Reduce false positives for -Wnonnull for VLA parameters [PR98541]

This patch limits the warning about NULL arguments to VLA
parameters declared [static n].

	PR c/98541

gcc/
	* gimple-ssa-warn-access.cc
	(pass_waccess::maybe_check_access_sizes): For VLA bounds
	in parameters, only warn about null pointers with 'static'.

gcc/testsuite:
	* gcc.dg/Wnonnull-4.c: Adapt test.
	* gcc.dg/Wstringop-overflow-40.c: Adapt test.

3 files changed, 27 insertions, 36 deletions

diff --git a/gcc/gimple-ssa-warn-access.cc b/gcc/gimple-ssa-warn-access.cc
index e439d1b..8b73429 100644
--- a/gcc/gimple-ssa-warn-access.cc
+++ b/gcc/gimple-ssa-warn-access.cc
@@ -3477,27 +3477,14 @@ pass_waccess::maybe_check_access_sizes (rdwr_map *rwm, tree fndecl, tree fntype,
 
       if (integer_zerop (ptr))
 	{
-	  if (sizidx >= 0 && tree_int_cst_sgn (sizrng[0]) > 0)
+	  if (!access.second.internal_p
+	      && sizidx >= 0 && tree_int_cst_sgn (sizrng[0]) > 0)
 	    {
 	      /* Warn about null pointers with positive sizes.  This is
 		 different from also declaring the pointer argument with
 		 attribute nonnull when the function accepts null pointers
 		 only when the corresponding size is zero.  */
-	      if (access.second.internal_p)
-		{
-		  const std::string argtypestr
-		    = access.second.array_as_string (ptrtype);
-
-		  if (warning_at (loc, OPT_Wnonnull,
-				  "argument %i of variable length "
-				  "array %s is null but "
-				  "the corresponding bound argument "
-				  "%i value is %s",
-				  ptridx + 1, argtypestr.c_str (),
-				  sizidx + 1, sizstr))
-		    arg_warned = OPT_Wnonnull;
-		}
-	      else if (warning_at (loc, OPT_Wnonnull,
+	      if (warning_at (loc, OPT_Wnonnull,
 				   "argument %i is null but "
 				   "the corresponding size argument "
 				   "%i value is %s",
diff --git a/gcc/testsuite/gcc.dg/Wnonnull-4.c b/gcc/testsuite/gcc.dg/Wnonnull-4.c
index 2c1c45a..1f14fbb 100644
--- a/gcc/testsuite/gcc.dg/Wnonnull-4.c
+++ b/gcc/testsuite/gcc.dg/Wnonnull-4.c
@@ -27,9 +27,9 @@ void test_fca_n (int r_m1)
   T (  0);
 
   // Verify positive bounds.
-  T (  1);          // { dg-warning "argument 2 of variable length array 'char\\\[n]' is null but the corresponding bound argument 1 value is 1" }
-  T (  9);          // { dg-warning "argument 2 of variable length array 'char\\\[n]' is null but the corresponding bound argument 1 value is 9" }
-  T (max);          // { dg-warning "argument 2 of variable length array 'char\\\[n]' is null but the corresponding bound argument 1 value is \\d+" }
+  T (  1);          // { dg-bogus "argument 2 of variable length array 'char\\\[n]' is null but the corresponding bound argument 1 value is 1" }
+  T (  9);          // { dg-bogus "argument 2 of variable length array 'char\\\[n]' is null but the corresponding bound argument 1 value is 9" }
+  T (max);          // { dg-bogus "argument 2 of variable length array 'char\\\[n]' is null but the corresponding bound argument 1 value is \\d+" }
 }
 
 
@@ -55,9 +55,9 @@ void test_fsa_x_n (int r_m1)
   T (  0);
 
