Add option eTypeOptionHideEmptyAggregates.

Summary:
For certain data structures, when the synthetic child provider returns
zero children, a summary like "Empty instance of <typename>" could be
more appropriate than something like "size=0 {}". This new option helps
hide the trailing "{}".

This is also exposed with a -h option for the command "type summary add".

Reviewers: granata.enrico

Subscribers: lldb-commits

Differential Revision: http://reviews.llvm.org/D11473

llvm-svn: 243166

3 files changed, 53 insertions, 2 deletions

diff --git a/lldb/test/python_api/formatters/TestFormattersSBAPI.py b/lldb/test/python_api/formatters/TestFormattersSBAPI.py
index b8806abf314..854b3acae58 100644
--- a/lldb/test/python_api/formatters/TestFormattersSBAPI.py
+++ b/lldb/test/python_api/formatters/TestFormattersSBAPI.py
@@ -302,6 +302,10 @@ class SBFormattersAPITestCase(TestBase):
         self.assertTrue(summary.IsValid(), "no summary found for foo* when one was in place")
         self.assertTrue(summary.GetData() == "hello static world", "wrong summary found for foo*")
 
+        self.expect("frame variable e1", substrs=["I am an empty Empty1 {}"])
+        self.expect("frame variable e2", substrs=["I am an empty Empty2"])
+        self.expect("frame variable e2", substrs=["I am an empty Empty2 {}"], matching=False)
+
     def force_synth_off(self):
         """Test that one can have the public API return non-synthetic SBValues if desired"""
         self.runCmd("file no_synth", CURRENT_EXECUTABLE_SET)
diff --git a/lldb/test/python_api/formatters/main.cpp b/lldb/test/python_api/formatters/main.cpp
index cf7e4c08ef8..f21c956144c 100644
--- a/lldb/test/python_api/formatters/main.cpp
+++ b/lldb/test/python_api/formatters/main.cpp
@@ -26,6 +26,9 @@ struct CCC
 	int a, b, c;
 };
 
+struct Empty1 { void *data; };
+struct Empty2 { void *data; };
+
 
 int main(int argc, char const *argv[]) {
 	JustAStruct foo;
@@ -49,5 +52,8 @@ int main(int argc, char const *argv[]) {
 
 	CCC ccc = {111, 222, 333};
 
+        Empty1 e1;
+        Empty2 e2;
+
 	return 0; // Set break point at this line.
 }
diff --git a/lldb/test/python_api/formatters/synth.py b/lldb/test/python_api/formatters/synth.py
index b1e95a91f67..5a30c9a94bb 100644
--- a/lldb/test/python_api/formatters/synth.py
+++ b/lldb/test/python_api/formatters/synth.py
@@ -48,6 +48,36 @@ class CCCSynthProvider(object):
             return self._sbvalue.GetChildMemberWithName("c")
 
 
+def empty1_summary(sbvalue, internal_dict):
+    return "I am an empty Empty1"
+
+
+class Empty1SynthProvider(object):
+    def __init__(self, sbvalue, internal_dict):
+        self._sbvalue = sbvalue
+
+    def num_children(self):
+        return 0
+
+    def get_child_at_index(self, index):
+        return None
+
+
+def empty2_summary(sbvalue, internal_dict):
+    return "I am an empty Empty2"
+
+
+class Empty2SynthProvider(object):
+    def __init__(self, sbvalue, internal_dict):
+        self._sbvalue = sbvalue
+
+    def num_children(self):
+        return 0
+
+    def get_child_at_index(self, index):
+        return None
+
+
 def __lldb_init_module(debugger,dict):
      debugger.CreateCategory("JASSynth").AddTypeSynthetic(lldb.SBTypeNameSpecifier("JustAStruct"),
         lldb.SBTypeSynthetic.CreateWithClassName("synth.jasSynthProvider"))
@@ -60,5 +90,16 @@ def __lldb_init_module(debugger,dict):
          lldb.SBTypeNameSpecifier("CCC"),
          lldb.SBTypeSummary.CreateWithFunctionName("synth.ccc_summary",
                                                    lldb.eTypeOptionCascade))
-
-
+     cat.AddTypeSynthetic(
+         lldb.SBTypeNameSpecifier("Empty1"),
+         lldb.SBTypeSynthetic.CreateWithClassName("synth.Empty1SynthProvider"))
+     cat.AddTypeSummary(
+         lldb.SBTypeNameSpecifier("Empty1"),
+         lldb.SBTypeSummary.CreateWithFunctionName("synth.empty1_summary"))
+     cat.AddTypeSynthetic(
+         lldb.SBTypeNameSpecifier("Empty2"),
+         lldb.SBTypeSynthetic.CreateWithClassName("synth.Empty2SynthProvider"))
+     cat.AddTypeSummary(
+         lldb.SBTypeNameSpecifier("Empty2"),
+         lldb.SBTypeSummary.CreateWithFunctionName("synth.empty2_summary",
+                                                   lldb.eTypeOptionHideEmptyAggregates))