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Diffstat (limited to 'clang/docs/SourceBasedCodeCoverage.rst')
| -rw-r--r-- | clang/docs/SourceBasedCodeCoverage.rst | 21 |
1 files changed, 19 insertions, 2 deletions
diff --git a/clang/docs/SourceBasedCodeCoverage.rst b/clang/docs/SourceBasedCodeCoverage.rst index 7ab78404e57..0586f2ec846 100644 --- a/clang/docs/SourceBasedCodeCoverage.rst +++ b/clang/docs/SourceBasedCodeCoverage.rst @@ -165,9 +165,9 @@ A few final notes: indexed profiles. To combine profiling data from multiple runs of a program, try e.g: -.. code-block:: console + .. code-block:: console - % llvm-profdata merge -sparse foo1.profraw foo2.profdata -o foo3.profdata + % llvm-profdata merge -sparse foo1.profraw foo2.profdata -o foo3.profdata Format compatibility guarantees =============================== @@ -184,3 +184,20 @@ Format compatibility guarantees * There is a third format in play: the format of the coverage mappings emitted into instrumented binaries. Tools must retain **backwards** compatibility with these formats. These formats are not forwards-compatible. + +Drawbacks and limitations +========================= + +* Code coverage does not handle stack unwinding in the presence of uncaught + exceptions precisely. Consider the following function: + + .. code-block:: cpp + + int f() { + may_throw(); + return 0; + } + + If the function ``may_throw()`` propagates an exception into ``f``, the code + coverage tool may mark the ``return`` statement as executed even though it is + not. |
