Print column info in backtraces et al. if available

[aprantl]

Summary

This patch allows LLDB to print column info in backtraces et al. if available, which is useful when the backtrace contains a frame like the following:

f(can_crash(0), can_crash(1));

[clayborg]

We shouldn't have the colon character be part of the ${line.column} formatting itself. See inlined comments.

source/Core/Debugger.cpp

123

Add the colon between the ${line.number} and ${line.column} here, not as part of the "${line.column}" formatting itself.

"{ at ${line.file.basename}:${line.number}:${line.column}}"

source/Core/FormatEntity.cpp

1821

Remove the colon character from format.

[aprantl]

source/Core/Debugger.cpp

123

But then the colon would be printed even if there is no column. Some frames may not have column info. I'd like to have it look like this:

frame #0 at hello.c:100:42
frame #1 at nocolumns.cpp:50
...

[clayborg]

See my inlined comments about returning true and false correctly for the column and the correction to the format string

source/Core/Debugger.cpp

123

If we return true/false correctly as detailed in inline comments, you just add an extra scope {} around the ":${line.column}" and it will not be printed if anything inside the extra scope returns false:

"{ at ${line.file.basename}:${line.number}{:${line.column}}}"

source/Core/FormatEntity.cpp

1824

return true here

1826

Remove this comment

1827

return false here

[aprantl]

Address review feedback.

Thanks you, I was wondering how to properly implement an optional element!

include/lldb/Core/FormatEntity.h

enum class Type {
       FunctionAddrOffsetConcrete,
       FunctionLineOffset,
       FunctionPCOffset,
       FunctionInitial,
       FunctionChanged,
       FunctionIsOptimized,
       LineEntryFile,
       LineEntryLineNumber,
+      LineEntryColumn,
       LineEntryStartAddress,
       LineEntryEndAddress,
       CurrentPCArrow
     };
 
     enum FormatType { None, UInt32, UInt64, CString };
 
     struct Definition {

packages/Python/lldbsuite/test/functionalities/asan/Makefile

 LEVEL = ../../make
 
 C_SOURCES := main.c
-CFLAGS_EXTRAS := -fsanitize=address -g
+CFLAGS_EXTRAS := -fsanitize=address -g -gcolumn-info
 
 include $(LEVEL)/Makefile.rules

packages/Python/lldbsuite/test/functionalities/asan/TestReportData.py

class AsanTestReportDataCase(TestBase):
     def setUp(self):
         # Call super's setUp().
         TestBase.setUp(self)
         self.line_malloc = line_number('main.c', '// malloc line')
         self.line_malloc2 = line_number('main.c', '// malloc2 line')
         self.line_free = line_number('main.c', '// free line')
         self.line_breakpoint = line_number('main.c', '// break line')
         self.line_crash = line_number('main.c', '// BOOM line')
+        self.col_crash = 16
 
     def asan_tests(self):
         exe = self.getBuildArtifact("a.out")
         self.expect(
             "file " + exe,
             patterns=["Current executable set to .*a.out"])
         self.runCmd("run")
 
def asan_tests(self):
                 'stopped',
                 'stop reason = Use of deallocated memory'])
 
         self.assertEqual(
             self.dbg.GetSelectedTarget().process.GetSelectedThread().GetStopReason(),
             lldb.eStopReasonInstrumentation)
 
         self.expect("bt", "The backtrace should show the crashing line",
-                    substrs=['main.c:%d' % self.line_crash])
+                    substrs=['main.c:%d:%d' % (self.line_crash, self.col_crash)])
 
         self.expect(
             "thread info -s",
             "The extended stop info should contain the ASan provided fields",
             substrs=[
                 "access_size",
                 "access_type",
                 "address",

source/Core/Debugger.cpp

#define MODULE_WITH_FUNC                                                       \
   "${module.file.basename}{`${function.name-with-args}"                        \
   "{${frame.no-debug}${function.pc-offset}}}}"
 
