I noticed that the existing code casts a function's address to 'long',
but that doesn't work correctly on some ABIs, like Win64, where long
is 32-bit and while pointers are 64-bit:
func_addr = (long) &write_basic_trace_file;
Fixing that showed there's actually another place in the file that
writes a function address to file, and therefore should clear the
Thumb bit. This commit adds a macro+function pair to centralize the
Thumb bit handling, and uses it in both places.
The rest is just enough changes to make the file build without
warnings with "-Wall -Wextra" with x86_64-w64-mingw32-gcc and
i686-w64-mingw32-gcc cross compilers, and with -m32/-m64 on x86_64
GNU/Linux. Currently with x86_64-w64-mingw32-gcc we get:
$ x86_64-w64-mingw32-gcc tfile.c -Wall -DTFILE_DIR=\"\"
tfile.c: In function 'start_trace_file':
tfile.c:51:23: error: 'S_IRGRP' undeclared (first use in this function)
S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH);
^
tfile.c:51:23: note: each undeclared identifier is reported only once for each function it appears in
tfile.c:51:31: error: 'S_IROTH' undeclared (first use in this function)
S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH);
^
tfile.c: In function 'add_memory_block':
tfile.c:79:10: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
ll_x = (unsigned long) addr;
^
tfile.c: In function 'write_basic_trace_file':
tfile.c:113:15: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
func_addr = (long) &write_basic_trace_file;
^
tfile.c:137:3: warning: passing argument 1 of 'add_memory_block' from incompatible pointer type [enabled by default]
add_memory_block (&testglob, sizeof (testglob));
^
tfile.c:72:1: note: expected 'char *' but argument is of type 'int *'
add_memory_block (char *addr, int size)
^
tfile.c:139:3: warning: passing argument 1 of 'add_memory_block' from incompatible pointer type [enabled by default]
add_memory_block (&testglob2, 1);
^
tfile.c:72:1: note: expected 'char *' but argument is of type 'int *'
add_memory_block (char *addr, int size)
^
tfile.c: In function 'write_error_trace_file':
tfile.c:185:3: warning: implicit declaration of function 'alloca' [-Wimplicit-function-declaration]
char *hex = alloca (len * 2 + 1);
^
tfile.c:185:15: warning: incompatible implicit declaration of built-in function 'alloca' [enabled by default]
char *hex = alloca (len * 2 + 1);
^
tfile.c:211:6: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
(long) &write_basic_trace_file);
^
Tested on x86_64 Fedora 20, -m64 and -m32.
Tested by Yao on arm targets.
gdb/testsuite/
2014-07-16 Pedro Alves <palves@redhat.com>
* gdb.trace/tfile.c: Include unistd.h and stdint.h.
(start_trace_file): Guard S_IRGRP and S_IROTH uses behind #ifdef.
(tfile_write_64, tfile_write_16, tfile_write_8, tfile_write_addr)
(tfile_write_buf): New functions.
(add_memory_block): Rewrite using the above.
(adjust_function_address): New function.
(FUNCTION_ADDRESS): New macro.
(write_basic_trace_file): Remove short_x local, and use
tfile_write_16. Change type of func_addr local to unsigned long
long. Use FUNCTION_ADDRESS instead of handling the Thumb bit
here. Cast argument of add_memory_block to char pointer.
(write_error_trace_file): Avoid alloca. Use FUNCTION_ADDRESS.
(main): Remove parameters.
* gdb.trace/tfile.exp: Remove nowarnings.
1b5d0ab34c