[gcc r16-7980] testsuite: Fix up gcc.dg/plugin/analyzer_cpython_plugin.cc [PR112520]

[Jakub Jelinek]

https://gcc.gnu.org/g:bc615c0d69e5587f7336c55cfb61f51f74429b60

commit r16-7980-gbc615c0d69e5587f7336c55cfb61f51f74429b60
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Tue Mar 10 13:26:09 2026 +0100

    testsuite: Fix up gcc.dg/plugin/analyzer_cpython_plugin.cc [PR112520]
    
    The recent r16-7938 PR112520 fix hasn't changed much in the testsuite
    results for me:
    @@ -154,41 +151,34 @@ FAIL: gcc.dg/plugin/cpython-plugin-test-
     FAIL: gcc.dg/plugin/cpython-plugin-test-PyList_Append.c -fplugin=./analyzer_cpython_plugin.so  (test for warnings, line 42)
     FAIL: gcc.dg/plugin/cpython-plugin-test-PyList_Append.c -fplugin=./analyzer_cpython_plugin.so  at line 18 (test for warnings, line 17)
     FAIL: gcc.dg/plugin/cpython-plugin-test-PyList_Append.c -fplugin=./analyzer_cpython_plugin.so  at line 43 (test for warnings, line 42)
    -FAIL: gcc.dg/plugin/cpython-plugin-test-PyList_Append.c -fplugin=./analyzer_cpython_plugin.so (internal compiler error: Segmentation fault)
    +FAIL: gcc.dg/plugin/cpython-plugin-test-PyList_Append.c -fplugin=./analyzer_cpython_plugin.so (internal compiler error: tree check: expected record_type or union_type or qual_union_type, have integer_type in get_field_by_name, at /home/jakub/src/gcc/gcc/testsuite/gcc.dg/plugin/analyzer_cpython_plugin.cc:62)
     FAIL: gcc.dg/plugin/cpython-plugin-test-PyList_Append.c -fplugin=./analyzer_cpython_plugin.so (test for excess errors)
     FAIL: gcc.dg/plugin/cpython-plugin-test-PyList_New.c -fplugin=./analyzer_cpython_plugin.so  (test for warnings, line 17)
     FAIL: gcc.dg/plugin/cpython-plugin-test-PyList_New.c -fplugin=./analyzer_cpython_plugin.so  (test for warnings, line 18)
     FAIL: gcc.dg/plugin/cpython-plugin-test-PyList_New.c -fplugin=./analyzer_cpython_plugin.so  (test for warnings, line 21)
     FAIL: gcc.dg/plugin/cpython-plugin-test-PyList_New.c -fplugin=./analyzer_cpython_plugin.so  (test for warnings, line 29)
     FAIL: gcc.dg/plugin/cpython-plugin-test-PyList_New.c -fplugin=./analyzer_cpython_plugin.so  at line 37 (test for warnings, line 36)
    -FAIL: gcc.dg/plugin/cpython-plugin-test-PyList_New.c -fplugin=./analyzer_cpython_plugin.so (internal compiler error: Segmentation fault)
    +FAIL: gcc.dg/plugin/cpython-plugin-test-PyList_New.c -fplugin=./analyzer_cpython_plugin.so (internal compiler error: tree check: expected record_type or union_type or qual_union_type, have integer_type in get_field_by_name, at /home/jakub/src/gcc/gcc/testsuite/gcc.dg/plugin/analyzer_cpython_plugin.cc:62)
     FAIL: gcc.dg/plugin/cpython-plugin-test-PyList_New.c -fplugin=./analyzer_cpython_plugin.so (test for excess errors)
     FAIL: gcc.dg/plugin/cpython-plugin-test-PyLong_FromLong.c -fplugin=./analyzer_cpython_plugin.so  (test for warnings, line 17)
     FAIL: gcc.dg/plugin/cpython-plugin-test-PyLong_FromLong.c -fplugin=./analyzer_cpython_plugin.so  (test for warnings, line 18)
     FAIL: gcc.dg/plugin/cpython-plugin-test-PyLong_FromLong.c -fplugin=./analyzer_cpython_plugin.so  (test for warnings, line 21)
     FAIL: gcc.dg/plugin/cpython-plugin-test-PyLong_FromLong.c -fplugin=./analyzer_cpython_plugin.so  (test for warnings, line 29)
     FAIL: gcc.dg/plugin/cpython-plugin-test-PyLong_FromLong.c -fplugin=./analyzer_cpython_plugin.so  at line 37 (test for warnings, line 36)
    -FAIL: gcc.dg/plugin/cpython-plugin-test-PyLong_FromLong.c -fplugin=./analyzer_cpython_plugin.so (internal compiler error: Segmentation fault)
    +FAIL: gcc.dg/plugin/cpython-plugin-test-PyLong_FromLong.c -fplugin=./analyzer_cpython_plugin.so (internal compiler error: tree check: expected record_type or union_type or qual_union_type, have integer_type in get_field_by_name, at /home/jakub/src/gcc/gcc/testsuite/gcc.dg/plugin/analyzer_cpython_plugin.cc:62)
     FAIL: gcc.dg/plugin/cpython-plugin-test-PyLong_FromLong.c -fplugin=./analyzer_cpython_plugin.so (test for excess errors)
    ...
    
