[PATCH 2/3] Test adding and removing a symbol file at runtime.

[Nicolas Blanc <nicolas dot blanc at intel dot com>]

This test exercises the commands 'add-symbol-file'
and 'remove-symbol-file'.

2013-04-04  Nicolas Blanc  <nicolas.blanc@intel.com>

gdb/testsuite
	* gdb.base/sym-file-lib.c: New file.
	* gdb.base/sym-file-lib.c: New file.
	* gdb.base/sym-file.exp: New file.

Signed-off-by: Nicolas Blanc <nicolas.blanc@intel.com>
---
 gdb/testsuite/gdb.base/sym-file-lib.c  |   21 ++
 gdb/testsuite/gdb.base/sym-file-main.c |  369 ++++++++++++++++++++++++++++++++
 gdb/testsuite/gdb.base/sym-file.exp    |  155 +++++++++++++
 3 files changed, 545 insertions(+), 0 deletions(-)
 create mode 100644 gdb/testsuite/gdb.base/sym-file-lib.c
 create mode 100644 gdb/testsuite/gdb.base/sym-file-main.c
 create mode 100644 gdb/testsuite/gdb.base/sym-file.exp

diff --git a/gdb/testsuite/gdb.base/sym-file-lib.c b/gdb/testsuite/gdb.base/sym-file-lib.c
new file mode 100644
index 0000000..32426b9
--- /dev/null
+++ b/gdb/testsuite/gdb.base/sym-file-lib.c
@@ -0,0 +1,21 @@
+/* Copyright 2013 Free Software Foundation, Inc.
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+
+extern int bar () { return 1; }       /* gdb break at bar */
+
+
+extern int foo (int a) { return a; }  /* gdb break at foo */
+
diff --git a/gdb/testsuite/gdb.base/sym-file-main.c b/gdb/testsuite/gdb.base/sym-file-main.c
new file mode 100644
index 0000000..a42f807
--- /dev/null
+++ b/gdb/testsuite/gdb.base/sym-file-main.c
@@ -0,0 +1,369 @@
+/* Copyright 2013 Free Software Foundation, Inc.
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <fcntl.h>
+#include </usr/include/elf.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+
+#ifdef TARGET_LP64
+typedef Elf64_Phdr Elf_Phdr;
+typedef Elf64_Ehdr Elf_Ehdr;
+typedef Elf64_Shdr Elf_Shdr;
+typedef Elf64_Sym Elf_Sym;
+typedef Elf64_Word Elf_Word;
+
+unsigned char inline elf_st_type (unsigned char st_info)
+{
+  return ELF64_ST_TYPE (st_info);
+}
+#elif defined TARGET_ILP32
+typedef Elf32_Phdr Elf_Phdr;
+typedef Elf32_Ehdr Elf_Ehdr;
+typedef Elf32_Shdr Elf_Shdr;
+typedef Elf32_Sym Elf_Sym;
+typedef Elf32_Word Elf_Word;
+
+unsigned char inline elf_st_type (unsigned char st_info)
+{
+  return ELF32_ST_TYPE (st_info);
+}
+#endif
+
+
+void gdb_add_symbol_file (void* addr, const char* file)
+{
+  return;
+}
+
+
+void gdb_remove_symbol_file (void* addr)
+{
+  return;
+}
+
+
+struct segment
+{
+  char* mapped_addr;
+  Elf_Phdr* phdr;
+  struct segment* next;
+};
+
+
+/* Load a program segment.  */
+struct segment* load (char * addr, Elf_Phdr* phdr, struct segment* tail_seg)
+{
+  /* For the sake of simplicity all operations are permitted.  */
+  unsigned perm = PROT_READ | PROT_WRITE | PROT_EXEC;
+
+  char* mapped_addr = (char*) mmap ((void*) phdr->p_vaddr,
+				     phdr->p_memsz, perm,
+				     MAP_ANONYMOUS | MAP_PRIVATE,
+				     -1, 0);
+
+  void * from = (void*) (addr + phdr->p_offset);
+  void * to = (void*) mapped_addr;
+
+  memcpy (to, from, phdr->p_filesz);
+
+  struct segment* seg = (struct segment*) malloc (sizeof (struct segment));
+
+  if (seg == 0)
+    return 0;
+
+  seg->mapped_addr = mapped_addr;
+  seg->phdr = phdr;
+  seg->next = 0;
+
+  if (tail_seg != 0)
+    tail_seg->next = seg;
+
+  return seg;
+}
+
+/* Load a shared library without calling the standard loader.  */
+int load_shlib (const char *file, Elf_Ehdr **ehdr_out, struct segment **seg_out)
+{
+  unsigned i = 0;
+
+  /* Map the lib in memory for reading.  */
