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From: Tom Tromey <tom@tromey.com>
To: gdb-patches@sourceware.org
Cc: Tom Tromey <tom@tromey.com>
Subject: [PATCH] Fix crash in is_nocall_function
Date: Sun, 11 Dec 2022 12:53:31 -0700	[thread overview]
Message-ID: <20221211195331.252485-1-tom@tromey.com> (raw)

is_nocall_function anticipates only being called for a function or a
method.  However, PR gdb/29871 points out a situation where an unusual
expression -- but one that parses to a valid, if extremely weird,
function call -- breaks this assumption.

This patch changes is_nocall_function to remove this assert and
instead simply return 'false' in this case.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=29871
---
 gdb/gdbtypes.c                   | 4 ++--
 gdb/gdbtypes.h                   | 4 +---
 gdb/testsuite/gdb.base/exprs.exp | 4 ++++
 3 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/gdb/gdbtypes.c b/gdb/gdbtypes.c
index 2166257f71e..30dd7744553 100644
--- a/gdb/gdbtypes.c
+++ b/gdb/gdbtypes.c
@@ -4037,8 +4037,8 @@ type_byte_order (const struct type *type)
 bool
 is_nocall_function (const struct type *type)
 {
-  gdb_assert (type->code () == TYPE_CODE_FUNC
-	      || type->code () == TYPE_CODE_METHOD);
+  if (type->code () != TYPE_CODE_FUNC && type->code () != TYPE_CODE_METHOD)
+    return false;
 
   return TYPE_CALLING_CONVENTION (type) == DW_CC_nocall;
 }
diff --git a/gdb/gdbtypes.h b/gdb/gdbtypes.h
index d7189ff9813..8fc5c97c95a 100644
--- a/gdb/gdbtypes.h
+++ b/gdb/gdbtypes.h
@@ -2845,9 +2845,7 @@ extern unsigned int overload_debug;
    to call by the debugger.
 
    This usually indicates that the function does not follow the target's
-   standard calling convention.
-
-   The TYPE argument must be of code TYPE_CODE_FUNC or TYPE_CODE_METHOD.  */
+   standard calling convention.  */
 
 extern bool is_nocall_function (const struct type *type);
 
diff --git a/gdb/testsuite/gdb.base/exprs.exp b/gdb/testsuite/gdb.base/exprs.exp
index 5bf03bf1320..b8698880339 100644
--- a/gdb/testsuite/gdb.base/exprs.exp
+++ b/gdb/testsuite/gdb.base/exprs.exp
@@ -271,3 +271,7 @@ gdb_test "print & (void) v_char" "value not located in memory."
 # Regression test for "&&".
 gdb_test "print null_t_struct && null_t_struct->v_int_member == 0" \
     " = 0"
+
+# Regression test for unusual function-call parse that caused a crash.
+gdb_test "print v_short++ (97)" \
+    "cast the call to its declared return type"
-- 
2.38.1


             reply	other threads:[~2022-12-11 19:53 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-12-11 19:53 Tom Tromey [this message]
2022-12-12  2:45 ` Simon Marchi

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