    The problem is that get_field_by_name now recurses on TREE_TYPE of
    everything in TYPE_FIELDS (which can be FIELD_DECL but many other
    things (though primarily for C++ and other languages)).  More importantly,
    it recurses even for FIELD_DECLs with scalar (e.g. INTEGER_TYPE) types
    and using TYPE_FIELDS on such types results in checking ICE.
    
    The following patch fixes that by only recursing on anonymous struct/union
    FIELD_DECLs.  For C those have NULL DECL_NAME, for C++ they would have
    IDENTIFIER_ANON_P IDENTIFIER_NODE as DECL_NAME (but it seems this plugin
    is only used for C).
    
    No FAILs from plugin.exp now:
    Running /usr/src/gcc/gcc/testsuite/gcc.dg/plugin/plugin.exp ...
    
                    === gcc Summary ===
    
    2026-03-10  Jakub Jelinek  <jakub@redhat.com>
    
            PR testsuite/112520
            * gcc.dg/plugin/analyzer_cpython_plugin.cc (get_field_by_name):
            If name is "ob_refcnt", recurse only for types of FIELD_DECLs
            with no DECL_NAME and record or union type.

Diff:
---
 gcc/testsuite/gcc.dg/plugin/analyzer_cpython_plugin.cc | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/gcc/testsuite/gcc.dg/plugin/analyzer_cpython_plugin.cc b/gcc/testsuite/gcc.dg/plugin/analyzer_cpython_plugin.cc
index 5aa79b1e6412..da1eed95cc3b 100644
--- a/gcc/testsuite/gcc.dg/plugin/analyzer_cpython_plugin.cc
+++ b/gcc/testsuite/gcc.dg/plugin/analyzer_cpython_plugin.cc
@@ -69,11 +69,14 @@ get_field_by_name (tree type, const char *name, bool complain = true)
 	      return field;
 	  }
 
-      /* Prior to python 3.11, ob_refcnt a field of PyObject.
+      /* Prior to python 3.11, ob_refcnt was a field of PyObject.
 	 In Python 3.11 ob_refcnt was moved to an anonymous union within
 	 PyObject (as part of PEP 683 "Immortal Objects, Using a
 	 Fixed Refcount").  */
-      if (0 == strcmp (name, "ob_refcnt"))
+      if (strcmp (name, "ob_refcnt") == 0
+	  && TREE_CODE (field) == FIELD_DECL
+	  && DECL_NAME (field) == NULL_TREE
+	  && RECORD_OR_UNION_TYPE_P (TREE_TYPE (field)))
 	if (tree subfield = get_field_by_name (TREE_TYPE (field), name, false))
 	  return subfield;
     }