From 80611f4be1f1bd3d5b22e6010a484446984fc69a Mon Sep 17 00:00:00 2001
From: Efimov Vasily <laer.18@gmail.com>
Date: Wed, 8 Jul 2020 21:11:17 +0300
Subject: [PATCH] misc: add a script automatizing git-based review

Signed-off-by: Efimov Vasily <laer.18@gmail.com>
---
 misc/review.sh | 296 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 296 insertions(+)
 create mode 100755 misc/review.sh

diff --git a/misc/review.sh b/misc/review.sh
new file mode 100755
index 000000000..f35ccc9d6
--- /dev/null
+++ b/misc/review.sh
@@ -0,0 +1,296 @@
+#!/bin/sh
+#\
+exec tclsh "$0" "$@"
+
+set manual \
+"
+To add a review follow those steps.
+1.  Create and checkout a review* branch starting at commit to be reviewed.
+    E.g.: review_0, review_1, ...
+2.  Add review (comments) by modifying a file(s).
+3.  'git add' and 'commit' changes to the review branch.
+4.  Go to step 2 to add more review for the commit being reviewed.
+5.  Go to step 1 to add review to other commits in the reviewed branch.
+6.  Checkout the branch being reviewed or another branch starting on last
+    commit of the review branch (actually after/on last review fork).
+7.  Run '\$argv0'.
+    It will list review* branches and build a commit sequence from review*
+    branches.
+    Then the tool choose first non-cherry-picked commit in the sequence and
+    cherry-pick it onto current branch.
+    Order of commits in from one review branch is preserved.
+    Order of review branch appending matches order of fork commits in the
+    reviewed branch.
+    List of cherry-picked commits is maintained in .review.state file.
+8.  Resolve possible conflicts as during regular cherry-pick.
+9.  Go to step 7 until all review commits are cherry-picked.
+10. Run '\$argv0 -clean' to remove review* branches.
+    The tool does not remove a branch that have a non-cherry-picked commit.
+11. Go to step 1 to review other branch.
+"
+
+set verb 0
+set mode "normal"
+
+proc main {} {
+    global verb
+    global mode
+
+    global argspec
+    global argv
+    global argc
+    set i 0
+    while {$i < $argc} {
+        set arg [lindex $argv $i]
+        incr i
+
+        if {[string index $arg 0] == "-"} {
+            set is_arg 1
+        } else {
+            set is_arg 0
+        }
+        if $is_arg {
+            switch -regexp $arg [preprocess_argspec $argspec]
+        } else {
+            unsupported_cli_arg $arg
+        }
+    }
+
+    if $verb {puts "mode $mode"}
+
+    # get review branches
+    global branches
+    set branches [list]
+    set branches_io [open {|git branch --list} r]
+
+    fforeach branch $branches_io {
+        set branch [string trim $branch " *"]
+        if {![startswith $branch review]} {continue}
+        lappend branches $branch
+    }
+    close $branches_io
+
+    global head_sha
+    set head_sha [sha HEAD]
+    if $verb {puts "HEAD SHA1 $head_sha"}
+
+    "do_$mode"
+}
+
+set argspec {
+    "v|verbose" "Verbose mode" {
+        set verb 1
+    }
+    "clean"  "Delete all review* branches" {
+        set mode "clean"
+    }
+    "h|help" "Pring help message" {
+        global argv0
+        global argspec
+
+        puts "Supported arguments (as regular expression)"
+
+        set i 0
+        while {$i < [llength $argspec]} {
+            set pattern [lindex $argspec $i]
+            incr i
+            if {"$pattern" != "default"} {
+                set message [lindex $argspec $i]
+                incr i
+                puts "  -($pattern)"
+                puts "      $message"
+            }
+            # skip handler
+            incr i
+        }
+        exit 0
+    }
+    "m|man|manual" "Print a manual" {
+        global manual
+        global argv0
+        if 1 "puts \"$manual\""
+    }
+    "default" {
+        unsupported_cli_arg [lindex $argv [expr $i - 1]]
+    }
+}
+
+proc preprocess_argspec {argspec} {
+    set res [list]
+
+    set i 0
+    while {$i < [llength $argspec]} {
+        set pattern [lindex $argspec $i]
+        incr i
+        if {"$pattern" != "default"} {
