[Lldb-commits] [PATCH] D137983: [lldb] Disable looking at pointee types to find synthetic value for non-ObjC

[Arthur Eubanks via Phabricator via lldb-commits]

This revision was automatically updated to reflect the committed changes.
Closed by commit rG8b80e8ee1fca: [lldb] Disable looking at pointee types to 
find synthetic value for non-ObjC (authored by aeubanks).

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Files:
  lldb/source/Core/ValueObject.cpp
  lldb/test/API/lang/cpp/incomplete-stl-types/Makefile
  lldb/test/API/lang/cpp/incomplete-stl-types/TestStlIncompleteTypes.py
  lldb/test/API/lang/cpp/incomplete-stl-types/f.cpp
  lldb/test/API/lang/cpp/incomplete-stl-types/main.cpp


Index: lldb/test/API/lang/cpp/incomplete-stl-types/main.cpp
===
--- /dev/null
+++ lldb/test/API/lang/cpp/incomplete-stl-types/main.cpp
@@ -0,0 +1,8 @@
+#include 
+
+void f(std::set );
+
+int main() {
+  std::set v;
+  f(v);
+}
Index: lldb/test/API/lang/cpp/incomplete-stl-types/f.cpp
===
--- /dev/null
+++ lldb/test/API/lang/cpp/incomplete-stl-types/f.cpp
@@ -0,0 +1,5 @@
+#include 
+
+void f(std::set ) {
+  // break here
+}
Index: lldb/test/API/lang/cpp/incomplete-stl-types/TestStlIncompleteTypes.py
===
--- /dev/null
+++ lldb/test/API/lang/cpp/incomplete-stl-types/TestStlIncompleteTypes.py
@@ -0,0 +1,18 @@
+"""
+Test situations where the debug info only has a declaration, no definition, for
+an STL container with a formatter.
+"""
+
+import lldb
+from lldbsuite.test.decorators import *
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test import lldbutil
+
+
+class TestStlIncompleteTypes(TestBase):
+def test(self):
+self.build()
+lldbutil.run_to_source_breakpoint(self, "// break here", 
lldb.SBFileSpec("f.cpp"))
+
+var = self.frame().GetValueForVariablePath("v")
+self.assertIn("set", var.GetDisplayTypeName())
Index: lldb/test/API/lang/cpp/incomplete-stl-types/Makefile
===
--- /dev/null
+++ lldb/test/API/lang/cpp/incomplete-stl-types/Makefile
@@ -0,0 +1,9 @@
+CXX_SOURCES := main.cpp f.cpp
+
+include Makefile.rules
+
+# Force main.cpp to be built with no debug information
+main.o: CFLAGS = $(CFLAGS_NO_DEBUG)
+
+# And force -flimit-debug-info on the rest.
+f.o: CFLAGS_EXTRAS += $(LIMIT_DEBUG_INFO_FLAGS)
Index: lldb/source/Core/ValueObject.cpp
===
--- lldb/source/Core/ValueObject.cpp
+++ lldb/source/Core/ValueObject.cpp
@@ -2673,7 +2673,10 @@
 // In case of incomplete child compiler type, use the pointee type and try
 // to recreate a new ValueObjectChild using it.
 if (!m_deref_valobj) {
-  if (HasSyntheticValue()) {
+  // FIXME(#59012): C++ stdlib formatters break with incomplete types (e.g.
+  // `std::vector &`). Remove ObjC restriction once that's resolved.
+  if (Language::LanguageIsObjC(GetPreferredDisplayLanguage()) &&
+  HasSyntheticValue()) {
 child_compiler_type = compiler_type.GetPointeeType();
 
