[clang] e6b49ce - [clang] Introduce CallGraphSection codegen option (#117037)

[via cfe-commits]

Author: Prabhu Rajasekaran
Date: 2025-10-11T13:59:18-07:00
New Revision: e6b49ceeaa0645a68c03f6526745354c085b045b

URL: https://github.com/llvm/llvm-project/commit/e6b49ceeaa0645a68c03f6526745354c085b045b
DIFF: https://github.com/llvm/llvm-project/commit/e6b49ceeaa0645a68c03f6526745354c085b045b.diff

LOG: [clang] Introduce CallGraphSection codegen option (#117037)

Added: 
    clang/test/Driver/call-graph-section.c

Modified: 
    clang/include/clang/Basic/CodeGenOptions.def
    clang/include/clang/Driver/Options.td
    clang/lib/CodeGen/BackendUtil.cpp
    clang/lib/Driver/ToolChains/Clang.cpp
    clang/lib/Driver/ToolChains/CommonArgs.cpp

Removed: 
    


################################################################################
diff  --git a/clang/include/clang/Basic/CodeGenOptions.def b/clang/include/clang/Basic/CodeGenOptions.def
index d924cb4f14c2c..90e1f8d1eb5e9 100644
--- a/clang/include/clang/Basic/CodeGenOptions.def
+++ b/clang/include/clang/Basic/CodeGenOptions.def
@@ -72,6 +72,8 @@ CODEGENOPT(EnableNoundefAttrs, 1, 0, Benign) ///< Enable emitting `noundef` attr
 CODEGENOPT(DebugPassManager, 1, 0, Benign) ///< Prints debug information for the new
                                            ///< pass manager.
 CODEGENOPT(DisableRedZone    , 1, 0, Benign) ///< Set when -mno-red-zone is enabled.
+CODEGENOPT(CallGraphSection, 1, 0, Benign) ///< Emit a call graph section into the
+                                           ///< object file.
 CODEGENOPT(EmitCallSiteInfo, 1, 0, Benign) ///< Emit call site info only in the case of
                                            ///< '-g' + 'O>0' level.
 CODEGENOPT(IndirectTlsSegRefs, 1, 0, Benign) ///< Set when -mno-tls-direct-seg-refs

diff  --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index c2f2ac5d2368a..a55a5236b2da1 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -4534,6 +4534,12 @@ defm data_sections : BoolFOption<"data-sections",
   PosFlag<SetTrue, [], [ClangOption, CC1Option],
           "Place each data in its own section">,
   NegFlag<SetFalse>>;
+defm experimental_call_graph_section
+    : BoolFOption<"experimental-call-graph-section",
+                  CodeGenOpts<"CallGraphSection">, DefaultFalse,
+                  PosFlag<SetTrue, [], [ClangOption, CC1Option],
+                          "Emit a call graph section">,
+                  NegFlag<SetFalse>>;
 defm stack_size_section : BoolFOption<"stack-size-section",
   CodeGenOpts<"StackSizeSection">, DefaultFalse,
   PosFlag<SetTrue, [], [ClangOption, CC1Option],

diff  --git a/clang/lib/CodeGen/BackendUtil.cpp b/clang/lib/CodeGen/BackendUtil.cpp
index 2d959827d6972..f8e8086afc36f 100644
--- a/clang/lib/CodeGen/BackendUtil.cpp
+++ b/clang/lib/CodeGen/BackendUtil.cpp
@@ -473,6 +473,7 @@ static bool initTargetOptions(const CompilerInstance &CI,
   Options.StackUsageOutput = CodeGenOpts.StackUsageOutput;
   Options.EmitAddrsig = CodeGenOpts.Addrsig;
   Options.ForceDwarfFrameSection = CodeGenOpts.ForceDwarfFrameSection;
+  Options.EmitCallGraphSection = CodeGenOpts.CallGraphSection;
   Options.EmitCallSiteInfo = CodeGenOpts.EmitCallSiteInfo;
   Options.EnableAIXExtendedAltivecABI = LangOpts.EnableAIXExtendedAltivecABI;
   Options.XRayFunctionIndex = CodeGenOpts.XRayFunctionIndex;

diff  --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
index d326a81feb762..bf755739760c0 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -6442,6 +6442,10 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
     CmdArgs.push_back(A->getValue());
   }
 
+  if (Args.hasFlag(options::OPT_fexperimental_call_graph_section,
+                   options::OPT_fno_experimental_call_graph_section, false))
+    CmdArgs.push_back("-fexperimental-call-graph-section");
+
   Args.addOptInFlag(CmdArgs, options::OPT_fstack_size_section,
                     options::OPT_fno_stack_size_section);
 

diff  --git a/clang/lib/Driver/ToolChains/CommonArgs.cpp b/clang/lib/Driver/ToolChains/CommonArgs.cpp
index 16cc1db0a2235..99400ac701fbe 100644
--- a/clang/lib/Driver/ToolChains/CommonArgs.cpp
+++ b/clang/lib/Driver/ToolChains/CommonArgs.cpp
@@ -1272,6 +1272,11 @@ void tools::addLTOOptions(const ToolChain &ToolChain, const ArgList &Args,
     CmdArgs.push_back(
         Args.MakeArgString(Twine(PluginOptPrefix) + "-stack-size-section"));
 
+  if (Args.hasFlag(options::OPT_fexperimental_call_graph_section,
+                   options::OPT_fno_experimental_call_graph_section, false))
+    CmdArgs.push_back(
+        Args.MakeArgString(Twine(PluginOptPrefix) + "-call-graph-section"));
+
   // Setup statistics file output.
   SmallString<128> StatsFile = getStatsFileName(Args, Output, *Input, D);
   if (!StatsFile.empty())

diff  --git a/clang/test/Driver/call-graph-section.c b/clang/test/Driver/call-graph-section.c
new file mode 100644
index 0000000000000..00fa896dffb87
--- /dev/null
+++ b/clang/test/Driver/call-graph-section.c
@@ -0,0 +1,5 @@
+// RUN: %clang -### -fexperimental-call-graph-section %s 2>&1 | FileCheck --check-prefix=CALL-GRAPH-SECTION %s
+// RUN: %clang -### -fexperimental-call-graph-section -fno-experimental-call-graph-section %s 2>&1 | FileCheck --check-prefix=NO-CALL-GRAPH-SECTION %s
+
+// CALL-GRAPH-SECTION: "-fexperimental-call-graph-section"
+// NO-CALL-GRAPH-SECTION-NOT: "-fexperimental-call-graph-section"