I've committed this patch to fix part of PR 51113. there are (at least) 3 issues
going on.
*) I'd forgotten to propagate symbol visibility from the fn-decl to the
externally visible gcov objects. I don't know if the PR actually exposed that
problem, but this patch fixes it.
*) I'd presumed too much about linker capabilities & ELF. For comdat functions,
the associated counter arrays are also externally visible. However, in
well-formed program that counter array will not be overridden *without* the
function itself also being overridden. Ergo, it is safe to use a PC-relative
offset to access the array from the function, in PIC code. Unfortunately, this
is not expressible in ELF. Because the array is externally visible and itself
weak, it is *separately* overridable. The fix is straight-forward. Rather than
take a short-cut, use make_decl_one_only, as it sets flags correctly so that PIC
access works. This fixes the testcase Markus attached to the PR.
*) There is another problem exposed by gold, but apparently not by ld. Markus
has managed to create a reproducible testcase that I can work from. I have a
handle on this, but not yet a fix.
I thought it best to commit a fix for the first 2 issues, as I think they're
orthogonal to the 3rd (from what I can see at the moment).
built & tested on i686-pc-linux-gnu. Many thanks to Markus in working with me
to create testcases and try out initial patches.
nathan
2011-11-20 Nathan Sidwell <nat...@acm.org>
PR gcov-profile/51113
* coverage.c (build_var): Propagate visibility for public decls.
testsuite/
* gcc.misc-tests/gcov-13.c: Check gcovpart-13b coverage
* gcc.misc-tests/gcov-16.c: New.
* gcc.misc-tests/gcov-17.c: New.
* g++.dg/gcov/gcov-8.C: New.
* g++.dg/gcov/gcov-9.C: New.
* g++.dg/gcov/gcov-10.C: New.
Index: coverage.c
===================================================================
--- coverage.c (revision 181523)
+++ coverage.c (working copy)
@@ -657,9 +657,8 @@ coverage_end_function (unsigned lineno_c
}
/* Build a coverage variable of TYPE for function FN_DECL. If COUNTER
- >= 0 it is a counter array, and thus local. Otherwise it is the
- function structure and needs to be globalized. All cases must be
- in the same comdat group as FN_DECL. */
+ >= 0 it is a counter array, otherwise it is the function structure.
+ Propagate appropriate linkage and visibility from the function decl. */
static tree
build_var (tree fn_decl, tree type, int counter)
@@ -668,29 +667,29 @@ build_var (tree fn_decl, tree type, int
tree fn_name = DECL_ASSEMBLER_NAME (fn_decl);
char *buf = (char *)alloca (IDENTIFIER_LENGTH (fn_name) + 10);
- if (counter >= 0)
- TREE_STATIC (var) = 1;
- else
- {
- TREE_PUBLIC (var) = TREE_PUBLIC (fn_decl);
- TREE_STATIC (var) = TREE_STATIC (fn_decl);
- }
- TREE_ADDRESSABLE (var) = 1;
- DECL_ALIGN (var) = TYPE_ALIGN (type);
-
if (counter < 0)
sprintf (buf, "__gcov__%s", IDENTIFIER_POINTER (fn_name));
else
sprintf (buf, "__gcov%u_%s", counter, IDENTIFIER_POINTER (fn_name));
DECL_NAME (var) = get_identifier (buf);
-
- /* Initialize assembler name so we can stream out. */
+ TREE_STATIC (var) = 1;
+ TREE_ADDRESSABLE (var) = 1;
+ DECL_ALIGN (var) = TYPE_ALIGN (type);
+ DECL_WEAK (var) = DECL_WEAK (fn_decl);
+ TREE_PUBLIC (var)
+ = TREE_PUBLIC (fn_decl) && (counter < 0 || DECL_WEAK (fn_decl));
+ if (DECL_ONE_ONLY (fn_decl))
+ make_decl_one_only (var, DECL_COMDAT_GROUP (fn_decl));
+
if (TREE_PUBLIC (var))
- DECL_ASSEMBLER_NAME (var);
+ {
+ DECL_VISIBILITY (var) = DECL_VISIBILITY (fn_decl);
+ DECL_VISIBILITY_SPECIFIED (var)
+ = DECL_VISIBILITY_SPECIFIED (fn_decl);
- DECL_WEAK (var) = TREE_PUBLIC (var) && DECL_WEAK (fn_decl);
- DECL_COMDAT (var) = DECL_COMDAT (fn_decl);
- DECL_COMDAT_GROUP (var) = DECL_COMDAT_GROUP (fn_decl);
+ /* Initialize assembler name so we can stream out. */
+ DECL_ASSEMBLER_NAME (var);
+ }
return var;
}
Index: testsuite/gcc.misc-tests/gcov-13.c