 if (child_compiler_type) {


Index: lldb/test/API/lang/cpp/incomplete-stl-types/main.cpp
===
--- /dev/null
+++ lldb/test/API/lang/cpp/incomplete-stl-types/main.cpp
@@ -0,0 +1,8 @@
+#include 
+
+void f(std::set );
+
+int main() {
+  std::set v;
+  f(v);
+}
Index: lldb/test/API/lang/cpp/incomplete-stl-types/f.cpp
===
--- /dev/null
+++ lldb/test/API/lang/cpp/incomplete-stl-types/f.cpp
@@ -0,0 +1,5 @@
+#include 
+
+void f(std::set ) {
+  // break here
+}
Index: lldb/test/API/lang/cpp/incomplete-stl-types/TestStlIncompleteTypes.py
===
--- /dev/null
+++ lldb/test/API/lang/cpp/incomplete-stl-types/TestStlIncompleteTypes.py
@@ -0,0 +1,18 @@
+"""
+Test situations where the debug info only has a declaration, no definition, for
+an STL container with a formatter.
+"""
+
+import lldb
+from lldbsuite.test.decorators import *
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test import lldbutil
+
+
+class TestStlIncompleteTypes(TestBase):
+def test(self):
+self.build()
+lldbutil.run_to_source_breakpoint(self, "// break here", lldb.SBFileSpec("f.cpp"))
+
+var = self.frame().GetValueForVariablePath("v")
+self.assertIn("set", var.GetDisplayTypeName())
Index: lldb/test/API/lang/cpp/incomplete-stl-types/Makefile
===
--- /dev/null
+++ lldb/test/API/lang/cpp/incomplete-stl-types/Makefile
@@ -0,0 +1,9 @@
+CXX_SOURCES := main.cpp f.cpp
+
+include Makefile.rules
+
+# Force main.cpp to be built with no debug information
+main.o: CFLAGS = $(CFLAGS_NO_DEBUG)
+
+# And force -flimit-debug-info on the rest.
+f.o: 

[Lldb-commits] [PATCH] D137983: [lldb] Disable looking at pointee types to find synthetic value for non-ObjC

[Pavel Labath via Phabricator via lldb-commits]

labath accepted this revision.
labath added a comment.
This revision is now accepted and ready to land.

Okay, here goes nothing.


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[Lldb-commits] [PATCH] D137983: [lldb] Disable looking at pointee types to find synthetic value for non-ObjC

[Arthur Eubanks via Phabricator via lldb-commits]

aeubanks added a comment.

would somebody be willing to lgtm the workaround while we investigate further 
since this is currently breaking a fairly typical debugging session?


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[Lldb-commits] [PATCH] D137983: [lldb] Disable looking at pointee types to find synthetic value for non-ObjC

[Arthur Eubanks via Phabricator via lldb-commits]

aeubanks added a comment.

In D137983#3930973 , @labath wrote:

> We have tests for shared libraries (grep for DYLIB_C(XX)_SOURCES)), but it's 
> easier to reproduce this problem by compiling one CU with -g0 -- see inline 
> comment. (If you are creating an "API" test for this, beware that their 
> default is to build everything with -fstandalone-debug, and you'll need to 
> explicitly change that (see LIMIT_DEBUG_INFO_FLAGS))

`lldb/test/API/lang/cpp/incomplete-types/` looks like exactly what I want, I've 
added a test based on that (and verified that lldb crashes in that test without 
the source change)

> This behavior (bug) is triggered by the `FrontEndWantsDereference` formatter 
> flag, which is why it manifests itself for (libc++) vector and friends. The 
> ObjC formatters don't set that flag so they should be safe. The libstdc++ 
> formatters don't set it either. Furthermore there doesn't seem to be a way to 
> set this flag by the user, so it is not possible to create a 
> libc++-independent reproducer (which is what I was going to suggest).
>
> I've been looking for a better way to fix this today (sorry about the delay), 
> but I haven't figured out anything better. There is this fundamental 
> recursion between the pretty printer (which wants to dereference a value) and 
> the dereferencing code (which wants to know if it has a pretty printer -- so 
> it can avoid dereferencing). Just removing the `HasSyntheticValue()`fixed the 
> bug for me -- but then we were able to "dereference" incomplete structs. It's 
> possible we may be able to allow the dereference to succeed here, but then 
> refuse to print the value somewhere down the line. I would like to hear what 
> @jingham things about all this.

