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* [PATCH] extend -Wstringop-overflow to allocated objects (PR 91582)
@ 2019-11-08 22:11 Martin Sebor
  2019-11-18 18:23 ` [PING][PATCH] " Martin Sebor
  2019-12-02 17:06 ` [PATCH] " Jeff Law
  0 siblings, 2 replies; 7+ messages in thread
From: Martin Sebor @ 2019-11-08 22:11 UTC (permalink / raw)
  To: gcc-patches

[-- Attachment #1: Type: text/plain, Size: 1624 bytes --]

Unless it's used with _FORTIFY_SOURCE, -Wstringop-overflow
doesn't consider out-of-bounds accesses to objects allocated
by alloca, malloc, other functions declared with attribute
alloc_size, or even VLAs with variable bounds.  This was
a known limitation of the checks (done just before expansion)
relying on the the object size pass when they were introduced
in GCC 7.

But since its introduction in GCC 7, the warning has evolved
beyond some of the limitations of the object size pass.  Unlike
it, the warning considers non-constant offsets and stores with
non-constant sizes.  Attached is a simple enhancement that
(finally) adds the ability to also detect overflow in allocated
objects to the warning.

With the patch GCC detects the overflow in code like this:

   char* f (void)
   {
     char s[] = "12345";
     char *p = malloc (strlen (s));
     strcpy (p, s);   // warning here
     return p;
   }

but not (yet) in something like this:

   char* g (const char *s)
   {
     char *p = malloc (strlen (s));
     strcpy (p, s);   // no warning (yet)
     return p;
   }

and quite a few other examples.  Doing better requires extending
the strlen pass.  I'm working on this extension and expect to
submit a patch before stage 1 ends.

Martin

PS I was originally planning to do all the allocation checking
in the strlen pass but it occurred to me that by also enhancing
the compute_objsize function, all warnings that use it will
benefit.  Besides -Wstringop-overflow this includes a subset
of -Warray-bounds, -Wformat-overflow, and -Wrestrict.  It's
nice when a small enhancement has such a broad positive effect.

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[-- Type: text/x-patch, Size: 29635 bytes --]

PR middle-end/91582 - missing heap overflow detection for strcpy

gcc/ChangeLog:

	* builtins.c (gimple_call_alloc_size): New function.
	(compute_objsize): Add argument.  Call gimple_call_alloc_size.
	Handle variable offsets and indices.
	* builtins.h (gimple_call_alloc_size): Declare.
	(compute_objsize): Add argument.
	* tree-ssa-strlen.c (handle_store): Handle calls to allocated objects.

gcc/testsuite/ChangeLog:

	* c-c++-common/Wstringop-truncation.c: Remove xfails.
	* gcc/testsuite/g++.dg/ext/attr-alloc_size.C: Suppress -Warray-bounds.
	* gcc.dg/Wstringop-overflow-22.c: New test.
	* gcc/testsuite/gcc.dg/attr-alloc_size.c: Suppress -Warray-bounds.
	* gcc/testsuite/gcc.dg/attr-copy-2.c: Same.
	* gcc.dg/builtin-stringop-chk-5.c: Remove xfails.
	* gcc.dg/builtin-stringop-chk-8.c: Same.  Correct the text of expected
	warnings.
	* gcc.target/i386/pr82002-2a.c: Prune expected warning.
	* gcc.target/i386/pr82002-2b.c: Same.

Index: gcc/builtins.c
===================================================================
--- gcc/builtins.c	(revision 277978)
+++ gcc/builtins.c	(working copy)
@@ -3563,6 +3563,80 @@ check_access (tree exp, tree, tree, tree dstwrite,
   return true;
 }
 
