On Fri, May 16, 2025 at 01:34:14PM +0000, Qing Zhao wrote: > Adding -fdiagnotics-details into GCC to provide more hints to the > end users on how the warnings come from, in order to help the user > to locate the exact location in source code on the specific warnings > due to compiler optimizations.
I just needed to examine an unexpected -Wrestrict warning, and discovered that this patch didn't help with it, but in looking at the implementation details, it turned out to be trivial to expand coverage to include -Wrestrict, which worked for me, and got me the diagnostics I needed[1]. Could you include this patch in the next version of the series too? I'll put it to use! :) -Kees [1] https://lore.kernel.org/all/202505191117.C094A90F88@keescook/ diff --git a/gcc/gimple-ssa-warn-restrict.cc b/gcc/gimple-ssa-warn-restrict.cc index a52307866cc4..0f6eddf01e4e 100644 --- a/gcc/gimple-ssa-warn-restrict.cc +++ b/gcc/gimple-ssa-warn-restrict.cc @@ -1448,6 +1448,8 @@ maybe_diag_overlap (location_t loc, gimple *call, builtin_access &acs) tree func = gimple_call_fndecl (call); + rich_location_with_details richloc (loc, call); + /* To avoid a combinatorial explosion of diagnostics format the offsets or their ranges as strings and use them in the warning calls below. */ char offstr[3][64]; @@ -1493,7 +1495,7 @@ maybe_diag_overlap (location_t loc, gimple *call, builtin_access &acs) if (sizrange[0] == sizrange[1]) { if (ovlsiz[0] == ovlsiz[1]) - warning_at (loc, OPT_Wrestrict, + warning_at (&richloc, OPT_Wrestrict, sizrange[0] == 1 ? (ovlsiz[0] == 1 ? G_("%qD accessing %wu byte at offsets %s " @@ -1510,7 +1512,7 @@ maybe_diag_overlap (location_t loc, gimple *call, builtin_access &acs) func, sizrange[0], offstr[0], offstr[1], ovlsiz[0], offstr[2]); else if (ovlsiz[1] >= 0 && ovlsiz[1] < maxobjsize.to_shwi ()) - warning_n (loc, OPT_Wrestrict, sizrange[0], + warning_n (&richloc, OPT_Wrestrict, sizrange[0], "%qD accessing %wu byte at offsets %s " "and %s overlaps between %wu and %wu bytes " "at offset %s", @@ -1520,7 +1522,7 @@ maybe_diag_overlap (location_t loc, gimple *call, builtin_access &acs) func, sizrange[0], offstr[0], offstr[1], ovlsiz[0], ovlsiz[1], offstr[2]); else - warning_n (loc, OPT_Wrestrict, sizrange[0], + warning_n (&richloc, OPT_Wrestrict, sizrange[0], "%qD accessing %wu byte at offsets %s and " "%s overlaps %wu or more bytes at offset %s", "%qD accessing %wu bytes at offsets %s and " @@ -1533,7 +1535,7 @@ maybe_diag_overlap (location_t loc, gimple *call, builtin_access &acs) if (sizrange[1] >= 0 && sizrange[1] < maxobjsize.to_shwi ()) { if (ovlsiz[0] == ovlsiz[1]) - warning_n (loc, OPT_Wrestrict, ovlsiz[0], + warning_n (&richloc, OPT_Wrestrict, ovlsiz[0], "%qD accessing between %wu and %wu bytes " "at offsets %s and %s overlaps %wu byte at " "offset %s", @@ -1543,7 +1545,7 @@ maybe_diag_overlap (location_t loc, gimple *call, builtin_access &acs) func, sizrange[0], sizrange[1], offstr[0], offstr[1], ovlsiz[0], offstr[2]); else if (ovlsiz[1] >= 0 && ovlsiz[1] < maxobjsize.to_shwi ()) - warning_at (loc, OPT_Wrestrict, + warning_at (&richloc, OPT_Wrestrict, "%qD accessing between %wu and %wu bytes at " "offsets %s and %s overlaps between %wu and %wu " "bytes at offset %s", @@ -1551,7 +1553,7 @@ maybe_diag_overlap (location_t loc, gimple *call, builtin_access &acs) offstr[0], offstr[1], ovlsiz[0], ovlsiz[1], offstr[2]); else - warning_at (loc, OPT_Wrestrict, + warning_at (&richloc, OPT_Wrestrict, "%qD accessing between %wu and %wu bytes at " "offsets %s and %s overlaps %wu or more bytes " "at offset %s", @@ -1564,7 +1566,7 @@ maybe_diag_overlap (location_t loc, gimple *call, builtin_access &acs) ovlsiz[1] = maxobjsize.to_shwi (); if (ovlsiz[0] == ovlsiz[1]) - warning_n (loc, OPT_Wrestrict, ovlsiz[0], + warning_n (&richloc, OPT_Wrestrict, ovlsiz[0], "%qD accessing %wu or more bytes at offsets " "%s and %s overlaps %wu byte at offset %s", "%qD accessing %wu or more bytes at offsets " @@ -1572,14 +1574,14 @@ maybe_diag_overlap (location_t loc, gimple *call, builtin_access &acs) func, sizrange[0], offstr[0], offstr[1], ovlsiz[0], offstr[2]); else if (ovlsiz[1] >= 0 && ovlsiz[1] < maxobjsize.to_shwi ()) - warning_at (loc, OPT_Wrestrict, + warning_at (&richloc, OPT_Wrestrict, "%qD accessing %wu or more bytes at offsets %s " "and %s overlaps between %wu and %wu bytes " "at offset %s", func, sizrange[0], offstr[0], offstr[1], ovlsiz[0], ovlsiz[1], offstr[2]); else - warning_at (loc, OPT_Wrestrict, + warning_at (&richloc, OPT_Wrestrict, "%qD accessing %wu or more bytes at offsets %s " "and %s overlaps %wu or more bytes at offset %s", func, sizrange[0], offstr[0], offstr[1], @@ -1607,14 +1609,14 @@ maybe_diag_overlap (location_t loc, gimple *call, builtin_access &acs) if (ovlsiz[1] == 1) { if (open_range) - warning_n (loc, OPT_Wrestrict, sizrange[1], + warning_n (&richloc, OPT_Wrestrict, sizrange[1], "%qD accessing %wu byte may overlap " "%wu byte", "%qD accessing %wu bytes may overlap " "%wu byte", func, sizrange[1], ovlsiz[1]); else - warning_n (loc, OPT_Wrestrict, sizrange[1], + warning_n (&richloc, OPT_Wrestrict, sizrange[1], "%qD accessing %wu byte at offsets %s " "and %s may overlap %wu byte at offset %s", "%qD accessing %wu bytes at offsets %s " @@ -1625,14 +1627,14 @@ maybe_diag_overlap (location_t loc, gimple *call, builtin_access &acs) } if (open_range) - warning_n (loc, OPT_Wrestrict, sizrange[1], + warning_n (&richloc, OPT_Wrestrict, sizrange[1], "%qD accessing %wu byte may overlap " "up to %wu bytes", "%qD accessing %wu bytes may overlap " "up to %wu bytes", func, sizrange[1], ovlsiz[1]); else - warning_n (loc, OPT_Wrestrict, sizrange[1], + warning_n (&richloc, OPT_Wrestrict, sizrange[1], "%qD accessing %wu byte at offsets %s and " "%s may overlap up to %wu bytes at offset %s", "%qD accessing %wu bytes at offsets %s and " @@ -1645,14 +1647,14 @@ maybe_diag_overlap (location_t loc, gimple *call, builtin_access &acs) if (sizrange[1] >= 0 && sizrange[1] < maxobjsize.to_shwi ()) { if (open_range) - warning_n (loc, OPT_Wrestrict, ovlsiz[1], + warning_n (&richloc, OPT_Wrestrict, ovlsiz[1], "%qD accessing between %wu and %wu bytes " "may overlap %wu byte", "%qD accessing between %wu and %wu bytes " "may overlap up to %wu bytes", func, sizrange[0], sizrange[1], ovlsiz[1]); else - warning_n (loc, OPT_Wrestrict, ovlsiz[1], + warning_n (&richloc, OPT_Wrestrict, ovlsiz[1], "%qD accessing between %wu and %wu bytes " "at offsets %s and %s may overlap %wu byte " "at offset %s", @@ -1664,7 +1666,7 @@ maybe_diag_overlap (location_t loc, gimple *call, builtin_access &acs) return true; } - warning_n (loc, OPT_Wrestrict, ovlsiz[1], + warning_n (&richloc, OPT_Wrestrict, ovlsiz[1], "%qD accessing %wu or more bytes at offsets %s " "and %s may overlap %wu byte at offset %s", "%qD accessing %wu or more bytes at offsets %s " -- Kees Cook
