[ProfileData] PR33517: Check for failure of symtab creation

With PR33517, it became apparent that symbol table creation can fail
when presented with malformed inputs. This patch makes that sort of
error detectable, so llvm-cov etc. can fail more gracefully.

Specifically, we now check that function names within the symbol table
aren't empty.

Testing: check-{llvm,clang,profile}, some unit test updates.
llvm-svn: 305765

1 files changed, 6 insertions, 1 deletions

diff --git a/llvm/lib/Transforms/Instrumentation/IndirectCallPromotion.cpp b/llvm/lib/Transforms/Instrumentation/IndirectCallPromotion.cpp
index 0d308810009..4089d81ea3e 100644
--- a/llvm/lib/Transforms/Instrumentation/IndirectCallPromotion.cpp
+++ b/llvm/lib/Transforms/Instrumentation/IndirectCallPromotion.cpp
@@ -642,7 +642,12 @@ static bool promoteIndirectCalls(Module &M, bool InLTO, bool SamplePGO) {
   if (DisableICP)
     return false;
   InstrProfSymtab Symtab;
-  Symtab.create(M, InLTO);
+  if (Error E = Symtab.create(M, InLTO)) {
+    std::string SymtabFailure = toString(std::move(E));
+    DEBUG(dbgs() << "Failed to create symtab: " << SymtabFailure << "\n");
+    (void)SymtabFailure;
+    return false;
+  }
   bool Changed = false;
   for (auto &F : M) {
     if (F.isDeclaration())