+/* If STMT is a call to an allocation function, returns the size
+   of the object allocated by the call.  */
+
+tree
+gimple_call_alloc_size (gimple *stmt)
+{
+  if (!stmt)
+    return NULL_TREE;
+
+  tree allocfntype;
+  if (tree fndecl = gimple_call_fndecl (stmt))
+    allocfntype = TREE_TYPE (fndecl);
+  else
+    allocfntype = gimple_call_fntype (stmt);
+
+  if (!allocfntype)
+    return NULL_TREE;
+
+  unsigned argidx1 = UINT_MAX, argidx2 = UINT_MAX;
+  tree at = lookup_attribute ("alloc_size", TYPE_ATTRIBUTES (allocfntype));
+  if (!at)
+    {
+      if (!gimple_call_builtin_p (stmt, BUILT_IN_ALLOCA_WITH_ALIGN))
+	return NULL_TREE;
+
+      argidx1 = 0;
+    }
+
+  unsigned nargs = gimple_call_num_args (stmt);
+
+  if (argidx1 == UINT_MAX)
+    {
+      tree atval = TREE_VALUE (at);
+      if (!atval)
+	return NULL_TREE;
+
+      argidx1 = TREE_INT_CST_LOW (TREE_VALUE (atval)) - 1;
+      if (nargs <= argidx1)
+	return NULL_TREE;
+
+      atval = TREE_CHAIN (atval);
+      if (atval)
+	{
+	  argidx2 = TREE_INT_CST_LOW (TREE_VALUE (atval)) - 1;
+	  if  (nargs <= argidx2)
+	    return NULL_TREE;
+	}
+    }
+
+  tree size = gimple_call_arg (stmt, argidx1);
+  tree n = argidx2 < nargs ? gimple_call_arg (stmt, argidx2) : integer_one_node;
+
+  /* To handle ranges do the math in wide_int and return the product
+     of the upper bounds as a constant.  Ignore anti-ranges.  */
+  wide_int rng1[2];
+  if (TREE_CODE (size) == INTEGER_CST)
+    rng1[0] = rng1[1] = wi::to_wide (size);
+  else if (TREE_CODE (size) != SSA_NAME
+	   || get_range_info (size, rng1, rng1 + 1) != VR_RANGE)
+    return NULL_TREE;
+
+  wide_int rng2[2];
+  if (TREE_CODE (n) == INTEGER_CST)
+    rng2[0] = rng2[1] = wi::to_wide (n);
+  else if (TREE_CODE (n) != SSA_NAME
+	   || get_range_info (n, rng2 + 1, rng2 + 1) != VR_RANGE)
+    return NULL_TREE;
+
+  const int prec = TYPE_PRECISION (sizetype);
+  rng1[1] = wide_int::from (rng1[1], prec, UNSIGNED);
+  rng2[1] = wide_int::from (rng2[1], prec, UNSIGNED);
+  return wide_int_to_tree (sizetype, rng1[1] * rng2[1]);
+}
+
 /* Helper to compute the size of the object referenced by the DEST
    expression which must have pointer type, using Object Size type
    OSTYPE (only the least significant 2 bits are used).  Return
@@ -3571,17 +3645,23 @@ check_access (tree exp, tree, tree, tree dstwrite,
    a non-constant offset in some range the returned value represents
    the largest size given the smallest non-negative offset in the
    range.  If nonnull, set *PDECL to the decl of the referenced
-   subobject if it can be determined, or to null otherwise.
+   subobject if it can be determined, or to null otherwise.  Likewise,
+   when POFF is nonnull *POFF is set to the offset into *PDECL.
    The function is intended for diagnostics and should not be used
    to influence code generation or optimization.  */
 
 tree
-compute_objsize (tree dest, int ostype, tree *pdecl /* = NULL */)
+compute_objsize (tree dest, int ostype, tree *pdecl /* = NULL */,
+		 tree *poff /* = NULL */)
 {
-  tree dummy = NULL_TREE;
+  tree dummy_decl = NULL_TREE;
   if (!pdecl)
-    pdecl = &dummy;
+    pdecl = &dummy_decl;
 
+  tree dummy_off = size_zero_node;
+  if (!poff)
+    poff = &dummy_off;
+
   unsigned HOST_WIDE_INT size;
 
   /* Only the two least significant bits are meaningful.  */
@@ -3593,6 +3673,13 @@ tree
   if (TREE_CODE (dest) == SSA_NAME)
     {
       gimple *stmt = SSA_NAME_DEF_STMT (dest);
+      if (is_gimple_call (stmt))
+	{
+	  /* If STMT is a call to an allocation function get the size
+	     from its argument(s).  */
+	  return gimple_call_alloc_size (stmt);
+	}
+
       if (!is_gimple_assign (stmt))
 	return NULL_TREE;
 
@@ -3608,7 +3695,7 @@ tree
 	  tree off = gimple_assign_rhs2 (stmt);
 	  if (TREE_CODE (off) == INTEGER_CST)
 	    {
-	      if (tree size = compute_objsize (dest, ostype, pdecl))
+	      if (tree size = compute_objsize (dest, ostype, pdecl, poff))
 		{
 		  wide_int wioff = wi::to_wide (off);
 		  wide_int wisiz = wi::to_wide (size);
@@ -3619,10 +3706,16 @@ tree
 		  if (wi::sign_mask (wioff))
 		    ;
 		  else if (wi::ltu_p (wioff, wisiz))
-		    return wide_int_to_tree (TREE_TYPE (size),
-					     wi::sub (wisiz, wioff));
+		    {
+		      *poff = size_binop (PLUS_EXPR, *poff, off);
+		      return wide_int_to_tree (TREE_TYPE (size),
+					       wi::sub (wisiz, wioff));
+		    }
 		  else
-		    return size_zero_node;
+		    {
+		      *poff = size_binop (PLUS_EXPR, *poff, off);
+		      return size_zero_node;
+		    }
 		}
 	    }
 	  else if (TREE_CODE (off) == SSA_NAME
@@ -3644,10 +3737,18 @@ tree
 			  || wi::sign_mask (max))
 			;
 		      else if (wi::ltu_p (min, wisiz))
-			return wide_int_to_tree (TREE_TYPE (size),
-						 wi::sub (wisiz, min));
+			{
+			  *poff = size_binop (PLUS_EXPR, *poff,
+					      wide_int_to_tree (sizetype, min));
+			  return wide_int_to_tree (TREE_TYPE (size),
+						   wi::sub (wisiz, min));
+			}
 		      else
-			return size_zero_node;
+			{
+			  *poff = size_binop (PLUS_EXPR, *poff,
+					      wide_int_to_tree (sizetype, min));
+			  return size_zero_node;
+			}
 		    }
 		}
 	    }
@@ -3666,19 +3767,17 @@ tree
     {
       tree ref = TREE_OPERAND (dest, 0);
       tree off = TREE_OPERAND (dest, 1);
-      if (tree size = compute_objsize (ref, ostype, pdecl))
+      if (tree size = compute_objsize (ref, ostype, pdecl, poff))
 	{
-	  /* If the declaration of the destination object is known
-	     to have zero size, return zero.  */
-	  if (integer_zerop (size))
-	    return integer_zero_node;
+	  /* A valid offset into a declared object cannot be negative.  */
+	  if (tree_int_cst_sgn (*poff) < 0)
+	    return size_zero_node;
 
