[Bug debug/92664] New: Wrong .debug_line section information when compiling stdin input with -g3
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92664
Bug ID: 92664
Summary: Wrong .debug_line section information when compiling
stdin input with -g3
Product: gcc
Version: 7.2.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: debug
Assignee: unassigned at gcc dot gnu.org
Reporter: robert.dumitru at cyberthorstudios dot com
Target Milestone: ---
Hello,
When compiling simple test programs with -g3 and input from the console (-
(stdin)), the .debug_line section is wrong.
Steps to reproduce this issue:
1. In your console type:
arm-none-eabi-gcc -mcpu=cortex-m4 -mthumb -mfloat-abi=hard -mfpu=fpv4-sp-d16
-O0 -g3 -c -o test.o -x c -
2. Copy and paste:
#include
int main(void)
{
printf("Hello World\n");
return 0;
}
3. Ctrl+Z and Return
4. If you type: arm-none-eabi-readelf --debug-dump=decodedline test.o
You get the following:
Contents of the .debug_line section:
CU: ./:
File nameLine numberStarting addressView
readelf: Warning: Badly formed extended line op encountered!
readelf: Warning: Badly formed extended line op encountered!
UNKNOWN (116): length 115
0 0xc
-10x1a
-10x1e
10x2a
UNKNOWN (0): length 4
-10x36
-60x42
-80x50
-70x5c
-70x60
-50x6c
UNKNOWN (0): length 2
20x76
20x84
70x92
30xa0
20xac
10xba
10xbe
30xca
UNKNOWN (0): length 4
-10xd8
-20xe4
-30xf2
-30xf6
-1 0x102
UNKNOWN (0): length 1
UNKNOWN (115): length 95
-2 0x110
-6 0x11e
-7 0x12a
-10 0x136
-10 0x13a
-8 0x146
UNKNOWN (0): length 1
UNKNOWN (112): length 95
5. Repeating the steps with -g instead of -g3 we get the right .debug_line
section:
Contents of the .debug_line section:
CU: ./:
File nameLine numberStarting addressView
3 0
4 0x4
5 0xa
6 0xc
60x14
[Bug c++/93380] New: Variable Length Array Evaluation will be wrong or cause GDB to crash due to GCC
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93380
Bug ID: 93380
Summary: Variable Length Array Evaluation will be wrong or
cause GDB to crash due to GCC
Product: gcc
Version: 7.2.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: robert.dumitru at cyberthorstudios dot com
Target Milestone: ---
We have the following code that runs on a cortex a9 of a Renesas RZ A1 board
and involves the declaration of a variable length array. I will present here
the code, the debug info for the variable and the disassembly code.
The sample code:
int main(void)
{
volatile int n;
int a = 1000;
int id_size = sizeof(cTaskList) / sizeof(V4_T_CTSK);
ID id[id_size];
for(;;){
for(n=0; n<9e2>: Abbrev Number: 38 (DW_TAG_variable)
<9e3> DW_AT_name: id
<9e6> DW_AT_decl_file : 1
<9e7> DW_AT_decl_line : 85
<9e8> DW_AT_type: <0x9f1>
<9ec> DW_AT_location: 3 byte block: 91 68 6 (DW_OP_fbreg: -24;
DW_OP_deref)
The disassembly code:
main():
20021230: push{r11, lr}
20021234: add r11, sp, #4
20021238: sub sp, sp, #24
82 int a = 1000;
2002123c: mov r3, #1000 ; 0x3e8
20021240: str r3, [r11, #-8]
84 int id_size = sizeof(cTaskList) / sizeof(V4_T_CTSK);
20021244: mov r3, #13
20021248: str r3, [r11, #-12]
85ID id[id_size];/* <-- debug session terminates with this
declaration */
2002124c: ldr r3, [r11, #-12]
20021250: sub r12, r3, #1
20021254: str r12, [r11, #-16]
20021258: mov r3, r12
2002125c: add r3, r3, #1
20021260: mov r0, r3
20021264: mov r1, #0
20021268: mov r2, #0
2002126c: mov r3, #0
20021270: lsl r3, r1, #5
20021274: orr r3, r3, r0, lsr #27
20021278: lsl r2, r0, #5
2002127c: mov r3, r12
20021280: add r3, r3, #1
20021284: mov r0, r3
20021288: mov r1, #0
2002128c: mov r2, #0
20021290: mov r3, #0
20021294: lsl r3, r1, #5
20021298: orr r3, r3, r0, lsr #27
2002129c: lsl r2, r0, #5
200212a0: mov r3, r12
200212a4: add r3, r3, #1
200212a8: lsl r3, r3, #2
200212ac: add r3, r3, #3
200212b0: add r3, r3, #7
200212b4: lsr r3, r3, #3
200212b8: lsl r3, r3, #3
200212bc: sub sp, sp, r3
200212c0: mov r3, sp
200212c4: add r3, r3, #3
200212c8: lsr r3, r3, #2
200212cc: lsl r3, r3, #2
200212d0: str r3, [r11, #-20]
89 for(n=0; n
[Bug debug/93380] Variable Length Array Evaluation will be wrong or cause GDB to crash due to GCC
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93380 --- Comment #2 from Robert Dumitru --- Hi Andrew, Thank you for your pointing out that. I will report the issue to ARM as well. However, regarding 1 and 2: 1. I understand this looks like a gdb bug, but my investigation pointed me to consider that what gdb does is correct- at least partially. It tries to read the memory to find the size of the array. If the memory is not initialised with the correct value, the size can be huge - hence - virtual memory exhausted bug. I will try and check with a newer gdb. Maybe gdb should know the expression can not be evaluated before right instructions are executed? 2. I checked with gcc 9.2.1 20191025 and the this still happens.
[Bug c/82283] Wrong warning with -Wmissing-field-initializers
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82283
Robert Dumitru changed:
What|Removed |Added
CC||robert.dumitru@cyberthorstu
||dios.com
--- Comment #10 from Robert Dumitru ---
We are experiencing the same issue:
The warning: missing initializer for field ... [-Wmissing-field-initializers]
is being thrown incorrectly.
The following code is correct, however [-Wmissing-field-initializers] are
shown.
struct test_t{
int value1;
int value2;
};
struct test_t test[] = {
[0].value1 = 1,
[0].value2 = 2,
[1].value1 = 10,
[1].value2 = 20
};
int main(){
return 0;
}
warning: missing initializer for field 'value2' of 'struct test_t'
[-Wmissing-field-initializers]
[0].value2 = 2,
warning: missing initializer for field 'value2' of 'struct test_t'
[-Wmissing-field-initializers]
[1].value2 = 20
The initialization is correct:
_test:
.long 1
.long 2
.long 10
.long 20
This bug was discovered first on version 8.3 but it can be reproduced on
version 10.2 as well. Please note you need the -Wextra flag in order to
reproduce this.
I think https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99081 is also relating to
this.
