[PATCH 2/2] Testsuite for varobj updation after symbol removal

[Taimoor Mirza <tmirza at codesourcery dot com>]

This patch provides testcases for variable object updation after removing
symbols. Test programs are same as used for testing remove-symbol-file
command in gdb.base. sym-file-main.c is modified to just add a global
variable for which varible object is created in testsuite.

Testing:
=======
This is tested for x86 target and also on ppc-linux-gnu and mips-gnu-linux
using both simulator and real boards.

2014-06-27  Taimoor Mirza  <tmirza@codesourcery.com>

	* gdb.mi/mi-var-invalidate.exp: Add tests to check global
	variable object change list is correct when its value is
	updated before removing symbols.
	* gdb.mi/sym-file-loader.c: New file.
	* gdb.mi/sym-file-loader.h: New file.
	* gdb.mi/sym-file-main.c: New file.
	* gdb.mi/sym-file-lib.c: New file.

---
 gdb/testsuite/gdb.mi/mi-var-invalidate.exp |   67 ++++++
 gdb/testsuite/gdb.mi/sym-file-lib.c        |   26 ++
 gdb/testsuite/gdb.mi/sym-file-loader.c     |  353 ++++++++++++++++++++++++++++
 gdb/testsuite/gdb.mi/sym-file-loader.h     |   99 ++++++++
 gdb/testsuite/gdb.mi/sym-file-main.c       |   84 +++++++
 5 files changed, 629 insertions(+)
 create mode 100644 gdb/testsuite/gdb.mi/sym-file-lib.c
 create mode 100644 gdb/testsuite/gdb.mi/sym-file-loader.c
 create mode 100644 gdb/testsuite/gdb.mi/sym-file-loader.h
 create mode 100644 gdb/testsuite/gdb.mi/sym-file-main.c

diff --git a/gdb/testsuite/gdb.mi/mi-var-invalidate.exp b/gdb/testsuite/gdb.mi/mi-var-invalidate.exp
index e6ba392..e3bf953 100644
--- a/gdb/testsuite/gdb.mi/mi-var-invalidate.exp
+++ b/gdb/testsuite/gdb.mi/mi-var-invalidate.exp
@@ -121,5 +121,72 @@ mi_gdb_test "-var-info-type global_simple" \
 	"\\^done,type=\"\"" \
 	"no type for invalid variable global_simple"
 
+# Test varobj updation after removing symbols.
+
+if {[skip_shlib_tests]} {
+    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 main_basename sym-file-main
+set loader_basename sym-file-loader
+set lib_basename sym-file-lib
+
+standard_testfile $main_basename.c $loader_basename.c $lib_basename.c
+
+set libsrc "${srcdir}/${subdir}/${srcfile3}"
+set test_bin_name "sym-test-file"
+set test_bin [standard_output_file ${test_bin_name}]
+set shlib_name [standard_output_file ${lib_basename}.so]
+set exec_opts [list debug "additional_flags= -I$srcdir/../../include/ \
+-D$target_size -DSHLIB_NAME\\=\"$shlib_name\""]
+
+if [get_compiler_info] {
+    return -1
+}
+
+if {[gdb_compile_shlib $libsrc $shlib_name {debug}] != ""} {
+    untested ${testfile}
+    return -1
+}
+
+if {[build_executable $testfile  $test_bin "$srcfile $srcfile2" $exec_opts]} {
+    return -1
+}
+
+mi_delete_breakpoints
+mi_gdb_load ${test_bin}
+
+# Create varobj for count variable.
+mi_create_varobj var_count count "Create global varobj for count"
+
+# Run to GDB_ADD_SYMBOl_FILE in $srcfile for adding
+#    $shlib_name.
+mi_runto gdb_add_symbol_file
+
+# Add $shlib_name using 'add-symbol-file'.
+mi_gdb_test "-interpreter-exec console \"add-symbol-file ${shlib_name} addr\"" \
+    "~\"add symbol table from file .*so.*at.*= $hex.*\\^done" \
+    "add-symbol-file ${shlib_name}"
+
+# Continue to gdb_remove_symbol_file in $srcfile.
