[bug report] perf jit: add source line info support

From: Dan Carpenter
Date: Wed Nov 30 2016 - 13:51:25 EST


Hello Stephane Eranian,

The patch 598b7c6919c7: "perf jit: add source line info support" from
Nov 30, 2015, leads to the following static checker warning:

./tools/perf/util/genelf_debug.c:211 emit_signed_LEB128()
warn: potential left shift more than type allows '57'

./tools/perf/util/genelf_debug.c
202 static void emit_signed_LEB128(struct buffer_ext *be, long data)
203 {
204 int more = 1;
205 int negative = data < 0;
206 int size = sizeof(long) * CHAR_BIT;
207 while (more) {
208 ubyte cur = data & 0x7F;
209 data >>= 7;
210 if (negative)
211 data |= - (1 << (size - 7));
^^^^^^^^^^^^^^^^^^^^^^^^^^^
This is a no-op on 64 bit systems. I suspect it's not intentional?

212 if ((data == 0 && !(cur & 0x40)) ||
213 (data == -1l && (cur & 0x40)))
214 more = 0;
215 else
216 cur |= 0x80;
217 buffer_ext_add(be, &cur, 1);
218 }
219 }

regards,
dan carpenter