8244669: convert clhsdb "mem" command from javascript to java

plummercj · plummercj · commit eaefb1a1ed9e · 2021-12-22T23:02:41.000Z
Reviewed-by: sspitsyn, kevinw, poonam
diff --git a/src/jdk.hotspot.agent/doc/clhsdb.html b/src/jdk.hotspot.agent/doc/clhsdb.html
@@ -42,7 +42,7 @@ <h3>Annotated output of CLHSDB help command</h3>
   dumpilt -a | id <font color="red">dump inline tree for C2 compilation</font>
   dumpreplaydata &lt;address&gt; | -a | &lt;thread_id&gt; [&gt;replay.txt] <font color="red">dump replay data into a file</font>
   echo [ true | false ] <font color="red">turn on/off command echo mode</font>
-  examine [ address/count ] | [ address,address] <font color="red">show contents of memory from given address</font>
+  examine { address[/count] | address,address } <font color="red">show contents of memory range</font>
   field [ type [ name fieldtype isStatic offset address ] ] <font color="red">print info about a field of HotSpot type</font>
   findpc address <font color="red">print info about pointer location</font>
   findsym name <font color="red">print address of symbol in the executable or shared library</font>
@@ -56,7 +56,7 @@ <h3>Annotated output of CLHSDB help command</h3>
   jstack [-v] <font color="red">show Java stack trace of all Java threads. -v is verbose mode</font>
   livenmethods <font color="red">show all live nmethods</font>
   longConstant [ name [ value ] ] <font color="red">print out hotspot long constant(s)s</font>
-  mem address [ length ] <font color="red">show contents of memory -- also shows closest ELF/COFF symbol if found</font>
+  mem [ -v ] { address[/count] | address,address } <font color="red">show contents of memory range. -v adds "findpc" info for addresses</font>
   pmap <font color="red">show Solaris pmap-like output</font>
   print expression <font color="red">print given Klass*, Method* or arbitrary address</font>
   printas type expression <font color="red">print given address as given HotSpot type. eg. print JavaThread &lt;address&gt;</font>
diff --git a/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/CommandProcessor.java b/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/CommandProcessor.java
@@ -364,6 +364,54 @@ Address parseAddress(String addr) {
         return VM.getVM().getDebugger().parseAddress(addr);
     }
 
+    String fillHexString(Address a, int width) {
+        String s = "0x0";
+        if (a != null) {
+            s = a.toString();
+        }
+        if (s.length() != width) {
+            return s.substring(0, 2) + "000000000000000000000".substring(0, width - s.length()) + s.substring(2);
+        }
+        return s;
+    }
+
+    class AddressRange {
+        private Address start;
+        private Address end;
+        AddressRange(Address start, Address end) {
+            this.start = start;
+            this.end = end;
+        }
+        Address getStart() {return start;}
+        Address getEnd() {return end;}
+    }
+
+    // Parses either address[/count] or address,address into address start/end values
+    AddressRange parseAddressRange(String arg, int formatSize) {
+        Pattern args1 = Pattern.compile("^(0x[0-9a-f]+)(/([0-9]*))?$");
+        Pattern args2 = Pattern.compile("^(0x[0-9a-f]+),(0x[0-9a-f]+)$");
+        Matcher m1 = args1.matcher(arg);
+        Matcher m2 = args2.matcher(arg);
+        Address start = null;
+        Address end   = null;
+
+        if (m1.matches()) {
+            start = VM.getVM().getDebugger().parseAddress(m1.group(1));
+            int count = 1;
+            if (m1.group(2) != null) {
+                count = Integer.parseInt(m1.group(3));
+            }
+            end = start.addOffsetTo(count * formatSize);
+            return new AddressRange(start, end);
+        } else if (m2.matches()) {
+            start = VM.getVM().getDebugger().parseAddress(m2.group(1));
+            end   = VM.getVM().getDebugger().parseAddress(m2.group(2));
+            return new AddressRange(start, end);
+        } else {
+            return null;
+        }
+    }
+
     private final Command[] commandList = {
         new Command("reattach", true) {
             public void doit(Tokens t) {
@@ -409,65 +457,40 @@ public void doit(Tokens t) {
                 }
             }
         },
-        new Command("examine", "examine [ address/count ] | [ address,address]", false) {
-            Pattern args1 = Pattern.compile("^(0x[0-9a-f]+)(/([0-9]*)([a-z]*))?$");
-            Pattern args2 = Pattern.compile("^(0x[0-9a-f]+),(0x[0-9a-f]+)(/[a-z]*)?$");
-
-            String fill(Address a, int width) {
-                String s = "0x0";
-                if (a != null) {
-                    s = a.toString();
-                }
-                if (s.length() != width) {
-                    return s.substring(0, 2) + "000000000000000000000".substring(0, width - s.length()) + s.substring(2);
-                }
-                return s;
-            }
-
+        new Command("examine", "examine { address[/count] | address,address }", false) {
             public void doit(Tokens t) {
                 if (t.countTokens() != 1) {
                     usage();
                 } else {
                     String arg = t.nextToken();
-                    Matcher m1 = args1.matcher(arg);
-                    Matcher m2 = args2.matcher(arg);
-                    Address start = null;
-                    Address end   = null;
                     int formatSize = (int)VM.getVM().getAddressSize();
-
-                    if (m1.matches()) {
-                        start = VM.getVM().getDebugger().parseAddress(m1.group(1));
-                        int count = 1;
-                        if (m1.group(2) != null) {
-                            count = Integer.parseInt(m1.group(3));
-                        }
-                        end = start.addOffsetTo(count * formatSize);
-                    } else if (m2.matches()) {
-                        start = VM.getVM().getDebugger().parseAddress(m2.group(1));
-                        end   = VM.getVM().getDebugger().parseAddress(m2.group(2));
-                    } else {
+                    AddressRange addressRange = parseAddressRange(arg, formatSize);
+                    if (addressRange == null) {
                         usage();
                         return;
                     }
+                    Address start = addressRange.getStart();
+                    Address end = addressRange.getEnd();
+
                     int line = 80;
                     int formatWidth = formatSize * 8 / 4 + 2;
 
