[PATCH v3 7/9] [gdb/testsuite] define jit function name via macro

[Mihails Strasuns <mihails.strasuns@intel.com>]

Replaces previous approach with patching resulting ELF binary after
loading - now that each test iteration works on a separately compiled
binary it is not necessary anymore.

Tests are still being ran without debug info to preserve original test
functionality but this change opens up the possibility to enable debug
info if needed too.

gdb/testsuite/ChangeLog:

2020-03-27  Mihails Strasuns  <mihails.strasuns@intel.com>

	* lib/jit-elf-helpers.exp: supply -DFUNCTION_NAME macro
	  definition when compiling jit-elf-solib.co
	* gdb.base/jit-elf-main.c: stop patching jit function name
	* gdb.base/jit-elf-solib.c: use FUNCTION_NAME macro value as a
	  function name

Signed-off-by: Mihails Strasuns <mihails.strasuns@intel.com>
Change-Id: Ie9296dd374cd1ae11c7d1b8bbe4f0b6b1d5e21b5
---
 gdb/testsuite/gdb.base/jit-elf-main.c  | 31 --------------------------
 gdb/testsuite/gdb.base/jit-elf-solib.c |  6 ++---
 gdb/testsuite/lib/jit-elf-helpers.exp  |  1 +
 3 files changed, 4 insertions(+), 34 deletions(-)

diff --git a/gdb/testsuite/gdb.base/jit-elf-main.c b/gdb/testsuite/gdb.base/jit-elf-main.c
index edf2f692f8..e25ea3f524 100644
--- a/gdb/testsuite/gdb.base/jit-elf-main.c
+++ b/gdb/testsuite/gdb.base/jit-elf-main.c
@@ -51,35 +51,6 @@ usage (void)
   exit (1);
 }
 
-/* Rename jit_function_XXXX to match idx  */
-
-static void
-update_name (const void *const addr, int idx)
-{
-  const ElfW (Ehdr) *const ehdr = (ElfW (Ehdr) *)addr;
-  ElfW (Shdr) *const shdr = (ElfW (Shdr) *)((char *)addr + ehdr->e_shoff);
-  ElfW (Phdr) *const phdr = (ElfW (Phdr) *)((char *)addr + ehdr->e_phoff);
-  int i;
-
-  for (i = 0; i < ehdr->e_shnum; ++i)
-    {
-      if (shdr[i].sh_type == SHT_STRTAB)
-        {
-          /* Note: we update both .strtab and .dynstr.  The latter would
-             not be correct if this were a regular shared library (.hash
-             would be wrong), but this is a simulation -- the library is
-             never exposed to the dynamic loader, so it all ends up ok.  */
-          char *const strtab = (char *)((ElfW (Addr))addr + shdr[i].sh_offset);
-          char *const strtab_end = strtab + shdr[i].sh_size;
-          char *p;
-
-          for (p = strtab; p < strtab_end; p += strlen (p) + 1)
-            if (strcmp (p, "jit_function_XXXX") == 0)
-              sprintf (p, "jit_function_%04d", idx);
-        }
-    }
-}
-
 /* Defined by the .exp file if testing attach.  */
 #ifndef ATTACH
 #define ATTACH 0
@@ -151,8 +122,6 @@ MAIN (int argc, char *argv[])
 	  exit (1);
 	}
 
-      update_name (addr, i);
-
       /* Link entry at the end of the list.  */
       entry->symfile_addr = (const char *)addr;
       entry->symfile_size = st.st_size;
diff --git a/gdb/testsuite/gdb.base/jit-elf-solib.c b/gdb/testsuite/gdb.base/jit-elf-solib.c
index 3bdebe9ed0..7901c58ac9 100644
--- a/gdb/testsuite/gdb.base/jit-elf-solib.c
+++ b/gdb/testsuite/gdb.base/jit-elf-solib.c
@@ -15,7 +15,7 @@
    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
-/* This simulates a JIT library.  The function is "renamed" after being
-   loaded into memory.  */
+/* This simulates a JIT library.  The function name is supplied during
+   compilation as a macro.  */
 
-int jit_function_XXXX() { return 42; }
+int FUNCTION_NAME() { return 42; }
diff --git a/gdb/testsuite/lib/jit-elf-helpers.exp b/gdb/testsuite/lib/jit-elf-helpers.exp
index 4d88ea3900..8a7a1796cc 100644
--- a/gdb/testsuite/lib/jit-elf-helpers.exp
+++ b/gdb/testsuite/lib/jit-elf-helpers.exp
@@ -82,6 +82,7 @@ proc compile_n_jit_so {count} {
 	# function" changes when debug info is present.
 	set addr [format 0x%x [expr $load_address + $load_increment * [expr $i-1]]]
 	set options [list \
+	    additional_flags=-DFUNCTION_NAME=[format "jit_function_%04d" $i] \
 	    additional_flags=-Xlinker \
 	    additional_flags=-Ttext-segment=$addr]
 	if { [gdb_compile_shlib $solib_srcfile $solib_binfile $options] != "" } {
-- 
2.25.2

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