builtins.c (compute_objsize): Add an argument and set it to offset into destination.

gcc/ChangeLog:

	* builtins.c (compute_objsize): Add an argument and set it to offset
	into destination.
	* builtins.h (compute_objsize): Add an argument.
	* tree-object-size.c (addr_object_size): Add an argument and set it
	to offset into destination.
	(compute_builtin_object_size): Same.
	* tree-object-size.h (compute_builtin_object_size): Add an argument.
	* tree-ssa-strlen.c (get_addr_stridx): Add an argument and set it
	to offset into destination.
	(maybe_warn_overflow): New function.
	(handle_store): Call maybe_warn_overflow to issue warnings.

gcc/testsuite/ChangeLog:

	* c-c++-common/Wstringop-overflow-2.c: Adjust text of expected messages.
	* g++.dg/warn/Wstringop-overflow-3.C: Same.
	* gcc.dg/Wstringop-overflow-17.c: Same.

From-SVN: r279248

gcc/ChangeLog

+2019-12-11  Martin Sebor  <msebor@redhat.com>
+
+	* builtins.c (compute_objsize): Add an argument and set it to offset
+	into destination.
+	* builtins.h (compute_objsize): Add an argument.
+	* tree-object-size.c (addr_object_size): Add an argument and set it
+	to offset into destination.
+	(compute_builtin_object_size): Same.
+	* tree-object-size.h (compute_builtin_object_size): Add an argument.
+	* tree-ssa-strlen.c (get_addr_stridx): Add an argument and set it
+	to offset into destination.
+	(maybe_warn_overflow): New function.
+	(handle_store): Call maybe_warn_overflow to issue warnings.
+
 2019-12-11  Jozef Lawrynowicz  <jozef.l@mittosystems.com>
 
 	* config/msp430/msp430.h (STARTFILE_SPEC) [!fexceptions]: Use

gcc/builtins.c

@@ -3817,7 +3817,7 @@ compute_objsize (tree dest, int ostype, tree *pdecl /* = NULL */,
   /* Only the two least significant bits are meaningful.  */
   ostype &= 3;
 
-  if (compute_builtin_object_size (dest, ostype, &size, pdecl))
+  if (compute_builtin_object_size (dest, ostype, &size, pdecl, poff))
     return build_int_cst (sizetype, size);
 
   if (TREE_CODE (dest) == SSA_NAME)
@@ -3924,7 +3924,7 @@ compute_objsize (tree dest, int ostype, tree *pdecl /* = NULL */,
 	  if (integer_zerop (size)
 	      && *pdecl && DECL_P (*pdecl)
 	      && *poff && integer_zerop (*poff))
-	    return integer_zero_node;
+	    return size_zero_node;
 
 	  /* A valid offset into a declared object cannot be negative.  */
 	  if (tree_int_cst_sgn (*poff) < 0)

gcc/testsuite/ChangeLog

@@ -22,6 +22,12 @@
 
 2019-12-11  Martin Sebor  <msebor@redhat.com>
 
+	* c-c++-common/Wstringop-overflow-2.c: Adjust text of expected messages.
+	* g++.dg/warn/Wstringop-overflow-3.C: Same.
+	* gcc.dg/Wstringop-overflow-17.c: Same.
+
+2019-12-11  Martin Sebor  <msebor@redhat.com>
+
 	PR middle-end/79221
 	* gcc.dg/Wstringop-overflow-26.c: New test.
 

gcc/testsuite/c-c++-common/Wstringop-overflow-2.c

@@ -10,7 +10,7 @@ void sink (void*);
 struct Ax
 {
   char n;
-  char a[];                     // { dg-message "destination object declared here" }
+  char a[];                     // { dg-message "declared here" }
 };
 
 // Verify warning for a definition with no initializer.
@@ -91,7 +91,7 @@ void gaxx (void)
 struct A0
 {
   char n;
-  char a[0];                    // { dg-message "destination object declared here" }
+  char a[0];                    // { dg-message "declared here" }
 };
 
 // Verify warning for a definition with no initializer.
@@ -158,7 +158,7 @@ void ga0x (void)
 struct A1
 {
   char n;
-  char a[1];                    // { dg-message "destination object declared here" }
+  char a[1];                    // { dg-message "declared here" }
 };
 
