[IR/Verifier] Don't visit DISubprograms more than needed.

Before this patch we happened to visit twice, one when scanning
MDNodes and the other one while visiting the function. Remove
the explicit call to visitDISubprogram there, so we don't emit
the same error twice in case the verifier fail and we save some
time when running it.
Thanks to Justin Bogner for the report and Adrian for the quick
review!

PR: 31995
llvm-svn: 295537

2 files changed, 17 insertions, 2 deletions

diff --git a/llvm/lib/IR/Verifier.cpp b/llvm/lib/IR/Verifier.cpp
index 9c2da10c9e1..c14e2bbdee4 100644
--- a/llvm/lib/IR/Verifier.cpp
+++ b/llvm/lib/IR/Verifier.cpp
@@ -2119,8 +2119,6 @@ void Verifier::visitFunction(const Function &F) {
   if (!N)
     return;
 
-  visitDISubprogram(*N);
-
   // Check that all !dbg attachments lead to back to N (or, at least, another
   // subprogram that describes the same function).
   //
diff --git a/llvm/test/DebugInfo/Generic/invalid.ll b/llvm/test/DebugInfo/Generic/invalid.ll
new file mode 100644
index 00000000000..fdb68d9cca3
--- /dev/null
+++ b/llvm/test/DebugInfo/Generic/invalid.ll
@@ -0,0 +1,17 @@
+; RUN: not opt -verify %s 2>&1 | FileCheck %s
+
+; Make sure we emit this diagnostic only once (which means we don't visit the
+; same DISubprogram twice.
+; CHECK: subprogram definitions must have a compile unit
+; CHECK-NEXT: !3 = distinct !DISubprogram(name: "patatino", scope: null, isLocal: false, isDefinition: true, isOptimized: false)
+; CHECK-NOT: subprogram definitions must have a compile unit
+; CHECK-NOT: !3 = distinct !DISubprogram(name: "patatino", scope: null, isLocal: false, isDefinition: true, isOptimized: false)
+
+define void @tinkywinky() !dbg !3 { ret void }
+
+!llvm.module.flags = !{!4}
+!llvm.dbg.cu = !{!0}
+!0 = distinct !DICompileUnit(language: 12, file: !1)
+!1 = !DIFile(filename: "/home/davide", directory: "/home/davide")
+!3 = distinct !DISubprogram(name: "patatino", isDefinition: true)
+!4 = !{i32 2, !"Debug Info Version", i32 3}