Re: [PATCH, MPX wrappers 2/3] Replace some function calls with wrapper calls during instrumentation

[Ilya Enkovich <enkovich dot gnu at gmail dot com>]

On 15 Nov 00:16, Jeff Law wrote:
> On 11/14/14 10:29, Ilya Enkovich wrote:
> >Hi,
> >
> >This patch adds wrapper calls.  It's simply achieved by using proper name for builtin clones.  Patches apply over builtins instrumentation series.
> >
> >Thanks,
> >Ilya
> >--
> >2014-11-14  Ilya Enkovich  <ilya.enkovich@intel.com>
> >
> >	* c-family/c.opt (fchkp-use-wrappers): New.
> >	* ipa-chkp.c (CHKP_WRAPPER_SYMBOL_PREFIX): New.
> >	(chkp_wrap_function): New.
> >	(chkp_build_instrumented_fndecl): Support wrapped
> >	functions.
> invoke.texi documentation please.
> 
> OK with the invoke.texi doc work.  Patch #3 is OK.
> 
> Jeff
> 

invoke.texi misses all chkp options description.  I fixed it.  Here is a new patch.

Thanks,
Ilya
--
2014-11-18  Ilya Enkovich  <ilya.enkovich@intel.com>

	* c-family/c.opt (fchkp-use-wrappers): New.
	* ipa-chkp.c (CHKP_WRAPPER_SYMBOL_PREFIX): New.
	(chkp_wrap_function): New.
	(chkp_build_instrumented_fndecl): Support wrapped
	functions.
	* doc/invoke.texi (-fcheck-pointer-bounds): New.
	(-fchkp-check-incomplete-type): New.
	(-fchkp-first-field-has-own-bounds): New.
	(-fchkp-narrow-bounds): New.
	(-fchkp-narrow-to-innermost-array): New.
	(-fchkp-optimize): New.
	(-fchkp-use-fast-string-functions): New.
	(-fchkp-use-nochk-string-functions): New.
	(-fchkp-use-static-bounds): New.
	(-fchkp-use-static-const-bounds): New.
	(-fchkp-treat-zero-dynamic-size-as-infinite): New.
	(-fchkp-check-read): New.
	(-fchkp-check-write): New.
	(-fchkp-store-bounds): New.
	(-fchkp-instrument-calls): New.
	(-fchkp-instrument-marked-only): New.
	(-fchkp-use-wrappers): New.


diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt
index 85dcb98..a9f8f99 100644
--- a/gcc/c-family/c.opt
+++ b/gcc/c-family/c.opt
@@ -1040,6 +1040,10 @@ fchkp-instrument-marked-only
 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_instrument_marked_only) Init(0)
 Instrument only functions marked with bnd_instrument attribute.
 
+fchkp-use-wrappers
+C ObjC C++ ObjC++ LTO Report Var(flag_chkp_use_wrappers) Init(1)
+Transform instrumented builtin calls into calls to wrappers.
+
 fcilkplus
 C ObjC C++ ObjC++ LTO Report Var(flag_cilkplus) Init(0)
 Enable Cilk Plus
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 89edddb..09a0683 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -299,6 +299,15 @@ Objective-C and Objective-C++ Dialects}.
 @gccoptlist{-d@var{letters}  -dumpspecs  -dumpmachine  -dumpversion @gol
 -fsanitize=@var{style} -fsanitize-recover -fsanitize-recover=@var{style} @gol
 -fasan-shadow-offset=@var{number} -fsanitize-undefined-trap-on-error @gol
+-fcheck-pointer-bounds -fchkp-check-incomplete-type @gol
+-fchkp-first-field-has-own-bounds -fchkp-narrow-bounds @gol
+-fchkp-narrow-to-innermost-array -fchkp-optimize @gol
+-fchkp-use-fast-string-functions -fchkp-use-nochk-string-functions @gol
+-fchkp-use-static-bounds -fchkp-use-static-const-bounds @gol
+-fchkp-treat-zero-dynamic-size-as-infinite -fchkp-check-read @gol
+-fchkp-check-read -fchkp-check-write -fchkp-store-bounds @gol
+-fchkp-instrument-calls -fchkp-instrument-marked-only @gol
+-fchkp-use-wrappers @gol
 -fdbg-cnt-list -fdbg-cnt=@var{counter-value-list} @gol
 -fdisable-ipa-@var{pass_name} @gol
 -fdisable-rtl-@var{pass_name} @gol
@@ -5693,6 +5702,117 @@ a @code{libubsan} library routine.  The advantage of this is that the
 @code{libubsan} library is not needed and will not be linked in, so this
 is usable even for use in freestanding environments.
 