 // Verify warning for a definition with no initializer.
@@ -256,7 +256,7 @@ void ga1x (void)
 struct A1i
 {
   char n;
-  char a[1];                    // { dg-message "destination object declared here" }
+  char a[1];                    // { dg-message "declared here" }
   char x;
 };
 

gcc/testsuite/g++.dg/warn/Wstringop-overflow-3.C

@@ -3,6 +3,8 @@
    { dg-do compile }
    { dg-options "-O2 -Wall -Wno-array-bounds" } */
 
+#define NOIPA __attribute__ ((noipa))
+
 void sink (void*);
 
 // Exercise flexible array members.
@@ -10,13 +12,13 @@ void sink (void*);
 struct Ax
 {
   char n;
-  char a[];                     // { dg-message "destination object declared here" }
+  char a[];                     // { dg-message "at offset \[0-2\] to object 'Ax::a' declared here" }
 };
 
 // Verify warning for a definition with no initializer.
 Ax ax_;
 
-void gax_ ()
+NOIPA void gax_ ()
 {
   ax_.a[0] = 0;                 // { dg-warning "\\\[-Wstringop-overflow" }
   ax_.a[1] = 0;                 // { dg-warning "\\\[-Wstringop-overflow" }
@@ -27,7 +29,7 @@ void gax_ ()
 // initialize the flexible array member.
 Ax ax0 = { 0 };
 
-void gax0 ()
+NOIPA void gax0 ()
 {
   ax0.a[0] = 0;                 // { dg-warning "\\\[-Wstringop-overflow" }
   ax0.a[1] = 0;                 // { dg-warning "\\\[-Wstringop-overflow" }
@@ -38,7 +40,7 @@ void gax0 ()
 // initializes the flexible array member to empty.
 Ax ax0_ = { 0, { } };
 
-void gax0_ ()
+NOIPA void gax0_ ()
 {
   ax0_.a[0] = 0;                // { dg-warning "\\\[-Wstringop-overflow" }
   ax0_.a[1] = 0;                // { dg-warning "\\\[-Wstringop-overflow" }
@@ -49,7 +51,7 @@ void gax0_ ()
 // an initializer.
 Ax ax1 = { 1, { 0 } };
 
-void gax1 ()
+NOIPA void gax1 ()
 {
   ax1.a[0] = 0;
   ax1.a[1] = 0;                 // { dg-warning "\\\[-Wstringop-overflow" }
@@ -58,7 +60,7 @@ void gax1 ()
 
 Ax ax2 = { 2, { 1, 0 } };
 
-void gax2 ()
+NOIPA void gax2 ()
 {
   ax2.a[0] = 0;
   ax2.a[1] = 0;
@@ -67,7 +69,7 @@ void gax2 ()
 
 
 // Verify no warning for an unknown struct object.
-void gaxp (Ax *p)
+NOIPA void gaxp (Ax *p)
 {
   p->a[0] = 0;
   p->a[3] = 0;
@@ -79,7 +81,7 @@ void gaxp (Ax *p)
 // initialized to any number of elements.
 extern Ax axx;
 
-void gaxx ()
+NOIPA void gaxx ()
 {
   axx.a[0] = 0;
   axx.a[3] = 0;
@@ -91,13 +93,13 @@ void gaxx ()
 struct A0
 {
   char n;
-  char a[0];                    // { dg-message "destination object declared here" }
+  char a[0];                    // { dg-message "at offset \[0-2\] to object 'A0::a' with size 0 declared here" }
 };
 
 // Verify warning for a definition with no initializer.
 A0 a0_;
 
-void ga0_ ()
+NOIPA void ga0_ ()
 {
   a0_.a[0] = 0;                 // { dg-warning "\\\[-Wstringop-overflow" }
   a0_.a[1] = 0;                 // { dg-warning "\\\[-Wstringop-overflow" }
@@ -108,7 +110,7 @@ void ga0_ ()
 // initialize the flexible array member.
 A0 a00 = { 0 };
 
-void ga00 ()
+NOIPA void ga00 ()
 {
   a00.a[0] = 0;                 // { dg-warning "\\\[-Wstringop-overflow" }
   a00.a[1] = 0;                 // { dg-warning "\\\[-Wstringop-overflow" }
@@ -119,7 +121,7 @@ void ga00 ()
 // initializes the flexible array member to empty.
 A0 a00_ = { 0, { } };
 
-void ga00_ ()
+NOIPA void ga00_ ()
 {
   a00_.a[0] = 0;                // { dg-warning "\\\[-Wstringop-overflow" }
   a00_.a[1] = 0;                // { dg-warning "\\\[-Wstringop-overflow" }
@@ -133,7 +135,7 @@ void ga00_ ()
 
