[PATCH v2 2/2] Use enums for human-readable exception information.
Hannes Domani via gdb-patches
gdb-patches@sourceware.org
Sat Feb 8 16:26:00 GMT 2020
Changes to $_siginfo type to this:
(gdb) pt $_siginfo
type = struct EXCEPTION_RECORD {
enum ExceptionCode ExceptionCode;
DWORD ExceptionFlags;
struct EXCEPTION_RECORD *ExceptionRecord;
PVOID ExceptionAddress;
DWORD NumberParameters;
union {
ULONG_PTR ExceptionInformation[15];
struct {...} AccessViolationInformation;
};
}
(gdb) pt $_siginfo.ExceptionCode
type = enum ExceptionCode {FATAL_APP_EXIT = 1073741845,
DBG_CONTROL_C = 1073807365, DBG_CONTROL_BREAK = 1073807368,
DATATYPE_MISALIGNMENT = 2147483650, BREAKPOINT, SINGLE_STEP,
ACCESS_VIOLATION = 3221225477, IN_PAGE_ERROR,
ILLEGAL_INSTRUCTION = 3221225501, NONCONTINUABLE_EXCEPTION = 3221225509,
INVALID_DISPOSITION, ARRAY_BOUNDS_EXCEEDED = 3221225612,
FLOAT_DENORMAL_OPERAND, FLOAT_DIVIDE_BY_ZERO, FLOAT_INEXACT_RESULT,
FLOAT_INVALID_OPERATION, FLOAT_OVERFLOW, FLOAT_STACK_CHECK,
FLOAT_UNDERFLOW, INTEGER_DIVIDE_BY_ZERO, INTEGER_OVERFLOW,
PRIV_INSTRUCTION, STACK_OVERFLOW = 3221225725, FAST_FAIL = 3221226505}
(gdb) pt $_siginfo.AccessViolationInformation
type = struct {
enum ViolationType Type;
PVOID Address;
}
(gdb) pt $_siginfo.AccessViolationInformation.Type
type = enum ViolationType {READ_ACCESS_VIOLATION, WRITE_ACCESS_VIOLATION,
DATA_EXECUTION_PREVENTION_VIOLATION = 8}
Which makes it easier to understand the reason of the exception:
(gdb) p $_siginfo
$1 = {
ExceptionCode = ACCESS_VIOLATION,
ExceptionFlags = 0,
ExceptionRecord = 0x0,
ExceptionAddress = 0x401632 <main+18>,
NumberParameters = 2,
{
ExceptionInformation = {1, 291, 0 <repeats 13 times>},
AccessViolationInformation = {
Type = WRITE_ACCESS_VIOLATION,
Address = 0x123
}
}
}
gdb/ChangeLog:
2020-02-08 Hannes Domani <ssbssa@yahoo.de>
* windows-tdep.c (struct enum_value_name): New struct.
(create_enum): New function.
(windows_get_siginfo_type): Create and use enum types.
---
v2:
- more comments
---
gdb/windows-tdep.c | 102 ++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 96 insertions(+), 6 deletions(-)
diff --git a/gdb/windows-tdep.c b/gdb/windows-tdep.c
index ad65b1b403..e9787887a4 100644
--- a/gdb/windows-tdep.c
+++ b/gdb/windows-tdep.c
@@ -680,6 +680,71 @@ windows_gdb_signal_to_target (struct gdbarch *gdbarch, enum gdb_signal signal)
return -1;
}
+struct enum_value_name
+{
+ uint32_t value;
+ const char *name;
+};
+
+/* Allocate a TYPE_CODE_ENUM type structure with its named values. */
+
+static struct type *
+create_enum (struct gdbarch *gdbarch, int bit, const char *name,
+ const struct enum_value_name *values, int count)
+{
+ struct type *type;
+ int i;
+
+ type = arch_type (gdbarch, TYPE_CODE_ENUM, bit, name);
+ TYPE_NFIELDS (type) = count;
+ TYPE_FIELDS (type) = (struct field *)
+ TYPE_ZALLOC (type, sizeof (struct field) * count);
+ TYPE_UNSIGNED (type) = 1;
+
+ for (i = 0; i < count; i++)
+ {
+ TYPE_FIELD_NAME (type, i) = values[i].name;
+ SET_FIELD_ENUMVAL (TYPE_FIELD (type, i), values[i].value);
+ }
+
+ return type;
+}
+
+static const struct enum_value_name exception_values[] =
+{
+ { 0x40000015, "FATAL_APP_EXIT" },
+ { 0x40010005, "DBG_CONTROL_C" },
+ { 0x40010008, "DBG_CONTROL_BREAK" },
+ { 0x80000002, "DATATYPE_MISALIGNMENT" },
+ { 0x80000003, "BREAKPOINT" },
+ { 0x80000004, "SINGLE_STEP" },
+ { 0xC0000005, "ACCESS_VIOLATION" },
+ { 0xC0000006, "IN_PAGE_ERROR" },
+ { 0xC000001D, "ILLEGAL_INSTRUCTION" },
+ { 0xC0000025, "NONCONTINUABLE_EXCEPTION" },
+ { 0xC0000026, "INVALID_DISPOSITION" },
+ { 0xC000008C, "ARRAY_BOUNDS_EXCEEDED" },
+ { 0xC000008D, "FLOAT_DENORMAL_OPERAND" },
