From 09f041390245da60411a9f0e08c4bedf7430585a Mon Sep 17 00:00:00 2001 From: Martin Sebor Date: Mon, 13 Apr 2020 15:31:44 -0600 Subject: [PATCH] PR c/92326 - wrong bound in zero-length array diagnostics gcc/c-family/ChangeLog: PR c/92326 * c-pretty-print.c (c_pretty_printer::direct_abstract_declarator): Avoid printing array bound for flexible array members. gcc/testsuite/ChangeLog: PR c/92326 * c-c++-common/Warray-bounds-8.c: New test. * gcc.dg/Warray-bounds-46.c: Adjust expected format of flexible array memebrs in diagnostics. * gcc.dg/Warray-bounds-49.c: Same. --- gcc/c-family/ChangeLog | 6 ++++++ gcc/c-family/c-pretty-print.c | 4 +++- gcc/testsuite/ChangeLog | 8 +++++++ gcc/testsuite/c-c++-common/Warray-bounds-8.c | 22 ++++++++++++++++++++ gcc/testsuite/gcc.dg/Warray-bounds-46.c | 22 ++++++++++---------- gcc/testsuite/gcc.dg/Warray-bounds-49.c | 20 +++++++++--------- 6 files changed, 60 insertions(+), 22 deletions(-) create mode 100644 gcc/testsuite/c-c++-common/Warray-bounds-8.c diff --git a/gcc/c-family/ChangeLog b/gcc/c-family/ChangeLog index 414d0c09be9..d0569d71803 100644 --- a/gcc/c-family/ChangeLog +++ b/gcc/c-family/ChangeLog @@ -1,3 +1,9 @@ +2020-04-13 Martin Sebor + + PR c/92326 + * c-pretty-print.c (c_pretty_printer::direct_abstract_declarator): Avoid + printing array bound for flexible array members. + 2020-04-13 Iain Sandoe * c-cppbuiltin.c (c_cpp_builtins): Update coroutines builtin diff --git a/gcc/c-family/c-pretty-print.c b/gcc/c-family/c-pretty-print.c index 0e4303f1a49..eccb63096fd 100644 --- a/gcc/c-family/c-pretty-print.c +++ b/gcc/c-family/c-pretty-print.c @@ -593,7 +593,9 @@ c_pretty_printer::direct_abstract_declarator (tree t) expression (fold_build2 (PLUS_EXPR, type, maxval, build_int_cst (type, 1))); } - else + else if (TYPE_SIZE (t)) + /* Print zero for zero-length arrays but not for flexible + array members whose TYPE_SIZE is null. */ pp_string (this, "0"); } pp_c_right_bracket (this); diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 8e2df1b6eda..723d4841016 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,11 @@ +2020-04-13 Martin Sebor + + PR c/92326 + * c-c++-common/Warray-bounds-8.c: New test. + * gcc.dg/Warray-bounds-46.c: Adjust expected format of flexible array + memebrs in diagnostics. + * gcc.dg/Warray-bounds-49.c: Same. + 2020-04-13 Patrick Palka PR c++/94521 diff --git a/gcc/testsuite/c-c++-common/Warray-bounds-8.c b/gcc/testsuite/c-c++-common/Warray-bounds-8.c new file mode 100644 index 00000000000..64202ddd5df --- /dev/null +++ b/gcc/testsuite/c-c++-common/Warray-bounds-8.c @@ -0,0 +1,22 @@ +/* PR c/92326 - wrong bound in zero-length array diagnostics + { dg-do compile } + { dg-options "-O2 -Wall" } */ + +extern int a0[0]; +extern int ax[]; + +void warn_global_array (void) +{ + a0[0] = 0; // { dg-warning "array bounds of 'int *\\\[0]'" } + ax[-1] = 0; // { dg-warning "array bounds of 'int *\\\[]'" } +} + + +struct S0 { int n, a0[0]; } s0; +struct Sx { int n, ax[]; } sx = { 0 }; + +void warn_member_array (void) +{ + s0.a0[0] = 0; // { dg-warning "array bounds of 'int *\\\[0]'" } + sx.ax[0] = 0; // { dg-warning "array bounds of 'int *\\\[]'" } +} diff --git a/gcc/testsuite/gcc.dg/Warray-bounds-46.c b/gcc/testsuite/gcc.dg/Warray-bounds-46.c index 74e78cbdbe8..9078c6f5998 100644 --- a/gcc/testsuite/gcc.dg/Warray-bounds-46.c +++ b/gcc/testsuite/gcc.dg/Warray-bounds-46.c @@ -95,13 +95,13 @@ void strcpy_global_array (void) /* GMA2 is external but because it's an array its definition in another translation unit may not provide an initializer for the flexible array member. Verify that a warning is issued for access to it. */ - T (gma2[0].ax, 1); // { dg-warning "'strcpy' offset \\\[157, 158] from the object at 'gma2' is out of the bounds of