-	  if (TREE_CODE (off) != INTEGER_CST
-	      || TREE_CODE (size) != INTEGER_CST)
-	    return NULL_TREE;
-
+	  /* Adjust SIZE either up or down by the sum of *POFF and OFF
+	     above.  */
 	  if (TREE_CODE (dest) == ARRAY_REF)
 	    {
+	      /* Convert the array index into a byte offset.  */
 	      tree eltype = TREE_TYPE (dest);
 	      tree tpsize = TYPE_SIZE_UNIT (eltype);
 	      if (tpsize && TREE_CODE (tpsize) == INTEGER_CST)
@@ -3687,9 +3786,74 @@ tree
 		return NULL_TREE;
 	    }
 
-	  if (tree_int_cst_lt (off, size))
-	    return fold_build2 (MINUS_EXPR, size_type_node, size, off);
-	  return integer_zero_node;
+	  wide_int offrng[2];
+	  if (TREE_CODE (off) == INTEGER_CST)
+	    offrng[0] = offrng[1] = wi::to_wide (off);
+	  else if (TREE_CODE (off) == SSA_NAME)
+	    {
+	      wide_int min, max;
+	      enum value_range_kind rng
+		= get_range_info (off, offrng, offrng + 1);
+	      if (rng != VR_RANGE)
+		return NULL_TREE;
+	    }
+	  else
+	    return NULL_TREE;
+
+	  /* Convert to the same precision to keep wide_int from "helpfuly"
+	     crashing whenever it sees other argumments.  */
+	  offrng[0] = wide_int::from (offrng[0], ADDR_MAX_BITSIZE, SIGNED);
+	  offrng[1] = wide_int::from (offrng[1], ADDR_MAX_BITSIZE, SIGNED);
+
+	  tree dstoff = *poff;
+	  if (integer_zerop (*poff))
+	    *poff = off;
+	  else if (!integer_zerop (off))
+	    {
+	      *poff = fold_convert (ptrdiff_type_node, *poff);
+	      off = fold_convert (ptrdiff_type_node, off);
+	      *poff = size_binop (PLUS_EXPR, *poff, off);
+	    }
+
+	  if (wi::sign_mask (offrng[0]) >= 0)
+	    {
+	      if (TREE_CODE (size) != INTEGER_CST)
+		return NULL_TREE;
+
+	      /* Return the difference between the size and the offset
+		 or zero if the offset is greater.  */
+	      wide_int wisize = wi::to_wide (size, ADDR_MAX_BITSIZE);
+	      if (wi::ltu_p (wisize, offrng[0]))
+		return size_zero_node;
+
+	      return wide_int_to_tree (sizetype, wisize - offrng[0]);
+	    }
+
+	  wide_int dstoffrng[2];
+	  if (TREE_CODE (dstoff) == INTEGER_CST)
+	    dstoffrng[0] = dstoffrng[1] = wi::to_wide (dstoff);
+	  else if (TREE_CODE (dstoff) == SSA_NAME)
+	    {
+	      enum value_range_kind rng
+		= get_range_info (dstoff, dstoffrng, dstoffrng + 1);
+	      if (rng != VR_RANGE)
+		return NULL_TREE;
+	    }
+	  else
+	    return NULL_TREE;
+
+	  dstoffrng[0] = wide_int::from (dstoffrng[0], ADDR_MAX_BITSIZE, SIGNED);
+	  dstoffrng[1] = wide_int::from (dstoffrng[1], ADDR_MAX_BITSIZE, SIGNED);
+
+	  wide_int declsize = wi::to_wide (size);
+	  if (wi::sign_mask (dstoffrng[0]) > 0)
+	    declsize += dstoffrng[0];
+
+	  offrng[1] += dstoffrng[1];
+	  if (wi::sign_mask (offrng[1]) < 0)
+	    return size_zero_node;
+
+	  return wide_int_to_tree (sizetype, declsize);
 	}
 
       return NULL_TREE;
@@ -3701,14 +3865,13 @@ tree
       return component_ref_size (dest);
     }
 
-  if (TREE_CODE (dest) != ADDR_EXPR)
-    return NULL_TREE;
+  if (TREE_CODE (dest) == ADDR_EXPR)
+    dest = TREE_OPERAND (dest, 0);
 
-  tree ref = TREE_OPERAND (dest, 0);
-  if (DECL_P (ref))
+  if (DECL_P (dest))
     {
-      *pdecl = ref;
-      return DECL_SIZE_UNIT (ref);
+      *pdecl = dest;
+      return DECL_SIZE_UNIT (dest);
     }
 
   tree type = TREE_TYPE (dest);
@@ -3718,7 +3881,7 @@ tree
   type = TYPE_MAIN_VARIANT (type);
 
