diff mbox series

Bug 27236 - Pointer comparison wrongly fails because of typedef change

Message ID 87sg6ogxp6.fsf@redhat.com
State New
Headers show
Series Bug 27236 - Pointer comparison wrongly fails because of typedef change | expand

Commit Message

Dodji Seketeli Jan. 26, 2021, 3:54 a.m. UTC
Hello,

Suppose we have a type struct S and a type T defined as:
  typedef struct S T;

Today, Libabigail considers that the two pointers "struct S*" and "T*"
are different.

The problem is that this can cause spurious change reports (as
reported by (abidw --abidiff) in binaries where we have the same type
defined more than once, each time using a different various around
this theme.

This patch make libabigail to now consider that "struct S*" and "T*"
are equal.  It does the same for references and arrays.

	 * src/abg-ir.cc (equals): In the overloads for pointer_type_def,
	reference_type_def and array_type_def, compare the pointed-to-type
	modulo typedefs.
	* tests/data/test-diff-dwarf/test42-PR21296-clanggcc-report0.txt: Adjust.
	* tests/data/test-diff-pkg/libICE-1.0.6-1.el6.x86_64.rpm--libICE-1.0.9-2.el7.x86_64.rpm-report-0.txt:
	Adjust.
	* tests/data/test-diff-pkg/spice-server-0.12.4-19.el7.x86_64-0.12.8-1.el7.x86_64-report-2.txt:
	Adjust.

Signed-off-by: Dodji Seketeli <dodji@redhat.com>

Applied to master.

---
 src/abg-ir.cc                                        | 12 +++++++++---
 .../test42-PR21296-clanggcc-report0.txt              |  2 --
 ...4.rpm--libICE-1.0.9-2.el7.x86_64.rpm-report-0.txt |  2 +-
 ....4-19.el7.x86_64-0.12.8-1.el7.x86_64-report-2.txt | 11 +----------
 4 files changed, 11 insertions(+), 16 deletions(-)
diff mbox series

Patch

diff --git a/src/abg-ir.cc b/src/abg-ir.cc
index 51e0c131..6d7a60a6 100644
--- a/src/abg-ir.cc
+++ b/src/abg-ir.cc
@@ -14101,7 +14101,9 @@  pointer_type_def::pointer_type_def(const type_base_sptr&	pointed_to,
 bool
 equals(const pointer_type_def& l, const pointer_type_def& r, change_kind* k)
 {
-  bool result = (l.get_pointed_to_type() == r.get_pointed_to_type());
+  // Compare the pointed-to-types modulo the typedefs they might have
+  bool result = (peel_typedef_type(l.get_pointed_to_type())
+		 == peel_typedef_type(r.get_pointed_to_type()));
   if (!result)
     if (k)
       {
@@ -14406,7 +14408,9 @@  equals(const reference_type_def& l, const reference_type_def& r, change_kind* k)
       return false;
     }
 
-  bool result = (l.get_pointed_to_type() == r.get_pointed_to_type());
+  // Compare the pointed-to-types modulo the typedefs they might have
+  bool result = (peel_typedef_type(l.get_pointed_to_type())
+		 == (peel_typedef_type(r.get_pointed_to_type())));
   if (!result)
     if (k)
       {
@@ -15226,7 +15230,9 @@  equals(const array_type_def& l, const array_type_def& r, change_kind* k)
 	  return false;
       }
 
-  if (l.get_element_type() != r.get_element_type())
+  // Compare the element types modulo the typedefs they might have
+  if (peel_typedef_type(l.get_element_type())
+      != peel_typedef_type(r.get_element_type()))
     {
       result = false;
       if (k)
diff --git a/tests/data/test-diff-dwarf/test42-PR21296-clanggcc-report0.txt b/tests/data/test-diff-dwarf/test42-PR21296-clanggcc-report0.txt
index 41114db3..61491027 100644
--- a/tests/data/test-diff-dwarf/test42-PR21296-clanggcc-report0.txt
+++ b/tests/data/test-diff-dwarf/test42-PR21296-clanggcc-report0.txt
@@ -55,8 +55,6 @@  Variables changes summary: 0 Removed, 0 Changed, 0 Added variable
   [C] 'function std::remove_reference<STR&>::type&& std::move<STR&>(STR&)' has some indirect sub-type changes:
     'function std::remove_reference<STR&>::type&& std::move<STR&>(STR&) {_ZSt4moveIR3STREONSt16remove_referenceIT_E4typeEOS3_}' now becomes 'function std::remove_reference<STR &>::type&& std::move<STR &>(STR&) {_ZSt4moveIR3STREONSt16remove_referenceIT_E4typeEOS3_}'
     return type changed:
-      in referenced type 'typedef std::remove_reference<STR&>::type':
-        typedef name changed from std::remove_reference<STR&>::type to std::remove_reference<STR &>::type
 
