Warning for use of a partially initialized complex is displayed on the wrong line (the one where the partial initialization is done) and is not consistent between target (or even within a given target, for instance between hardfloat and softfloat on arm-none-eabi target). This patch correctly retains the line location when expanding a complex move, stop warning when a COMPLEX_EXPR is constructed but instead warn when it is used, and for cases where a branch is involved, get the line location from the phi argument involved as a fallback. This fixes PR39246.
The ChangeLog are as follows: *** gcc/ChangeLog *** 2014-05-04 Thomas Preud'homme <thomas.preudho...@arm.com> PR middle-end/39246 * tree-complex.c (expand_complex_move): Keep line info when expanding complex move. * tree-ssa-uninit.c (warn_uninit): New argument. Ignore assignment of complex expression. Use new argument to display correct location for values coming from phi statement. (warn_uninitialized_vars): Adapt to new signature of warn_uninit. (warn_uninitialized_phi): Pass location of phi argument to warn_uninit. * tree-ssa.c (ssa_undefined_value_p): For SSA_NAME initialized by a COMPLEX_EXPR, recurse on each part of the COMPLEX_EXPR. *** gcc/testsuite/ChangeLog *** 2014-05-04 Thomas Preud'homme <thomas.preudho...@arm.com> * gcc.dg/uninit-13.c: Move warning on the actual source line where the uninitialized complex is used. * gcc.dg/uninit-17.c: New test to check partial initialization of complex with branches. * gcc.dg/uninit-17-O0.c: Likewise. Bootstrapped on x86_64-linux-gnu with no regression in the testsuite. Also tested a cross-build of gcc for arm-none-eabi target and run the regression testsuite in qemu for cortex-m3 without any regression and the uninit-13.c test fixed. Ok for stage1? Patch with proper formatting in attachment. diff --git a/gcc/testsuite/gcc.dg/uninit-13.c b/gcc/testsuite/gcc.dg/uninit-13.c index 631e8de..5e88a8a 100644 --- a/gcc/testsuite/gcc.dg/uninit-13.c +++ b/gcc/testsuite/gcc.dg/uninit-13.c @@ -5,6 +5,6 @@ typedef _Complex float C; C foo() { C f; - __imag__ f = 0; /* { dg-warning "is used" "unconditional" } */ - return f; + __imag__ f = 0; + return f; /* { dg-warning "is used" "unconditional" } */ } diff --git a/gcc/testsuite/gcc.dg/uninit-17-O0.c b/gcc/testsuite/gcc.dg/uninit-17-O0.c new file mode 100644 index 0000000..0eaef05 --- /dev/null +++ b/gcc/testsuite/gcc.dg/uninit-17-O0.c @@ -0,0 +1,15 @@ +/* { dg-do compile } */ +/* { dg-options "-Wuninitialized" } */ + +typedef _Complex float C; +C foo(int cond) +{ + C f; + __imag__ f = 0; + if (cond) + { + __real__ f = 1; + return f; + } + return f; +} diff --git a/gcc/testsuite/gcc.dg/uninit-17.c b/gcc/testsuite/gcc.dg/uninit-17.c new file mode 100644 index 0000000..8a95f15 --- /dev/null +++ b/gcc/testsuite/gcc.dg/uninit-17.c @@ -0,0 +1,15 @@ +/* { dg-do compile } */ +/* { dg-options "-O -Wuninitialized" } */ + +typedef _Complex float C; +C foo(int cond) +{ + C f; + __imag__ f = 0; + if (cond) + { + __real__ f = 1; + return f; + } + return f; /* { dg-warning "may be used" "unconditional" } */ +} diff --git a/gcc/tree-complex.c b/gcc/tree-complex.c index a97aaf9..2286e2e 100644 --- a/gcc/tree-complex.c +++ b/gcc/tree-complex.c @@ -831,12 +831,15 @@ expand_complex_move (gimple_stmt_iterator *gsi, tree type) { tree x; gimple t; + location_t loc; + loc = gimple_location (stmt); r = extract_component (gsi, rhs, 0, false); i = extract_component (gsi, rhs, 1, false); x = build1 (REALPART_EXPR, inner_type, unshare_expr (lhs)); t = gimple_build_assign (x, r); + gimple_set_location (t, loc); gsi_insert_before (gsi, t, GSI_SAME_STMT); if (stmt == gsi_stmt (*gsi)) @@ -849,6 +852,7 @@ expand_complex_move (gimple_stmt_iterator *gsi, tree type) { x = build1 (IMAGPART_EXPR, inner_type, unshare_expr (lhs)); t = gimple_build_assign (x, i); + gimple_set_location (t, loc); gsi_insert_before (gsi, t, GSI_SAME_STMT); stmt = gsi_stmt (*gsi); diff --git a/gcc/tree-ssa-uninit.c b/gcc/tree-ssa-uninit.c index ae251cc..4310e7e 100644 --- a/gcc/tree-ssa-uninit.c +++ b/gcc/tree-ssa-uninit.c @@ -123,17 +123,25 @@ uninit_undefined_value_p (tree t) { /* Emit a warning for EXPR based on variable VAR at the point in the program T, an SSA_NAME, is used being uninitialized. The exact - warning text is in MSGID and LOCUS may contain a location or be null. - WC is the warning