While porting recent support for a build info section in the gcda from google/4_8 to 4_9 and doing manual testing, I discovered that it does not interact well with the COMDAT fixup handling. This patch fixes the issue, and adds a test case that exposes the problem without the fix.
Here is the google/4_8 patch - I plan to commit there first then port it along with the original build info patch to 4_9. Passes regression tests - ok for google branches? Thanks, Teresa 2014-09-10 Teresa Johnson <tejohn...@google.com> libgcc: * libgcov-driver.c (gcov_scan_to_function_data): Rename from gcov_scan_summary_end, scan past BUILD_INFO section. (gcov_dump_module_info): Rename gcov_scan_summary_end to gcov_scan_to_function_data. gcc/testsuite: * g++.dg/tree-prof/lipo/buildinfo.txt: Input for -fprofile-generate-buildinfo option. * g++.dg/tree-prof/lipo/comdat_fixup_0.C: New test. * g++.dg/tree-prof/lipo/comdat_fixup_1.C: Ditto. * g++.dg/tree-prof/lipo/comdat_fixup_2.C: Ditto. * g++.dg/tree-prof/lipo/comdat_fixup.h: Ditto. * lib/profopt.exp: Declare srcdir for use in test options. Index: libgcc/libgcov-driver.c =================================================================== --- libgcc/libgcov-driver.c (revision 214976) +++ libgcc/libgcov-driver.c (working copy) @@ -428,13 +428,15 @@ struct gcov_filename_aux{ #include "libgcov-driver-system.c" /* Scan through the current open gcda file corresponding to GI_PTR - to locate the end position of the last summary, returned in - SUMMARY_END_POS_P. Return 0 on success, -1 on error. */ + to locate the end position just before function data should be rewritten, + returned in SUMMARY_END_POS_P. E.g. scan past the last summary and other + sections that won't be rewritten, like the build info. Return 0 on success, + -1 on error. */ static int -gcov_scan_summary_end (struct gcov_info *gi_ptr, - gcov_position_t *summary_end_pos_p) +gcov_scan_to_function_data (struct gcov_info *gi_ptr, + gcov_position_t *summary_end_pos_p) { - gcov_unsigned_t tag, version, stamp; + gcov_unsigned_t tag, version, stamp, i, length; tag = gcov_read_unsigned (); if (tag != GCOV_DATA_MAGIC) { @@ -467,6 +469,28 @@ static int return -1; } + /* If there is a build info section, scan past it as well. */ + if (tag == GCOV_TAG_BUILD_INFO) + { + length = gcov_read_unsigned (); + gcov_unsigned_t num_strings = 0; + char **build_info_strings = gcov_read_build_info (length, &num_strings); + if (!build_info_strings) + { + gcov_error ("profiling:%s:Error reading build info\n", gi_filename); + return -1; + } + + for (i = 0; i < num_strings; i++) + free (build_info_strings[i]); + free (build_info_strings); + + *summary_end_pos_p = gcov_position (); + tag = gcov_read_unsigned (); + } + /* The next section should be the function counters. */ + gcc_assert (tag == GCOV_TAG_FUNCTION); + return 0; } @@ -1031,10 +1055,10 @@ gcov_dump_module_info (struct gcov_filename_aux *g if (changed) { - /* Scan file to find the end of the summary section, which is + /* Scan file to find the start of the function section, which is where we will start re-writing the counters. */ gcov_position_t summary_end_pos; - if (gcov_scan_summary_end (gi_ptr, &summary_end_pos) == -1) + if (gcov_scan_to_function_data (gi_ptr, &summary_end_pos) == -1) gcov_error ("profiling:%s:Error scanning summaries\n", gi_filename); else Index: gcc/testsuite/g++.dg/tree-prof/lipo/buildinfo.txt =================================================================== --- gcc/testsuite/g++.dg/tree-prof/lipo/buildinfo.txt (revision 0) +++ gcc/testsuite/g++.dg/tree-prof/lipo/buildinfo.txt (revision 0) @@ -0,0 +1 @@ +Test -fprofile-generate-buildinfo option Index: gcc/testsuite/g++.dg/tree-prof/lipo/comdat_fixup_0.C =================================================================== --- gcc/testsuite/g++.dg/tree-prof/lipo/comdat_fixup_0.C (revision 0) +++ gcc/testsuite/g++.dg/tree-prof/lipo/comdat_fixup_0.C (revision 0) @@ -0,0 +1,9 @@ +/* { dg-options "-O2 -fno-inline -fprofile-generate-buildinfo=$srcdir/g++.dg/tree-prof/lipo/buildinfo.txt" } */ +#include <stdio.h> + +extern int foo1(int x); +extern int foo2(int x); +int main() +{ + printf ("Result = %d\n", foo1(1) + foo2(1)); +} Index: gcc/testsuite/g++.dg/tree-prof/lipo/comdat_fixup_1.C =================================================================== --- gcc/testsuite/g++.dg/tree-prof/lipo/comdat_fixup_1.C (revision 0) +++ gcc/testsuite/g++.dg/tree-prof/lipo/comdat_fixup_1.C (revision 0) @@ -0,0 +1,7 @@ +/* { dg-options "-O2 -fno-inline" } */ +#include "comdat_fixup.h" +int foo1(int x) +{ + Foo f; + return f.foo(x); +} Index: gcc/testsuite/g++.dg/tree-prof/lipo/comdat_fixup_2.C =================================================================== --- gcc/testsuite/g++.dg/tree-prof/lipo/comdat_fixup_2.C (revision 0) +++ gcc/testsuite/g++.dg/tree-prof/lipo/comdat_fixup_2.C (revision 0) @@ -0,0 +1,7 @@ +/* { dg-options "-O2 -fno-inline" } */ +#include "comdat_fixup.h" +int foo2(int x) +{ + Foo f; + return f.foo(x); +} Index: gcc/testsuite/g++.dg/tree-prof/lipo/comdat_fixup.h =================================================================== --- gcc/testsuite/g++.dg/tree-prof/lipo/comdat_fixup.h (revision 0) +++ gcc/testsuite/g++.dg/tree-prof/lipo/comdat_fixup.h (revision 0) @@ -0,0 +1,5 @@ +class Foo +{ + public: + int foo(int x) { return x; } +}; Index: gcc/testsuite/lib/profopt.exp =================================================================== --- gcc/testsuite/lib/profopt.exp (revision 214976) +++ gcc/testsuite/lib/profopt.exp (working copy) @@ -169,6 +169,8 @@ proc profopt-final-code { which final_code name } # SRC is the full pathname of the testcase. # proc profopt-get-options { src } { + global srcdir + # dg-options sets a variable called dg-extra-tool-flags. set dg-extra-tool-flags "" -- Teresa Johnson | Software Engineer | tejohn...@google.com | 408-460-2413