   [C] 'function void tpl<std::tuple<STR&&> >(std::tuple<STR&&>)' has some indirect sub-type changes:
     'function void tpl<std::tuple<STR&&> >(std::tuple<STR&&>) {_Z3tplISt5tupleIJO3STREEEvT_}' now becomes 'function void tpl<std::tuple<STR &&> >(std::tuple<STR &&>) {_Z3tplISt5tupleIJO3STREEEvT_}'
diff --git a/tests/data/test-diff-pkg/libICE-1.0.6-1.el6.x86_64.rpm--libICE-1.0.9-2.el7.x86_64.rpm-report-0.txt b/tests/data/test-diff-pkg/libICE-1.0.6-1.el6.x86_64.rpm--libICE-1.0.9-2.el7.x86_64.rpm-report-0.txt
index 59202ee4..2172e1c4 100644
--- a/tests/data/test-diff-pkg/libICE-1.0.6-1.el6.x86_64.rpm--libICE-1.0.9-2.el7.x86_64.rpm-report-0.txt
+++ b/tests/data/test-diff-pkg/libICE-1.0.6-1.el6.x86_64.rpm--libICE-1.0.9-2.el7.x86_64.rpm-report-0.txt
@@ -15,7 +15,7 @@ 
         underlying type '_IceConn*' changed:
           in pointed to type 'struct _IceConn' at ICEconn.h:131:1:
             type size hasn't changed
-            2 data member changes (3 filtered):
+            2 data member changes (2 filtered):
               type of 'IceListenObj _IceConn::listen_obj' changed:
                 underlying type '_IceListenObj*' changed:
                   in pointed to type 'struct _IceListenObj' at ICElibint.h:120:1:
diff --git a/tests/data/test-diff-pkg/spice-server-0.12.4-19.el7.x86_64-0.12.8-1.el7.x86_64-report-2.txt b/tests/data/test-diff-pkg/spice-server-0.12.4-19.el7.x86_64-0.12.8-1.el7.x86_64-report-2.txt
index 550ef6f3..5463d5e1 100644
--- a/tests/data/test-diff-pkg/spice-server-0.12.4-19.el7.x86_64-0.12.8-1.el7.x86_64-report-2.txt
+++ b/tests/data/test-diff-pkg/spice-server-0.12.4-19.el7.x86_64-0.12.8-1.el7.x86_64-report-2.txt
@@ -303,16 +303,7 @@ 
                                                                       type of 'CommonChannel CursorChannel::common' changed, as reported earlier
                                                               type of 'QXLInstance* RedWorker::qxl' changed:
                                                                 in pointed to type 'typedef QXLInstance' at spice-qxl.h:34:1:
-                                                                  underlying type 'struct QXLInstance' at spice.h:259:1 changed:
-                                                                    type size hasn't changed
-                                                                    1 data member change:
-                                                                      type of 'QXLState* QXLInstance::st' changed:
-                                                                        in pointed to type 'typedef QXLState' at spice-qxl.h:35:1:
-                                                                          underlying type 'struct QXLState' at reds.h:93:1 changed:
-                                                                            type size hasn't changed
-                                                                            1 data member change:
-                                                                              type of 'RedDispatcher* QXLState::dispatcher' changed:
-                                                                                pointed to type 'struct RedDispatcher' changed, as being reported
+                                                                  underlying type 'struct QXLInstance' changed, as being reported
                                                               type of 'RedDispatcher* RedWorker::red_dispatcher' changed:
                                                                 in pointed to type 'typedef RedDispatcher':
                                                                   entity changed from 'typedef RedDispatcher' to compatible type 'struct RedDispatcher'