+mi_runto gdb_remove_symbol_file
+
+#  Remove $shlib_name using 'remove-symbol-file'.
+mi_gdb_test "-interpreter-exec console \"remove-symbol-file -a addr\"" \
+                ".*\\^done"\
+                "remove-symbol-file test"
+
+# Check var_count varobj changelist is not empty.
+mi_varobj_update var_count {var_count} "Update var_count"
+
 mi_gdb_exit
 return 0
diff --git a/gdb/testsuite/gdb.mi/sym-file-lib.c b/gdb/testsuite/gdb.mi/sym-file-lib.c
new file mode 100644
index 0000000..dae5188
--- /dev/null
+++ b/gdb/testsuite/gdb.mi/sym-file-lib.c
@@ -0,0 +1,26 @@
+/* Copyright 2013-2014 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.mi/sym-file-loader.c b/gdb/testsuite/gdb.mi/sym-file-loader.c
new file mode 100644
index 0000000..c72a1d1
--- /dev/null
+++ b/gdb/testsuite/gdb.mi/sym-file-loader.c
@@ -0,0 +1,353 @@
+/* Copyright 2013-2014 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 <unistd.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+
+#include "sym-file-loader.h"
+
+#ifdef TARGET_LP64
+
+uint8_t
+elf_st_type (uint8_t st_info)
+{
+  return ELF64_ST_TYPE (st_info);
+}
+
+#elif defined TARGET_ILP32
+
+uint8_t
+elf_st_type (uint8_t st_info)
+{
+  return ELF32_ST_TYPE (st_info);
+}
+
+#endif
+
+/* Load a program segment.  */
+
+static struct segment *
+load (uint8_t *addr, Elf_External_Phdr *phdr, struct segment *tail_seg)
+{
+  struct segment *seg = NULL;
+  uint8_t *mapped_addr = NULL;
+  void *from = NULL;
+  void *to = NULL;
+
+  /* For the sake of simplicity all operations are permitted.  */
+  unsigned perm = PROT_READ | PROT_WRITE | PROT_EXEC;
+
+  mapped_addr = (uint8_t *) mmap ((void *) GETADDR (phdr, p_vaddr),
+				  GET (phdr, p_memsz), perm,
+				  MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
+
+  from = (void *) (addr + GET (phdr, p_offset));
+  to = (void *) mapped_addr;
+
+  memcpy (to, from, GET (phdr, p_filesz));
+
+  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;
+}
+
+/* Mini shared library loader.  No reallocation
+   is performed for the sake of simplicity.  */
+
+int
+load_shlib (const char *file, Elf_External_Ehdr **ehdr_out,
+	    struct segment **seg_out)
+{
+  uint64_t i;
+  int fd;
+  off_t fsize;
+  uint8_t *addr;
+  Elf_External_Ehdr *ehdr;
+  Elf_External_Phdr *phdr;
+  struct segment *head_seg = NULL;
+  struct segment *tail_seg = NULL;
+
+  /* Map the lib in memory for reading.  */
+  fd = open (file, O_RDONLY);
+  if (fd < 0)
+    {
+      perror ("fopen failed.");
+      return -1;
+    }
+
+  fsize = lseek (fd, 0, SEEK_END);
+
+  if (fsize < 0)
+    {
+      perror ("lseek failed.");
+      return -1;
+    }
+
+  addr = (uint8_t *) mmap (NULL, fsize, PROT_READ, MAP_PRIVATE, fd, 0);
+  if (addr == (uint8_t *) -1)
+    {
+      perror ("mmap failed.");
+      return -1;
+    }
+
+  /* Check if the lib is an ELF file.  */
+  ehdr = (Elf_External_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 (void *) != 4)
+	{
+	  printf ("Architecture mismatch.");
+	  return -1;
+	}
+    }
