Commit Graph

8 Commits

Author SHA1 Message Date
Vedant Kumar 61763b65af [Coverage] Discard the last uncompleted deferred region in a decl
Discard the last uncompleted deferred region in a decl, if one exists.
This prevents lines at the end of a function containing only whitespace
or closing braces from being marked as uncovered, if they follow a
region terminator (return/break/etc).

The previous behavior was to heuristically complete deferred regions at
the end of a decl. In practice this ended up being too brittle for too
little gain. Users would complain that there was no way to reach full
code coverage because whitespace at the end of a function would be
marked uncovered.

rdar://40238228

Differential Revision: https://reviews.llvm.org/D46918

llvm-svn: 333609
2018-05-30 23:35:44 +00:00
Vedant Kumar f9a0d44eea [Coverage] Emit deferred regions in headers
There are some limitations with emitting regions in macro expansions
because we don't gather file IDs within the expansions. Fix the check
that prevents us from emitting deferred regions in expansions to make an
exception for headers, which is something we can handle.

rdar://35373009

llvm-svn: 317760
2017-11-09 02:33:40 +00:00
Vedant Kumar 341bf42991 [Coverage] Discard deferred region in closing if-else
A trailing deferred region isn't necessary in a function that ends with
this pattern:

  ...
  else {
    ...
    return;
  }

Special-case this pattern so that the closing curly brace of the
function isn't marked as uncovered. This issue came up in PR34962.

llvm-svn: 315982
2017-10-17 07:47:39 +00:00
Vedant Kumar ef8e05ff07 [Coverage] Remove deferred region for trailing return, fixes PR34611
As a special case, throw away deferred regions for trailing returns.
This allows the closing curly brace to have a count, and is less
distracting.

llvm-svn: 313603
2017-09-19 00:29:46 +00:00
Vedant Kumar a1c4deb792 [Coverage] Use a new API to label gap areas
This will make it possible for llvm-cov to pick better line execution
counts, and is part of the fix for llvm.org/PR34612.

llvm-svn: 313598
2017-09-18 23:37:30 +00:00
Vedant Kumar 747b0e2905 [Coverage] Precise region termination with deferred regions (reapply)
The current coverage implementation doesn't handle region termination
very precisely. Take for example an `if' statement with a `return':

  void f() {
    if (true) {
      return; // The `if' body's region is terminated here.
    }
    // This line gets the same coverage as the `if' condition.
  }

If the function `f' is called, the line containing the comment will be
marked as having executed once, which is not correct.

The solution here is to create a deferred region after terminating a
region. The deferred region is completed once the start location of the
next statement is known, and is then pushed onto the region stack.
In the cases where it's not possible to complete a deferred region, it
can safely be dropped.

Testing: lit test updates, a stage2 coverage-enabled build of clang

This is a reapplication but there are no changes from the original commit.
With D36813, the segment builder in llvm will be able to handle deferred
regions correctly.

llvm-svn: 312818
2017-09-08 18:44:56 +00:00
Vedant Kumar a7764adcbb Revert "[Coverage] Precise region termination with deferred regions"
This reverts commit r310010. I don't think there's anything wrong with
this commit, but it's causing clang to generate output that llvm-cov
doesn't do a good job with and the fix isn't immediately clear.

See Eli's comment in D36250 for more context.

I'm reverting the clang change so the coverage bot can revert back to
producing sensible output, and to give myself some time to investigate
what went wrong in llvm.

llvm-svn: 310154
2017-08-05 00:34:10 +00:00
Vedant Kumar 85e6dce1eb [Coverage] Precise region termination with deferred regions
The current coverage implementation doesn't handle region termination
very precisely. Take for example an `if' statement with a `return':

  void f() {
    if (true) {
      return; // The `if' body's region is terminated here.
    }
    // This line gets the same coverage as the `if' condition.
  }

If the function `f' is called, the line containing the comment will be
marked as having executed once, which is not correct.

The solution here is to create a deferred region after terminating a
region. The deferred region is completed once the start location of the
next statement is known, and is then pushed onto the region stack.
In the cases where it's not possible to complete a deferred region, it
can safely be dropped.

Testing: lit test updates, a stage2 coverage-enabled build of clang
llvm-svn: 310010
2017-08-04 00:29:20 +00:00