   if (TREE_CODE (type) == ARRAY_TYPE
-      && !array_at_struct_end_p (ref))
+      && !array_at_struct_end_p (dest))
     {
       if (tree size = TYPE_SIZE_UNIT (type))
 	return TREE_CODE (size) == INTEGER_CST ? size : NULL_TREE;
Index: gcc/builtins.h
===================================================================
--- gcc/builtins.h	(revision 277978)
+++ gcc/builtins.h	(working copy)
@@ -134,7 +134,8 @@ extern tree fold_call_stmt (gcall *, bool);
 extern void set_builtin_user_assembler_name (tree decl, const char *asmspec);
 extern bool is_simple_builtin (tree);
 extern bool is_inexpensive_builtin (tree);
-extern tree compute_objsize (tree, int, tree * = NULL);
+tree gimple_call_alloc_size (gimple *);
+extern tree compute_objsize (tree, int, tree * = NULL, tree * = NULL);
 
 extern bool readonly_data_expr (tree exp);
 extern bool init_target_chars (void);
Index: gcc/testsuite/c-c++-common/Wstringop-truncation.c
===================================================================
--- gcc/testsuite/c-c++-common/Wstringop-truncation.c	(revision 277978)
+++ gcc/testsuite/c-c++-common/Wstringop-truncation.c	(working copy)
@@ -300,8 +300,7 @@ void test_strncpy_array (Dest *pd, int i, const ch
   CPY (pd->a5, s, 5);               /* { dg-warning "specified bound 5 equals destination size" } */
   CPY (pd->a5, s, sizeof pd->a5);   /* { dg-warning "specified bound 5 equals destination size" } */
 
-  /* The following is not yet handled.  */
-  CPY (pd->a5 + i, s, sizeof pd->a5);   /* { dg-warning "specified bound 5 equals destination size" "member array" { xfail *-*-* } } */
+  CPY (pd->a5 + i, s, sizeof pd->a5);   /* { dg-warning "specified bound 5 equals destination size" "member array" } */
 
   /* Verify that a copy that nul-terminates is not diagnosed.  */
   CPY (pd->a5, "1234", sizeof pd->a5);
@@ -425,7 +424,7 @@ void test_strncpy_alloc (const char* s)
   size_t n = 7;
   char *d = (char *)__builtin_malloc (n);
 
-  CPY (d, s, n);                    /* { dg-warning "specified bound 7 equals destination size" "bug 79016" { xfail *-*-* } } */
+  CPY (d, s, n);                    /* { dg-warning "specified bound 7 equals destination size" } */
 
   Dest *pd = (Dest *)__builtin_malloc (sizeof *pd * n);
   CPY (pd->a5, s, 5);               /* { dg-warning "specified bound 5 equals destination size" } */
Index: gcc/testsuite/g++.dg/ext/attr-alloc_size.C
===================================================================
--- gcc/testsuite/g++.dg/ext/attr-alloc_size.C	(revision 277978)
+++ gcc/testsuite/g++.dg/ext/attr-alloc_size.C	(working copy)
@@ -1,6 +1,6 @@
 /* PR c++/87541 - ICE using a constant decl as an attribute alloc_size argument
    { dg-do compile }
-   { dg-options "-O2 -Wall" } */
+   { dg-options "-O2 -Wall -Wno-array-bounds" } */
 
 #define ALLOC_SIZE(N)   __attribute__ ((alloc_size (N)))
 
