[Qemu-devel] [PATCH] qapi: Make the include directive idempotent.

[Benoît Canet]

The purpose of this change is to help create a json file containing
common definitions.

The history used to detect multiple inclusions is not a stack anymore
but a regular list.

The cycle detection check where updated and leaved in place to make
sure the code will never enter into an infinite recursion loop.

Signed-off-by: Benoit Canet <address@hidden>
---
 scripts/qapi.py                               |   13 ++++++-------
 tests/Makefile                                |    3 ++-
 tests/qapi-schema/include-cycle.err           |    3 ---
 tests/qapi-schema/include-cycle.exit          |    2 +-
 tests/qapi-schema/include-cycle.out           |    3 +++
 tests/qapi-schema/include-idempotent.exit     |    1 +
 tests/qapi-schema/include-idempotent.json     |    3 +++
 tests/qapi-schema/include-idempotent.out      |    3 +++
 tests/qapi-schema/include-self-cycle.err      |    1 -
 tests/qapi-schema/include-self-cycle.exit     |    2 +-
 tests/qapi-schema/include-self-cycle.out      |    3 +++
 tests/qapi-schema/sub-include-idempotent.json |    3 +++
 12 files changed, 26 insertions(+), 14 deletions(-)
 create mode 100644 tests/qapi-schema/include-idempotent.err
 create mode 100644 tests/qapi-schema/include-idempotent.exit
 create mode 100644 tests/qapi-schema/include-idempotent.json
 create mode 100644 tests/qapi-schema/include-idempotent.out
 create mode 100644 tests/qapi-schema/sub-include-idempotent.json

diff --git a/scripts/qapi.py b/scripts/qapi.py
index ec806aa..0ed44c8 100644
--- a/scripts/qapi.py
+++ b/scripts/qapi.py
@@ -79,7 +79,7 @@ class QAPISchema:
             input_relname = fp.name
         self.input_dir = os.path.dirname(input_fname)
         self.input_file = input_relname
-        self.include_hist = include_hist + [(input_relname, input_fname)]
+        include_hist.append((input_relname, input_fname))
         self.parent_info = parent_info
         self.src = fp.read()
         if self.src == '' or self.src[-1] != '\n':
@@ -102,17 +102,16 @@ class QAPISchema:
                                         'Expected a file name (string), got: 
%s'
                                         % include)
                 include_path = os.path.join(self.input_dir, include)
-                if any(include_path == elem[1]
-                       for elem in self.include_hist):
-                    raise QAPIExprError(expr_info, "Inclusion loop for %s"
-                                        % include)
+                # make include idempotent by skipping further includes
+                if include_path in [x[1] for x in  include_hist]:
+                    continue
                 try:
                     fobj = open(include_path, 'r')
                 except IOError as e:
                     raise QAPIExprError(expr_info,
                                         '%s: %s' % (e.strerror, include))
-                exprs_include = QAPISchema(fobj, include,
-                                           self.include_hist, expr_info)
+                exprs_include = QAPISchema(fobj, include, include_hist,
+                                           expr_info)
                 self.exprs.extend(exprs_include.exprs)
             else:
                 expr_elem = {'expr': expr,
diff --git a/tests/Makefile b/tests/Makefile
index a8d45be..c587b4a 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -182,7 +182,8 @@ check-qapi-schema-y := $(addprefix tests/qapi-schema/, \
         flat-union-string-discriminator.json \
         include-simple.json include-relpath.json include-format-err.json \
         include-non-file.json include-no-file.json include-before-err.json \
-        include-nested-err.json include-self-cycle.json include-cycle.json)
+        include-nested-err.json include-self-cycle.json include-cycle.json \
+        include-idempotent.json)
 
