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riscv-gcc-1
Commit 665db3ae by Jeff Law
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re PR c/87028 (false positive -Wstringop-truncation strncpy with global variable source string) 

	PR c/87028
	* calls.c (get_attr_nonstring_decl): Avoid setting *REF to
	SSA_NAME_VAR.
	* gcc/gimple-low.c (lower_stmt): Fold builtin calls here.
	* gimplify (maybe_fold_stmt): Avoid folding builtin calls.

	PR c/87028
	* c-c++-common/Wstringop-truncation.c: Remove xfails.
	* gcc.dg/Wstringop-truncation-5.c: New test.
	* gcc.dg/strcmpopt_1.c: Adjust.
	* gcc.dg/tree-ssa/pr79697.c: Same.

From-SVN: r266833
parent c43137e8
Showing with 179 additions and 15 deletions
gcc/ChangeLog
2018-12-05 Richard Biener <rguenther@suse.de>
Martin Sebor <msebor@redhat.com>
PR c/87028
* calls.c (get_attr_nonstring_decl): Avoid setting *REF to
SSA_NAME_VAR.
* gcc/gimple-low.c (lower_stmt): Fold builtin calls here.
* gimplify (maybe_fold_stmt): Avoid folding builtin calls.
2018-12-05 Iain Sandoe <iain@sandoe.co.uk>
* configure.ac (gcc_cv_otool): Set.
gcc/calls.c
......@@ -1503,6 +1503,7 @@ tree
get_attr_nonstring_decl (tree expr, tree *ref)
{
tree decl = expr;
tree var = NULL_TREE;
if (TREE_CODE (decl) == SSA_NAME)
{
gimple *def = SSA_NAME_DEF_STMT (decl);
......@@ -1515,17 +1516,25 @@ get_attr_nonstring_decl (tree expr, tree *ref)
|| code == VAR_DECL)
decl = gimple_assign_rhs1 (def);
}
else if (tree var = SSA_NAME_VAR (decl))
decl = var;
else
var = SSA_NAME_VAR (decl);
}
if (TREE_CODE (decl) == ADDR_EXPR)
decl = TREE_OPERAND (decl, 0);
/* To simplify calling code, store the referenced DECL regardless of
the attribute determined below, but avoid storing the SSA_NAME_VAR
obtained above (it's not useful for dataflow purposes). */
if (ref)
*ref = decl;
if (TREE_CODE (decl) == ARRAY_REF)
/* Use the SSA_NAME_VAR that was determined above to see if it's
declared nonstring. Otherwise drill down into the referenced
DECL. */
if (var)
decl = var;
else if (TREE_CODE (decl) == ARRAY_REF)
decl = TREE_OPERAND (decl, 0);
else if (TREE_CODE (decl) == COMPONENT_REF)
decl = TREE_OPERAND (decl, 1);
......
gcc/gimple-low.c
......@@ -32,6 +32,7 @@ along with GCC; see the file COPYING3. If not see
#include "gimple-low.h"
#include "predict.h"
#include "gimple-predict.h"
#include "gimple-fold.h"
/* The differences between High GIMPLE and Low GIMPLE are the
following:
......@@ -378,6 +379,12 @@ lower_stmt (gimple_stmt_iterator *gsi, struct lower_data *data)
gsi_next (gsi);
return;
}
/* We delay folding of built calls from gimplification to
here so the IL is in consistent state for the diagnostic
machineries job. */
if (gimple_call_builtin_p (stmt))
fold_stmt (gsi);
}
break;
......
gcc/gimplify.c
......@@ -3192,6 +3192,10 @@ maybe_fold_stmt (gimple_stmt_iterator *gsi)
return false;
else if ((ctx->region_type & ORT_HOST_TEAMS) == ORT_HOST_TEAMS)
return false;
/* Delay folding of builtins until the IL is in consistent state
so the diagnostic machinery can do a better job. */
if (gimple_call_builtin_p (gsi_stmt (*gsi)))
return false;
return fold_stmt (gsi);
}
......
gcc/testsuite/ChangeLog
2018-12-05 Martin Sebor <msebor@redhat.com>
PR c/87028
* c-c++-common/Wstringop-truncation.c: Remove xfails.
* gcc.dg/Wstringop-truncation-5.c: New test.