+  else if (ehdr->e_ident[EI_CLASS] == ELFCLASS64)
+    {
+      if (sizeof (void *) != 8)
+	{
+	  printf ("Architecture mismatch.");
+	  return -1;
+	}
+    }
+
+  /* Load the program segments.  For the sake of simplicity
+     assume that no reallocation is needed.  */
+  phdr = (Elf_External_Phdr *) (addr + GET (ehdr, e_phoff));
+  for (i = 0; i < GET (ehdr, e_phnum); i++, phdr++)
+    {
+      if (GET (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_External_Shdr *
+find_shdrtab (Elf_External_Ehdr *ehdr)
+{
+  return (Elf_External_Shdr *) (((uint8_t *) ehdr) + GET (ehdr, e_shoff));
+}
+
+/* Return the string table of the section headers.  */
+
+const char *
+find_shstrtab (Elf_External_Ehdr *ehdr, uint64_t *size)
+{
+  const Elf_External_Shdr *shdr;
+  const Elf_External_Shdr *shstr;
+
+  if (GET (ehdr, e_shnum) <= GET (ehdr, e_shstrndx))
+    {
+      printf ("The index of the string table is corrupt.");
+      return NULL;
+    }
+
+  shdr = find_shdrtab (ehdr);
+
+  shstr = &shdr[GET (ehdr, e_shstrndx)];
+  *size = GET (shstr, sh_size);
+  return ((const char *) ehdr) + GET (shstr, sh_offset);
+}
+
+/* Return the string table named SECTION.  */
+
+const char *
+find_strtab (Elf_External_Ehdr *ehdr,
+	     const char *section, uint64_t *strtab_size)
+{
+  uint64_t shstrtab_size = 0;
+  const char *shstrtab;
+  uint64_t i;
+  const Elf_External_Shdr *shdr = find_shdrtab (ehdr);
+
+  /* Get the string table of the section headers.  */
+  shstrtab = find_shstrtab (ehdr, &shstrtab_size);
+  if (shstrtab == NULL)
+    return NULL;
+
+  for (i = 0; i < GET (ehdr, e_shnum); i++)
+    {
+      uint64_t name = GET (shdr + i, sh_name);
+      if (GET (shdr + i, sh_type) == SHT_STRTAB && name <= shstrtab_size
+	  && strcmp ((const char *) &shstrtab[name], section) == 0)
+	{
+	  *strtab_size = GET (shdr + i, sh_size);
+	  return ((const char *) ehdr) + GET (shdr + i, sh_offset);
+	}
+
+    }
+  return NULL;
+}
+
+/* Return the section header named SECTION.  */
+
+Elf_External_Shdr *
+find_shdr (Elf_External_Ehdr *ehdr, const char *section)
+{
+  uint64_t shstrtab_size = 0;
+  const char *shstrtab;
+  uint64_t i;
+
+  /* Get the string table of the section headers.  */
+  shstrtab = find_shstrtab (ehdr, &shstrtab_size);
+  if (shstrtab == NULL)
+    return NULL;
+
+  Elf_External_Shdr *shdr = find_shdrtab (ehdr);
+  for (i = 0; i < GET (ehdr, e_shnum); i++)
+    {
+      uint64_t name = GET (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_External_Sym *
+find_symtab (Elf_External_Ehdr *ehdr, uint64_t *symtab_size)
+{
+  uint64_t i;
+  const Elf_External_Shdr *shdr = find_shdrtab (ehdr);
+
+  for (i = 0; i < GET (ehdr, e_shnum); i++)
+    {
+      if (GET (shdr + i, sh_type) == SHT_SYMTAB)
+	{
+	  *symtab_size = GET (shdr + i, sh_size) / sizeof (Elf_External_Sym);
+	  return (Elf_External_Sym *) (((const char *) ehdr) +
+				       GET (shdr + i, sh_offset));
+	}
+    }
+  return NULL;
+}
+
+/* Translate a file offset to an address in a loaded segment.  */