Thanks for the investigation!
Actually some libstdc++ formatters do also set `FrontEndWantsDereference`, so 
this is reproable with

  $ cat /tmp/main.cc
  #include 
  
  void f(std::set& v);
  
  int main() {
  std::set v;
  f(v);
  }
  $ cat /tmp/a.cc
  #include 
  
  void f(std::set& v) {
  // break
  }
  $ bin/clang++ -g0 /tmp/main.cc -o /tmp/main.o  -c && bin/clang++ -g /tmp/a.cc 
-o /tmp/a.o  -c && bin/clang++ /tmp/a.o /tmp/main.o -o /tmp/a
  $ bin/lldb /tmp/a -b -o 'br set -n f'  -o run

with and without `-stdlib=libc++`

maybe a more targeted solution would be to change the added condition to when 
`FrontEndWantsDereference` is set, but that's more annoying to thread through 
the code. I think this should be ok as a temporary workaround if we don't have 
a proper fix soonish?


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[Lldb-commits] [PATCH] D137983: [lldb] Disable looking at pointee types to find synthetic value for non-ObjC

[Arthur Eubanks via Phabricator via lldb-commits]

aeubanks updated this revision to Diff 476199.
aeubanks added a comment.

add test


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Files:
  lldb/source/Core/ValueObject.cpp
  lldb/test/API/lang/cpp/incomplete-stl-types/Makefile
  lldb/test/API/lang/cpp/incomplete-stl-types/TestStlIncompleteTypes.py
  lldb/test/API/lang/cpp/incomplete-stl-types/f.cpp
  lldb/test/API/lang/cpp/incomplete-stl-types/main.cpp


Index: lldb/test/API/lang/cpp/incomplete-stl-types/main.cpp
===
--- /dev/null
+++ lldb/test/API/lang/cpp/incomplete-stl-types/main.cpp
@@ -0,0 +1,8 @@
+#include 
+
+void f(std::set );
+
+int main() {
+  std::set v;
+  f(v);
+}
Index: lldb/test/API/lang/cpp/incomplete-stl-types/f.cpp
===
--- /dev/null
+++ lldb/test/API/lang/cpp/incomplete-stl-types/f.cpp
@@ -0,0 +1,5 @@
+#include 
+
+void f(std::set ) {
+  // break here
+}
Index: lldb/test/API/lang/cpp/incomplete-stl-types/TestStlIncompleteTypes.py
===
--- /dev/null
+++ lldb/test/API/lang/cpp/incomplete-stl-types/TestStlIncompleteTypes.py
@@ -0,0 +1,18 @@
+"""
+Test situations where the debug info only has a declaration, no definition, for
+an STL container with a formatter.
+"""
+
+import lldb
+from lldbsuite.test.decorators import *
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test import lldbutil
+
+
+class TestStlIncompleteTypes(TestBase):
+def test(self):
+self.build()
+lldbutil.run_to_source_breakpoint(self, "// break here", 
lldb.SBFileSpec("f.cpp"))
+
+var = self.frame().GetValueForVariablePath("v")
+self.assertIn("set", var.GetDisplayTypeName())
Index: lldb/test/API/lang/cpp/incomplete-stl-types/Makefile
===
--- /dev/null
+++ lldb/test/API/lang/cpp/incomplete-stl-types/Makefile
@@ -0,0 +1,9 @@
+CXX_SOURCES := main.cpp f.cpp
+
+include Makefile.rules
+
+# Force main.cpp to be built with no debug information
+main.o: CFLAGS = $(CFLAGS_NO_DEBUG)
+
+# And force -flimit-debug-info on the rest.
+f.o: CFLAGS_EXTRAS += $(LIMIT_DEBUG_INFO_FLAGS)
Index: lldb/source/Core/ValueObject.cpp
===
--- lldb/source/Core/ValueObject.cpp
+++ lldb/source/Core/ValueObject.cpp
@@ -2673,7 +2673,10 @@
 // In case of incomplete child compiler type, use the pointee type and try
 // to recreate a new ValueObjectChild using it.
 if (!m_deref_valobj) {
-  if (HasSyntheticValue()) {
+  // FIXME(#59012): C++ stdlib formatters break with incomplete types (e.g.
+  // `std::vector &`). Remove ObjC restriction once that's resolved.
+  if (Language::LanguageIsObjC(GetPreferredDisplayLanguage()) &&
+  HasSyntheticValue()) {
 child_compiler_type = compiler_type.GetPointeeType();
 
