[lldb] Guarantee the lifetimes of all strings returned from SBAPI

LLDB should guarantee that the strings returned by SBAPI methods
live forever. I went through every method that returns a string and made
sure that it was added to the ConstString StringPool before returning if
it wasn't obvious that it was already doing so.
I've also updated the docs to document this behavior.

Differential Revision: https://reviews.llvm.org/D150804

1 files changed, 21 insertions, 21 deletions

diff --git a/lldb/source/API/SBModule.cpp b/lldb/source/API/SBModule.cpp
index e7c2b45..b865502 100644
--- a/lldb/source/API/SBModule.cpp
+++ b/lldb/source/API/SBModule.cpp
@@ -173,20 +173,20 @@ const uint8_t *SBModule::GetUUIDBytes() const {
 const char *SBModule::GetUUIDString() const {
   LLDB_INSTRUMENT_VA(this);
 
-  const char *uuid_cstr = nullptr;
   ModuleSP module_sp(GetSP());
-  if (module_sp) {
-    // We are going to return a "const char *" value through the public API, so
-    // we need to constify it so it gets added permanently the string pool and
-    // then we don't need to worry about the lifetime of the string as it will
-    // never go away once it has been put into the ConstString string pool
-    uuid_cstr = ConstString(module_sp->GetUUID().GetAsString()).GetCString();
-  }
-
-  if (uuid_cstr && uuid_cstr[0]) {
+  if (!module_sp)
+    return nullptr;
+
+  // We are going to return a "const char *" value through the public API, so
+  // we need to constify it so it gets added permanently the string pool and
+  // then we don't need to worry about the lifetime of the string as it will
+  // never go away once it has been put into the ConstString string pool
+  const char *uuid_cstr =
+      ConstString(module_sp->GetUUID().GetAsString()).GetCString();
+  // Note: SBModule::GetUUIDString's expected behavior is to return nullptr if
+  // the string we get is empty, so we must perform this check before returning.
+  if (uuid_cstr && uuid_cstr[0])
     return uuid_cstr;
-  }
-
   return nullptr;
 }
 
@@ -579,15 +579,15 @@ const char *SBModule::GetTriple() {
   LLDB_INSTRUMENT_VA(this);
 
   ModuleSP module_sp(GetSP());
-  if (module_sp) {
-    std::string triple(module_sp->GetArchitecture().GetTriple().str());
-    // Unique the string so we don't run into ownership issues since the const
-    // strings put the string into the string pool once and the strings never
-    // comes out
-    ConstString const_triple(triple.c_str());
-    return const_triple.GetCString();
-  }
-  return nullptr;
+  if (!module_sp)
+    return nullptr;
+
+  std::string triple(module_sp->GetArchitecture().GetTriple().str());
+  // Unique the string so we don't run into ownership issues since the const
+  // strings put the string into the string pool once and the strings never
+  // comes out
+  ConstString const_triple(triple.c_str());
+  return const_triple.GetCString();
 }
 
 uint32_t SBModule::GetAddressByteSize() {