[Lldb-commits] [lldb] [lldb] Support custom printf formatting for variables (PR #81196)

[Dave Lee via lldb-commits]

https://github.com/kastiglione updated https://github.com/llvm/llvm-project/pull/81196

>From 81a2034ff2b41e30a1f5b82c86b4d5d4c429ed52 Mon Sep 17 00:00:00 2001
From: Dave Lee <davelee.com at gmail.com>
Date: Thu, 8 Feb 2024 13:59:12 -0800
Subject: [PATCH 1/2] [lldb] Support custom printf formatting for variables

---
 lldb/source/Core/FormatEntity.cpp | 25 +++++++++++++++++++++++--
 1 file changed, 23 insertions(+), 2 deletions(-)

diff --git a/lldb/source/Core/FormatEntity.cpp b/lldb/source/Core/FormatEntity.cpp
index fa5eadc6ff4e9a..0e929203935304 100644
--- a/lldb/source/Core/FormatEntity.cpp
+++ b/lldb/source/Core/FormatEntity.cpp
@@ -883,8 +883,29 @@ static bool DumpValue(Stream &s, const SymbolContext *sc,
   }
 
   if (!is_array_range) {
-    LLDB_LOGF(log,
-              "[Debugger::FormatPrompt] dumping ordinary printable output");
+    if (!entry.printf_format.empty()) {
+      auto type_info = target->GetTypeInfo();
+      if (type_info & eTypeIsInteger) {
+        if (type_info & eTypeIsSigned) {
+          bool success = false;
+          auto integer = target->GetValueAsSigned(0, &success);
+          if (success) {
+            LLDB_LOGF(log, "dumping using printf format");
+            s.Printf(entry.printf_format.c_str(), integer);
+            return true;
+          }
+        } else {
+          bool success = false;
+          auto integer = target->GetValueAsUnsigned(0, &success);
+          if (success) {
+            LLDB_LOGF(log, "dumping using printf format");
+            s.Printf(entry.printf_format.c_str(), integer);
+            return true;
+          }
+        }
+      }
+    }
+    LLDB_LOGF(log, "dumping ordinary printable output");
     return target->DumpPrintableRepresentation(s, val_obj_display,
                                                custom_format);
   } else {

>From 335ab1de4b39257e3bbb3bd969a0dd6991747558 Mon Sep 17 00:00:00 2001
From: Dave Lee <davelee.com at gmail.com>
Date: Tue, 13 Feb 2024 13:26:35 -0800
Subject: [PATCH 2/2] Factor out DumpValueWithPrintf; Add test

---
 lldb/source/Core/FormatEntity.cpp             | 45 +++++++++++--------
 .../custom-printf-summary/Makefile            |  2 +
 .../TestCustomPrintfSummary.py                | 11 +++++
 .../custom-printf-summary/main.c              | 13 ++++++
 4 files changed, 52 insertions(+), 19 deletions(-)
 create mode 100644 lldb/test/API/functionalities/data-formatter/custom-printf-summary/Makefile
 create mode 100644 lldb/test/API/functionalities/data-formatter/custom-printf-summary/TestCustomPrintfSummary.py
 create mode 100644 lldb/test/API/functionalities/data-formatter/custom-printf-summary/main.c

diff --git a/lldb/source/Core/FormatEntity.cpp b/lldb/source/Core/FormatEntity.cpp
index 0e929203935304..57a05507d844cf 100644
--- a/lldb/source/Core/FormatEntity.cpp
+++ b/lldb/source/Core/FormatEntity.cpp
@@ -658,6 +658,25 @@ static char ConvertValueObjectStyleToChar(
   return '\0';
 }
 