+            set docstring [lindex $argspec $i]
+            incr i
+            set pattern "^-+($pattern)$"
+        }
+        set handler [lindex $argspec $i]
+        incr i
+        lappend res $pattern $handler
+    }
+
+    return $res
+}
+
+proc unsupported_cli_arg {arg} {
+    puts "Unsupported argument $arg"
+    global argv0
+    puts [exec "$argv0" "-h"]
+    exit 1
+}
+
+proc do_normal {} {
+    global verb
+    global branches
+
+    set cherry_pick [list]
+
+    foreach branch $branches {
+        set ins_pos [llength $cherry_pick]
+        if $verb {puts "ins_pos $ins_pos"}
+
+        foreach commit [commits_to_cherry_pick $branch] {
+            # rev-list returns commits from newest to elder, reverse it
+            set cherry_pick [linsert $cherry_pick $ins_pos $commit]
+        }
+    }
+
+    if $verb {puts "cherry pick order: $cherry_pick"}
+
+    set cherry_picked [read_cherry_picked]
+
+    if $verb {puts "already cherry picked [llength $cherry_picked]"}
+
+    foreach commit $cherry_pick {
+        if {[lsearch $cherry_picked $commit] >= 0} {continue}
+        puts "cherry-picking $commit"
+        mark_cherry_picked $commit
+
+        set git_io [open |[list "git" "cherry-pick" $commit 2>&1] r]
+        while {1} {
+            if {[gets $git_io line] < 0} {break}
+            puts $line
+        }
+        close $git_io
+        # TODO: detect errors (e.g. merge conflicts)
+        # TODO: break only after errors
+        break
+    }
+}
+
+proc do_clean {} {
+    global verb
+    global branches
+
+    set cherry_picked [read_cherry_picked]
+    set skipped_branches [list]
+
+    foreach branch $branches {
+        set not_cherry_picked ""
+        foreach commit [commits_to_cherry_pick $branch] {
+            if {[lsearch $cherry_picked $commit] < 0} {
+                set not_cherry_picked $commit
+                break
+            }
+        }
+
+        if {$not_cherry_picked != "" } {
+            puts "Branc $branch has at least one not cherry-picked commit"
+            puts "   $not_cherry_picked"
+            lappend skipped_branches $branch
+            continue
+        }
+
+        if $verb {puts "deleting $branch"}
+
+        run_command "git" "branch" "-D" "$branch"
+    }
+
+    if {[llength $skipped_branches] == 0} {
+        # all review branches have been deleted (review ended)
+        if {[file exists ".review.state"]} {
+            if $verb {puts "removing .review.state"}
+            file delete ".review.state"
+        }
+    }
+}
+
+proc run_command {args} {
+    set args [linsert $args end 2>@1]
+    set io [open |$args r]
+    fforeach line $io {puts $line}
+    catch {close $io}
+}
+
+
+# returns commits of review
+proc commits_to_cherry_pick {branch} {
+    global verb
+    global head_sha
+
+    set ret [list]
+
+    set branch_sha [sha $branch]
+    if $verb {puts "$branch $branch_sha"}
+    set start_sha [git merge-base $branch $head_sha]
+    if $verb {puts "Merge base: $start_sha"}
+
+    # get commits of review
+    set log_io [open "|git rev-list $start_sha..$branch_sha" r]
+    fforeach line $log_io {
+        if $verb {puts $line}
+        lappend ret $line
+    }
+    close $log_io
+    return $ret
+}
+
+proc mark_cherry_picked {commit} {
+    set io [open ".review.state" a+]
+    puts $io $commit
+    close $io
+}
+
+proc read_cherry_picked {} {
+    if {![file exists ".review.state"]} {
+        return [list]
+    }
+
+    set io [open ".review.state" r]
+    set ret [list]
+    fforeach line $io {lappend ret $line}
+    return $ret
+}
+
+proc sha {rev} {
+    return [git rev-parse $rev]
+}
+
+proc git {args} {
+    return [first_line "git $args"]
+}
+
+proc first_line {cmd} {
+    set io [open "|$cmd" r]
+    if {[gets $io line] < 1} {
+        set line ""
+    }
+    close $io
+    return $line
+}
+
+proc fforeach {var io cb} {
+    while {1} {
+        if {[gets $io line] < 0} break
+        uplevel 1 "set $var \"$line\"; $cb"
+    }
+}
+
+proc startswith {line prefix} {
+    return [expr [string first "$prefix" "$line"] == 0]
+}
+
+main