: FileCheck %s -input-file=%t.f.dot -check-prefix=F
+;RUN: FileCheck %s -input-file=%t.func.dot -check-prefix=Func
+;RUN: not test -f %t.other.dot
+
+;RUN: opt < %s -dot-cfg-only -cfg-dot-filename-prefix=%t-only -cfg-func-name=f 2>/dev/null
+;RUN: FileCheck %s -input-file=%t-only.f.dot -check-prefix=F
+;RUN: FileCheck %s -input-file=%t-only.func.dot -check-prefix=Func
+;RUN: not test -f %t-only.other.dot
+
+;END.
+
+; F: digraph "CFG for 'f' function"
+define void @f(i32) {
+entry:
+  %check = icmp sgt i32 %0, 0
+  br i1 %check, label %if, label %exit
+if:                     ; preds = %entry
+  br label %exit
+exit:                   ; preds = %entry, %if
+  ret void
+}
+
+; Func: digraph "CFG for 'func' function"
+define void @func(i32) {
+entry:
+  %check = icmp sgt i32 %0, 0
+  br label %exit
+exit:                   ; preds = %entry
+  ret void
+}
+
+define void @other(i32) {
+entry:
+  %check = icmp sgt i32 %0, 0
+  br label %exit
+exit:                   ; preds = %entry
+  ret void
+}
+