 
 // Verify no warning for an unknown struct object.
-void ga0p (A0 *p)
+NOIPA void ga0p (A0 *p)
 {
   p->a[0] = 0;
   p->a[3] = 0;
@@ -145,7 +147,7 @@ void ga0p (A0 *p)
 // flexible array member) may not be initialized.
 extern A0 a0x;
 
-void ga0x ()
+NOIPA void ga0x ()
 {
   a0x.a[0] = 0;                 // { dg-warning "\\\[-Wstringop-overflow" }
   a0x.a[3] = 0;                 // { dg-warning "\\\[-Wstringop-overflow" }
@@ -158,13 +160,13 @@ void ga0x ()
 struct A1
 {
   char n;
-  char a[1];                    // { dg-message "destination object declared here" }
+  char a[1];                    // { dg-message "at offset \[1-9\] to object 'A1::a' with size 1 declared here" }
 };
 
 // Verify warning for a definition with no initializer.
 A1 a1_;
 
-void ga1_ ()
+NOIPA void ga1_ ()
 {
   a1_.a[0] = 0;
   a1_.a[1] = 0;                 // { dg-warning "\\\[-Wstringop-overflow" }
@@ -175,7 +177,7 @@ void ga1_ ()
 // initialize the one-element array member.
 A1 a1__ = { 0 };
 
-void ga1__ ()
+NOIPA void ga1__ ()
 {
   a1__.a[0] = 0;
   a1__.a[1] = 0;                 // { dg-warning "\\\[-Wstringop-overflow" }
@@ -186,7 +188,7 @@ void ga1__ ()
 // initializes the one-element array member to empty.
 A1 a1_0 = { 0, { } };
 
-void ga1_0_ ()
+NOIPA void ga1_0_ ()
 {
   a1_0.a[0] = 0;
   a1_0.a[1] = 0;                // { dg-warning "\\\[-Wstringop-overflow" }
@@ -197,7 +199,7 @@ void ga1_0_ ()
 // initializes the one-element array member.
 A1 a1_1 = { 0, { 1 } };
 
-void ga1_1 ()
+NOIPA void ga1_1 ()
 {
   a1_1.a[0] = 0;
   a1_1.a[1] = 0;                // { dg-warning "\\\[-Wstringop-overflow" }
@@ -206,7 +208,7 @@ void ga1_1 ()
 
 
 // Verify no warning for an unknown struct object.
-void ga1p (A1 *p)
+NOIPA void ga1p (A1 *p)
 {
   p->a[0] = 0;
   p->a[3] = 0;
@@ -219,7 +221,7 @@ void ga1p (A1 *p)
 // a single element.
 extern A1 a1x;
 
-void ga1x ()
+NOIPA void ga1x ()
 {
   a1x.a[0] = 0;
   a1x.a[3] = 0;                 // { dg-warning "\\\[-Wstringop-overflow" }
@@ -232,14 +234,14 @@ void ga1x ()
 struct A1i
 {
   char n;
-  char a[1];                    // { dg-message "destination object declared here" }
+  char a[1];                    // { dg-message "at offset \[1-9\] to object 'A1i::a' with size 1 declared here" }
   char x;
 };
 
 // Verify warning for a definition with no initializer.
 A1i a1i_;
 
-void ga1i_ ()
+NOIPA void ga1i_ ()
 {
   a1i_.a[0] = 0;
   a1i_.a[1] = 0;                // { dg-warning "\\\[-Wstringop-overflow" }
@@ -250,7 +252,7 @@ void ga1i_ ()
 // initialize the one-element array member.
 A1i a1i__ = { 0 };
 
-void ga1i__ ()
+NOIPA void ga1i__ ()
 {
   a1i__.a[0] = 0;
   a1i__.a[1] = 0;                // { dg-warning "\\\[-Wstringop-overflow" }
@@ -261,7 +263,7 @@ void ga1i__ ()
 // initializes the one-element array member to empty.
 A1 a1i_0 = { 0, { } };
 
-void ga1i_0_ ()
+NOIPA void ga1i_0_ ()
 {
   a1i_0.a[0] = 0;
   a1i_0.a[1] = 0;               // { dg-warning "\\\[-Wstringop-overflow" }
@@ -272,7 +274,7 @@ void ga1i_0_ ()
 // initializes the one-element array member.
 A1 a1i_1 = { 0, { 1 } };
 