   // Verify positive bounds.
-  T (  1);          // { dg-warning "argument 2 of variable length array 'short int\\\[]\\\[n]' is null but the corresponding bound argument 1 value is 1" }
-  T (  9);          // { dg-warning "argument 2 of variable length array 'short int\\\[]\\\[n]' is null but the corresponding bound argument 1 value is 9" }
-  T (max);          // { dg-warning "argument 2 of variable length array 'short int\\\[]\\\[n]' is null but the corresponding bound argument 1 value is \\d+" }
+  T (  1);          // { dg-bogus "argument 2 of variable length array 'short int\\\[]\\\[n]' is null but the corresponding bound argument 1 value is 1" }
+  T (  9);          // { dg-bogus "argument 2 of variable length array 'short int\\\[]\\\[n]' is null but the corresponding bound argument 1 value is 9" }
+  T (max);          // { dg-bogus "argument 2 of variable length array 'short int\\\[]\\\[n]' is null but the corresponding bound argument 1 value is \\d+" }
 }
 
 
@@ -83,9 +83,9 @@ void test_fia_1_n (int r_m1)
   T (  0);
 
   // Verify positive bounds.
-  T (  1);          // { dg-warning "argument 2 of variable length array 'int\\\[1]\\\[n]' is null but the corresponding bound argument 1 value is 1" }
-  T (  9);          // { dg-warning "argument 2 of variable length array 'int\\\[1]\\\[n]' is null but the corresponding bound argument 1 value is 9" }
-  T (max);          // { dg-warning "argument 2 of variable length array 'int\\\[1]\\\[n]' is null but the corresponding bound argument 1 value is \\d+" }
+  T (  1);          // { dg-bogus "argument 2 of variable length array 'int\\\[1]\\\[n]' is null but the corresponding bound argument 1 value is 1" }
+  T (  9);          // { dg-bogus "argument 2 of variable length array 'int\\\[1]\\\[n]' is null but the corresponding bound argument 1 value is 9" }
+  T (max);          // { dg-bogus "argument 2 of variable length array 'int\\\[1]\\\[n]' is null but the corresponding bound argument 1 value is \\d+" }
 }
 
 
@@ -111,9 +111,9 @@ void test_fla_3_n (int r_m1)
   T (  0);
 
   // Verify positive bounds.
-  T (  1);          // { dg-warning "argument 2 of variable length array 'long int\\\[3]\\\[n]' is null but the corresponding bound argument 1 value is 1" }
-  T (  9);          // { dg-warning "argument 2 of variable length array 'long int\\\[3]\\\[n]' is null but the corresponding bound argument 1 value is 9" }
-  T (max);          // { dg-warning "argument 2 of variable length array 'long int\\\[3]\\\[n]' is null but the corresponding bound argument 1 value is \\d+" }
+  T (  1);          // { dg-bogus "argument 2 of variable length array 'long int\\\[3]\\\[n]' is null but the corresponding bound argument 1 value is 1" }
+  T (  9);          // { dg-bogus "argument 2 of variable length array 'long int\\\[3]\\\[n]' is null but the corresponding bound argument 1 value is 9" }
+  T (max);          // { dg-bogus "argument 2 of variable length array 'long int\\\[3]\\\[n]' is null but the corresponding bound argument 1 value is \\d+" }
 }
 
 
@@ -139,9 +139,9 @@ void test_fda_n_5 (int r_m1)
   T (  0);
 
   // Verify positive bounds.
-  T (  1);          // { dg-warning "argument 2 of variable length array 'double\\\[n]\\\[5]' is null but the corresponding bound argument 1 value is 1" }
-  T (  9);          // { dg-warning "argument 2 of variable length array 'double\\\[n]\\\[5]' is null but the corresponding bound argument 1 value is 9" }
-  T (max);          // { dg-warning "argument 2 of variable length array 'double\\\[n]\\\[5]' is null but the corresponding bound argument 1 value is \\d+" }
+  T (  1);          // { dg-bogus "argument 2 of variable length array 'double\\\[n]\\\[5]' is null but the corresponding bound argument 1 value is 1" }
+  T (  9);          // { dg-bogus "argument 2 of variable length array 'double\\\[n]\\\[5]' is null but the corresponding bound argument 1 value is 9" }
+  T (max);          // { dg-bogus "argument 2 of variable length array 'double\\\[n]\\\[5]' is null but the corresponding bound argument 1 value is \\d+" }
 }
 