Index: gcc/testsuite/gcc.dg/Wstringop-overflow-22.c
===================================================================
--- gcc/testsuite/gcc.dg/Wstringop-overflow-22.c	(nonexistent)
+++ gcc/testsuite/gcc.dg/Wstringop-overflow-22.c	(working copy)
@@ -0,0 +1,285 @@
+/* PR middle-end/91582 - missing heap overflow detection for strcpy
+   { dg-do compile }
+   { dg-options "-O2 -Wall -Wno-array-bounds -ftrack-macro-expansion=0" } */
+
+#include "range.h"
+
+#define ATTR(...)   __attribute__ ((__VA_ARGS__))
+#define NOIPA       ATTR (noipa)
+
+extern void* alloca (size_t);
+extern void* calloc (size_t, size_t);
+extern void* malloc (size_t);
+
+extern ATTR (alloc_size (1), malloc) void*
+  alloc1 (size_t, int);
+extern ATTR (alloc_size (2), malloc) void*
+  alloc2 (int, size_t);
+extern ATTR (alloc_size (2, 4), malloc) void*
+  alloc2_4 (int, size_t, int, size_t);
+
+extern char* strcpy (char*, const char*);
+
+void sink (void*);
+
+#define S36 "0123456789abcdefghijklmnopqrstuvwxyz"
+#define S(N) (S36 + sizeof S36 - N - 1)
+
+#define T(src, alloc) do {			\
+    char *s = src;				\
+    char *d = alloc;				\
+    strcpy (d, s);				\
+    sink (d);					\
+  } while (0)
+
+
+NOIPA void test_strcpy_alloca (void)
+{
+  size_t r_0_1 = UR (0, 1);
+  size_t r_1_2 = UR (1, 2);
+  size_t r_2_3 = UR (2, 3);
+
+  T (S (0), alloca (r_0_1));
+  T (S (1), alloca (r_0_1));      // { dg-warning "\\\[-Wstringop-overflow" }
+
+  T (S (0), alloca (r_1_2));
+  T (S (1), alloca (r_1_2));
+  T (S (2), alloca (r_1_2));      // { dg-warning "\\\[-Wstringop-overflow" }
+
+  T (S (0), alloca (r_2_3));
+  T (S (2), alloca (r_2_3));
+  T (S (3), alloca (r_2_3));      // { dg-warning "\\\[-Wstringop-overflow" }
+  T (S (9), alloca (r_2_3));      // { dg-warning "\\\[-Wstringop-overflow" }
+}
+
+NOIPA void test_strcpy_calloc (void)
+{
+  size_t r_1_2 = UR (1, 2);
+  size_t r_2_3 = UR (2, 3);
+
+  T (S (0), calloc (r_1_2, 1));
+  T (S (1), calloc (r_1_2, 1));
+  T (S (2), calloc (r_1_2, 1));   // { dg-warning "\\\[-Wstringop-overflow" }
+
+  T (S (2), calloc (r_2_3, 1));
+  T (S (3), calloc (r_2_3, 1));   // { dg-warning "\\\[-Wstringop-overflow" }
+
+  T (S (0), calloc (1, r_1_2));
+  T (S (1), calloc (1, r_1_2));
+  T (S (2), calloc (1, r_1_2));   // { dg-warning "\\\[-Wstringop-overflow" }
+
+  T (S (2), calloc (1, r_2_3));
+  T (S (3), calloc (1, r_2_3));   // { dg-warning "\\\[-Wstringop-overflow" }
+
+  T (S (0), calloc (r_1_2, 2));
+  T (S (1), calloc (r_1_2, 2));
+  T (S (2), calloc (r_1_2, 2));
+  T (S (3), calloc (r_1_2, 2));
+  T (S (4), calloc (r_1_2, 2));   // { dg-warning "\\\[-Wstringop-overflow" }
+
+  T (S (0), calloc (r_2_3, 2));
+  T (S (1), calloc (r_2_3, 2));
+  T (S (2), calloc (r_2_3, 2));
+  T (S (5), calloc (r_2_3, 2));
+  T (S (6), calloc (r_2_3, 2));   // { dg-warning "\\\[-Wstringop-overflow" }
+
+  T (S (0), calloc (r_1_2, 2));
+  T (S (1), calloc (r_1_2, 2));
+  T (S (2), calloc (r_1_2, 2));
+  T (S (3), calloc (r_1_2, 2));
+  T (S (4), calloc (r_1_2, 2));   // { dg-warning "\\\[-Wstringop-overflow" }
+
+  T (S (0), calloc (r_2_3, 2));
+  T (S (1), calloc (r_2_3, 2));
+  T (S (2), calloc (r_2_3, 2));
+  T (S (5), calloc (r_2_3, 2));
+  T (S (6), calloc (r_2_3, 2));   // { dg-warning "\\\[-Wstringop-overflow" }
+
+  T (S (0), calloc (r_1_2, r_2_3));
+  T (S (1), calloc (r_1_2, r_2_3));
+  T (S (2), calloc (r_1_2, r_2_3));
+  T (S (3), calloc (r_1_2, r_2_3));
+  T (S (4), calloc (r_1_2, r_2_3));
+  T (S (5), calloc (r_1_2, r_2_3));
+  T (S (6), calloc (r_1_2, r_2_3));   // { dg-warning "\\\[-Wstringop-overflow" }
+  T (S (9), calloc (r_1_2, r_2_3));   // { dg-warning "\\\[-Wstringop-overflow" }
+}
+
+
+NOIPA void test_strcpy_malloc (void)
+{
+  size_t r_0_1 = UR (0, 1);
+  size_t r_1_2 = UR (1, 2);
+  size_t r_2_3 = UR (2, 3);
+
+  T (S (0), malloc (r_0_1));
+  T (S (1), malloc (r_0_1));      // { dg-warning "\\\[-Wstringop-overflow" }
+
+  T (S (0), malloc (r_1_2));
+  T (S (1), malloc (r_1_2));
+  T (S (2), malloc (r_1_2));      // { dg-warning "\\\[-Wstringop-overflow" }
+
+  T (S (0), malloc (r_2_3));
+  T (S (2), malloc (r_2_3));
+  T (S (3), malloc (r_2_3));      // { dg-warning "\\\[-Wstringop-overflow" }
+  T (S (9), malloc (r_2_3));      // { dg-warning "\\\[-Wstringop-overflow" }
+}
+
+
+NOIPA void test_strcpy_alloc1 (void)
+{
+  size_t r_0_1 = UR (0, 1);
+  size_t r_1_2 = UR (1, 2);
+  size_t r_2_3 = UR (2, 3);
+
+#define alloc1(n) alloc1 (n, 1)
+
+  T (S (0), alloc1 (r_0_1));
+  T (S (1), alloc1 (r_0_1));      // { dg-warning "\\\[-Wstringop-overflow" }
+
+  T (S (0), alloc1 (r_1_2));
+  T (S (1), alloc1 (r_1_2));
+  T (S (2), alloc1 (r_1_2));      // { dg-warning "\\\[-Wstringop-overflow" }
+
+  T (S (0), alloc1 (r_2_3));
+  T (S (2), alloc1 (r_2_3));
+  T (S (3), alloc1 (r_2_3));      // { dg-warning "\\\[-Wstringop-overflow" }
+  T (S (9), alloc1 (r_2_3));      // { dg-warning "\\\[-Wstringop-overflow" }
