[LLVMdev] Coverage mapping issue: Malformed profile data (original) (raw)

Dmitry Volyntsev xeioexception at gmail.com
Tue Feb 10 07:15:32 PST 2015


Hi all!

It seems I came across on issue with coverage mapping (http://www.llvm.org/docs/CoverageMappingFormat.html)

check on: llvm revision: r228136 clang Last Changed Rev: 228121 build: Debug+Asserts OS: ubuntu 14.04

Here is simple snippets

test1.c: NOT OK

#include <stdio.h>

static int foo() { return 42; } int main() { return 0; }

cp src/test1.c src/test.c; rm -fr default.profraw test.profdata ; clang -c -o obj/test.o src/test.c -I -g -O0 -fprofile-instr-generate -fcoverage-mapping; clang -o bin/test obj/test.o -I -g -O0 -fprofile-instr-generate -fcoverage-mapping; ./bin/test ; llvm-profdata merge -o test.profdata default.profraw; llvm-cov show ./bin/test -instr-profile=test.profdata

error: Failed to load coverage: Malformed profile data

test2.c: OK

#include <stdio.h>

static int foo() { return 42; } int main() { return foo(); }

cp src/test2.c src/test.c; rm -fr default.profraw test.profdata ; clang -c -o obj/test.o src/test.c -I -g -O0 -fprofile-instr-generate -fcoverage-mapping; clang -o bin/test obj/test.o -I -g -O0 -fprofile-instr-generate -fcoverage-mapping; ./bin/test ; llvm-profdata merge -o test.profdata default.profraw; llvm-cov show ./bin/test -instr-profile=test.profdata

/home/xeioex/workspace/clang/experiments/llvm-cov/test/src/test.c: | 1|#include <stdio.h> | 2| 1| 3|static int foo() { return 42; } 1| 4|int main() { 1| 5| return foo(); 1| 6|}

test3.c: OK

#include <stdio.h>

int foo() { return 42; } int main() { return 0; }

cp src/test3.c src/test.c; rm -fr default.profraw test.profdata ; clang -c -o obj/test.o src/test.c -I -g -O0 -fprofile-instr-generate -fcoverage-mapping; clang -o bin/test obj/test.o -I -g -O0 -fprofile-instr-generate -fcoverage-mapping; ./bin/test ; llvm-profdata merge -o test.profdata default.profraw; llvm-cov show ./bin/test -instr-profile=test.profdata

/home/xeioex/workspace/clang/experiments/llvm-cov/test/src/test.c: | 1|#include <stdio.h> | 2| 0| 3|int foo() { return 42; } 1| 4|int main() { 1| 5| return 0; 1| 6|}

As far I can understand issue somehow related to unused static functions.

Also, as I can track down the problem raised because of lib/ProfileData/CoverageMappingReader.cpp (SectionData::get) expects that function's names located inside __llvm_prf_names section but it not true in case of test1.c, instead some function names located inside .rodata section.

Is it known issue? any hints, how to avoid or workaround it?

-- Be happy, Best regards, Dmitry Volyntsev



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