 if (child_compiler_type) {


Index: lldb/test/API/lang/cpp/incomplete-stl-types/main.cpp
===
--- /dev/null
+++ lldb/test/API/lang/cpp/incomplete-stl-types/main.cpp
@@ -0,0 +1,8 @@
+#include 
+
+void f(std::set );
+
+int main() {
+  std::set v;
+  f(v);
+}
Index: lldb/test/API/lang/cpp/incomplete-stl-types/f.cpp
===
--- /dev/null
+++ lldb/test/API/lang/cpp/incomplete-stl-types/f.cpp
@@ -0,0 +1,5 @@
+#include 
+
+void f(std::set ) {
+  // break here
+}
Index: lldb/test/API/lang/cpp/incomplete-stl-types/TestStlIncompleteTypes.py
===
--- /dev/null
+++ lldb/test/API/lang/cpp/incomplete-stl-types/TestStlIncompleteTypes.py
@@ -0,0 +1,18 @@
+"""
+Test situations where the debug info only has a declaration, no definition, for
+an STL container with a formatter.
+"""
+
+import lldb
+from lldbsuite.test.decorators import *
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test import lldbutil
+
+
+class TestStlIncompleteTypes(TestBase):
+def test(self):
+self.build()
+lldbutil.run_to_source_breakpoint(self, "// break here", lldb.SBFileSpec("f.cpp"))
+
+var = self.frame().GetValueForVariablePath("v")
+self.assertIn("set", var.GetDisplayTypeName())
Index: lldb/test/API/lang/cpp/incomplete-stl-types/Makefile
===
--- /dev/null
+++ lldb/test/API/lang/cpp/incomplete-stl-types/Makefile
@@ -0,0 +1,9 @@
+CXX_SOURCES := main.cpp f.cpp
+
+include Makefile.rules
+
+# Force main.cpp to be built with no debug information
+main.o: CFLAGS = $(CFLAGS_NO_DEBUG)
+
+# And force -flimit-debug-info on the rest.
+f.o: CFLAGS_EXTRAS += $(LIMIT_DEBUG_INFO_FLAGS)
Index: lldb/source/Core/ValueObject.cpp

[Lldb-commits] [PATCH] D137983: [lldb] Disable looking at pointee types to find synthetic value for non-ObjC

[Pavel Labath via Phabricator via lldb-commits]

labath added a comment.

We have tests for shared libraries (grep for DYLIB_C(XX)_SOURCES)), but it's 
easier to reproduce this problem by compiling one CU with -g0 -- see inline 
comment. (If you are creating an "API" test for this, beware that their default 
is to build everything with -fstandalone-debug, and you'll need to explicitly 
change that (see LIMIT_DEBUG_INFO_FLAGS))

This behavior (bug) is triggered by the `FrontEndWantsDereference` formatter 
flag, which is why it manifests itself for (libc++) vector and friends. The 
ObjC formatters don't set that flag so they should be safe. The libstdc++ 
formatters don't set it either. Furthermore there doesn't seem to be a way to 
set this flag by the user, so it is not possible to create a libc++-independent 
reproducer (which is what I was going to suggest).

