[InstrProf] Support for external functions in text format.

Summary:
External functions appearing as indirect call targets could not be
found in the SymTab, and the value:counter record was represented,
in the text format, using an empty string for the name. This would
then cause a silent parsing error when reading.

This CL:
- adds explicit support for such functions
- fixes the places where we would not propagate errors when reading
- addresses a performance issue due to eager resorting of the SymTab.

Reviewers: xur, eraman, davidxl

Reviewed By: davidxl

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D44717

llvm-svn: 328132

1 files changed, 0 insertions, 3 deletions

diff --git a/llvm/unittests/ProfileData/InstrProfTest.cpp b/llvm/unittests/ProfileData/InstrProfTest.cpp
index 79f880e475c..309241dfe6b 100644
--- a/llvm/unittests/ProfileData/InstrProfTest.cpp
+++ b/llvm/unittests/ProfileData/InstrProfTest.cpp
@@ -769,7 +769,6 @@ TEST_P(MaybeSparseInstrProfTest, value_prof_data_read_write_mapping) {
   Symtab.mapAddress(uint64_t(callee3), 0x3000ULL);
   Symtab.mapAddress(uint64_t(callee4), 0x4000ULL);
   // Missing mapping for callee5
-  Symtab.finalizeSymtab();
 
   VPData->deserializeTo(Record, &Symtab.getAddrHashMap());
 
@@ -858,8 +857,6 @@ TEST_P(MaybeSparseInstrProfTest, instr_prof_symtab_test) {
   EXPECT_THAT_ERROR(Symtab.addFuncName("blah_1"), Succeeded());
   EXPECT_THAT_ERROR(Symtab.addFuncName("blah_2"), Succeeded());
   EXPECT_THAT_ERROR(Symtab.addFuncName("blah_3"), Succeeded());
-  // Finalize it
-  Symtab.finalizeSymtab();
 
   // Check again
   R = Symtab.getFuncName(IndexedInstrProf::ComputeHash("blah_1"));