Hi, I’d like to ping the patch:
https://gcc.gnu.org/pipermail/gcc-patches/2021-December/587014.html Please take a look and let me know whether it’s okay for committing? Thanks. Qing > On Dec 16, 2021, at 9:59 AM, Qing Zhao via Gcc-patches > <gcc-patches@gcc.gnu.org> wrote: > > Hi, > > This is the 2nd version of the patch. > The original patch is at: > > https://gcc.gnu.org/pipermail/gcc-patches/2021-December/586341.html > > In addition to resolve the two issues mentioned in the original patch, > This patch also can be used as a very good workaround for the issue in > PR103720 > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103720 > > And as I checked, the patch can fix all the bogus uninitialized warnings when > building kernel with -O2 + -ftrivial-auto-var-init=zero + -Wuninitialized. > > So, this is a very important patch that need to be included into gcc12. > > Compared to the 1st patch, the major changes are to resolve Martin’s comments > on > tree-ssa-uninit.c > > 1. Add some meaningful temporaries to break the long expression to make it > Readable. And also add comments to explain the purpose of the statement; > > 2. Resolve the memory leakage of the dynamically created string. > > The patch has been bootstrapped and regressing tested on both x86 and > aarch64, no issues. > Okay for commit? > > thanks. > > Qing > > ================================================= > > ******Compared to the 1st version, the code change is: > > --- a/gcc/tree-ssa-uninit.c > +++ b/gcc/tree-ssa-uninit.c > @@ -182,9 +182,22 @@ warn_uninit (opt_code opt, tree t, tree var, const char > *gmsgid, > @@ -798,26 +798,35 @@ > if (!var && !SSA_NAME_VAR (t)) > { > gimple *def_stmt = SSA_NAME_DEF_STMT (t); > -@@ -197,9 +210,34 @@ warn_uninit (opt_code opt, tree t, tree var, const char > *gmsgid, > +@@ -197,9 +210,43 @@ warn_uninit (opt_code opt, tree t, tree var, const char > *gmsgid, > && zerop (gimple_assign_rhs2 (def_stmt))) > var = SSA_NAME_VAR (v); > } > + > + if (gimple_call_internal_p (def_stmt, IFN_DEFERRED_INIT)) > + { > ++ tree lhs_var = NULL_TREE; > ++ tree lhs_var_name = NULL_TREE; > ++ const char *lhs_var_name_str = NULL; > + /* Get the variable name from the 3rd argument of call. */ > + var_name = gimple_call_arg (def_stmt, 2); > + var_name = TREE_OPERAND (TREE_OPERAND (var_name, 0), 0); > + var_name_str = TREE_STRING_POINTER (var_name); > + > -+ if (is_gimple_assign (context) > -+ && TREE_CODE (gimple_assign_lhs (context)) == VAR_DECL > -+ && DECL_NAME (gimple_assign_lhs (context)) > -+ && IDENTIFIER_POINTER (DECL_NAME (gimple_assign_lhs (context)))) > -+ if (strcmp > -+ (IDENTIFIER_POINTER (DECL_NAME (gimple_assign_lhs > (context))), > -+ var_name_str) == 0) > -+ return; > ++ /* Ignore the call to .DEFERRED_INIT that define the original > ++ var itself. */ > ++ if (is_gimple_assign (context)) > ++ { > ++ if (TREE_CODE (gimple_assign_lhs (context)) == VAR_DECL) > ++ lhs_var = gimple_assign_lhs (context); > ++ else if (TREE_CODE (gimple_assign_lhs (context)) == SSA_NAME) > ++ lhs_var = SSA_NAME_VAR (gimple_assign_lhs (context)); > ++ } > ++ if (lhs_var > ++ && (lhs_var_name = DECL_NAME (lhs_var)) > ++ && (lhs_var_name_str = IDENTIFIER_POINTER (lhs_var_name)) > ++ && (strcmp (lhs_var_name_str, var_name_str) == 0)) > ++ return; > + > + /* Get the variable declaration location from the def_stmt. */ > + var_decl_loc = gimple_location (def_stmt); > @@ -834,7 +843,7 @@ > return; > > /* Avoid warning if we've already done so or if the warning has been > -@@ -207,36 +245,56 @@ warn_uninit (opt_code opt, tree t, tree var, const > char *gmsgid, > +@@ -207,36 +254,54 @@ warn_uninit (opt_code opt, tree t, tree var, const > char *gmsgid, > if (((warning_suppressed_p (context, OPT_Wuninitialized) > || (gimple_assign_single_p (context) > && get_no_uninit_warning (gimple_assign_rhs1 (context))))) > @@ -863,25 +872,24 @@ > > auto_diagnostic_group d; > - if (!warning_at (location, opt, gmsgid, var)) > +- return; > + char *gmsgid_final = XNEWVEC (char, strlen (gmsgid) + 5); > + gmsgid_final[0] = 0; > -+ if (var) > -+ strcat (gmsgid_final, "%qD "); > -+ else if (var_name) > -+ strcat (gmsgid_final, "%qs "); > ++ strcat (gmsgid_final, var ? "%qD " : "%qs "); > + strcat (gmsgid_final, gmsgid); > + > -+ if (var && !warning_at (location, opt, gmsgid_final, var)) > -+ return; > -+ else if (var_name && !warning_at (location, opt, gmsgid_final, > var_name_str)) > - return; > ++ if ((var && !warning_at (location, opt, gmsgid_final, var)) > ++ || (var_name && !warning_at (location, opt, gmsgid_final, > var_name_str))) > ++ { > ++ XDELETE (gmsgid_final); > ++ return; > ++ } > ++ XDELETE (gmsgid_final); > > /* Avoid subsequent warnings for reads of the same variable again. */ > - suppress_warning (var, opt); > -+ if (var) > -+ suppress_warning (var, opt); > -+ else if (repl_var) > -+ suppress_warning (repl_var, opt); > ++ if (var || repl_var) > ++ suppress_warning (var ? var : repl_var, opt); > > /* Issue a note pointing to the read variable unless the warning > is at the same location. */ > @@ -898,7 +906,7 @@ > } > > ******The complete patch is: > > > > > <0001-Enable-Wuninitialized-ftrivial-auto-var-init-for-add.patch>