+}
+
+NOIPA void test_strcpy_alloc2 (void)
+{
+  size_t r_0_1 = UR (0, 1);
+  size_t r_1_2 = UR (1, 2);
+  size_t r_2_3 = UR (2, 3);
+
+#define alloc2(n) alloc2 (1, n)
+
+  T (S (0), alloc1 (r_0_1));
+  T (S (1), alloc1 (r_0_1));      // { dg-warning "\\\[-Wstringop-overflow" }
+
+  T (S (0), alloc1 (r_1_2));
+  T (S (1), alloc1 (r_1_2));
+  T (S (2), alloc1 (r_1_2));      // { dg-warning "\\\[-Wstringop-overflow" }
+
+  T (S (0), alloc1 (r_2_3));
+  T (S (2), alloc1 (r_2_3));
+  T (S (3), alloc1 (r_2_3));      // { dg-warning "\\\[-Wstringop-overflow" }
+  T (S (9), alloc1 (r_2_3));      // { dg-warning "\\\[-Wstringop-overflow" }
+}
+
+
+NOIPA void test_strcpy_alloc2_4 (void)
+{
+  size_t r_1_2 = UR (1, 2);
+  size_t r_2_3 = UR (2, 3);
+
+#define alloc2_4(n1, n2) alloc2_4 (1, n1, 2, n2)
+
+  T (S (0), alloc2_4 (r_1_2, 1));
+  T (S (1), alloc2_4 (r_1_2, 1));
+  T (S (2), alloc2_4 (r_1_2, 1));   // { dg-warning "\\\[-Wstringop-overflow" }
+
+  T (S (2), alloc2_4 (r_2_3, 1));
+  T (S (3), alloc2_4 (r_2_3, 1));   // { dg-warning "\\\[-Wstringop-overflow" }
+
+  T (S (0), alloc2_4 (1, r_1_2));
+  T (S (1), alloc2_4 (1, r_1_2));
+  T (S (2), alloc2_4 (1, r_1_2));   // { dg-warning "\\\[-Wstringop-overflow" }
+
+  T (S (2), alloc2_4 (1, r_2_3));
+  T (S (3), alloc2_4 (1, r_2_3));   // { dg-warning "\\\[-Wstringop-overflow" }
+
+  T (S (0), alloc2_4 (r_1_2, 2));
+  T (S (1), alloc2_4 (r_1_2, 2));
+  T (S (2), alloc2_4 (r_1_2, 2));
+  T (S (3), alloc2_4 (r_1_2, 2));
+  T (S (4), alloc2_4 (r_1_2, 2));   // { dg-warning "\\\[-Wstringop-overflow" }
+
+  T (S (0), alloc2_4 (r_2_3, 2));
+  T (S (1), alloc2_4 (r_2_3, 2));
+  T (S (2), alloc2_4 (r_2_3, 2));
+  T (S (5), alloc2_4 (r_2_3, 2));
+  T (S (6), alloc2_4 (r_2_3, 2));   // { dg-warning "\\\[-Wstringop-overflow" }
+
+  T (S (0), alloc2_4 (r_1_2, 2));
+  T (S (1), alloc2_4 (r_1_2, 2));
+  T (S (2), alloc2_4 (r_1_2, 2));
+  T (S (3), alloc2_4 (r_1_2, 2));
+  T (S (4), alloc2_4 (r_1_2, 2));   // { dg-warning "\\\[-Wstringop-overflow" }
+
+  T (S (0), alloc2_4 (r_2_3, 2));
+  T (S (1), alloc2_4 (r_2_3, 2));
+  T (S (2), alloc2_4 (r_2_3, 2));
+  T (S (5), alloc2_4 (r_2_3, 2));
+  T (S (6), alloc2_4 (r_2_3, 2));   // { dg-warning "\\\[-Wstringop-overflow" }
+
+  T (S (0), alloc2_4 (r_1_2, r_2_3));
+  T (S (1), alloc2_4 (r_1_2, r_2_3));
+  T (S (2), alloc2_4 (r_1_2, r_2_3));
+  T (S (3), alloc2_4 (r_1_2, r_2_3));
+  T (S (4), alloc2_4 (r_1_2, r_2_3));
+  T (S (5), alloc2_4 (r_1_2, r_2_3));
+  T (S (6), alloc2_4 (r_1_2, r_2_3));   // { dg-warning "\\\[-Wstringop-overflow" }
+  T (S (9), alloc2_4 (r_1_2, r_2_3));   // { dg-warning "\\\[-Wstringop-overflow" }
+}
+
+#undef T
+#define T(T, src, n) do {			\
+    char *s = src;				\
+    T vla[n];					\
+    char *d = (char*)vla;			\
+    strcpy (d, s);				\
+    sink (vla);					\
+  } while (0)
+
+NOIPA void test_strcpy_vla (void)
+{
+  size_t r_0_1 = UR (0, 1);
+  size_t r_1_2 = UR (1, 2);
+  size_t r_2_3 = UR (2, 3);
+
+  T (char, S (0), r_0_1);
+  T (char, S (1), r_0_1);       // { dg-warning "\\\[-Wstringop-overflow" }
+
+  T (char, S (0), r_1_2);
+  T (char, S (1), r_1_2);
+  T (char, S (2), r_1_2);       // { dg-warning "\\\[-Wstringop-overflow" }
+
+  T (char, S (0), r_2_3);
+  T (char, S (2), r_2_3);
+  T (char, S (3), r_2_3);       // { dg-warning "\\\[-Wstringop-overflow" }
+  T (char, S (9), r_2_3);       // { dg-warning "\\\[-Wstringop-overflow" }
+
+#ifdef __INT16_TYPE__
+  typedef __INT16_TYPE__ int16_t;
+
+  T (int16_t, S (0), r_1_2);
+  T (int16_t, S (2), r_1_2);
+  T (int16_t, S (3), r_1_2);
+  T (int16_t, S (4), r_1_2);    // { dg-warning "\\\[-Wstringop-overflow" }
+  T (int16_t, S (5), r_1_2);    // { dg-warning "\\\[-Wstringop-overflow" }
+  T (int16_t, S (9), r_1_2);    // { dg-warning "\\\[-Wstringop-overflow" }
+
+  T (int16_t, S (0), r_2_3);
+  T (int16_t, S (2), r_2_3);
+  T (int16_t, S (3), r_2_3);
+  T (int16_t, S (4), r_2_3);
+  T (int16_t, S (5), r_2_3);
+  T (int16_t, S (6), r_2_3);    // { dg-warning "\\\[-Wstringop-overflow" }
+#endif
+
+#ifdef __INT32_TYPE__
+  typedef __INT32_TYPE__ int32_t;
+
+  T (int32_t, S ( 0), r_2_3);
+  T (int32_t, S ( 2), r_2_3);
+  T (int32_t, S ( 3), r_2_3);
+  T (int32_t, S ( 4), r_2_3);
+  T (int32_t, S ( 5), r_2_3);
+  T (int32_t, S ( 6), r_2_3);
+  T (int32_t, S (11), r_2_3);
+  T (int32_t, S (12), r_2_3);    // { dg-warning "\\\[-Wstringop-overflow" }
+  T (int32_t, S (36), r_2_3);    // { dg-warning "\\\[-Wstringop-overflow" }
+#endif
+}
Index: gcc/testsuite/gcc.dg/attr-alloc_size.c
===================================================================
--- gcc/testsuite/gcc.dg/attr-alloc_size.c	(revision 277978)
+++ gcc/testsuite/gcc.dg/attr-alloc_size.c	(working copy)
@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-options "-O2 -Wall -ftrack-macro-expansion=0" } */
+/* { dg-options "-O2 -Wall -Wno-array-bounds -ftrack-macro-expansion=0" } */
 