+  int fd = open (file, O_RDONLY);
+  if (fd  < 0)
+    {
+      perror ("fopen failed.");
+      return -1;
+    }
+
+  off_t fsize = lseek (fd, 0, SEEK_END);
+
+  if (fsize < 0)
+    {
+      perror ("lseek failed.");
+      return -1;
+    }
+
+   char* addr = (char*) mmap (NULL, fsize, PROT_READ, MAP_PRIVATE, fd, 0);
+   if (addr == (char*) -1)
+     {
+       perror ("mmap failed.");
+       return -1;
+     }
+
+  /* Check if the lib is an ELF file.  */
+  Elf_Ehdr* ehdr = (Elf_Ehdr*) addr;
+  if (ehdr->e_ident[EI_MAG0] != ELFMAG0
+      || ehdr->e_ident[EI_MAG1] != ELFMAG1
+      || ehdr->e_ident[EI_MAG2] != ELFMAG2
+      || ehdr->e_ident[EI_MAG3] != ELFMAG3)
+    {
+      printf ("Not an ELF file: %x\n", ehdr->e_ident[EI_MAG0]);
+      return -1;
+    }
+
+  if (ehdr->e_ident[EI_CLASS] == ELFCLASS32)
+    {
+      if (sizeof (int*) != 4)
+	{
+	  printf ("Architecture mismatch.");
+	  return -1;
+	}
+    }
+  else if (ehdr->e_ident[EI_CLASS] == ELFCLASS64)
+    {
+      if (sizeof (int*) != 8)
+	{
+	  printf ("Architecture mismatch.");
+	  return -1;
+	}
+    }
+
+
+  /* Load the program segments.  For the sake of simplicity
+     assume that no reallocation is needed.  */
+  Elf_Phdr* phdr = (Elf_Phdr*) (addr + ehdr->e_phoff);
+  struct segment* head_seg = 0;
+  struct segment* tail_seg = 0;
+  for (i=0; i < ehdr->e_phnum; i++, phdr++)
+    {
+      if (phdr->p_type == PT_LOAD)
+	{
+	  struct segment* next_seg = load (addr, phdr, tail_seg);
+	  if (next_seg == 0)
+	    continue;
+	  tail_seg = next_seg;
+	  if (head_seg == 0)
+	    head_seg = next_seg;
+	}
+    }
+  *ehdr_out = ehdr;
+  *seg_out = head_seg;
+  return 0;
+}
+
+
+/* Return the section-header table.  */
+Elf_Shdr* find_shdrtab (Elf_Ehdr *ehdr)
+{
+  return  (Elf_Shdr*) (((char*) ehdr) + ehdr->e_shoff);
+}
+
+
+/* Return the string table of the section headers.  */
+const char* find_shstrtab (Elf_Ehdr *ehdr, unsigned *size)
+{
+  const Elf_Shdr *shdr = find_shdrtab (ehdr);
+
+  if (ehdr->e_shnum <= ehdr->e_shstrndx)
+    {
+      printf ("The index of the string table is corrupt.");
+      return NULL;
+    }
+  const Elf_Shdr* shstr = &shdr[ehdr->e_shstrndx];
+  *size = shstr->sh_size;
+  return ((const char*) ehdr) + shstr->sh_offset;
+}
+
+
+/* Return the string table named SECTION. */
+const char* find_strtab (Elf_Ehdr *ehdr,
+			 const char* shstrtab, unsigned shstrtab_size,
+			 const char* section, unsigned *strtab_size)
+{
+  const Elf_Shdr* shdr =  find_shdrtab (ehdr);
+  unsigned i = 0;
+  for (i=0; i < ehdr->e_shnum; i++)
+    {
+      Elf_Word name = shdr[i].sh_name;
+      if (shdr[i].sh_type == SHT_STRTAB && name <= shstrtab_size
+	  && strcmp ((const char*) &shstrtab[name], section) == 0)
+	{
+	  *strtab_size = shdr[i].sh_size;
+	  return ((const char*) ehdr) + shdr[i].sh_offset;
+	}
+
+    }
+  return NULL;
+}
+
+
+/* Return the section header named SECTION.  */
+Elf_Shdr* find_shdr (Elf_Ehdr* ehdr, const char *section,
+		     const char *shstrtab, unsigned shstrtab_size)
+{
+  Elf_Shdr *shdr = find_shdrtab (ehdr);
+  unsigned i = 0;
+  for (i=0; i < ehdr->e_shnum; i++)
+    {
+      Elf_Word name = shdr[i].sh_name;
+      if (name <= shstrtab_size)
+	{
+	  if (strcmp ((const char*) &shstrtab[name], section) == 0)
+	    return &shdr[i];
+	}
+
+    }
+  return NULL;
+}
+
+/* Return the symbol table.  */
+Elf_Sym* find_symtab (Elf_Ehdr* ehdr, unsigned *symtab_size)
+{
+  unsigned i = 0;
+  const Elf_Shdr *shdr = find_shdrtab (ehdr);
