[Lldb-commits] [lldb] r201473 - elf-core: Plug latent memory leak

[Ed Maste]

Author: emaste
Date: Sat Feb 15 22:01:54 2014
New Revision: 201473

URL: http://llvm.org/viewvc/llvm-project?rev=201473&view=rev
Log:
elf-core: Plug latent memory leak

ProcessElfCore::ParseThreadContextsFromNoteSegment was leaking
ThreadData for each ELF note found in core file.  We now allocate it
only once and use std::unique_ptr to ensure it is always being freed.

While at it make ParseFreeBSDThrMisc and ParseFreeBSDPrStatus take
ThreadData by reference, rather than pointer, since those arguments are
not optional.

Patch by Piotr Rak.

http://llvm-reviews.chandlerc.com/D2813

Modified:
    lldb/trunk/source/Plugins/Process/elf-core/ProcessElfCore.cpp

Modified: lldb/trunk/source/Plugins/Process/elf-core/ProcessElfCore.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/Process/elf-core/ProcessElfCore.cpp?rev=201473&r1=201472&r2=201473&view=diff
==============================================================================
--- lldb/trunk/source/Plugins/Process/elf-core/ProcessElfCore.cpp (original)
+++ lldb/trunk/source/Plugins/Process/elf-core/ProcessElfCore.cpp Sat Feb 15 22:01:54 2014
@@ -370,7 +370,7 @@ enum {
 
 // Parse a FreeBSD NT_PRSTATUS note - see FreeBSD sys/procfs.h for details.
 static void
-ParseFreeBSDPrStatus(ThreadData *thread_data, DataExtractor &data,
+ParseFreeBSDPrStatus(ThreadData &thread_data, DataExtractor &data,
                      ArchSpec &arch)
 {
     lldb::offset_t offset = 0;
@@ -391,20 +391,20 @@ ParseFreeBSDPrStatus(ThreadData *thread_
     else
         offset += 16;
 
-    thread_data->signo = data.GetU32(&offset); // pr_cursig
+    thread_data.signo = data.GetU32(&offset); // pr_cursig
     offset += 4;        // pr_pid
     if (lp64)
         offset += 4;
     
     size_t len = data.GetByteSize() - offset;
-    thread_data->gpregset = DataExtractor(data, offset, len);
+    thread_data.gpregset = DataExtractor(data, offset, len);
 }
 
 static void
-ParseFreeBSDThrMisc(ThreadData *thread_data, DataExtractor &data)
+ParseFreeBSDThrMisc(ThreadData &thread_data, DataExtractor &data)
 {
     lldb::offset_t offset = 0;
-    thread_data->name = data.GetCStr(&offset, 20);
+    thread_data.name = data.GetCStr(&offset, 20);
 }
 
 /// Parse Thread context from PT_NOTE segment and store it in the thread list
@@ -426,13 +426,13 @@ ParseFreeBSDThrMisc(ThreadData *thread_d
 ///    For case (b) there may be either one NT_PRPSINFO per thread, or a single
 ///    one that applies to all threads (depending on the platform type).
 void
-ProcessElfCore::ParseThreadContextsFromNoteSegment(const elf::ELFProgramHeader *segment_header, 
+ProcessElfCore::ParseThreadContextsFromNoteSegment(const elf::ELFProgramHeader *segment_header,
                                                    DataExtractor segment_data)
 {
     assert(segment_header && segment_header->p_type == llvm::ELF::PT_NOTE);
 
     lldb::offset_t offset = 0;
-    ThreadData *thread_data = new ThreadData();
+    std::unique_ptr<ThreadData> thread_data(new ThreadData);
     bool have_prstatus = false;
     bool have_prpsinfo = false;
 
@@ -455,7 +455,7 @@ ProcessElfCore::ParseThreadContextsFromN
             assert(thread_data->gpregset.GetByteSize() > 0);
             // Add the new thread to thread list
             m_thread_data.push_back(*thread_data);
-            thread_data = new ThreadData();
+            *thread_data = ThreadData();
             have_prstatus = false;
             have_prpsinfo = false;
         }
@@ -472,7 +472,7 @@ ProcessElfCore::ParseThreadContextsFromN
             {
                 case NT_FREEBSD_PRSTATUS:
                     have_prstatus = true;
-                    ParseFreeBSDPrStatus(thread_data, note_data, arch);
+                    ParseFreeBSDPrStatus(*thread_data, note_data, arch);
                     break;
                 case NT_FREEBSD_FPREGSET:
                     thread_data->fpregset = note_data;
@@ -481,7 +481,7 @@ ProcessElfCore::ParseThreadContextsFromN
                     have_prpsinfo = true;
                     break;
                 case NT_FREEBSD_THRMISC:
-                    ParseFreeBSDThrMisc(thread_data, note_data);
+                    ParseFreeBSDThrMisc(*thread_data, note_data);
                     break;
                 case NT_FREEBSD_PROCSTAT_AUXV:
                     // FIXME: FreeBSD sticks an int at the beginning of the note