+ { 0xC000008E, "FLOAT_DIVIDE_BY_ZERO" },
+ { 0xC000008F, "FLOAT_INEXACT_RESULT" },
+ { 0xC0000090, "FLOAT_INVALID_OPERATION" },
+ { 0xC0000091, "FLOAT_OVERFLOW" },
+ { 0xC0000092, "FLOAT_STACK_CHECK" },
+ { 0xC0000093, "FLOAT_UNDERFLOW" },
+ { 0xC0000094, "INTEGER_DIVIDE_BY_ZERO" },
+ { 0xC0000095, "INTEGER_OVERFLOW" },
+ { 0xC0000096, "PRIV_INSTRUCTION" },
+ { 0xC00000FD, "STACK_OVERFLOW" },
+ { 0xC0000409, "FAST_FAIL" },
+};
+
+static const struct enum_value_name violation_values[] =
+{
+ { 0, "READ_ACCESS_VIOLATION" },
+ { 1, "WRITE_ACCESS_VIOLATION" },
+ { 8, "DATA_EXECUTION_PREVENTION_VIOLATION" },
+};
+
/* Implement the "get_siginfo_type" gdbarch method. */
static struct type *
@@ -687,7 +752,8 @@ windows_get_siginfo_type (struct gdbarch *gdbarch)
{
struct windows_gdbarch_data *windows_gdbarch_data;
struct type *dword_type, *pvoid_type, *ulongptr_type;
- struct type *siginfo_ptr_type, *siginfo_type;
+ struct type *code_enum, *violation_enum;
+ struct type *violation_type, *para_type, *siginfo_ptr_type, *siginfo_type;
windows_gdbarch_data = get_windows_gdbarch_data (gdbarch);
if (windows_gdbarch_data->siginfo_type != NULL)
@@ -700,12 +766,38 @@ windows_get_siginfo_type (struct gdbarch *gdbarch)
ulongptr_type = arch_integer_type (gdbarch, gdbarch_ptr_bit (gdbarch),
1, "ULONG_PTR");
+ /* ExceptionCode value names */
+ code_enum = create_enum (gdbarch, gdbarch_int_bit (gdbarch),
+ "ExceptionCode", exception_values,
+ ARRAY_SIZE (exception_values));
+
+ /* ACCESS_VIOLATION type names */
+ violation_enum = create_enum (gdbarch, gdbarch_ptr_bit (gdbarch),
+ "ViolationType", violation_values,
+ ARRAY_SIZE (violation_values));
+
+ /* ACCESS_VIOLATION information */
+ violation_type = arch_composite_type (gdbarch, NULL, TYPE_CODE_STRUCT);
+ append_composite_type_field (violation_type, "Type", violation_enum);
+ append_composite_type_field (violation_type, "Address", pvoid_type);
+
+ /* Unnamed union of the documented field ExceptionInformation,
+ and the alternative AccessViolationInformation (which displays
+ human-readable values for ExceptionCode ACCESS_VIOLATION). */
+ para_type = arch_composite_type (gdbarch, NULL, TYPE_CODE_UNION);
+ append_composite_type_field (para_type, "ExceptionInformation",
+ lookup_array_range_type (ulongptr_type, 0, 14));
+ append_composite_type_field (para_type, "AccessViolationInformation",
+ violation_type);
+
siginfo_type = arch_composite_type (gdbarch, "EXCEPTION_RECORD",
TYPE_CODE_STRUCT);
siginfo_ptr_type = arch_pointer_type (gdbarch, gdbarch_ptr_bit (gdbarch),
NULL, siginfo_type);
- append_composite_type_field (siginfo_type, "ExceptionCode", dword_type);
+ /* ExceptionCode is documented as type DWORD, but here a helper
+ enum type is used instead to display a human-readable value. */
+ append_composite_type_field (siginfo_type, "ExceptionCode", code_enum);
append_composite_type_field (siginfo_type, "ExceptionFlags", dword_type);
append_composite_type_field (siginfo_type, "ExceptionRecord",
siginfo_ptr_type);
@@ -713,10 +805,8 @@ windows_get_siginfo_type (struct gdbarch *gdbarch)
pvoid_type);
append_composite_type_field (siginfo_type, "NumberParameters", dword_type);
/* The 64-bit variant needs some padding. */
- append_composite_type_field_aligned (siginfo_type, "ExceptionInformation",
- lookup_array_range_type (ulongptr_type,
- 0, 14),
- TYPE_LENGTH (ulongptr_type));
+ append_composite_type_field_aligned (siginfo_type, "",
+ para_type, TYPE_LENGTH (ulongptr_type));
windows_gdbarch_data->siginfo_type = siginfo_type;
--
2.25.0
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