+  for (i=0; i < ehdr->e_shnum; i++)
+    {
+      if (shdr[i].sh_type == SHT_SYMTAB)
+	{
+	  *symtab_size = shdr[i].sh_size / sizeof (Elf_Sym);
+	  return (Elf_Sym*) (((const char*) ehdr) + shdr[i].sh_offset);
+	}
+    }
+  return NULL;
+}
+
+
+/* Lookup the offset of FUNC.  */
+int lookup_function (const char *func,
+		     Elf_Sym *symtab, unsigned symtab_size,
+		     const char *strtab, unsigned strtab_size,
+		     unsigned *offset)
+{
+  unsigned i = 0;
+  for (i=0; i < symtab_size; i++)
+    {
+      Elf_Sym* sym = &symtab[i];
+
+      if (elf_st_type (sym->st_info) != STT_FUNC)
+	continue;
+
+      if (sym->st_name < strtab_size)
+	{
+	  const char* name = &strtab[sym->st_name];
+	  if (strcmp (name, func) == 0)
+	    {
+	      *offset = (unsigned) sym->st_value;
+	      return 0;
+	    }
+       }
+    }
+
+  return -1;
+}
+
+
+int main (int argc, const char* argv[])
+{
+  /* Load a shared library without relying on the standard
+     loader to test GDB's commands for adding and removing
+     symbol files at runtime.  */
+
+  const char *file = SHLIB_NAME;
+
+  Elf_Ehdr *ehdr = 0;
+  struct segment *head_seg = 0;
+
+  if (load_shlib (file, &ehdr, &head_seg) != 0)
+    return -1;
+
+  /* Get the string table for the section headers.  */
+  unsigned shstrtab_size = 0;
+  const char* shstrtab = find_shstrtab (ehdr, &shstrtab_size);
+
+  if (shstrtab == NULL)
+    return -1;
+
+  /* Get the text section.  */
+  Elf_Shdr* text = find_shdr (ehdr, ".text", shstrtab, shstrtab_size);
+  if (text == NULL)
+    return -1;
+
+  char* base_addr = head_seg->mapped_addr + text->sh_offset;
+
+  /* Notify GDB to add the symbol file.  */
+  gdb_add_symbol_file (base_addr, file);
+
+  /* Get the string table for the symbols.  */
+  unsigned strtab_size = 0;
+  const char* strtab = find_strtab (ehdr, shstrtab, shstrtab_size,
+				    ".strtab", &strtab_size);
+  if (strtab == NULL)
+    {
+      printf (".strtab not found.");
+      return -1;
+    }
+
+  /* Get the symbol table.  */
+  unsigned symtab_size = 0;
+  Elf_Sym* symtab = find_symtab (ehdr, &symtab_size);
+  if (symtab == NULL)
+    {
+      printf ("symtab not found.");
+      return -1;
+    }
+
+  /* Call BAR from SHLIB_NAME.  */
+  unsigned bar_offset = 0;
+  if (lookup_function ("bar",
+		       symtab, symtab_size,
+		       strtab, strtab_size,
+		       &bar_offset) != 0)
+    return -1;
+
+  int (*pbar) () = (int (*) ()) (head_seg->mapped_addr + bar_offset);
+
+  int value1 = (*pbar) ();
+
+
+  /* Call FOO from SHLIB_NAME.  */
+  unsigned foo_offset = 0;
+  if (lookup_function ("foo",
+		       symtab, symtab_size,
+		       strtab, strtab_size,
+		       &foo_offset) != 0)
+    return -1;
+
+  int (*pfoo) (int) =  (int (*) (int)) (head_seg->mapped_addr + foo_offset);
+
+  int value2 = (*pfoo) (2);
+
+  /* Notify GDB to remove the symbol file.  */
+  gdb_remove_symbol_file (base_addr);
+
+  return 0;
+}
+
diff --git a/gdb/testsuite/gdb.base/sym-file.exp b/gdb/testsuite/gdb.base/sym-file.exp
new file mode 100644
index 0000000..2c995a4
--- /dev/null
+++ b/gdb/testsuite/gdb.base/sym-file.exp
@@ -0,0 +1,155 @@
+# Copyright 2013 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+
+# Test adding and removing a symbol file dynamically:
+# 1)  Load the main executable.
+# 2)  Run to GDB_ADD_SYMBOl_FILE in $srcfile.
+# 3)  Set a pending breakpoint at BAR in $libsrc.
+# 4)  Load $shlib_name using 'add-symbol-file'.
+# 5)  Continue to BAR in $libsrc.