 #define MODULE_WITH_FUNC_NO_ARGS                                               \
   "{ "                                                                         \
   "${module.file.basename}{`${function.name-without-args}"                     \
   "{${frame.no-debug}${function.pc-offset}}}}"
 
-#define FILE_AND_LINE "{ at ${line.file.basename}:${line.number}}"
+#define FILE_AND_LINE                                                          \
+  "{ at ${line.file.basename}:${line.number}{:${line.column}}}"
 #define IS_OPTIMIZED "{${function.is-optimized} [opt]}"
 
 #define DEFAULT_THREAD_FORMAT                                                  \
   "thread #${thread.index}: tid = ${thread.id%tid}"                            \
   "{, ${frame.pc}}" MODULE_WITH_FUNC FILE_AND_LINE                             \
   "{, name = '${thread.name}'}"                                                \
   "{, queue = '${thread.queue}'}"                                              \
   "{, activity = '${thread.info.activity.name}'}"                              \

source/Core/FormatEntity.cpp

static FormatEntity::Entry::Definition g_function_child_entries[] = {
     ENTRY("pc-offset", FunctionPCOffset, UInt64),
     ENTRY("initial-function", FunctionInitial, None),
     ENTRY("changed", FunctionChanged, None),
     ENTRY("is-optimized", FunctionIsOptimized, None)};
 
 static FormatEntity::Entry::Definition g_line_child_entries[] = {
     ENTRY_CHILDREN("file", LineEntryFile, None, g_file_child_entries),
     ENTRY("number", LineEntryLineNumber, UInt32),
+    ENTRY("column", LineEntryColumn, UInt32),
     ENTRY("start-addr", LineEntryStartAddress, UInt64),
     ENTRY("end-addr", LineEntryEndAddress, UInt64),
 };
 
 static FormatEntity::Entry::Definition g_module_child_entries[] = {
     ENTRY_CHILDREN("file", ModuleFile, None, g_file_child_entries),
 };
 
switch (t) {
     ENUM_TO_CSTR(FunctionAddrOffsetConcrete);
     ENUM_TO_CSTR(FunctionLineOffset);
     ENUM_TO_CSTR(FunctionPCOffset);
     ENUM_TO_CSTR(FunctionInitial);
     ENUM_TO_CSTR(FunctionChanged);
     ENUM_TO_CSTR(FunctionIsOptimized);
     ENUM_TO_CSTR(LineEntryFile);
     ENUM_TO_CSTR(LineEntryLineNumber);
+    ENUM_TO_CSTR(LineEntryColumn);
     ENUM_TO_CSTR(LineEntryStartAddress);
     ENUM_TO_CSTR(LineEntryEndAddress);
     ENUM_TO_CSTR(CurrentPCArrow);
   }
   return "???";
 }
 
 #undef ENUM_TO_CSTR
if (sc && sc->line_entry.IsValid()) {
       const char *format = "%" PRIu32;
       if (!entry.printf_format.empty())
         format = entry.printf_format.c_str();
       s.Printf(format, sc->line_entry.line);
       return true;
     }
     return false;
 
+  case Entry::Type::LineEntryColumn:
+    if (sc && sc->line_entry.IsValid() && sc->line_entry.column) {
+      const char *format = "%" PRIu32;
+      if (!entry.printf_format.empty())
+        format = entry.printf_format.c_str();
+      s.Printf(format, sc->line_entry.column);
+      return true;
+    }
+    return false;
+
   case Entry::Type::LineEntryStartAddress:
   case Entry::Type::LineEntryEndAddress:
     if (sc && sc->line_entry.range.GetBaseAddress().IsValid()) {
       Address addr = sc->line_entry.range.GetBaseAddress();
 
       if (entry.type == Entry::Type::LineEntryEndAddress)
         addr.Slide(sc->line_entry.range.GetByteSize());
       if (DumpAddress(s, sc, exe_ctx, addr, false))