-                    out.print(fill(start, formatWidth));
+                    out.print(fillHexString(start, formatWidth));
                     out.print(": ");
                     int width = line - formatWidth - 2;
 
                     boolean needsPrintln = true;
                     while (start != null && start.lessThan(end)) {
                         Address val = start.getAddressAt(0);
-                        out.print(fill(val, formatWidth));
+                        out.print(fillHexString(val, formatWidth));
                         needsPrintln = true;
                         width -= formatWidth;
                         start = start.addOffsetTo(formatSize);
                         if (width <= formatWidth) {
                             out.println();
                             needsPrintln = false;
                             if (start.lessThan(end)) {
-                                out.print(fill(start, formatWidth));
+                                out.print(fillHexString(start, formatWidth));
                                 out.print(": ");
                                 width = line - formatWidth - 2;
                             }
@@ -482,6 +505,63 @@ public void doit(Tokens t) {
                 }
             }
         },
+        new Command("mem", "mem [-v] { address[/count] | address,address }", false) {
+            public void doit(Tokens t) {
+                int formatSize = (int)VM.getVM().getAddressSize();
+                boolean verbose = false;
+                String arg;
+
+                if (t.countTokens() == 2) {
+                    arg = t.nextToken();
+                    if (arg.equals("-v")) {
+                        verbose = true;
+                    } else {
+                        usage();
+                        return;
+                    }
+                }
+                if (t.countTokens() != 1) {
+                    usage();
+                    return;
+                }
+
+                arg = t.nextToken();
+                AddressRange addressRange = parseAddressRange(arg, formatSize);
+                if (addressRange == null) {
+                    usage();
+                    return;
+                }
+                Address start = addressRange.getStart();
+                Address end = addressRange.getEnd();
+
+                if (verbose) {
+                    // Do the equivalent of a findpc on the start address.
+                    PointerLocation loc = PointerFinder.find(start);
+                    loc.printOn(out);
+                }
+
+                int formatWidth = formatSize * 8 / 4 + 2;
+                while (start != null && start.lessThan(end)) {
+                    out.print(fillHexString(start, formatWidth));
+                    out.print(": ");
+                    Address val = start.getAddressAt(0);
+                    out.print(fillHexString(val, formatWidth));
+                    if (verbose) {
+                        // If we know what this is a pointer to, then print additional information.
+                        PointerLocation loc = PointerFinder.find(val);
+                        if (!loc.isUnknown()) {
+                            out.print(" ");
+                            loc.printOn(out, false, false);
+                        } else {
+                            out.println();
+                        }
+                    } else {
+                        out.println();
+                    }
+                    start = start.addOffsetTo(formatSize);
+                }
+            }
+        },
         new Command("dumpreplaydata", "dumpreplaydata { <address > | -a | <thread_id> }", false) {
             // This is used to dump replay data from ciInstanceKlass, ciMethodData etc
             // default file name is replay.txt, also if java crashes in compiler
diff --git a/test/hotspot/jtreg/serviceability/sa/ClhsdbFindPC.java b/test/hotspot/jtreg/serviceability/sa/ClhsdbFindPC.java
@@ -191,6 +191,19 @@ private static void testFindPC(boolean withXcomp, boolean withCore) throws Excep
                                           methodAddr));
             runTest(withCore, cmds, expStrMap);
 
+            // Run "mem -v <addr>/30" on a Method*. The first line will look like:
+            //   Address 0x0000152e30403530: Method jdk/test/lib/apps/LingeredApp.steadyState(Ljava/lang/Object;)V@0x0000152e30403530
+            // Followed by lines displaying the memory contents, including interpretation
+            // of any contents that are addresses.
+            cmdStr = "mem -v " + methodAddr + "/30";
+            cmds = List.of(cmdStr);
+            expStrMap = new HashMap<>();
+            expStrMap.put(cmdStr, List.of("Method jdk/test/lib/apps/LingeredApp.steadyState",
+                                          methodAddr,
+                                          /* The following is from a field in the Method object. */
+                                          "In interpreter codelet: method entry point"));
+            runTest(withCore, cmds, expStrMap);
+
             // Run findpc on a JavaThread*. We can find one in the jstack output.
             // The tid for a thread is it's JavaThread*. For example:
             //  "main" #1 prio=5 tid=0x00000080263398f0 nid=0x277e0 ...
