rclone/vendor/cloud.google.com/go/internal/snipdoc/snipdoc.awk
2018-01-16 13:20:59 +00:00

116 lines
2.6 KiB
Awk

# Copyright 2017 Google Inc. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# snipdoc merges code snippets from Go source files into a template to
# produce another go file (typically doc.go).
#
# Call with one or more .go files and a template file.
#
# awk -f snipmd.awk foo.go bar.go doc.template
#
# In the Go files, start a snippet with
# //[ NAME
# and end it with
# //]
#
# In the template, write
# [NAME]
# on a line by itself to insert the snippet NAME on that line.
#
# The following transformations are made to the Go code:
# - Trailing blank lines are removed.
# - `ELLIPSIS` and `_ = ELLIPSIS` are replaced by `...`
/^[ \t]*\/\/\[/ { # start snippet in Go file
if (inGo()) {
if ($2 == "") {
die("missing snippet name")
}
curSnip = $2
next
}
}
/^[ \t]*\/\/]/ { # end snippet in Go file
if (inGo()) {
if (curSnip != "") {
# Remove all trailing newlines.
gsub(/[\t\n]+$/, "", snips[curSnip])
curSnip = ""
next
} else {
die("//] without corresponding //[")
}
}
}
ENDFILE {
if (curSnip != "") {
die("unclosed snippet: " curSnip)
}
}
/^\[.*\]$/ { # Snippet marker in template file.
if (inTemplate()) {
name = substr($1, 2, length($1)-2)
if (snips[name] == "") {
die("no snippet named " name)
}
printf("%s\n", snips[name])
afterSnip = 1
next
}
}
# Matches every line.
{
if (curSnip != "") {
# If the first line in the snip has no indent, add the indent.
if (snips[curSnip] == "") {
if (index($0, "\t") == 1) {
extraIndent = ""
} else {
extraIndent = "\t"
}
}
line = $0
# Replace ELLIPSIS.
gsub(/_ = ELLIPSIS/, "...", line)
gsub(/ELLIPSIS/, "...", line)
snips[curSnip] = snips[curSnip] extraIndent line "\n"
} else if (inTemplate()) {
afterSnip = 0
# Copy to output.
print
}
}
function inTemplate() {
return match(FILENAME, /\.template$/)
}
function inGo() {
return match(FILENAME, /\.go$/)
}
function die(msg) {
printf("%s:%d: %s\n", FILENAME, FNR, msg) > "/dev/stderr"
exit 1
}