+
+int
+translate_offset (uint64_t file_offset, struct segment *seg, void **addr)
+{
+  while (seg)
+    {
+      uint64_t p_from, p_to;
+
+      Elf_External_Phdr *phdr = seg->phdr;
+
+      if (phdr == NULL)
+	{
+	  seg = seg->next;
+	  continue;
+	}
+
+      p_from = GET (phdr, p_offset);
+      p_to = p_from + GET (phdr, p_filesz);
+
+      if (p_from <= file_offset && file_offset < p_to)
+	{
+	  *addr = (void *) (seg->mapped_addr + (file_offset - p_from));
+	  return 0;
+	}
+      seg = seg->next;
+    }
+
+  return -1;
+}
+
+/* Lookup the address of FUNC.  */
+
+int
+lookup_function (const char *func,
+		 Elf_External_Ehdr *ehdr, struct segment *seg, void **addr)
+{
+  const char *strtab;
+  uint64_t strtab_size = 0;
+  Elf_External_Sym *symtab;
+  uint64_t symtab_size = 0;
+  uint64_t i;
+
+  /* Get the string table for the symbols.  */
+  strtab = find_strtab (ehdr, ".strtab", &strtab_size);
+  if (strtab == NULL)
+    {
+      printf (".strtab not found.");
+      return -1;
+    }
+
+  /* Get the symbol table.  */
+  symtab = find_symtab (ehdr, &symtab_size);
+  if (symtab == NULL)
+    {
+      printf ("symbol table not found.");
+      return -1;
+    }
+
+  for (i = 0; i < symtab_size; i++)
+    {
+      Elf_External_Sym *sym = &symtab[i];
+
+      if (elf_st_type (GET (sym, st_info)) != STT_FUNC)
+	continue;
+
+      if (GET (sym, st_name) < strtab_size)
+	{
+	  const char *name = &strtab[GET (sym, st_name)];
+	  if (strcmp (name, func) == 0)
+	    {
+
+	      uint64_t offset = GET (sym, st_value);
+	      return translate_offset (offset, seg, addr);
+	    }
+	}
+    }
+
+  return -1;
+}
diff --git a/gdb/testsuite/gdb.mi/sym-file-loader.h b/gdb/testsuite/gdb.mi/sym-file-loader.h
new file mode 100644
index 0000000..03dc7e1
--- /dev/null
+++ b/gdb/testsuite/gdb.mi/sym-file-loader.h
@@ -0,0 +1,99 @@
+/* Copyright 2013-2014 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/>.
+*/
+
+#ifndef __SYM_FILE_LOADER__
+#define __SYM_FILE_LOADER__
+
+#include <inttypes.h>
+#include <ansidecl.h>
+#include <elf/common.h>
+#include <elf/external.h>
+
+#ifdef TARGET_LP64
+
+typedef Elf64_External_Phdr Elf_External_Phdr;
+typedef Elf64_External_Ehdr Elf_External_Ehdr;
+typedef Elf64_External_Shdr Elf_External_Shdr;
+typedef Elf64_External_Sym Elf_External_Sym;
+typedef uint64_t Elf_Addr;
+
+#elif defined TARGET_ILP32
+
+typedef Elf32_External_Phdr Elf_External_Phdr;
+typedef Elf32_External_Ehdr Elf_External_Ehdr;
+typedef Elf32_External_Shdr Elf_External_Shdr;
+typedef Elf32_External_Sym Elf_External_Sym;
+typedef uint32_t Elf_Addr;
+
+#endif
+
+#define GET(hdr, field) (\
+sizeof ((hdr)->field) == 1 ? (uint64_t) (hdr)->field[0] : \
+sizeof ((hdr)->field) == 2 ? (uint64_t) *(uint16_t *) (hdr)->field : \
+sizeof ((hdr)->field) == 4 ? (uint64_t) *(uint32_t *) (hdr)->field : \
+sizeof ((hdr)->field) == 8 ? *(uint64_t *) (hdr)->field : \
+*(uint64_t *) NULL)
+
+#define GETADDR(hdr, field) (\
+sizeof ((hdr)->field) == sizeof (Elf_Addr) ? *(Elf_Addr *) (hdr)->field : \
