[Bug target/67400] -fno-plt doesn't work with function pointers

[hjl.tools at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67400

H.J. Lu <hjl.tools at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2015-08-31
   Target Milestone|---                         |6.0
     Ever confirmed|0                           |1

--- Comment #1 from H.J. Lu <hjl.tools at gmail dot com> ---
Another pointer bug:

[hjl@gnu-6 pr18900]$ cat y.c
extern void foo (void);

typedef void (*func_p) (void);

const func_p p1 = &foo;
[hjl@gnu-6 pr18900]$ make y.o
/export/build/gnu/gcc/build-x86_64-linux/gcc/xgcc
-B/export/build/gnu/gcc/build-x86_64-linux/gcc/ -B./ -O2 -fno-plt   -c -o y.o
y.c
[hjl@gnu-6 pr18900]$ readelf -SW y.o
There are 11 section headers, starting at offset 0x1e8:

Section Headers:
  [Nr] Name              Type            Address          Off    Size   ES Flg
Lk Inf Al
  [ 0]                   NULL            0000000000000000 000000 000000 00     
0   0  0
  [ 1] .text             PROGBITS        0000000000000000 000040 000000 00  AX 
0   0  1
  [ 2] .data             PROGBITS        0000000000000000 000040 000000 00  WA 
0   0  1
  [ 3] .bss              NOBITS          0000000000000000 000040 000000 00  WA 
0   0  1
  [ 4] .rodata           PROGBITS        0000000000000000 000040 000008 00   A 
0   0  8
  [ 5] .rela.rodata      RELA            0000000000000000 000178 000018 18   I 
9   4  8
  [ 6] .comment          PROGBITS        0000000000000000 000048 00002a 01  MS 
0   0  1
  [ 7] .note.GNU-stack   PROGBITS        0000000000000000 000072 000000 00     
0   0  1
  [ 8] .shstrtab         STRTAB          0000000000000000 000190 000052 00     
0   0  1
  [ 9] .symtab           SYMTAB          0000000000000000 000078 0000f0 18    
10   8  8
  [10] .strtab           STRTAB          0000000000000000 000168 00000c 00     
0   0  1
Key to Flags:
  W (write), A (alloc), X (execute), M (merge), S (strings), l (large)
  I (info), L (link order), G (group), T (TLS), E (exclude), x (unknown)
  O (extra OS processing required) o (OS specific), p (processor specific)
[hjl@gnu-6 pr18900]$ /export/build/gnu/gcc/build-x86_64-linux/gcc/xgcc
-B/export/build/gnu/gcc/build-x86_64-linux/gcc/ -B./ -O2 -fno-plt   -c -o y.o
y.c -fpie
[hjl@gnu-6 pr18900]$ readelf -SW y.o
There are 11 section headers, starting at offset 0x1e8:

Section Headers:
  [Nr] Name              Type            Address          Off    Size   ES Flg
Lk Inf Al
  [ 0]                   NULL            0000000000000000 000000 000000 00     
0   0  0
  [ 1] .text             PROGBITS        0000000000000000 000040 000000 00  AX 
0   0  1
  [ 2] .data             PROGBITS        0000000000000000 000040 000000 00  WA 
0   0  1
  [ 3] .bss              NOBITS          0000000000000000 000040 000000 00  WA 
0   0  1
  [ 4] .data.rel.ro      PROGBITS        0000000000000000 000040 000008 00  WA 
0   0  8
  [ 5] .rela.data.rel.ro RELA            0000000000000000 000178 000018 18   I 
9   4  8
  [ 6] .comment          PROGBITS        0000000000000000 000048 00002a 01  MS 
0   0  1
  [ 7] .note.GNU-stack   PROGBITS        0000000000000000 000072 000000 00     
0   0  1
  [ 8] .shstrtab         STRTAB          0000000000000000 000190 000057 00     
0   0  1
  [ 9] .symtab           SYMTAB          0000000000000000 000078 0000f0 18    
10   8  8
  [10] .strtab           STRTAB          0000000000000000 000168 00000c 00     
0   0  1
Key to Flags:
  W (write), A (alloc), X (execute), M (merge), S (strings), l (large)
  I (info), L (link order), G (group), T (TLS), E (exclude), x (unknown)
  O (extra OS processing required) o (OS specific), p (processor specific)
[hjl@gnu-6 pr18900]$ 

-fno-plt should use .data.rel.ro section, not .rodata section for
function pointer.