referenced subobject 'ax' with type 'char\\\[0]' at offset 157" } - T (gma2[0].ax, 7); // { dg-warning "'strcpy' offset \\\[157, 164] from the object at 'gma2' is out of the bounds of referenced subobject 'ax' with type 'char\\\[0]' at offset 157" } + T (gma2[0].ax, 1); // { dg-warning "'strcpy' offset \\\[157, 158] from the object at 'gma2' is out of the bounds of referenced subobject 'ax' with type 'char\\\[]' at offset 157" } + T (gma2[0].ax, 7); // { dg-warning "'strcpy' offset \\\[157, 164] from the object at 'gma2' is out of the bounds of referenced subobject 'ax' with type 'char\\\[]' at offset 157" } - /* IGMA_ is internal and provides on definition for the flexible array - member. Verify that a warnin is issued for out-of-bounds accesses + /* IGMA2_ is internal and provides no definition for the flexible array + member. Verify that a warning is issued for out-of-bounds accesses to it. */ - T (igma2_[0].ax, 1); // { dg-warning "'strcpy' offset \\\[157, 158] from the object at 'igma2_' is out of the bounds of referenced subobject 'ax' with type 'char\\\[0]' at offset 157" } + T (igma2_[0].ax, 1); // { dg-warning "'strcpy' offset \\\[157, 158] from the object at 'igma2_' is out of the bounds of referenced subobject 'ax' with type 'char\\\[]' at offset 157" } T (igma_3.ax, 0); T (igma_3.ax, 1); @@ -134,7 +134,7 @@ void strcpy_local (void) T (lma.a17, 16); T (lma.a17, 17); // { dg-warning "'strcpy' offset 157 from the object at 'lma' is out of the bounds of referenced subobject 'a17' with type 'char\\\[17]' at offset 140" } - T (lma.ax, 0); // { dg-warning "'strcpy' offset 157 from the object at 'lma' is out of the bounds of referenced subobject 'ax' with type 'char\\\[0]' at offset 157" } + T (lma.ax, 0); // { dg-warning "'strcpy' offset 157 from the object at 'lma' is out of the bounds of referenced subobject 'ax' with type 'char\\\[]' at offset 157" } } @@ -191,11 +191,11 @@ void strcpy_ref (struct MA17 *pma) array. The warning assumes that PMA doesn't point to the last element of the array which could in theory have nonzero elements without overlapping other objects. */ - T (pma[1].ax, 0); // { dg-warning "'strcpy' offset 314 from the object at 'pma' is out of the bounds of referenced subobject 'ax' with type 'char\\\[0]' at offset 314" } - T ((pma + 1)->ax, 1); // { dg-warning "'strcpy' offset \\\[314, 315] from the object at 'pma' is out of the bounds of referenced subobject 'ax' with type 'char\\\[0]' at offset 314" } - T ((pma + 1)[1].ax, 2); // { dg-warning "'strcpy' offset \\\[471, 473] from the object at 'pma' is out of the bounds of referenced subobject 'ax' with type 'char\\\[0]' at offset 471" } - T ((*(pma + 2)).ax, 2); // { dg-warning "'strcpy' offset \\\[471, 473] from the object at 'pma' is out of the bounds of referenced subobject 'ax' with type 'char\\\[0]' at offset 471" } - T (pma[3].ax, 9); // { dg-warning "'strcpy' offset \\\[628, 637] from the object at 'pma' is out of the bounds of referenced subobject 'ax' with type 'char\\\[0]' at offset 628" } + T (pma[1].ax, 0); // { dg-warning "'strcpy' offset 314 from the object at 'pma' is out of the bounds of referenced subobject 'ax' with type 'char\\\[]' at offset 314" } + T ((pma + 1)->ax, 1); // { dg-warning "'strcpy' offset \\\[314, 315] from the object at 'pma' is out of the bounds of referenced subobject 'ax' with type 'char\\\[]' at offset 314" } + T ((pma + 1)[1].ax, 2); // { dg-warning "'strcpy' offset \\\[471, 473] from the object at 'pma' is out of the bounds of referenced subobject 'ax' with type 'char\\\[]' at offset 471" } + T ((*(pma + 2)).ax, 2); // { dg-warning "'strcpy' offset \\\[471, 473] from the object at 'pma' is out of the bounds of referenced subobject 'ax' with type 'char\\\[]' at offset 