 
@@ -167,7 +167,7 @@ void test_fca_n_n (int r_m1)
   T (  0);
 
   // Verify positive bounds.
-  T (  1);          // { dg-warning "argument 2 of variable length array 'char\\\[n]\\\[n]' is null but the corresponding bound argument 1 value is 1" }
-  T (  9);          // { dg-warning "argument 2 of variable length array 'char\\\[n]\\\[n]' is null but the corresponding bound argument 1 value is 9" }
-  T (max);          // { dg-warning "argument 2 of variable length array 'char\\\[n]\\\[n]' is null but the corresponding bound argument 1 value is \\d+" }
+  T (  1);          // { dg-bogus "argument 2 of variable length array 'char\\\[n]\\\[n]' is null but the corresponding bound argument 1 value is 1" }
+  T (  9);          // { dg-bogus "argument 2 of variable length array 'char\\\[n]\\\[n]' is null but the corresponding bound argument 1 value is 9" }
+  T (max);          // { dg-bogus "argument 2 of variable length array 'char\\\[n]\\\[n]' is null but the corresponding bound argument 1 value is \\d+" }
 }
diff --git a/gcc/testsuite/gcc.dg/Wstringop-overflow-40.c b/gcc/testsuite/gcc.dg/Wstringop-overflow-40.c
index 386c92d..9e0ad1f 100644
--- a/gcc/testsuite/gcc.dg/Wstringop-overflow-40.c
+++ b/gcc/testsuite/gcc.dg/Wstringop-overflow-40.c
@@ -11,6 +11,7 @@ void fxa2 (int16_t[2]) __attribute__ ((nonnull));
 void fas2 (int16_t[static 2]);
 
 void fvla (unsigned n, int16_t[n]);
+void fvlaS (unsigned n, int16_t[static n]);
 
 void test_array_1_dim (void)
 {
@@ -33,7 +34,8 @@ void test_array_1_dim (void)
   fas2 (a1);                  // { dg-warning "'fas2' accessing 4 bytes in a region of size 2 " }
   fas2 (&i);                  // { dg-warning "'fas2' accessing 4 bytes in a region of size 2 " }
 
-  fvla (1, 0);                // { dg-warning "\\\[-Wnonnull" }
+  fvla (1, 0);
+  fvlaS (1, 0);               // { dg-warning "\\\[-Wnonnull" }
   fvla (1, &i);
   fvla (2, a2);
   fvla (2, a1);               // { dg-warning "'fvla' accessing 4 bytes in a region of size 2 " }
@@ -47,6 +49,7 @@ void fxac2 (const int16_t[2]) __attribute__ ((nonnull));
 void facs2 (const int16_t[static 2]);
 
 void fvlac (unsigned n, const int16_t[n]);
+void fvlacS (unsigned n, const int16_t[static n]);
 
 void test_const_array_1_dim (void)
 {
@@ -69,7 +72,8 @@ void test_const_array_1_dim (void)
   facs2 (a1);                 // { dg-warning "'facs2' reading 4 bytes from a region of size 2 " }
   facs2 (&i);                 // { dg-warning "'facs2' reading 4 bytes from a region of size 2 " }
 
-  fvlac (1, 0);               // { dg-warning "\\\[-Wnonnull" }
+  fvlac (1, 0);
+  fvlacS (1, 0);              // { dg-warning "\\\[-Wnonnull" }
   fvlac (1, &i);
   fvlac (2, a2);
   fvlac (2, a1);              // { dg-warning "'fvlac' reading 4 bytes from a region of size 2 " }