[clang] [clang][frontend] Make DumpModuleInfoAction emit the full macro (PR #85745)

[Zhang Yi via cfe-commits]

https://github.com/zhanyi22333 updated https://github.com/llvm/llvm-project/pull/85745

>From d29678159c34a668259fbed601df975275190105 Mon Sep 17 00:00:00 2001
From: Zhang Yi <18994118902 at 163.com>
Date: Mon, 18 Mar 2024 20:22:39 -0700
Subject: [PATCH 1/2] [clang][frontend] change DumpModuleInfoAction test cases.

---
 clang/test/Modules/cxx20-module-file-info-macros.cpp | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/clang/test/Modules/cxx20-module-file-info-macros.cpp b/clang/test/Modules/cxx20-module-file-info-macros.cpp
index 3b67e9b9acd410..fad218bdfc9638 100644
--- a/clang/test/Modules/cxx20-module-file-info-macros.cpp
+++ b/clang/test/Modules/cxx20-module-file-info-macros.cpp
@@ -37,8 +37,8 @@
 
 // CHECK: Macro Definitions:
 // CHECK-DAG: REDEFINE
-// CHECK-DAG: FUNC_Macro
-// CHECK-DAG: CONSTANT
+// CHECK-DAG: FUNC_Macro(X) (X+1)
+// CHECK-DAG: CONSTANT 43
 // CHECK-DAG: FOO
 // CHECK-NEXT: ===
 
@@ -46,8 +46,8 @@
 #include "foo.h"
 #undef REDEFINE
 // CHECK: Macro Definitions:
-// CHECK-DAG: CONSTANT
-// CHECK-DAG: FUNC_Macro
+// CHECK-DAG: CONSTANT 43
+// CHECK-DAG: FUNC_Macro(X) (X+1)
 // CHECK-DAG: FOO
 // CHECK-NEXT: ===
 

>From 37e6d22a1aa4930521b85d13b7860a168416e256 Mon Sep 17 00:00:00 2001
From: Zhang Yi <18994118902 at 163.com>
Date: Mon, 18 Mar 2024 20:23:00 -0700
Subject: [PATCH 2/2] [clang][frontend] Make DumpModuleInfoAction emit the full
 macro

---
 clang/lib/Frontend/FrontendActions.cpp | 35 +++++++++++++++++++++++---
 1 file changed, 32 insertions(+), 3 deletions(-)

diff --git a/clang/lib/Frontend/FrontendActions.cpp b/clang/lib/Frontend/FrontendActions.cpp
index 81fcd8d5ae9bd3..c6ed8231af0ecd 100644
--- a/clang/lib/Frontend/FrontendActions.cpp
+++ b/clang/lib/Frontend/FrontendActions.cpp
@@ -925,15 +925,44 @@ void DumpModuleInfoAction::ExecuteAction() {
 
     // Emit the macro definitions in the module file so that we can know how
     // much definitions in the module file quickly.
-    // TODO: Emit the macro definition bodies completely.
     if (auto FilteredMacros = llvm::make_filter_range(
             R->getPreprocessor().macros(),
             [](const auto &Macro) { return Macro.first->isFromAST(); });
         !FilteredMacros.empty()) {
       Out << "   Macro Definitions:\n";
       for (/*<IdentifierInfo *, MacroState> pair*/ const auto &Macro :
-           FilteredMacros)
-        Out << "     " << Macro.first->getName() << "\n";
+           FilteredMacros) {
+        SourceManager &SM = PP.getSourceManager();
+        clang::MacroInfo *MacroInfo = PP.getMacroInfo(Macro.first);
+        if (MacroInfo) {
+          bool isInvalid = true;
+          const char *ContentStrPtr =
+              SM.getCharacterData(MacroInfo->getDefinitionLoc(), &isInvalid);
+          if (!isInvalid) {
+            int ContentLength = 0;
+            while (!(*(ContentStrPtr + ContentLength) == '\n') ||
+                   *(ContentStrPtr + ContentLength - 1) == '\\') {
+              ContentLength++;
+            }
+            std::string MacroContent =
+                std::string(ContentStrPtr, ContentLength);
+            // Replace '\\\n' with space
+            size_t pos = 0;
+            while ((pos = MacroContent.find("\\\n", pos)) !=
+                   std::string::npos) {
+              MacroContent.replace(pos, 2, " ");
+            }
+            // Merge spaces
+            auto new_end = std::unique(
+                MacroContent.begin(), MacroContent.end(),
+                [](char a, char b) { return a == ' ' && b == ' '; });
+            MacroContent.erase(new_end, MacroContent.end());
+            Out << "     " << MacroContent << '\n';
+          }
+        } else {
+          Out << "     " << Macro.first->getName() << "\n";
+        }
+      }
     }
 
     // Now let's print out any modules we did not see as part of the Primary.