===================================================================
--- testsuite/gcc.misc-tests/gcov-13.c (revision 181507)
+++ testsuite/gcc.misc-tests/gcov-13.c (working copy)
@@ -16,3 +16,4 @@ int main ()
}
/* { dg-final { run-gcov { -a gcov-13.c } } } */
+/* { dg-final { run-gcov { -a gcovpart-13b.c } } } */
Index: testsuite/gcc.misc-tests/gcov-16.c
===================================================================
--- testsuite/gcc.misc-tests/gcov-16.c (revision 0)
+++ testsuite/gcc.misc-tests/gcov-16.c (revision 0)
@@ -0,0 +1,11 @@
+/* Test visibility is copied */
+
+/* { dg-options "-fprofile-arcs -fvisibility=hidden" } */
+/* { dg-require-visibility "" } */
+/* { dg-require-weak "" } */
+
+void Foo ()
+{
+}
+
+ /* { dg-final { scan-assembler "\\.hidden\t__gcov__Foo" } } */
Index: testsuite/gcc.misc-tests/gcov-17.c
===================================================================
--- testsuite/gcc.misc-tests/gcov-17.c (revision 0)
+++ testsuite/gcc.misc-tests/gcov-17.c (revision 0)
@@ -0,0 +1,11 @@
+/* Test visibility is copied */
+
+/* { dg-options "-fprofile-arcs" } */
+/* { dg-require-visibility "" } */
+/* { dg-require-weak "" } */
+
+void __attribute__ ((visibility ("hidden"), weak)) Foo ()
+{
+}
+
+/* { dg-final { scan-assembler "\\.hidden\t__gcov__Foo" } } */
Index: testsuite/g++.dg/gcov/gcov-8.C
===================================================================
--- testsuite/g++.dg/gcov/gcov-8.C (revision 0)
+++ testsuite/g++.dg/gcov/gcov-8.C (revision 0)
@@ -0,0 +1,13 @@
+/* { dg-options "-fprofile-arcs -fvisibility=hidden" } */
+/* { dg-require-visibility "" } */
+
+struct __attribute__((visibility ("hidden"))) X
+{
+ void Fink ();
+};
+
+void X::Fink ()
+{
+}
+
+/* { dg-final { scan-assembler "\\.hidden\t__gcov___ZN1X4FinkEv" } } */
Index: testsuite/g++.dg/gcov/gcov-9.C
===================================================================
--- testsuite/g++.dg/gcov/gcov-9.C (revision 0)
+++ testsuite/g++.dg/gcov/gcov-9.C (revision 0)
@@ -0,0 +1,15 @@
+/* { dg-options "-fprofile-arcs -fvisibility-inlines-hidden" } */
+/* { dg-require-visibility "" } */
+
+inline void Boo ()
+{
+}
+
+extern "C" void (*Foo ()) ()
+{
+ return Boo;
+}
+
+/* { dg-final { scan-assembler "\\.hidden\t__gcov___Z3Boov" } } */
+/* { dg-final { scan-assembler "__gcov__Foo:" } } */
+/* { dg-final { scan-assembler-not "\\.hidden\t__gcov__Foo" } } */
Index: testsuite/g++.dg/gcov/gcov-10.C
===================================================================
--- testsuite/g++.dg/gcov/gcov-10.C (revision 0)
+++ testsuite/g++.dg/gcov/gcov-10.C (revision 0)
@@ -0,0 +1,20 @@
+/* Ensure PIC sequence used for comdat functions */
+
+/* { dg-options "-fprofile-arcs -ftest-coverage -fpic" } */
+/* { dg-do run { target native } } */
+/* { dg-require-effective-target fpic } */
+
+inline int __attribute__ ((noinline)) Foo ()
+{
+ static int x[1];
+
+ return x[0]++; /* count (1) */
+}
+
+int main ()
+{
+ Foo (); /* count (1) */
+ return 0; /* count (1) */
+}
+
+/* { dg-final { run-gcov gcov-10.C } } */
Index: testsuite/g++.dg/gcov/gcov-11.C
===================================================================
--- testsuite/g++.dg/gcov/gcov-11.C (revision 0)
+++ testsuite/g++.dg/gcov/gcov-11.C (revision 0)
@@ -0,0 +1,42 @@
+/* Check that unexecuted exception processing regions are shown
+ distinct from unexecuted normal regions. */
+
+/* { dg-options "-fprofile-arcs -ftest-coverage" } */
+/* { dg-do run { target native } } */
+
+void Baz (int i)
+{
+ if (i)
+ throw 1;
+}
+
+void Boz () throw ()
+{
+}
+
+int main ()
+{
+ try
+ {
+ Baz (0); /* count (1) */
+ Baz (0); /* count (1) */
+ }
+ catch (...)
+ {
+ Boz (); /* count (=====) */
+ }
+
+ try
+ {
+ Baz (1); /* count (1) */
+ Baz (0); /* count (#####) */
+ }
+ catch (...)
+ {
+ Boz (); /* count (1) */
+ }
+
+ return 0; /* count (1) */
+}
+
+/* { dg-final { run-gcov gcov-11.C } } */
