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Diffstat (limited to 'doc/developer-notes.md')
| -rw-r--r-- | doc/developer-notes.md | 59 |
1 files changed, 53 insertions, 6 deletions
diff --git a/doc/developer-notes.md b/doc/developer-notes.md index add2fb5004..95c46b05fe 100644 --- a/doc/developer-notes.md +++ b/doc/developer-notes.md @@ -265,7 +265,7 @@ General C++ the `.h` to the `.cpp` should not result in build errors - Use the RAII (Resource Acquisition Is Initialization) paradigm where possible. For example by using - `scoped_pointer` for allocations in a function. + `unique_ptr` for allocations in a function. - *Rationale*: This avoids memory and resource leaks, and ensures exception safety @@ -284,10 +284,9 @@ C++ data structures - *Rationale*: Behavior is undefined. In C++ parlor this means "may reformat the universe", in practice this has resulted in at least one hard-to-debug crash bug -- Watch out for vector out-of-bounds exceptions. `&vch[0]` is illegal for an - empty vector, `&vch[vch.size()]` is always illegal. Use `begin_ptr(vch)` and - `end_ptr(vch)` to get the begin and end pointer instead (defined in - `serialize.h`) +- Watch out for out-of-bounds vector access. `&vch[vch.size()]` is illegal, + including `&vch[0]` for an empty vector. Use `vch.data()` and `vch.data() + + vch.size()` instead. - Vector bounds checking is only enabled in debug mode. Do not rely on it @@ -323,7 +322,7 @@ Strings and formatting buffer overflows and surprises with `\0` characters. Also some C string manipulations tend to act differently depending on platform, or even the user locale -- Use `ParseInt32`, `ParseInt64`, `ParseDouble` from `utilstrencodings.h` for number parsing +- Use `ParseInt32`, `ParseInt64`, `ParseUInt32`, `ParseUInt64`, `ParseDouble` from `utilstrencodings.h` for number parsing - *Rationale*: These functions do overflow checking, and avoid pesky locale issues @@ -381,3 +380,51 @@ GUI - *Rationale*: Model classes pass through events and data from the core, they should not interact with the user. That's where View classes come in. The converse also holds: try to not directly access core data structures from Views. + +Git and github tips +--------------------- + +- For resolving merge/rebase conflicts, it can be useful to enable diff3 style using + `git config merge.conflictstyle diff3`. Instead of + + <<< + yours + === + theirs + >>> + + you will see + + <<< + yours + ||| + original + === + theirs + >>> + + This may make it much clearer what caused the conflict. In this style, you can often just look + at what changed between *original* and *theirs*, and mechanically apply that to *yours* (or the other way around). + +- When reviewing patches which change indentation in C++ files, use `git diff -w` and `git show -w`. This makes + the diff algorithm ignore whitespace changes. This feature is also available on github.com, by adding `?w=1` + at the end of any URL which shows a diff. + +- When reviewing patches that change symbol names in many places, use `git diff --word-diff`. This will instead + of showing the patch as deleted/added *lines*, show deleted/added *words*. + +- When reviewing patches that move code around, try using + `git diff --patience commit~:old/file.cpp commit:new/file/name.cpp`, and ignoring everything except the + moved body of code which should show up as neither `+` or `-` lines. In case it was not a pure move, this may + even work when combined with the `-w` or `--word-diff` options described above. + +- When looking at other's pull requests, it may make sense to add the following section to your `.git/config` + file: + + [remote "upstream-pull"] + fetch = +refs/pull/*:refs/remotes/upstream-pull/* + url = git@github.com:bitcoin/bitcoin.git + + This will add an `upstream-pull` remote to your git repository, which can be fetched using `git fetch --all` + or `git fetch upstream-pull`. Afterwards, you can use `upstream-pull/NUMBER/head` in arguments to `git show`, + `git checkout` and anywhere a commit id would be acceptable to see the changes from pull request NUMBER. |