+@item -fcheck-pointer-bounds
+@opindex fcheck-pointer-bounds
+@opindex fno-check-pointer-bounds
+Enable Pointer Bounds Checker instrumentation.  Each memory reference
+is instrumented with checks of pointer used for memory access against
+bounds associated with that pointer.  Generated instrumentation may
+be controlled by various @option{-fchkp-*} options.
+
+@item -fchkp-check-incomplete-type
+@opindex fchkp-check-incomplete-type
+@opindex fno-chkp-check-incomplete-type
+Generate pointer bounds checks for variables with incomplete type.
+Enabled by default
+
+@item -fchkp-narrow-bounds
+@opindex fchkp-narrow-bounds
+@opindex fno-chkp-narrow-bounds
+Controls bounds used by Pointer Bounds Checker for pointers to object
+fields.  If narrowing is enabled then field bounds are used.  Otherwise
+object bounds are used.  See also @option{-fchkp-narrow-to-innermost-array}
+and @option{-fchkp-first-field-has-own-bounds}.  Enabled by default.
+
+@item -fchkp-first-field-has-own-bounds
+@opindex fchkp-first-field-has-own-bounds
+@opindex fno-chkp-first-field-has-own-bounds
+Forces Pointer Bounds Checker to use narrowed bounds for address of the
+first field in the structure.  By default pointer to the first field has
+the same bounds as pointer to the whole structure.
+
+@item -fchkp-narrow-to-innermost-array
+@opindex fchkp-narrow-to-innermost-array
+@opindex fno-chkp-narrow-to-innermost-array
+Forces Pointer Bounds Checker to use bounds of the innermost arrays in
+case of nested static arryas access.  By default it is disabled and
+bounds of the outermost array are used.
+
+@item -fchkp-optimize
+@opindex fchkp-optimize
+@opindex fno-chkp-optimize
+Enables Pointer Bounds Checker optimizations.  Enabled by default at
+optimization levels @option{-O}, @option{-O2}, @option{-O3}.
+
+@item -fchkp-use-fast-string-functions
+@opindex fchkp-use-fast-string-functions
+@opindex fno-chkp-use-fast-string-functions
+Allow to use *_nobnd versions of string functions (not copying bounds)
+by Pointer Bounds Checker.  Disabled by default.
+
+@item -fchkp-use-nochk-string-functions
+@opindex fchkp-use-nochk-string-functions
+@opindex fno-chkp-use-nochk-string-functions
+Allow to use *_nochk versions of string functions (not checking bounds)
+by Pointer Bounds Checker.  Disabled by default.
+
+@item -fchkp-use-static-bounds
+@opindex fchkp-use-static-bounds
+@opindex fno-chkp-use-static-bounds
+Allow Pointer Bounds Checker to generate static bounds holding
+bounds of static variables.  Enabled by default.
+
+@item -fchkp-use-static-const-bounds
+@opindex fchkp-use-static-const-bounds
+@opindex fno-chkp-use-static-const-bounds
+Use statically initialized bounds for constant bounds instead of
+generating them each time it is required.  By default enabled when
+@option{-fchkp-use-static-bounds} is enabled.
+
+@item -fchkp-treat-zero-dynamic-size-as-infinite
+@opindex fchkp-treat-zero-dynamic-size-as-infinite
+@opindex fno-chkp-treat-zero-dynamic-size-as-infinite
+With this option zero size obtained dynamically for objects with
+incomplete type will be treated as infinite by Pointer Bounds
+Checker.  It may be helpful if program is linked with a library
+missing size information for some symbols.  Disabled by default.
+
+@item -fchkp-check-read
+@opindex fchkp-check-read
+@opindex fno-chkp-check-read
+Instructs Pointer Bounds Checker to generate checks for all read
+accesses to memory.  Enabled by default.
+
+@item -fchkp-check-write
+@opindex fchkp-check-write
+@opindex fno-chkp-check-write
+Instructs Pointer Bounds Checker to generate checks for all write
+accesses to memory.  Enabled by default.
+
+@item -fchkp-store-bounds
+@opindex fchkp-store-bounds
+@opindex fno-chkp-store-bounds
+Instructs Pointer Bounds Checker to generate bounds stores for
+pointer writes.  Enabled by default.
+
+@item -fchkp-instrument-calls
+@opindex fchkp-instrument-calls
+@opindex fno-chkp-instrument-calls
+Instructs Pointer Bounds Checker to pass pointer bounds to calls.
+Enabled by default.
+
+@item -fchkp-instrument-marked-only
+@opindex fchkp-instrument-marked-only
+@opindex fno-chkp-instrument-marked-only
+Instructs Pointer Bounds Checker to instrument only functions
+marked with bnd_instrument attribute.  Disabled by default.
+
+@item -fchkp-use-wrappers
+@opindex fchkp-use-wrappers
+@opindex fno-chkp-use-wrappers
+Allows Pointer Bounds Checker to replace calls to builtin function
+with calls to wrapper functions.  Enabled by default.
+
 @item -fdump-final-insns@r{[}=@var{file}@r{]}
 @opindex fdump-final-insns
 Dump the final internal representation (RTL) to @var{file}.  If the
diff --git a/gcc/ipa-chkp.c b/gcc/ipa-chkp.c
index 46b2139..00b398a 100644
--- a/gcc/ipa-chkp.c
+++ b/gcc/ipa-chkp.c
@@ -89,6 +89,44 @@ along with GCC; see the file COPYING3.  If not see
     removed.  */
 