I've been looking for a better way to fix this today (sorry about the delay), 
but I haven't figured out anything better. There is this fundamental recursion 
between the pretty printer (which wants to dereference a value) and the 
dereferencing code (which wants to know if it has a pretty printer -- so it can 
avoid dereferencing). Just removing the `HasSyntheticValue()`fixed the bug for 
me -- but then we were able to "dereference" incomplete structs. It's possible 
we may be able to allow the dereference to succeed here, but then refuse to 
print the value somewhere down the line. I would like to hear what @jingham 
things about all this.




Comment at: lldb/source/Core/ValueObject.cpp:2676-2677
 if (!m_deref_valobj) {
-  if (HasSyntheticValue()) {
+  // FIXME: C++ stdlib formatters break with incomplete types (e.g.
+  // `std::vector &`). Remove ObjC restriction once that's resolved.
+  if (Language::LanguageIsObjC(GetPreferredDisplayLanguage()) &&

aeubanks wrote:
> dblaikie wrote:
> > Maybe worth filing a bug and referencing it here?
> > 
> > Is this limitation still necessary if the incomplete type has template 
> > parameter DIEs? (I guess probably yes, because it'll be missing member 
> > descriptions, etc)
> > 
> > & does this path get hit if the type is declared in one CU but defined in 
> > another? (& does the inf recurse/crash loop still get hit in that case, 
> > without this patch?)
> > Maybe worth filing a bug and referencing it here?
> Filed https://github.com/llvm/llvm-project/issues/59012, added here
> 
> > Is this limitation still necessary if the incomplete type has template 
> > parameter DIEs? (I guess probably yes, because it'll be missing member 
> > descriptions, etc)
> yes (I incorrectly mentioned in person that this works with 
> `-gsimple-template-names`, it actually still infinite recurses)
> 
> > & does this path get hit if the type is declared in one CU but defined in 
> > another? (& does the inf recurse/crash loop still get hit in that case, 
> > without this patch?)
> if the declaration is in a shared library and the main binary has the 
> definition, we hit this
> if we have two CUs, one with a declaration, one with a definition, but both 
> linked into the same binary, we don't hit the issue
> AFAICT lldb restricts looking up debug info to the binary/shared library, but 
> otherwise prefers definitions over declarations?
Yes, but if one of those CUs (the one that was supposed to contain the 
definition) is built without debug info, then we end up exactly in the same 
situation (a binary without a definition of a type), but without the 
complications that shared libraries bring.


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[Lldb-commits] [PATCH] D137983: [lldb] Disable looking at pointee types to find synthetic value for non-ObjC

[Arthur Eubanks via Phabricator via lldb-commits]

aeubanks added inline comments.



Comment at: lldb/source/Core/ValueObject.cpp:2676-2677
 if (!m_deref_valobj) {
-  if (HasSyntheticValue()) {
+  // FIXME: C++ stdlib formatters break with incomplete types (e.g.
+  // `std::vector &`). Remove ObjC restriction once that's resolved.
+  if (Language::LanguageIsObjC(GetPreferredDisplayLanguage()) &&

dblaikie wrote:
> Maybe worth filing a bug and referencing it here?
> 
> Is this limitation still necessary if the incomplete type has template 
> parameter DIEs? (I guess probably yes, because it'll be missing member 
> descriptions, etc)
> 
> & does this path get hit if the type is declared in one CU but defined in 
> another? (& does the inf recurse/crash loop still get hit in that case, 
> without this patch?)
> Maybe worth filing a bug and referencing it here?
Filed https://github.com/llvm/llvm-project/issues/59012, added here

> Is this limitation still necessary if the incomplete type has template 
> parameter DIEs? (I guess probably yes, because it'll be missing member 
> descriptions, etc)
yes (I incorrectly mentioned in person that this works with 
`-gsimple-template-names`, it actually still infinite recurses)

> & does this path get hit if the type is declared in one CU but defined in 
> another? (& does the inf recurse/crash loop still get hit in that case, 
> without this patch?)
if the declaration is in a shared library and the main binary has the 
definition, we hit this
if we have two CUs, one with a declaration, one with a definition, but both 
linked into the same binary, we don't hit the issue
AFAICT lldb restricts looking up debug info to the binary/shared library, but 
otherwise prefers definitions over declarations?