 GENERATED_HEADERS += tests/test-qapi-types.h tests/test-qapi-visit.h 
tests/test-qmp-commands.h
 
diff --git a/tests/qapi-schema/include-cycle.err 
b/tests/qapi-schema/include-cycle.err
index 602cf62..e69de29 100644
--- a/tests/qapi-schema/include-cycle.err
+++ b/tests/qapi-schema/include-cycle.err
@@ -1,3 +0,0 @@
-In file included from tests/qapi-schema/include-cycle.json:1:
-In file included from include-cycle-b.json:1:
-include-cycle-c.json:1: Inclusion loop for include-cycle.json
diff --git a/tests/qapi-schema/include-cycle.exit 
b/tests/qapi-schema/include-cycle.exit
index d00491f..573541a 100644
--- a/tests/qapi-schema/include-cycle.exit
+++ b/tests/qapi-schema/include-cycle.exit
@@ -1 +1 @@
-1
+0
diff --git a/tests/qapi-schema/include-cycle.out 
b/tests/qapi-schema/include-cycle.out
index e69de29..b7f89a4 100644
--- a/tests/qapi-schema/include-cycle.out
+++ b/tests/qapi-schema/include-cycle.out
@@ -0,0 +1,3 @@
+[]
+[]
+[]
diff --git a/tests/qapi-schema/include-idempotent.err 
b/tests/qapi-schema/include-idempotent.err
new file mode 100644
index 0000000..e69de29
diff --git a/tests/qapi-schema/include-idempotent.exit 
b/tests/qapi-schema/include-idempotent.exit
new file mode 100644
index 0000000..573541a
--- /dev/null
+++ b/tests/qapi-schema/include-idempotent.exit
@@ -0,0 +1 @@
+0
diff --git a/tests/qapi-schema/include-idempotent.json 
b/tests/qapi-schema/include-idempotent.json
new file mode 100644
index 0000000..94113c6
--- /dev/null
+++ b/tests/qapi-schema/include-idempotent.json
@@ -0,0 +1,3 @@
+{ 'include': 'comments.json' }
+{ 'include': 'sub-include-idempotent.json' }
+{ 'include': 'comments.json' }
diff --git a/tests/qapi-schema/include-idempotent.out 
b/tests/qapi-schema/include-idempotent.out
new file mode 100644
index 0000000..4ce3dcf
--- /dev/null
+++ b/tests/qapi-schema/include-idempotent.out
@@ -0,0 +1,3 @@
+[OrderedDict([('enum', 'Status'), ('data', ['good', 'bad', 'ugly'])])]
+[{'enum_name': 'Status', 'enum_values': ['good', 'bad', 'ugly']}]
+[]
diff --git a/tests/qapi-schema/include-self-cycle.err 
b/tests/qapi-schema/include-self-cycle.err
index 981742a..e69de29 100644
--- a/tests/qapi-schema/include-self-cycle.err
+++ b/tests/qapi-schema/include-self-cycle.err
@@ -1 +0,0 @@
-tests/qapi-schema/include-self-cycle.json:1: Inclusion loop for 
include-self-cycle.json
diff --git a/tests/qapi-schema/include-self-cycle.exit 
b/tests/qapi-schema/include-self-cycle.exit
index d00491f..573541a 100644
--- a/tests/qapi-schema/include-self-cycle.exit
+++ b/tests/qapi-schema/include-self-cycle.exit
@@ -1 +1 @@
-1
+0
diff --git a/tests/qapi-schema/include-self-cycle.out 
b/tests/qapi-schema/include-self-cycle.out
index e69de29..b7f89a4 100644
--- a/tests/qapi-schema/include-self-cycle.out
+++ b/tests/qapi-schema/include-self-cycle.out
@@ -0,0 +1,3 @@
+[]
+[]
+[]
diff --git a/tests/qapi-schema/sub-include-idempotent.json 
b/tests/qapi-schema/sub-include-idempotent.json
new file mode 100644
index 0000000..94113c6
--- /dev/null
+++ b/tests/qapi-schema/sub-include-idempotent.json
@@ -0,0 +1,3 @@
+{ 'include': 'comments.json' }
+{ 'include': 'sub-include-idempotent.json' }
+{ 'include': 'comments.json' }
-- 
1.7.10.4