From ded77cc92373f73bc0206f515a059488451546a8 Mon Sep 17 00:00:00 2001
From: Dehao Chen <dehao@google.com>
Date: Tue, 22 Nov 2016 22:50:01 +0000
Subject: [PATCH] Before sample pgo annotation, do not inline a function that
 has no debug info. (NFC)

If there is no debug info in the callee, inlining it will not help annotator. This avoids infinite loop as reported in PR/31119.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@287710 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Transforms/IPO/SampleProfile.cpp          |  2 ++
 .../SampleProfile/Inputs/nodebug.prof         |  2 ++
 test/Transforms/SampleProfile/early-inline.ll |  3 ++-
 test/Transforms/SampleProfile/nodebug.ll      | 20 +++++++++++++++++++
 4 files changed, 26 insertions(+), 1 deletion(-)
 create mode 100644 test/Transforms/SampleProfile/Inputs/nodebug.prof
 create mode 100644 test/Transforms/SampleProfile/nodebug.ll

diff --git a/lib/Transforms/IPO/SampleProfile.cpp b/lib/Transforms/IPO/SampleProfile.cpp
index 6e1818b2f58..cf0e02e8ecc 100644
--- a/lib/Transforms/IPO/SampleProfile.cpp
+++ b/lib/Transforms/IPO/SampleProfile.cpp
@@ -651,6 +651,8 @@ bool SampleProfileLoader::inlineHotFunctions(Function &F) {
       InvokeInst *II = dyn_cast<InvokeInst>(I);
       Function *CalledFunction =
           (CI == nullptr ? II->getCalledFunction() : CI->getCalledFunction());
+      if (!CalledFunction || !CalledFunction->getSubprogram())
+        continue;
       DebugLoc DLoc = I->getDebugLoc();
       uint64_t NumSamples = findCalleeFunctionSamples(*I)->getTotalSamples();
       if ((CI && InlineFunction(CI, IFI)) || (II && InlineFunction(II, IFI))) {
diff --git a/test/Transforms/SampleProfile/Inputs/nodebug.prof b/test/Transforms/SampleProfile/Inputs/nodebug.prof
new file mode 100644
index 00000000000..48596035758
--- /dev/null
+++ b/test/Transforms/SampleProfile/Inputs/nodebug.prof
@@ -0,0 +1,2 @@
+foo:100:10
+ 0: bar:10
diff --git a/test/Transforms/SampleProfile/early-inline.ll b/test/Transforms/SampleProfile/early-inline.ll
index 6e55ab1eec7..780ff4751f4 100644
--- a/test/Transforms/SampleProfile/early-inline.ll
+++ b/test/Transforms/SampleProfile/early-inline.ll
@@ -28,7 +28,7 @@ define void @_Z3foov() #0 personality i8* bitcast (i32 (...)* @__gxx_personality
 }
 
 ; Function Attrs: nounwind uwtable
-define internal void @_ZL3barv() #1 {
+define internal void @_ZL3barv() !dbg !12 {
   ret void
 }
 
@@ -45,3 +45,4 @@ declare i32 @__gxx_personality_v0(...)
 !9 = !DILocation(line: 6, column: 3, scope: !6)
 !10 = !DILocation(line: 8, column: 5, scope: !11)
 !11 = distinct !DILexicalBlock(scope: !6, file: !1, line: 7, column: 7)
+!12 = distinct !DISubprogram(linkageName: "_ZL3barv", scope: !1, line: 20, scopeLine: 20, unit: !0)
diff --git a/test/Transforms/SampleProfile/nodebug.ll b/test/Transforms/SampleProfile/nodebug.ll
new file mode 100644
index 00000000000..d1c53c1a6f2
--- /dev/null
+++ b/test/Transforms/SampleProfile/nodebug.ll
@@ -0,0 +1,20 @@
+; RUN: opt < %s -sample-profile -sample-profile-file=%S/Inputs/nodebug.prof
+
+define void @foo() !dbg !3 {
+  call void @bar(), !dbg !4
+  ret void
+}
+
+define void @bar() {
+  call void @bar()
+  ret void
+}
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!2}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1)
+!1 = !DIFile(filename: "t", directory: "/tmp/")
+!2 = !{i32 2, !"Debug Info Version", i32 3}
+!3 = distinct !DISubprogram(name: "a", scope: !1, file: !1, line: 10, unit: !0)
+!4 = !DILocation(line: 10, scope: !3)
-- 
2.50.1