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[Lldb-commits] [PATCH] D137983: [lldb] Disable looking at pointee types to find synthetic value for non-ObjC

[Arthur Eubanks via Phabricator via lldb-commits]

aeubanks updated this revision to Diff 475627.
aeubanks added a comment.

add bug


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Files:
  lldb/source/Core/ValueObject.cpp


Index: lldb/source/Core/ValueObject.cpp
===
--- lldb/source/Core/ValueObject.cpp
+++ lldb/source/Core/ValueObject.cpp
@@ -2673,7 +2673,10 @@
 // In case of incomplete child compiler type, use the pointee type and try
 // to recreate a new ValueObjectChild using it.
 if (!m_deref_valobj) {
-  if (HasSyntheticValue()) {
+  // FIXME(#59012): C++ stdlib formatters break with incomplete types (e.g.
+  // `std::vector &`). Remove ObjC restriction once that's resolved.
+  if (Language::LanguageIsObjC(GetPreferredDisplayLanguage()) &&
+  HasSyntheticValue()) {
 child_compiler_type = compiler_type.GetPointeeType();
 
 if (child_compiler_type) {


Index: lldb/source/Core/ValueObject.cpp
===
--- lldb/source/Core/ValueObject.cpp
+++ lldb/source/Core/ValueObject.cpp
@@ -2673,7 +2673,10 @@
 // In case of incomplete child compiler type, use the pointee type and try
 // to recreate a new ValueObjectChild using it.
 if (!m_deref_valobj) {
-  if (HasSyntheticValue()) {
+  // FIXME(#59012): C++ stdlib formatters break with incomplete types (e.g.
+  // `std::vector &`). Remove ObjC restriction once that's resolved.
+  if (Language::LanguageIsObjC(GetPreferredDisplayLanguage()) &&
+  HasSyntheticValue()) {
 child_compiler_type = compiler_type.GetPointeeType();
 
 if (child_compiler_type) {
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[Lldb-commits] [PATCH] D137983: [lldb] Disable looking at pointee types to find synthetic value for non-ObjC

[David Blaikie via Phabricator via lldb-commits]

dblaikie added inline comments.



Comment at: lldb/source/Core/ValueObject.cpp:2676-2677
 if (!m_deref_valobj) {
-  if (HasSyntheticValue()) {
+  // FIXME: C++ stdlib formatters break with incomplete types (e.g.
+  // `std::vector &`). Remove ObjC restriction once that's resolved.
+  if (Language::LanguageIsObjC(GetPreferredDisplayLanguage()) &&

Maybe worth filing a bug and referencing it here?

Is this limitation still necessary if the incomplete type has template 
parameter DIEs? (I guess probably yes, because it'll be missing member 
descriptions, etc)

& does this path get hit if the type is declared in one CU but defined in 
another? (& does the inf recurse/crash loop still get hit in that case, without 
this patch?)


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[Lldb-commits] [PATCH] D137983: [lldb] Disable looking at pointee types to find synthetic value for non-ObjC

[Arthur Eubanks via Phabricator via lldb-commits]

aeubanks added a comment.

also I'm don't understand how this code doesn't infinite recurse on ObjC and 
can't trace it because I don't have a mac

if anybody has an actual way of fixing this I'd be happy with that too


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[Lldb-commits] [PATCH] D137983: [lldb] Disable looking at pointee types to find synthetic value for non-ObjC

[Arthur Eubanks via Phabricator via lldb-commits]

aeubanks added a comment.
Herald added a subscriber: JDevlieghere.