-void ga1i_1 ()
+NOIPA void ga1i_1 ()
 {
   a1i_1.a[0] = 0;
   a1i_1.a[1] = 0;               // { dg-warning "\\\[-Wstringop-overflow" }
@@ -281,7 +283,7 @@ void ga1i_1 ()
 
 
 // Verify no warning for an unknown struct object.
-void ga1ip (A1i *p)
+NOIPA void ga1ip (A1i *p)
 {
   p->a[0] = 0;
   p->a[3] = 0;                  // { dg-warning "\\\[-Wstringop-overflow" }
@@ -292,7 +294,7 @@ void ga1ip (A1i *p)
 // Verify no warning for an extern struct object.
 extern A1i a1ix;
 
-void ga1ix ()
+NOIPA void ga1ix ()
 {
   a1ix.a[0] = 0;
   a1ix.a[3] = 0;                 // { dg-warning "\\\[-Wstringop-overflow" }
@@ -305,7 +307,7 @@ void ga1ix ()
 struct Bx
 {
   char n;
-  char a[];                     // { dg-message "destination object declared here" }
+  char a[];                     // { dg-message "at offset 0 to object 'Bx::a' declared here" }
 
   // Verify the warning for a constant.
   Bx () { a[0] = 0; }           // { dg-warning "\\\[-Wstringop-overflow" }
@@ -315,13 +317,13 @@ struct Bx
   Bx (int i) { a[i] = 0; }      // { dg-warning "\\\[-Wstringop-overflow" }
 };
 
-void gbx (void)
+NOIPA void gbx (void)
 {
   struct Bx bx;
   sink (&bx);
 }
 
-void gbxi (int i)
+NOIPA void gbxi (int i)
 {
   struct Bx bxi (i);
   sink (&bxi);
@@ -330,13 +332,13 @@ void gbxi (int i)
 struct B0
 {
   char n;
-  char a[0];                    // { dg-message "destination object declared here" }
+  char a[0];                    // { dg-message "at offset 0 to object 'B0::a' with size 0 declared here" }
 
   B0 () { a[0] = 0; }           // { dg-warning "\\\[-Wstringop-overflow" }
 };
 
 
-void gb0 (void)
+NOIPA void gb0 (void)
 {
   struct B0 b0;
   sink (&b0);
@@ -346,12 +348,12 @@ void gb0 (void)
 struct B1
 {
   char n;
-  char a[1];                    // { dg-message "destination object declared here" }
+  char a[1];                    // { dg-message "at offset 1 to object 'B1::a' with size 1 declared here" }
 
   B1 () { a[1] = 0; }           // { dg-warning "\\\[-Wstringop-overflow" }
 };
 
-void gb1 (void)
+NOIPA void gb1 (void)
 {
   struct B1 b1;
   sink (&b1);
@@ -360,12 +362,12 @@ void gb1 (void)
 
 struct B123
 {
-  char a[123];                  // { dg-message "destination object declared here" }
+  char a[123];                  // { dg-message "at offset 123 to object 'B123::a' with size 123 declared here" }
 
   B123 () { a[123] = 0; }       // { dg-warning "\\\[-Wstringop-overflow" }
 };
 
-void gb123 (void)
+NOIPA void gb123 (void)
 {
   struct B123 b123;
   sink (&b123);
@@ -374,12 +376,12 @@ void gb123 (void)
 
 struct B234
 {
-  char a[234];                  // { dg-message "destination object declared here" }
+  char a[234];                  // { dg-message "at offset 234 to object 'B234::a' with size 234 declared here" }
 
   B234 (int i) { a[i] = 0; }    // { dg-warning "\\\[-Wstringop-overflow" }
 };
 
-void g234 (void)
+NOIPA void g234 (void)
 {
   struct B234 b234 (234);
   sink (&b234);

gcc/testsuite/gcc.dg/Wstringop-overflow-17.c

@@ -13,7 +13,7 @@ void sink (void*);
 
 void call_copy_n (const char *s)
 {
-  char a[3];        // { dg-message "destination object declared here" }
+  char a[3];        // { dg-message "declared here" }
   copy_n (a, "1234567", 7);
   sink (a);
 }

gcc/tree-object-size.c

@@ -55,7 +55,7 @@ static const unsigned HOST_WIDE_INT unknown[4] = {
 static tree compute_object_offset (const_tree, const_tree);
 static bool addr_object_size (struct object_size_info *,
 			      const_tree, int, unsigned HOST_WIDE_INT *,
-			      tree * = NULL);
+			      tree * = NULL, tree * = NULL);
 static unsigned HOST_WIDE_INT alloc_object_size (const gcall *, int);
 static tree pass_through_call (const gcall *);
 static void collect_object_sizes_for (struct object_size_info *, tree);
@@ -174,13 +174,15 @@ compute_object_offset (const_tree expr, const_tree var)
 static bool
 addr_object_size (struct object_size_info *osi, const_tree ptr,
 		  int object_size_type, unsigned HOST_WIDE_INT *psize,
-		  tree *pdecl /* = NULL */)
+		  tree *pdecl /* = NULL */, tree *poff /* = NULL */)
 {
   tree pt_var, pt_var_size = NULL_TREE, var_size, bytes;
 