code. */ + warning text is in MSGID and DATA is the gimple stmt with info about + the location in source code. When DATA is a GIMPLE_PHI, PHIARG_IDX + gives which argument of the phi node to take the location from. WC + is the warning code. */ static void -warn_uninit (enum opt_code wc, tree t, - tree expr, tree var, const char *gmsgid, void *data) +warn_uninit (enum opt_code wc, tree t, tree expr, tree var, + const char *gmsgid, void *data, location_t phiarg_loc) { gimple context = (gimple) data; location_t location, cfun_loc; expanded_location xloc, floc; + /* Ignore COMPLEX_EXPR as initializing only a part of a complex + turns in a COMPLEX_EXPR with the not initialized part being + set to its previous (undefined) value. */ + if (is_gimple_assign (context) + && gimple_assign_rhs_code (context) == COMPLEX_EXPR) + return; if (!has_undefined_value_p (t)) return; @@ -146,9 +154,12 @@ warn_uninit (enum opt_code wc, tree t, || TREE_NO_WARNING (expr)) return; - location = (context != NULL && gimple_has_location (context)) - ? gimple_location (context) - : DECL_SOURCE_LOCATION (var); + if (context != NULL && gimple_has_location (context)) + location = gimple_location (context); + else if (phiarg_loc != UNKNOWN_LOCATION) + location = phiarg_loc; + else + location = DECL_SOURCE_LOCATION (var); location = linemap_resolve_location (line_table, location, LRK_SPELLING_LOCATION, NULL); @@ -200,12 +211,12 @@ warn_uninitialized_vars (bool warn_possibly_uninitialized) warn_uninit (OPT_Wuninitialized, use, SSA_NAME_VAR (use), SSA_NAME_VAR (use), "%qD is used uninitialized in this function", - stmt); + stmt, UNKNOWN_LOCATION); else if (warn_possibly_uninitialized) warn_uninit (OPT_Wmaybe_uninitialized, use, SSA_NAME_VAR (use), SSA_NAME_VAR (use), "%qD may be used uninitialized in this function", - stmt); + stmt, UNKNOWN_LOCATION); } /* For memory the only cheap thing we can do is see if we @@ -236,12 +247,12 @@ warn_uninitialized_vars (bool warn_possibly_uninitialized) warn_uninit (OPT_Wuninitialized, use, gimple_assign_rhs1 (stmt), base, "%qE is used uninitialized in this function", - stmt); + stmt, UNKNOWN_LOCATION); else if (warn_possibly_uninitialized) warn_uninit (OPT_Wmaybe_uninitialized, use, gimple_assign_rhs1 (stmt), base, "%qE may be used uninitialized in this function", - stmt); + stmt, UNKNOWN_LOCATION); } } } @@ -2247,6 +2258,8 @@ warn_uninitialized_phi (gimple phi, vec<gimple> *worklist, unsigned uninit_opnds; gimple uninit_use_stmt = 0; tree uninit_op; + int phiarg_index; + location_t loc; /* Don't look at virtual operands. */ if (virtual_operand_p (gimple_phi_result (phi))) @@ -2271,13 +2284,18 @@ warn_uninitialized_phi (gimple phi, vec<gimple> *worklist, if (!uninit_use_stmt) return; - uninit_op = gimple_phi_arg_def (phi, MASK_FIRST_SET_BIT (uninit_opnds)); + phiarg_index = MASK_FIRST_SET_BIT (uninit_opnds); + uninit_op = gimple_phi_arg_def (phi, phiarg_index); if (SSA_NAME_VAR (uninit_op) == NULL_TREE) return; + if (gimple_phi_arg_has_location (phi, phiarg_index)) + loc = gimple_phi_arg_location (phi, phiarg_index); + else + loc = UNKNOWN_LOCATION; warn_uninit (OPT_Wmaybe_uninitialized, uninit_op, SSA_NAME_VAR (uninit_op), SSA_NAME_VAR (uninit_op), "%qD may be used uninitialized in this function", - uninit_use_stmt); + uninit_use_stmt, loc); } diff --git a/gcc/tree-ssa.c b/gcc/tree-ssa.c index 1ea639d..499bd06 100644 --- a/gcc/tree-ssa.c +++ b/gcc/tree-ssa.c @@ -1246,6 +1246,7 @@ tree_ssa_strip_useless_type_conversions (tree exp) bool ssa_undefined_value_p (tree t) { + gimple def_stmt; tree var = SSA_NAME_VAR (t); if (!var) @@ -1262,7 +1263,22 @@ ssa_undefined_value_p (tree t) return false; /* The value is undefined iff its definition statement is empty. */ - return gimple_nop_p (SSA_NAME_DEF_STMT (t)); + def_stmt = SSA_NAME_DEF_STMT (t); + if (gimple_nop_p (def_stmt)) + return true; + + /* Check if the complex was not only partially defined. */ + if (is_gimple_assign (def_stmt) + && gimple_assign_rhs_code (def_stmt) == COMPLEX_EXPR) + { + tree rhs1, rhs2; + + rhs1 = gimple_assign_rhs1 (def_stmt); + rhs2 = gimple_assign_rhs2 (def_stmt); + return (TREE_CODE (rhs1) == SSA_NAME && ssa_undefined_value_p (rhs1)) + || (TREE_CODE (rhs2) == SSA_NAME && ssa_undefined_value_p (rhs2)); + } + return false; }
gcc32rm-91.1.1.diff
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