wip stack analysis

1 files changed, 184 insertions, 0 deletions

diff --git a/stack.py b/stack.py
new file mode 100644
index 0000000..c1e36d3
--- /dev/null
+++ b/stack.py
@@ -0,0 +1,184 @@
+#!/usr/bin/env python3
+import re
+import sys
+import typing
+
+# Parse the "VCG" language
+#
+# https://www.rw.cdl.uni-saarland.de/people/sander/private/html/gsvcg1.html
+#
+# The formal syntax is found at
+# ftp://ftp.cs.uni-sb.de/pub/graphics/vcg/vcg.tgz `doc/grammar.txt`.
+
+
+class VCGElem:
+    typ: str
+    lineno: int
+    attrs: dict[str, str]
+
+
+def parse_vcg(reader: typing.TextIO) -> typing.Iterator[VCGElem]:
+    re_beg = re.compile(r"(edge|node):\s*\{\s*")
+    _re_tok = r"[a-zA-Z_][a-zA-Z0-9_]*"
+    _re_str = r'"(?:[^\"]|\\.)*"'
+    re_attr = re.compile(
+        "(" + _re_tok + r")\s*:\s*(" + _re_tok + "|" + _re_str + r")\s*"
+    )
+    re_end = re.compile(r"\}\s*$")
+    re_skip = re.compile(r"(graph:\s*\{\s*title\s*:\s*" + _re_str + r"\s*|\})\s*")
+    re_esc = re.compile(r"\\.")
+
+    for lineno, line in enumerate(reader):
+        pos = 0
+
+        def _raise(msg: str) -> typing.NoReturn:
+            nonlocal lineno
+            nonlocal line
+            nonlocal pos
+            e = SyntaxError(msg)
+            e.lineno = lineno
+            e.offset = pos
+            e.text = line
+            raise e
+
+        if re_skip.fullmatch(line):
+            continue
+
+        elem = VCGElem()
+        elem.lineno = lineno
+
+        m = re_beg.match(line, pos=pos)
+        if not m:
+            _raise("does not look like a VCG line")
+        elem.typ = m.group(1)
+        pos = m.end()
+
+        elem.attrs = {}
+        while True:
+            if re_end.match(line, pos=pos):
+                break
+            m = re_attr.match(line, pos=pos)
+            if not m:
+                _raise("unexpected character")
+            k = m.group(1)
+            v = m.group(2)
+            if k in elem.attrs:
+                _raise(f"duplicate key: {repr(k)}")
+            if v.startswith('"'):
+
+                def unesc(esc: re.Match[str]) -> str:
+                    match esc.group(0)[1:]:
+                        case "n":
+                            return "\n"
+                        case '"':
+                            return '"'
+                        case "\\":
+                            return "\\"
+                        case _:
+                            _raise(f"invalid escape code {repr(esc.group(0))}")
+
+                v = re_esc.sub(unesc, v[1:-1])
+            elem.attrs[k] = v
+            pos = m.end()
+
+        yield elem
+
+
+class Node:
+    # from .title (`static` functions are prefixed with the
+    # compilation unit .c file, which is fine, we'll just leave it).
+    funcname: str
+    # .label is "{funcname}\n{location}\n{nstatic} bytes (static}\n{ndynamic} dynamic objects"
+    location: str
+    nstatic: int
+    ndynamic: int
+
+    # edges with .sourcename set to this node
+    calls: set[str]
+
+def main() -> None:
+    re_label = re.compile(
+        r"(?P<funcname>[^\n]+)\n"
+        + r"(?P<location>[^\n]+:[0-9]+:[0-9]+)\n"
+        + r"(?P<nstatic>[0-9]+) bytes \(static\)\n"
+        + r"(?P<ndynamic>[0-9]+) dynamic objects",
+        flags=re.MULTILINE,
+    )
+
+    graph: dict[str, Node] = dict()
+
+    for elem in parse_vcg(sys.stdin):
+        match elem.typ:
+            case "node":
+                node = Node()
+                node.calls = set()
+                skip = False
+                for k, v in elem.attrs.items():
+                    match k:
+                        case "title":
+                            node.funcname = v
+                        case "label":
+                            if elem.attrs.get("shape", "") != "ellipse":
+                                m = re_label.fullmatch(v)
+                                if not m:
+                                    raise ValueError(
+                                        f"unexpected label value {repr(v)}"
+                                    )
+                                node.location = m.group("location")
+                                node.nstatic = int(m.group("nstatic"))
+                                node.ndynamic = int(m.group("ndynamic"))
+                        case "shape":
+                            if v != "ellipse":
+                                raise ValueError(f"unexpected shape value {repr(v)}")
+                            skip = True
+                        case _:
+                            raise ValueError(f"unknown edge key {repr(k)}")
+                if not skip:
+                    if node.funcname in graph:
+                        raise ValueError(f"duplicate node {repr(node.funcname)}")
+                    graph[node.funcname] = node
+            case "edge":
+                caller: str | None = None
+                callee: str | None = None
+                for k, v in elem.attrs.items():
+                    match k:
+                        case "sourcename":
+                            caller = v
+                        case "targetname":
+                            callee = v
+                        case "label":
+                            pass
+                        case _:
+                            raise ValueError(f"unknown edge key {repr(k)}")
+                if caller is None or callee is None:
+                    raise ValueError(f"incomplete edge: {repr(elem.attrs)}")
+                if caller not in graph:
+                    raise ValueError(f"unknown caller: {caller}")
+                graph[caller].calls.add(callee)
+            case _:
+                raise ValueError(f"unknown elem type {repr(elem.typ)}")
+
+    # x
+
+    missing: set[str] = set()
+    def nstatic(funcname: str) -> int:
+        if funcname not in graph:
+            missing.add(funcname)
+            return 0
+        node = graph[funcname]
+        return node.nstatic + max([0, *[nstatic(call) for call in node.calls]])
+
+    namelen = max(len(name) for name in graph if name.endswith("_cr"))
+    print(("="*namelen)+" =======")
+
+    for funcname in graph:
+        if funcname.endswith("_cr"):
+            print(f"{funcname}\t{nstatic(funcname)}")
+
+    print(("="*namelen)+" =======")
+
+    for funcname in sorted(missing):
+        print(f"{funcname}\tmissing")
+
+if __name__ == "__main__":
+    main()