[analyzer] print() JSONify: Stable LocationContext IDs

[Charusso]

Summary

-

[NoQ]

In normal dumps i'd rather have it the old way because it's similar to how stack frames are displayed in the debugger.

And in exploded graph rewriter we can always reverse our lists if we want; this number isn't really telling us much.

[NoQ]

I think i'd rather remove it entirely.

[Charusso]

In D63727#1556821, @NoQ wrote:

I think i'd rather remove it entirely.

I have seen a TODO in the differentiation of such indices, just why I made it. Okai.

clang/lib/Analysis/AnalysisDeclContext.cpp

void LocationContext::printJson(raw_ostream &Out, const char *NL,
                                     printMoreInfoPerContext) const {
   ASTContext &Ctx = getAnalysisDeclContext()->getASTContext();
   PrintingPolicy PP(Ctx.getLangOpts());
   PP.TerseOutput = 1;
 
   const SourceManager &SM =
       getAnalysisDeclContext()->getASTContext().getSourceManager();
 
-  unsigned Frame = 0;
+  unsigned LCtxCount = 0;
+  for (const LocationContext *LCtx = this; LCtx; LCtx = LCtx->getParent())
+    ++LCtxCount;
+
   for (const LocationContext *LCtx = this; LCtx; LCtx = LCtx->getParent()) {
     Indent(Out, Space, IsDot)
         << "{ \"lctx_id\": " << LCtx->getID() << ", \"location_context\": \"";
     switch (LCtx->getKind()) {
     case StackFrame:
-      Out << '#' << Frame << " Call\", \"calling\": \"";
-      ++Frame;
+      Out << '#' << LCtxCount << " Call\", \"calling\": \"";
+      --LCtxCount;
       if (const auto *D = dyn_cast<NamedDecl>(LCtx->getDecl()))
         Out << D->getQualifiedNameAsString();
       else
         Out << "anonymous code";
 
       Out << "\", \"call_line\": ";
       if (const Stmt *S = cast<StackFrameContext>(LCtx)->getCallSite()) {
         Out << '\"';

clang/test/Analysis/dump_egraph.cpp

 
 void foo() {
   // Test that dumping symbols conjured on null statements doesn't crash.
   T t;
 
   new S;
 }
 
-// CHECK: \"location_context\": \"#0 Call\", \"calling\": \"foo\", \"call_line\": null, \"items\": [\l        \{ \"stmt_id\": {{[0-9]+}}, \"kind\": \"construct into local variable\", \"argument_index\": null, \"pretty\": \"T t;\", \"value\": \"&t\"
+// CHECK: \"location_context\": \"#1 Call\", \"calling\": \"foo\", \"call_line\": null, \"items\": [\l        \{ \"stmt_id\": {{[0-9]+}}, \"kind\": \"construct into local variable\", \"argument_index\": null, \"pretty\": \"T t;\", \"value\": \"&t\"
 
-// CHECK: \"location_context\": \"#0 Call\", \"calling\": \"T::T\", \"call_line\": \"16\", \"items\": [\l        \{ \"init_id\": {{[0-9]+}}, \"kind\": \"construct into member variable\", \"argument_index\": null, \"pretty\": \"s\", \"value\": \"&t-\>s\"
+// CHECK: \"location_context\": \"#2 Call\", \"calling\": \"T::T\", \"call_line\": \"16\", \"items\": [\l        \{ \"init_id\": {{[0-9]+}}, \"kind\": \"construct into member variable\", \"argument_index\": null, \"pretty\": \"s\", \"value\": \"&t-\>s\"
 
 // CHECK: \"cluster\": \"t\", \"pointer\": \"{{0x[0-9a-f]+}}\", \"items\": [\l        \{ \"kind\": \"Default\", \"offset\": 0, \"value\": \"conj_$2\{int, LC5, no stmt, #1\}\"
 
 // CHECK: \"dynamic_types\": [\l\{ \"region\": \"HeapSymRegion\{conj_$1\{struct S *, LC1, S{{[0-9]+}}, #1\}\}\", \"dyn_type\": \"struct S\", \"sub_classable\": false\}\l

clang/test/Analysis/expr-inspection.c

 
 // CHECK:      "program_state": {
 // CHECK-NEXT:   "store": { "pointer": "{{0x[0-9a-f]+}}", "items": [
 // CHECK-NEXT:     { "cluster": "y", "pointer": "{{0x[0-9a-f]+}}", "items": [
 // CHECK-NEXT:       { "kind": "Direct", "offset": 0, "value": "2 S32b" }
 // CHECK-NEXT:     ]}
 // CHECK-NEXT:   ]},
 // CHECK-NEXT:   "environment": { "pointer": "{{0x[0-9a-f]+}}", "items": [
-// CHECK-NEXT:     { "lctx_id": 1, "location_context": "#0 Call", "calling": "foo", "call_line": null, "items": [
+// CHECK-NEXT:     { "lctx_id": 1, "location_context": "#1 Call", "calling": "foo", "call_line": null, "items": [
 // CHECK-NEXT:       { "stmt_id": {{[0-9]+}}, "pretty": "clang_analyzer_printState", "value": "&code{clang_analyzer_printState}" }
 // CHECK-NEXT:     ]}
 // CHECK-NEXT:   ]},
 // CHECK-NEXT:   "constraints": [
 // CHECK-NEXT:     { "symbol": "reg_$0<int x>", "range": "{ [-2147483648, 13] }" }
 // CHECK-NEXT:   ],
 // CHECK-NEXT:   "dynamic_types": null,
 // CHECK-NEXT:   "constructing_objects": null,
 // CHECK-NEXT:   "checker_messages": null
 // CHECK-NEXT: }