 extern void abort (void);
 
Index: gcc/testsuite/gcc.dg/attr-copy-2.c
===================================================================
--- gcc/testsuite/gcc.dg/attr-copy-2.c	(revision 277978)
+++ gcc/testsuite/gcc.dg/attr-copy-2.c	(working copy)
@@ -2,7 +2,7 @@
    Exercise attribute copy for functions.
    { dg-do compile }
    { dg-require-alias "" }
-   { dg-options "-O2 -Wall" } */
+   { dg-options "-O2 -Wall -Wno-array-bounds" } */
 
 #define Assert(expr)   typedef char AssertExpr[2 * !!(expr) - 1]
 
Index: gcc/testsuite/gcc.dg/builtin-stringop-chk-5.c
===================================================================
--- gcc/testsuite/gcc.dg/builtin-stringop-chk-5.c	(revision 277978)
+++ gcc/testsuite/gcc.dg/builtin-stringop-chk-5.c	(working copy)
@@ -1,4 +1,4 @@
-/* Test exercising -Wrawmem-overflow and -Wstringop-overflow warnings.  */
+/* Test exercising -Wstringop-overflow warnings.  */
 /* { dg-do compile } */
 /* { dg-options "-O2 -Wstringop-overflow=1" } */
 
@@ -49,7 +49,7 @@ void test_memop_warn_local (const void *src)
   memcpy (a, src, n);   /* { dg-warning "writing between 8 and 32 bytes into a region of size 4 overflows the destination" } */
   escape (a, src);
 
-  /* At -Wrawmem-overflow=1 the destination is considered to be
+  /* At -Wstringop-overflow=1 the destination is considered to be
      the whole array and its size is therefore sizeof a.  */
   memcpy (&a[0], src, n);   /* { dg-warning "writing between 8 and 32 bytes into a region of size 4 overflows the destination" } */
   escape (a, src);
@@ -110,12 +110,12 @@ void test_memop_warn_alloc (const void *src)
 
   struct A *a = __builtin_malloc (sizeof *a * 2);
 
-  memcpy (a, src, n);   /* { dg-warning "writing between 8 and 32 bytes into a region of size 4 overflows the destination" "memcpy into allocated" { xfail *-*-*} } */
+  memcpy (a, src, n);   /* { dg-warning "writing between 8 and 32 bytes into a region of size 4 overflows the destination" "memcpy into allocated" } */
   escape (a, src);
 
-  /* At -Wrawmem-overflow=1 the destination is considered to be
+  /* At -Wstringop-overflow=1 the destination is considered to be
      the whole array and its size is therefore sizeof a.  */
-  memcpy (&a[0], src, n);   /* { dg-warning "writing between 8 and 32 bytes into a region of size 4 overflows the destination" "memcpy into allocated" { xfail *-*-*} } */
+  memcpy (&a[0], src, n);   /* { dg-warning "writing between 8 and 32 bytes into a region of size 4 overflows the destination" "memcpy into allocated" } */
   escape (a, src);
 
   /* Verify the same as above but by writing into the first mmeber
@@ -127,7 +127,7 @@ void test_memop_warn_alloc (const void *src)
 
   struct B *b = __builtin_malloc (sizeof *b * 2);
 