 #define CHKP_BOUNDS_OF_SYMBOL_PREFIX "__chkp_bounds_of_"
+#define CHKP_WRAPPER_SYMBOL_PREFIX "__mpx_wrapper_"
+
+/* Return 1 calls to FNDECL should be replaced with
+   a call to wrapper function.  */
+static bool
+chkp_wrap_function (tree fndecl)
+{
+  if (!flag_chkp_use_wrappers)
+    return false;
+
+  if (DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
+    {
+      switch (DECL_FUNCTION_CODE (fndecl))
+	{
+	case BUILT_IN_STRLEN:
+	case BUILT_IN_STRCPY:
+	case BUILT_IN_STRNCPY:
+	case BUILT_IN_STPCPY:
+	case BUILT_IN_STPNCPY:
+	case BUILT_IN_STRCAT:
+	case BUILT_IN_STRNCAT:
+	case BUILT_IN_MEMCPY:
+	case BUILT_IN_MEMPCPY:
+	case BUILT_IN_MEMSET:
+	case BUILT_IN_MEMMOVE:
+	case BUILT_IN_BZERO:
+	case BUILT_IN_MALLOC:
+	case BUILT_IN_CALLOC:
+	case BUILT_IN_REALLOC:
+	  return 1;
+
+	default:
+	  return 0;
+	}
+    }
+
+  return false;
+}
 
 /* Build a clone of FNDECL with a modified name.  */
 
@@ -113,11 +151,20 @@ chkp_build_instrumented_fndecl (tree fndecl)
      because it conflicts with decl merging algorithms in LTO.
      Achieve the result by using transparent alias name for the
      instrumented version.  */
-  s = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (fndecl));
-  s += ".chkp";
-  new_name = get_identifier (s.c_str ());
-  IDENTIFIER_TRANSPARENT_ALIAS (new_name) = 1;
-  TREE_CHAIN (new_name) = DECL_ASSEMBLER_NAME (fndecl);
+  if (chkp_wrap_function(fndecl))
+    {
+      s = CHKP_WRAPPER_SYMBOL_PREFIX;
+      s += IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (fndecl));
+      new_name = get_identifier (s.c_str ());
+    }
+  else
+    {
+      s = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (fndecl));
+      s += ".chkp";
+      new_name = get_identifier (s.c_str ());
+      IDENTIFIER_TRANSPARENT_ALIAS (new_name) = 1;
+      TREE_CHAIN (new_name) = DECL_ASSEMBLER_NAME (fndecl);
+    }
   SET_DECL_ASSEMBLER_NAME (new_decl, new_name);
 
   /* For functions with body versioning will make a copy of arguments.