lldb crash repro

  $ cat /tmp/a.cc
  #include 
  
  void f(std::vector& v) {
  *(volatile int*) nullptr = 0;
  }
  $ cat /tmp/main.cc
  #include 
  
  void f(std::vector& v);
  
  int main() {
  std::vector v ;
  f(v);
  }
  $ ./build/bin/clang++ -g /tmp/a.cc -o /tmp/a.so -shared -stdlib=libc++ 
-fuse-ld=lld -Wl,-rpath,$PWD/build/rel/lib
  $ ./build/bin/clang++ -g /tmp/main.cc /tmp/a.so -o /tmp/a -stdlib=libc++ 
-fuse-ld=lld -Wl,-rpath,$PWD/build/rel/lib
  $ ./build/bin/lldb /tmp/a -b -o run
  # crash

any help with adding a test case for this would be appreciated, I'm not sure if 
there's any testing for shared libraries in lldb?


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[Lldb-commits] [PATCH] D137983: [lldb] Disable looking at pointee types to find synthetic value for non-ObjC

[Arthur Eubanks via Phabricator via lldb-commits]

aeubanks created this revision.
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After D134378 , we started seeing crashes 
with incomplete types (in the
context of shared libraries).

When trying to print a `std::vector &` with only debug info for a
declaration, we now try to use the formatter after D134378 
. With an
incomplete type, this somehow goes into infinite recursion with the
frames

  lldb_private::ValueObject::Dereference
  lldb_private::ValueObjectSynthetic::CreateSynthFilter
  lldb_private::ValueObjectSynthetic::ValueObjectSynthetic
  lldb_private::ValueObject::CalculateSyntheticValue
  lldb_private::ValueObject::HasSyntheticValue

The reason this only started appearing after D134378 
 was because
previously with incomplete types, for names with `<`, lldb would attempt
to parse template parameter DIEs, which were empty, then create an empty
`ClassTemplateSpecializationDecl` which overrode the name used to lookup
a formatter in `FormattersMatchData()` to not include template
parameters (e.g. `std::vector<> &`). After D134378 
 we don't create a
`ClassTemplateSpecializationDecl` when there are no template parameters
and the name to lookup a formatter is the original name (e.g.
`std::vector &`).

The code to try harder with incomplete child compiler types was added in
D79554  for ObjC purposes.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D137983

Files:
  lldb/source/Core/ValueObject.cpp


Index: lldb/source/Core/ValueObject.cpp
===
--- lldb/source/Core/ValueObject.cpp
+++ lldb/source/Core/ValueObject.cpp
@@ -2673,7 +2673,10 @@
 // In case of incomplete child compiler type, use the pointee type and try
 // to recreate a new ValueObjectChild using it.
 if (!m_deref_valobj) {
-  if (HasSyntheticValue()) {
+  // FIXME: C++ stdlib formatters break with incomplete types (e.g.
+  // `std::vector &`). Remove ObjC restriction once that's resolved.
+  if (Language::LanguageIsObjC(GetPreferredDisplayLanguage()) &&
+  HasSyntheticValue()) {
 child_compiler_type = compiler_type.GetPointeeType();
 
 if (child_compiler_type) {


Index: lldb/source/Core/ValueObject.cpp
===
--- lldb/source/Core/ValueObject.cpp
+++ lldb/source/Core/ValueObject.cpp
@@ -2673,7 +2673,10 @@
 // In case of incomplete child compiler type, use the pointee type and try
 // to recreate a new ValueObjectChild using it.
 if (!m_deref_valobj) {
-  if (HasSyntheticValue()) {
+  // FIXME: C++ stdlib formatters break with incomplete types (e.g.
+  // `std::vector &`). Remove ObjC restriction once that's resolved.
+  if (Language::LanguageIsObjC(GetPreferredDisplayLanguage()) &&
+  HasSyntheticValue()) {
 child_compiler_type = compiler_type.GetPointeeType();
 
 if (child_compiler_type) {
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