From 9d9b332b3662f2ea1fc0c8fdae43082e36f93948 Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Wed, 29 May 2019 15:36:25 -0400 Subject: [PATCH] Fix: test_bitfield: extend coverage: 0-len signed write/read MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit By convention, a 0-len bitfield write is a no-op, and a 0-len read sets the value of the output to 0. So we can "encode" the value 0 over a length of 0 bit. Cover this in the test-cases for signed types. It is already covered for the unsigned test-cases. Signed-off-by: Mathieu Desnoyers Change-Id: Ib6038b98167ef2cfa8c504d7ac29498e71827b38 Signed-off-by: Jérémie Galarneau Reviewed-on: https://review.lttng.org/c/babeltrace/+/1341 Tested-by: jenkins --- tests/lib/test_bitfield.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/tests/lib/test_bitfield.c b/tests/lib/test_bitfield.c index bc61e118..2dc65719 100644 --- a/tests/lib/test_bitfield.c +++ b/tests/lib/test_bitfield.c @@ -387,7 +387,9 @@ void run_test_signed_write(int src_i, long long src_ll) long long readval; unsigned int s, l; - if (src_i & 0x80000000U) + if (!src_i) + nrbits_i = 0; /* The number of bits needed to represent 0 is 0. */ + else if (src_i & 0x80000000U) nrbits_i = fls_u32(~src_i) + 1; /* Find least significant bit conveying sign */ else nrbits_i = fls_u32(src_i) + 1; /* Keep sign at 0 */ @@ -438,7 +440,9 @@ void run_test_signed_write(int src_i, long long src_ll) } pass(SIGNED_INT_WRITE_TEST_DESC_FMT_STR, src_i); - if (src_ll & 0x8000000000000000ULL) + if (!src_ll) + nrbits_ll = 0; /* The number of bits needed to represent 0 is 0. */ + else if (src_ll & 0x8000000000000000ULL) nrbits_ll = fls_u64(~src_ll) + 1; /* Find least significant bit conveying sign */ else nrbits_ll = fls_u64(src_ll) + 1; /* Keep sign at 0 */ @@ -503,7 +507,9 @@ void run_test_signed_read(int src_i, long long src_ll) long long readval_ll; unsigned int s, l; - if (src_i & 0x80000000U) + if (!src_i) + nrbits_i = 0; /* The number of bits needed to represent 0 is 0. */ + else if (src_i & 0x80000000U) nrbits_i = fls_u32(~src_i) + 1; /* Find least significant bit conveying sign */ else nrbits_i = fls_u32(src_i) + 1; /* Keep sign at 0 */ @@ -554,6 +560,8 @@ void run_test_signed_read(int src_i, long long src_ll) } pass(SIGNED_INT_READ_TEST_DESC_FMT_STR, src_i); + if (!src_ll) + nrbits_ll = 0; /* The number of bits needed to represent 0 is 0. */ if (src_ll & 0x8000000000000000ULL) nrbits_ll = fls_u64(~src_ll) + 1; /* Find least significant bit conveying sign */ else -- 2.34.1