Summary: | uninitialized variable false positive prevents bootstrap with -fipa-cp-clone | ||
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Product: | gcc | Reporter: | Matt Hargett <matt> |
Component: | middle-end | Assignee: | Not yet assigned to anyone <unassigned> |
Status: | RESOLVED FIXED | ||
Severity: | normal | CC: | dcb314 |
Priority: | P3 | Keywords: | build, diagnostic |
Version: | 4.7.0 | ||
Target Milestone: | --- | ||
Host: | Target: | ||
Build: | Known to work: | ||
Known to fail: | Last reconfirmed: | ||
Bug Depends on: | |||
Bug Blocks: | 24639 |
Description
Matt Hargett
2011-12-14 00:56:38 UTC
Most likely what is happening is cp_parser_compound_statement is being inlined and it is not cost worthly to do the jump thread for check_body_p. Narrowed this down to -O2 -fipa-cp-clone that triggers the warning. I think I may be seeing something similar. I've been trying to bootstrap using "-g -O3" in BOOT_CFLAGS. That doesn't work, but "-g -O2" of course does. After trying out all the flags individually that make the difference from -O2 to -O3, it is the -fipa-cp-clone flag that is the only one that breaks bootstrap. The rest of the flags are fine. On trunk snapshot of 20130130, I get ../../src/trunk/gcc/c/c-parser.c: In function ‘c_expr c_parser_postfix_expression_after_primary(c_parser*, location_t, c_expr)’: ../../src/trunk/gcc/c/c-parser.c:6908:16: error: ‘origtypes’ may be used uninitialized in this function [-Werror=maybe-uninitialized] origtypes); ^ This looks a false positive to me. http://gcc.gnu.org/ml/gcc-patches/2013-02/msg00324.html ought to fix the origtypes issue. (In reply to comment #3) > I've been trying to bootstrap using "-g -O3" in BOOT_CFLAGS. > That doesn't work, but "-g -O2" of course does. I am pleased to be able to say that BOOT_CFLAGS= -g -O3 works for revision 196574 (Sat 09 March 2013). I'll use this as my new default build setting, so when it stops working I'll be able to put in a bug report. This is a long way from -g -O3 being the default for all architectures, but it is a good step forward. I think this bug is fixed. (In reply to David Binderman from comment #5) > (In reply to comment #3) > > I've been trying to bootstrap using "-g -O3" in BOOT_CFLAGS. > > That doesn't work, but "-g -O2" of course does. > > I am pleased to be able to say that BOOT_CFLAGS= -g -O3 > works for revision 196574 (Sat 09 March 2013). > > I'll use this as my new default build setting, > so when it stops working I'll be able to put in a bug report. > > This is a long way from -g -O3 being the default > for all architectures, but it is a good step forward. > > I think this bug is fixed. OK, closing as FIXED then. |