* gcc.dg/strcmpopt_1.c: Adjust.
* gcc.dg/tree-ssa/pr79697.c: Same.
2018-12-05 Richard Sandiford <richard.sandiford@arm.com>
PR tree-optimization/88064
......
gcc/testsuite/c-c++-common/Wstringop-truncation.c
......@@ -329,9 +329,8 @@ void test_strncpy_array (Dest *pd, int i, const char* s)
of the array to NUL is not diagnosed. */
{
/* This might be better written using memcpy() but it's safe so
it probably shouldn't be diagnosed. It currently triggers
a warning because of bug 81704. */
strncpy (dst7, "0123456", sizeof dst7); /* { dg-bogus "\\\[-Wstringop-truncation]" "bug 81704" { xfail *-*-* } } */
it shouldn't be diagnosed. */
strncpy (dst7, "0123456", sizeof dst7); /* { dg-bogus "\\\[-Wstringop-truncation]" } */
dst7[sizeof dst7 - 1] = '\0';
sink (dst7);
}
......@@ -350,7 +349,7 @@ void test_strncpy_array (Dest *pd, int i, const char* s)
}
{
strncpy (pd->a5, "01234", sizeof pd->a5); /* { dg-bogus "\\\[-Wstringop-truncation]" "bug 81704" { xfail *-*-* } } */
strncpy (pd->a5, "01234", sizeof pd->a5); /* { dg-bogus "\\\[-Wstringop-truncation]" } */
pd->a5[sizeof pd->a5 - 1] = '\0';
sink (pd);
}
......
gcc/testsuite/gcc.dg/Wstringop-truncation-5.c 0 → 100644
/* PR tree-optimization/87028 - false positive -Wstringop-truncation
strncpy with global variable source string
{ dg-do compile }
{ dg-options "-O2 -Wstringop-truncation" } */
char *strncpy (char *, const char *, __SIZE_TYPE__);
#define STR "1234567890"
struct S
{
char a[5], b[5];
};
const char arr[] = STR;
const char* const ptr = STR;
const char arr2[][10] = { "123", STR };
void test_literal (struct S *s)
{
strncpy (s->a, STR, sizeof s->a - 1); /* { dg-bogus "\\\[-Wstringop-truncation]" } */
s->a[sizeof s->a - 1] = '\0';
}
void test_global_arr (struct S *s)
{
strncpy (s->a, arr, sizeof s->a - 1); /* { dg-bogus "\\\[-Wstringop-truncation]" } */
s->a [sizeof s->a - 1] = '\0';
}
void test_global_arr2 (struct S *s)
{
strncpy (s->a, arr2[1], sizeof s->a - 1); /* { dg-bogus "\\\[-Wstringop-truncation]" } */
s->a [sizeof s->a - 1] = '\0';
strncpy (s->b, arr2[0], sizeof s->a - 1);
}
void test_global_ptr (struct S *s)
{
strncpy (s->a, ptr, sizeof s->a - 1); /* { dg-bogus "\\\[-Wstringop-truncation]" } */
s->a [sizeof s->a - 1] = '\0';
}
void test_local_arr (struct S *s)
{
const char arr[] = STR;
strncpy (s->a, arr, sizeof s->a - 1);
s->a [sizeof s->a - 1] = '\0';
}
void test_local_ptr (struct S *s)
{
const char* const ptr = STR;
strncpy (s->a, ptr, sizeof s->a - 1); /* { dg-bogus "\\\[-Wstringop-truncation]" } */
s->a [sizeof s->a - 1] = '\0';
}
void test_compound_literal (struct S *s)
{
strncpy (s->a, (char[]){ STR }, sizeof s->a - 1);
s->a [sizeof s->a - 1] = '\0';
}
/* PR tree-optimization/87028 - false positive -Wstringop-truncation
strncpy with global variable source string
{ dg-do compile }
{ dg-options "-O2 -Wstringop-truncation" } */
char *strncpy (char *, const char *, __SIZE_TYPE__);
#define STR "1234567890"
struct S
{
char a[5], b[5];
};
const char arr[] = STR;
const char* const ptr = STR;
const char arr2[][10] = { "123", STR };
void test_literal (struct S *s)
{