471" } + T (pma[3].ax, 9); // { dg-warning "'strcpy' offset \\\[628, 637] from the object at 'pma' is out of the bounds of referenced subobject 'ax' with type 'char\\\[]' at offset 628" } T (pma[-1].a1, 0); T (pma[-1].a1, 1); // { dg-warning "'strcpy' offset -152 from the object at 'pma' is out of the bounds of referenced subobject 'a1' with type 'char\\\[1]' at offset -153" } diff --git a/gcc/testsuite/gcc.dg/Warray-bounds-49.c b/gcc/testsuite/gcc.dg/Warray-bounds-49.c index 7a847acf4d2..f271dd526b8 100644 --- a/gcc/testsuite/gcc.dg/Warray-bounds-49.c +++ b/gcc/testsuite/gcc.dg/Warray-bounds-49.c @@ -17,7 +17,7 @@ void test_a0 (void) // The first three elements fit in the tail padding. a0.a2[0] = 0; a0.a2[1] = 1; a0.a2[2] = 2; - a0.a2[3] = 3; // { dg-warning "array subscript 3 is above array bounds of 'short int\\\[0]'" } + a0.a2[3] = 3; // { dg-warning "array subscript 3 is above array bounds of 'short int\\\[]'" } } @@ -27,7 +27,7 @@ void test_a1 (void) { a1.a2[0] = 0; a1.a2[1] = 1; a1.a2[2] = 2; - a1.a2[3] = 3; // { dg-warning "array subscript 3 is above array bounds of 'short int\\\[0]'" } + a1.a2[3] = 3; // { dg-warning "array subscript 3 is above array bounds of 'short int\\\[]'" } } @@ -37,7 +37,7 @@ void test_a2 (void) { a2.a2[0] = 0; a2.a2[1] = 1; a2.a2[2] = 2; - a2.a2[3] = 3; // { dg-warning "array subscript 3 is above array bounds of 'short int\\\[0]'" } + a2.a2[3] = 3; // { dg-warning "array subscript 3 is above array bounds of 'short int\\\[]'" } } @@ -47,7 +47,7 @@ void test_a3 (void) { a3.a2[0] = 0; a3.a2[1] = 1; a3.a2[2] = 2; - a3.a2[3] = 3; // { dg-warning "array subscript 3 is above array bounds of 'short int\\\[0]'" } + a3.a2[3] = 3; // { dg-warning "array subscript 3 is above array bounds of 'short int\\\[]'" } } @@ -57,7 +57,7 @@ void test_a4 (void) { a4.a2[0] = 0; a4.a2[1] = 1; a4.a2[2] = 2; a4.a2[3] = 3; - a4.a2[4] = 4; // { dg-warning "array subscript 4 is above array bounds of 'short int\\\[0]'" } + a4.a2[4] = 4; // { dg-warning "array subscript 4 is above array bounds of 'short int\\\[]'" } } @@ -67,7 +67,7 @@ void test_a5 (void) { a5.a2[0] = 0; a5.a2[1] = 1; a5.a2[2] = 2; a5.a2[3] = 3; a5.a2[4] = 4; - a5.a2[5] = 5; // { dg-warning "array subscript 5 is above array bounds of 'short int\\\[0]'" } + a5.a2[5] = 5; // { dg-warning "array subscript 5 is above array bounds of 'short int\\\[]'" } } @@ -78,7 +78,7 @@ void test_a6 (void) a6.a2[0] = 0; a6.a2[1] = 1; a6.a2[2] = 2; a6.a2[3] = 3; a6.a2[4] = 4; a6.a2[5] = 5; - a6.a2[6] = 6; // { dg-warning "array subscript 6 is above array bounds of 'short int\\\[0]'" } + a6.a2[6] = 6; // { dg-warning "array subscript 6 is above array bounds of 'short int\\\[]'" } } @@ -89,7 +89,7 @@ void test_a7 (void) a7.a2[0] = 0; a7.a2[1] = 1; a7.a2[2] = 2; a7.a2[3] = 3; a7.a2[4] = 4; a7.a2[5] = 5; a7.a2[5] = 5; a7.a2[6] = 6; - a7.a2[7] = 7; // { dg-warning "array subscript 7 is above array bounds of 'short int\\\[0]'" } + a7.a2[7] = 7; // { dg-warning "array subscript 7 is above array bounds of 'short int\\\[]'" } } @@ -100,7 +100,7 @@ void test_a8 (void) a8.a2[0] = 0; a8.a2[1] = 1; a8.a2[2] = 2; a8.a2[3] = 3; a8.a2[4] = 4; a8.a2[5] = 5; a8.a2[5] = 5; a8.a2[6] = 6; a8.a2[7] = 7; - a8.a2[8] = 8; // { dg-warning "array subscript 8 is above array bounds of 'short int\\\[0]'" } + a8.a2[8] = 8; // { dg-warning "array subscript 8 is above array bounds of 'short int\\\[]'" } } @@ -111,5 +111,5 @@ void test_a9 (void) a8.a2[0] = 8; a8.a2[1] = 7; a8.a2[2] = 6; a8.a2[3] = 5; a8.a2[4] = 4; a8.a2[5] = 3; a8.a2[5] = 2; a8.a2[6] = 1; a8.a2[7] = 0; - a8.a2[9] = 8; // { dg-warning "array subscript 9 is above array bounds of 'short int\\\[0]'" } + a8.a2[9] = 8; // { dg-warning "array subscript 9 is above array bounds of 'short int\\\[]'" } } -- 2.30.2