warning_at() calls with the %G directive rely on the gimple statement
for both their location and the inlining context. When the statement
is not associated with a location, the warning doesn't point at any
line even if the location argument passed to the call was valid.
The attached patch changes the percent_G_percent handler to fall back
on the provided location in that case, and the recently added warning
for char assignments to pass to the function a fallback location if
the statement doesn't have one.
Tested on x86_64-linux.
Martin
PR middle-end/91599 - GCC does not say where warning is happening
gcc/ChangeLog:
PR middle-end/91599
* tree-ssa-strlen.c (handle_store): Use a fallback location if
the statement doesn't have one.
* gimple-pretty-print.c (percent_G_format): Same.
gcc/testsuite/ChangeLog:
PR middle-end/91599
* gcc.dg/Wstringop-overflow-16.c: New test.
Index: gcc/tree-ssa-strlen.c
===================================================================
--- gcc/tree-ssa-strlen.c (revision 275047)
+++ gcc/tree-ssa-strlen.c (working copy)
@@ -4036,7 +4036,12 @@ handle_store (gimple_stmt_iterator *gsi)
if (tree dstsize = compute_objsize (lhs, 1, &decl))
if (compare_tree_int (dstsize, lenrange[2]) < 0)
{
+ /* Fall back on the LHS location if the statement
+ doesn't have one. */
location_t loc = gimple_nonartificial_location (stmt);
+ if (loc == UNKNOWN_LOCATION)
+ loc = tree_nonartificial_location (lhs);
+ loc = expansion_point_location_if_in_system_header (loc);
if (warning_n (loc, OPT_Wstringop_overflow_,
lenrange[2],
"%Gwriting %u byte into a region of size %E",
Index: gcc/gimple-pretty-print.c
===================================================================
--- gcc/gimple-pretty-print.c (revision 275047)
+++ gcc/gimple-pretty-print.c (working copy)
@@ -3034,8 +3034,12 @@ percent_G_format (text_info *text)
{
gimple *stmt = va_arg (*text->args_ptr, gimple*);
+ /* Fall back on the rich location if the statement doesn't have one. */
+ location_t loc = gimple_location (stmt);
+ if (loc == UNKNOWN_LOCATION)
+ loc = text->m_richloc->get_loc ();
tree block = gimple_block (stmt);
- percent_K_format (text, gimple_location (stmt), block);
+ percent_K_format (text, loc, block);
}
#if __GNUC__ >= 10
Index: gcc/testsuite/gcc.dg/Wstringop-overflow-16.c
===================================================================
--- gcc/testsuite/gcc.dg/Wstringop-overflow-16.c (nonexistent)
+++ gcc/testsuite/gcc.dg/Wstringop-overflow-16.c (working copy)
@@ -0,0 +1,21 @@
+/* PR middle-end/91599 - GCC does not say where warning is happening
+ { dg-do compile }
+ { dg-options "-O2 -Wall" } */
+
+struct charseq {
+ unsigned char bytes[0]; // { dg-message "object declared here" }
+};
+
+struct locale_ctype_t {
+ struct charseq *mboutdigits[10];
+};
+
+void ctype_finish (struct locale_ctype_t *ctype)
+{
+ long unsigned int cnt;
+ for (cnt = 0; cnt < 20; ++cnt) {
+ static struct charseq replace[2];
+ replace[0].bytes[1] = '\0'; // { dg-warning "\\\[-Wstringop-overflow" }
+ ctype->mboutdigits[cnt] = &replace[0];
+ }
+}