strncpy (s->a, STR, sizeof s->a - 1); /* { dg-bogus "\\\[-Wstringop-truncation]" } */
s->a[sizeof s->a - 1] = '\0';
}
void test_global_arr (struct S *s)
{
strncpy (s->a, arr, sizeof s->a - 1); /* { dg-bogus "\\\[-Wstringop-truncation]" } */
s->a [sizeof s->a - 1] = '\0';
}
void test_global_arr2 (struct S *s)
{
strncpy (s->a, arr2[1], sizeof s->a - 1); /* { dg-bogus "\\\[-Wstringop-truncation]" } */
s->a [sizeof s->a - 1] = '\0';
strncpy (s->b, arr2[0], sizeof s->a - 1);
}
void test_global_ptr (struct S *s)
{
strncpy (s->a, ptr, sizeof s->a - 1); /* { dg-bogus "\\\[-Wstringop-truncation]" } */
s->a [sizeof s->a - 1] = '\0';
}
void test_local_arr (struct S *s)
{
const char arr[] = STR;
strncpy (s->a, arr, sizeof s->a - 1);
s->a [sizeof s->a - 1] = '\0';
}
void test_local_ptr (struct S *s)
{
const char* const ptr = STR;
strncpy (s->a, ptr, sizeof s->a - 1); /* { dg-bogus "\\\[-Wstringop-truncation]" } */
s->a [sizeof s->a - 1] = '\0';
}
void test_compound_literal (struct S *s)
{
strncpy (s->a, (char[]){ STR }, sizeof s->a - 1);
s->a [sizeof s->a - 1] = '\0';
}
gcc/testsuite/gcc.dg/fold-bcopy.c
/* PR tree-optimization/80933 - redundant bzero/bcopy calls not eliminated
{ dg-do compile }
{ dg-options "-O0 -Wall -fdump-tree-gimple" } */
{ dg-options "-O1 -Wall -fdump-tree-lower" } */
void f0 (void *dst, const void *src, unsigned n)
{
......@@ -46,9 +46,9 @@ void f6 (void *p)
/* Verify that calls to bcmp, bcopy, and bzero have all been removed
and one of each replaced with memcmp, memmove, and memset, respectively.
The remaining three should be eliminated.
{ dg-final { scan-tree-dump-not "bcmp|bcopy|bzero" "gimple" } }
{ dg-final { scan-tree-dump-times "memcmp|memmove|memset" 3 "gimple" } }
{ dg-final { scan-tree-dump-not "bcmp|bcopy|bzero" "lower" } }
{ dg-final { scan-tree-dump-times "memcmp|memmove|memset" 3 "lower" } }
Verify that the bcopy to memmove transformation correctly transposed
the source and destination pointer arguments.
{ dg-final { scan-tree-dump-times "memmove \\(dst, src" 1 "gimple" } } */
{ dg-final { scan-tree-dump-times "memmove \\(dst, src" 1 "lower" } } */
gcc/testsuite/gcc.dg/strcmpopt_1.c
/* { dg-do run } */
/* { dg-options "-fdump-tree-gimple" } */
/* { dg-options "-fdump-tree-lower" } */
#include <string.h>
#include <stdlib.h>
......@@ -25,4 +25,4 @@ int main ()
return 0;
}
/* { dg-final { scan-tree-dump-times "strcmp \\(" 2 "gimple" } } */
/* { dg-final { scan-tree-dump-times "strcmp \\(" 2 "lower" } } */
gcc/testsuite/gcc.dg/tree-ssa/pr79697.c
/* { dg-do compile } */
/* { dg-options "-O2 -fdump-tree-gimple -fdump-tree-cddce-details -fdump-tree-optimized" } */
/* { dg-options "-O2 -fdump-tree-lower -fdump-tree-cddce-details -fdump-tree-optimized" } */
void f(void)
{
......@@ -18,4 +18,4 @@ void h(void)
/* { dg-final { scan-tree-dump "Deleting : __builtin_strdup" "cddce1" } } */
/* { dg-final { scan-tree-dump "Deleting : __builtin_strndup" "cddce1" } } */
/* { dg-final { scan-tree-dump "__builtin_malloc" "gimple" } } */
/* { dg-final { scan-tree-dump "__builtin_malloc" "lower" } } */
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