-  tree dummy;
+  tree dummy_decl, dummy_off = size_zero_node;
   if (!pdecl)
-    pdecl = &dummy;
+    pdecl = &dummy_decl;
+  if (!poff)
+    poff = &dummy_off;
 
   gcc_assert (TREE_CODE (ptr) == ADDR_EXPR);
 
@@ -201,7 +203,7 @@ addr_object_size (struct object_size_info *osi, const_tree ptr,
 	  || TREE_CODE (TREE_OPERAND (pt_var, 0)) != SSA_NAME)
 	{
 	  compute_builtin_object_size (TREE_OPERAND (pt_var, 0),
-				       object_size_type & ~1, &sz, pdecl);
+				       object_size_type & ~1, &sz, pdecl, poff);
 	}
       else
 	{
@@ -376,6 +378,7 @@ addr_object_size (struct object_size_info *osi, const_tree ptr,
 	    bytes = size_zero_node;
 	  else
 	    bytes = size_binop (MINUS_EXPR, var_size, bytes);
+	  *poff = bytes;
 	}
       if (var != pt_var
 	  && pt_var_size
@@ -390,6 +393,7 @@ addr_object_size (struct object_size_info *osi, const_tree ptr,
 		bytes2 = size_zero_node;
 	      else
 		bytes2 = size_binop (MINUS_EXPR, pt_var_size, bytes2);
+	      *poff = size_binop (PLUS_EXPR, *poff, bytes2);
 	      bytes = size_binop (MIN_EXPR, bytes, bytes2);
 	    }
 	}
@@ -496,10 +500,16 @@ pass_through_call (const gcall *call)
 bool
 compute_builtin_object_size (tree ptr, int object_size_type,
 			     unsigned HOST_WIDE_INT *psize,
-			     tree *pdecl /* = NULL */)
+			     tree *pdecl /* = NULL */, tree *poff /* = NULL */)
 {
   gcc_assert (object_size_type >= 0 && object_size_type <= 3);
 
+  tree dummy_decl, dummy_off = size_zero_node;
+  if (!pdecl)
+    pdecl = &dummy_decl;
+  if (!poff)
+    poff = &dummy_off;
+
   /* Set to unknown and overwrite just before returning if the size
      could be determined.  */
   *psize = unknown[object_size_type];
@@ -508,7 +518,7 @@ compute_builtin_object_size (tree ptr, int object_size_type,
     init_offset_limit ();
 
   if (TREE_CODE (ptr) == ADDR_EXPR)
-    return addr_object_size (NULL, ptr, object_size_type, psize, pdecl);
+    return addr_object_size (NULL, ptr, object_size_type, psize, pdecl, poff);
 
   if (TREE_CODE (ptr) != SSA_NAME
       || !POINTER_TYPE_P (TREE_TYPE (ptr)))
@@ -533,11 +543,12 @@ compute_builtin_object_size (tree ptr, int object_size_type,
 
 	      if (tree_fits_shwi_p (offset)
 		  && compute_builtin_object_size (ptr, object_size_type,
-						  psize, pdecl))
+						  psize, pdecl, poff))
 		{
 		  /* Return zero when the offset is out of bounds.  */
 		  unsigned HOST_WIDE_INT off = tree_to_shwi (offset);
 		  *psize = off < *psize ? *psize - off : 0;
+		  *poff = offset;
 		  return true;
 		}
 	    }

gcc/tree-object-size.h

@@ -23,6 +23,6 @@ along with GCC; see the file COPYING3.  If not see
 extern void init_object_sizes (void);
 extern void fini_object_sizes (void);
 extern bool compute_builtin_object_size (tree, int, unsigned HOST_WIDE_INT *,
-					 tree * = NULL);
+					 tree * = NULL, tree * = NULL);
 
 #endif  // GCC_TREE_OBJECT_SIZE_H