+*(Elf_Addr *) NULL)
+
+struct segment
+{
+  uint8_t *mapped_addr;
+  Elf_External_Phdr *phdr;
+  struct segment *next;
+};
+
+/* Mini shared library loader.  No reallocation is performed
+   for the sake of simplicity.  */
+
+int
+load_shlib (const char *file, Elf_External_Ehdr **ehdr_out,
+	    struct segment **seg_out);
+
+/* Return the section-header table.  */
+
+Elf_External_Shdr *find_shdrtab (Elf_External_Ehdr *ehdr);
+
+/* Return the string table of the section headers.  */
+
+const char *find_shstrtab (Elf_External_Ehdr *ehdr, uint64_t *size);
+
+/* Return the string table named SECTION.  */
+
+const char *find_strtab (Elf_External_Ehdr *ehdr,
+			 const char *section, uint64_t *strtab_size);
+
+/* Return the section header named SECTION.  */
+
+Elf_External_Shdr *find_shdr (Elf_External_Ehdr *ehdr, const char *section);
+
+/* Return the symbol table.  */
+
+Elf_External_Sym *find_symtab (Elf_External_Ehdr *ehdr,
+			       uint64_t *symtab_size);
+
+/* Translate a file offset to an address in a loaded segment.  */
+
+int translate_offset (uint64_t file_offset, struct segment *seg, void **addr);
+
+/* Lookup the address of FUNC.  */
+
+int
+lookup_function (const char *func, Elf_External_Ehdr* ehdr,
+		 struct segment *seg, void **addr);
+
+#endif
diff --git a/gdb/testsuite/gdb.mi/sym-file-main.c b/gdb/testsuite/gdb.mi/sym-file-main.c
new file mode 100644
index 0000000..8260824
--- /dev/null
+++ b/gdb/testsuite/gdb.mi/sym-file-main.c
@@ -0,0 +1,84 @@
+/* Copyright 2013-2014 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 <stdlib.h>
+#include <stdio.h>
+
+#include "sym-file-loader.h"
+
+// Global variable
+int count = 0;
+
+void
+gdb_add_symbol_file (void *addr, const char *file)
+{
+  return;
+}
+
+void
+gdb_remove_symbol_file (void *addr)
+{
+  return;
+}
+
+/* Load a shared library without relying on the standard
+   loader to test GDB's commands for adding and removing
+   symbol files at runtime.  */
+
+int
+main (int argc, const char *argv[])
+{
+  const char *file = SHLIB_NAME;
+  Elf_External_Ehdr *ehdr = NULL;
+  struct segment *head_seg = NULL;
+  Elf_External_Shdr *text;
+  char *text_addr = NULL;
+  int (*pbar) () = NULL;
+  int (*pfoo) (int) = NULL;
+
+  if (load_shlib (file, &ehdr, &head_seg) != 0)
+    return -1;
+
+  /* Get the text section.  */
+  text = find_shdr (ehdr, ".text");
+  if (text == NULL)
+    return -1;
+
+  /* Notify GDB to add the symbol file.  */
+  if (translate_offset (GET (text, sh_offset), head_seg, (void **) &text_addr)
+      != 0)
+    return -1;
+
+  gdb_add_symbol_file (text_addr, file);
+
+  /* Call bar from SHLIB_NAME.  */
+  if (lookup_function ("bar", ehdr, head_seg, (void *) &pbar) != 0)
+    return -1;
+
+  (*pbar) ();
+
+  /* Call foo from SHLIB_NAME.  */
+  if (lookup_function ("foo", ehdr, head_seg, (void *) &pfoo) != 0)
+    return -1;
+
+  (*pfoo) (2);
+
+  count++;
+
+  /* Notify GDB to remove the symbol file.  */
+  gdb_remove_symbol_file (text_addr);
+
+  return 0;
+}
-- 
1.7.9.5