+static bool DumpValueWithPrintf(Stream &s, llvm::StringRef format,
+                                ValueObject &target) {
+  auto type_info = target.GetTypeInfo();
+  if (type_info & eTypeIsInteger) {
+    if (type_info & eTypeIsSigned) {
+      if (auto integer = target.GetValueAsSigned()) {
+        s.Printf(format.data(), *integer);
+        return true;
+      }
+    } else {
+      if (auto integer = target.GetValueAsUnsigned()) {
+        s.Printf(format.data(), *integer);
+        return true;
+      }
+    }
+  }
+  return false;
+}
+
 static bool DumpValue(Stream &s, const SymbolContext *sc,
                       const ExecutionContext *exe_ctx,
                       const FormatEntity::Entry &entry, ValueObject *valobj) {
@@ -884,25 +903,13 @@ static bool DumpValue(Stream &s, const SymbolContext *sc,
 
   if (!is_array_range) {
     if (!entry.printf_format.empty()) {
-      auto type_info = target->GetTypeInfo();
-      if (type_info & eTypeIsInteger) {
-        if (type_info & eTypeIsSigned) {
-          bool success = false;
-          auto integer = target->GetValueAsSigned(0, &success);
-          if (success) {
-            LLDB_LOGF(log, "dumping using printf format");
-            s.Printf(entry.printf_format.c_str(), integer);
-            return true;
-          }
-        } else {
-          bool success = false;
-          auto integer = target->GetValueAsUnsigned(0, &success);
-          if (success) {
-            LLDB_LOGF(log, "dumping using printf format");
-            s.Printf(entry.printf_format.c_str(), integer);
-            return true;
-          }
-        }
+      if (DumpValueWithPrintf(s, entry.printf_format, *target)) {
+        LLDB_LOGF(log, "dumping using printf format");
+        return true;
+      } else {
+        LLDB_LOG(log,
+                 "unsupported printf format '{0}' - for type info flags {1}",
+                 entry.printf_format, target->GetTypeInfo());
       }
     }
     LLDB_LOGF(log, "dumping ordinary printable output");
diff --git a/lldb/test/API/functionalities/data-formatter/custom-printf-summary/Makefile b/lldb/test/API/functionalities/data-formatter/custom-printf-summary/Makefile
new file mode 100644
index 00000000000000..c9319d6e6888a4
--- /dev/null
+++ b/lldb/test/API/functionalities/data-formatter/custom-printf-summary/Makefile
@@ -0,0 +1,2 @@
+C_SOURCES := main.c
+include Makefile.rules
diff --git a/lldb/test/API/functionalities/data-formatter/custom-printf-summary/TestCustomPrintfSummary.py b/lldb/test/API/functionalities/data-formatter/custom-printf-summary/TestCustomPrintfSummary.py
new file mode 100644
index 00000000000000..7d196c66caaa79
--- /dev/null
+++ b/lldb/test/API/functionalities/data-formatter/custom-printf-summary/TestCustomPrintfSummary.py
@@ -0,0 +1,11 @@
+import lldb
+from lldbsuite.test.lldbtest import *
+import lldbsuite.test.lldbutil as lldbutil
+
+
+class TestCase(TestBase):
+    def test(self):
+        self.build()
+        lldbutil.run_to_source_breakpoint(self, "break here", lldb.SBFileSpec("main.c"))
+        self.runCmd("type summary add -s '${var.ubyte%%2.2X}${var.sbyte%%2.2X}!' Bytes")
+        self.expect("v bytes", substrs=[" = 1001!"])
diff --git a/lldb/test/API/functionalities/data-formatter/custom-printf-summary/main.c b/lldb/test/API/functionalities/data-formatter/custom-printf-summary/main.c
new file mode 100644
index 00000000000000..8f92b9dafd32f3
--- /dev/null
+++ b/lldb/test/API/functionalities/data-formatter/custom-printf-summary/main.c
@@ -0,0 +1,13 @@
+#include <stdint.h>
+#include <stdio.h>
+
+struct Bytes {
+  uint8_t ubyte;
+  int8_t sbyte;
+};
+
+int main() {
+  struct Bytes bytes = {0x10, 0x01};
+  (void)bytes;
+  printf("break here\n");
+}