From 1ebf0641a5201939cbaa1cc4f008bb8eda68895c Mon Sep 17 00:00:00 2001 From: Bernd Edlinger Date: Wed, 29 Aug 2018 22:16:09 +0000 Subject: [PATCH] re PR middle-end/87053 (wrong code with c_strlen) gcc: 2018-08-22 Bernd Edlinger PR middle-end/87053 * builtins.c (c_strlen): Improve range checks. testsuite: 2018-08-22 Bernd Edlinger PR middle-end/87053 * gcc.c-torture/execute/pr87053.c: New test. From-SVN: r263968 --- gcc/ChangeLog | 5 +++++ gcc/builtins.c | 11 ++++++++--- gcc/testsuite/ChangeLog | 5 +++++ gcc/testsuite/gcc.c-torture/execute/pr87053.c | 17 +++++++++++++++++ 4 files changed, 35 insertions(+), 3 deletions(-) create mode 100644 gcc/testsuite/gcc.c-torture/execute/pr87053.c diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 3cf10ca..8865f31 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,8 @@ +2018-08-29 Bernd Edlinger + + PR middle-end/87053 + * builtins.c (c_strlen): Improve range checks. + 2018-08-29 Martin Sebor Jeff Law diff --git a/gcc/builtins.c b/gcc/builtins.c index c9de1e6..58ea747 100644 --- a/gcc/builtins.c +++ b/gcc/builtins.c @@ -567,7 +567,7 @@ string_length (const void *ptr, unsigned eltsize, unsigned maxelts) tree c_strlen (tree src, int only_value, unsigned eltsize) { - gcc_assert (eltsize == 1 || eltsize == 2 || eltsize == 4); + gcc_checking_assert (eltsize == 1 || eltsize == 2 || eltsize == 4); STRIP_NOPS (src); if (TREE_CODE (src) == COND_EXPR && (only_value || !TREE_SIDE_EFFECTS (TREE_OPERAND (src, 0)))) @@ -656,10 +656,10 @@ c_strlen (tree src, int only_value, unsigned eltsize) a null character if we can represent it as a single HOST_WIDE_INT. */ if (byteoff == 0) eltoff = 0; - else if (! tree_fits_shwi_p (byteoff)) + else if (! tree_fits_uhwi_p (byteoff) || tree_to_uhwi (byteoff) % eltsize) eltoff = -1; else - eltoff = tree_to_shwi (byteoff) / eltsize; + eltoff = tree_to_uhwi (byteoff) / eltsize; /* If the offset is known to be out of bounds, warn, and call strlen at runtime. */ @@ -691,6 +691,11 @@ c_strlen (tree src, int only_value, unsigned eltsize) unsigned len = string_length (ptr + eltoff * eltsize, eltsize, strelts - eltoff); + /* Don't know what to return if there was no zero termination. + Ideally this would turn into a gcc_checking_assert over time. */ + if (len > maxelts - eltoff) + return NULL_TREE; + return ssize_int (len); } diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index e38dab2..317cb47 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2018-08-29 Bernd Edlinger + + PR middle-end/87053 + * gcc.c-torture/execute/pr87053.c: New test. + 2018-08-29 Jakub Jelinek PR c++/87095 diff --git a/gcc/testsuite/gcc.c-torture/execute/pr87053.c b/gcc/testsuite/gcc.c-torture/execute/pr87053.c new file mode 100644 index 0000000..0170731 --- /dev/null +++ b/gcc/testsuite/gcc.c-torture/execute/pr87053.c @@ -0,0 +1,17 @@ +/* PR middle-end/87053 */ + +const union +{ struct { + char x[4]; + char y[4]; + }; + struct { + char z[8]; + }; +} u = {{"1234", "567"}}; + +int main () +{ + if (__builtin_strlen (u.z) != 7) + __builtin_abort (); +} -- 2.7.4