+# 6)  Set a breakpiont at FOO in $librc.
+# 7)  Continue to FOO in $libsrc.
+# 8)  Set a breakpoint at GDB_REMOVE_SYMBOL_FILE.
+# 9)  Continue to GDB_REMOVE_SYMBOL_FILE in $srcfile.
+# 10) Remove $shlib_name using 'remove-symbol-file'.
+# 11) Check that the breakpoints at FOO and BAR are pending.
+# 12) Check that the execution can continue without error.
+
+
+if [skip_shlib_tests] {
+    return 0
+}
+
+
+if [is_remote target] {
+    return 0
+}
+
+set target_size TARGET_UNKNOWN
+if [is_lp64_target] {
+    set target_size TARGET_LP64
+} elseif [is_ilp32_target] {
+   set target_size TARGET_ILP32
+} else {
+    return 0
+}
+
+set testfile sym-file-main
+set libfile sym-file-lib
+set srcfile ${testfile}.c
+set binfile ${objdir}/${subdir}/${testfile}
+
+set libsrc "${srcdir}/${subdir}/${libfile}.c"
+set libname "${libfile}.so"
+set shlib_name "${objdir}/${subdir}/${libname}"
+set libobj "${objdir}/${subdir}/${libname}"
+set execsrc "${srcdir}/${subdir}/${srcfile}"
+set exec_opts [list debug "additional_flags=-D$target_size -DSHLIB_NAME\\=\"$shlib_name\""]
+
+remote_exec build "rm -f ${binfile}"
+
+if [get_compiler_info] {
+    return -1
+}
+
+
+if { [gdb_compile_shlib $libsrc $libobj {debug}] != ""
+     || [gdb_compile $execsrc ${binfile} executable $exec_opts] != "" } {
+    untested ${testfile}
+    return
+}
+
+gdb_exit
+gdb_start
+gdb_reinitialize_dir $srcdir/$subdir
+
+# 1) Load the main executable.
+set result [gdb_load ${binfile}]
+if { $result != 0 } then {
+   return
+}
+
+# 2) Run to GDB_ADD_SYMBOl_FILE in $srcfile for adding
+#    $shlib_name.
+set result [runto gdb_add_symbol_file]
+if { !$result } then {
+   return
+}
+
+# 3) Set a pending breakpoint at BAR in $libsrc.
+set result [gdb_breakpoint bar allow-pending]
+if { !$result } then {
+   return
+}
+
+# 4) Add $shlib_name using 'add-symbol-file'.
+set result [gdb_test "add-symbol-file ${shlib_name} addr" \
+		     "Reading symbols from .*${shlib_name}\\.\\.\\.done\\." \
+		     "add-symbol-file ${shlib_name}.*" \
+		     "add symbol table from file \".*${shlib_name}\"\
+ at.*\\(y or n\\) " \
+		     "y"]
+if { $result != 0 } then {
+   return
+}
+
+# 5) Continue to BAR in $libsrc to ensure that the breakpoint
+#    was bound correctly after adding $shilb_name.
+set lnum_bar [gdb_get_line_number "break at bar" $libsrc]
+gdb_continue_to_breakpoint bar ".*$libfile\\.c:$lnum_bar.*"
+
+# 6) Set a breakpoint at FOO in $libsrc.
+set result [gdb_breakpoint foo]
+if { !$result } then {
+    return
+}
+
+# 7) Continue to FOO in $libsrc to ensure that the breakpoint
+#    was bound correctly.
+set lnum_foo [gdb_get_line_number "break at foo" $libsrc]
+gdb_continue_to_breakpoint foo ".*$libfile\\.c:$lnum_foo.*"
+
+
+# 8) Set a breakpint at GDB_REMOVE_SYMBOL_FILE in $srcfile for
+#    removing $shlib_name.
+set result [gdb_breakpoint gdb_remove_symbol_file]
+if { !$result } then {
+    return
+}
+
+# 9) Continue to GDB_REMOVE_SYMBOL_FILE in $srcfile.
+gdb_continue_to_breakpoint gdb_remove_symbol_file
+
+# 10) Remove $shlib_name using 'remove-symbol-file'.
+set result [gdb_test "remove-symbol-file addr" ""]
+if { $result != 0 } then {
+    return
+}
+
+# 11) Check that the breakpoints at FOO and BAR are pending after removing
+#     $shlib_name.
+gdb_test "info breakpoints 2" \
+	 ".*PENDING.*" \
+	 "check if Breakpoint 2 is pending."
+
+gdb_test "info breakpoints 3" \
+	 ".*PENDING.*" \
+	 "check if Breakpoint 3 is pending."
+
+# 12) Check that the execution can continue without error.
+gdb_continue_to_end
+
+
-- 
1.7.6.5