-  memcpy (&b[0], src, n);   /* { dg-warning "writing between 12 and 32 bytes into a region of size 8 overflows the destination" "memcpy into allocated" { xfail *-*-*} } */
+  memcpy (&b[0], src, n);   /* { dg-warning "writing between 12 and 32 bytes into a region of size 8 overflows the destination" "memcpy into allocated" } */
   escape (b);
 
   /* The following idiom of clearing multiple members of a struct is
Index: gcc/testsuite/gcc.dg/builtin-stringop-chk-8.c
===================================================================
--- gcc/testsuite/gcc.dg/builtin-stringop-chk-8.c	(revision 277978)
+++ gcc/testsuite/gcc.dg/builtin-stringop-chk-8.c	(working copy)
@@ -102,9 +102,9 @@ void test_memop_warn_alloc (void *p)
 
   struct A *a = __builtin_malloc (sizeof *a * 2);
 
-  memcpy (p, a, n);   /* { dg-warning "reading between 8 and 32 bytes from region of size 4" "memcpy from allocated" { xfail *-*-*} } */
+  memcpy (p, a, n);   /* { dg-warning "reading between 8 and 32 bytes from a region of size 4" "memcpy from allocated" } */
 
-  memcpy (p, &a[0], n);   /* { dg-warning "reading between 8 and 32 bytes from a region of size 4" "memcpy from allocated" { xfail *-*-*} } */
+  memcpy (p, &a[0], n);   /* { dg-warning "reading between 8 and 32 bytes from a region of size 4" "memcpy from allocated" } */
 
   memcpy (p, &a[0].a, n);   /* { dg-warning "reading between 8 and 32 bytes from a region of size 4" "memcpy from allocated" { xfail *-*-*} } */
 
@@ -112,13 +112,13 @@ void test_memop_warn_alloc (void *p)
 
   struct B *b = __builtin_malloc (sizeof *b * 2);
 
-  memcpy (p, &b[0], n);   /* { dg-warning "reading between 12 and 32 bytes from a region of size 8" "memcpy from allocated" { xfail *-*-*} } */
+  memcpy (p, &b[0], n);   /* { dg-warning "reading between 12 and 32 bytes from a region of size 8" "memcpy from allocated" } */
 
   /* Verify memchr/memcmp.  */
   n = sizeof *b * 2 + 1;
 
-  memchr (b, 1, n);   /* { dg-warning "reading 5 bytes from a region of size 4" "memcmp from allocated" { xfail *-*-* } } */
-  memcmp (p, b, n);   /* { dg-warning "reading 5 bytes from a region of size 4" "memcmp from allocated" { xfail *-*-* } } */
+  memchr (b, 1, n);   /* { dg-warning "reading 9 bytes from a region of size 8" "memcmp from allocated" } */
+  memcmp (p, b, n);   /* { dg-warning "reading 9 bytes from a region of size 8" "memcmp from allocated" } */
 }
 
 
Index: gcc/testsuite/gcc.target/i386/pr82002-2a.c
===================================================================
--- gcc/testsuite/gcc.target/i386/pr82002-2a.c	(revision 277978)
+++ gcc/testsuite/gcc.target/i386/pr82002-2a.c	(working copy)
@@ -10,3 +10,5 @@ b ()
   a (c);
   a (c);
 }
+
+/* { dg-prune-output "\\\[-Wstringop-overflow" }  */
Index: gcc/testsuite/gcc.target/i386/pr82002-2b.c
===================================================================
--- gcc/testsuite/gcc.target/i386/pr82002-2b.c	(revision 277978)
+++ gcc/testsuite/gcc.target/i386/pr82002-2b.c	(working copy)
@@ -10,3 +10,5 @@ b ()
   a (c);
   a (c);
 }
+
+/* { dg-prune-output "\\\[-Wstringop-overflow" }  */
Index: gcc/tree-ssa-strlen.c
===================================================================
--- gcc/tree-ssa-strlen.c	(revision 277978)
+++ gcc/tree-ssa-strlen.c	(working copy)
@@ -4384,8 +4384,22 @@ handle_store (gimple_stmt_iterator *gsi, bool *zer
 			       stmt, lenrange[2], dstsize))
 		  {
 		    if (decl)
-		      inform (DECL_SOURCE_LOCATION (decl),
-			      "destination object declared here");
+		      {
+			if (TREE_CODE (decl) == SSA_NAME)
+			  {
+			    gimple *stmt = SSA_NAME_DEF_STMT (decl);
+			    if (is_gimple_call (stmt))
+			      {
+				tree allocfn = gimple_call_fndecl (stmt);
+				inform (gimple_location (stmt),
+					"destination region allocated by %qD "
+					"here", allocfn);
+			      }
+			  }
+			else
+			  inform (DECL_SOURCE_LOCATION (decl),
+				  "destination object declared here");
+		      }
 		    gimple_set_no_warning (stmt, true);
 		  }
 	      }

^ permalink raw reply	[flat|nested] 7+ messages in thread
end of thread, other threads:[~2019-12-06 17:03 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-11-08 22:11 [PATCH] extend -Wstringop-overflow to allocated objects (PR 91582) Martin Sebor
2019-11-18 18:23 ` [PING][PATCH] " Martin Sebor
2019-11-25 17:54   ` [PING 2][PATCH] " Martin Sebor
2019-12-02 17:06 ` [PATCH] " Jeff Law
2019-12-05  1:37   ` Martin Sebor
2019-12-06 15:44     ` Christophe Lyon
2019-12-06 17:03       ` Martin Sebor

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