[Flang][Driver] Predefine pic/pie macros based on configured level

[imciner2]

Predefine the __pic__/__pie__/__PIC__/__PIE__ macros based on the configured relocation level. This logic mirrors that of the clang driver, where __pic__/__PIC__ are defined for both PIC and PIE modes, but __pie__/__PIE__ are only defined for PIE mode.

Fixes #135275

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[llvmbot]

@llvm/pr-subscribers-flang-driver

Author: Ian McInerney (imciner2)

Changes

Predefine the pic/pie/PIC/PIE macros based on the configured relocation level. This logic mirrors that of the clang driver, where pic/PIC are defined for both PIC and PIE modes, but pie/PIE are only defined for PIE mode.

Fixes #135275

---

Full diff: https://github.com/llvm/llvm-project/pull/153449.diff

3 Files Affected:

• (modified) flang/lib/Frontend/CompilerInvocation.cpp (+10)
• (added) flang/test/Preprocessing/defines_pic_compiler.F90 (+31)
• (added) flang/test/Preprocessing/defines_pic_frontend.F90 (+38)

diff --git a/flang/lib/Frontend/CompilerInvocation.cpp b/flang/lib/Frontend/CompilerInvocation.cpp
index 111c5aa48726f..7ea11a0809104 100644
--- a/flang/lib/Frontend/CompilerInvocation.cpp
+++ b/flang/lib/Frontend/CompilerInvocation.cpp
@@ -1696,6 +1696,16 @@ void CompilerInvocation::setDefaultPredefinitions() {
   fortranOptions.predefinitions.emplace_back("__flang_patchlevel__",
                                              FLANG_VERSION_PATCHLEVEL_STRING);
 
+  // Add predefinitions based on the relocation model
+  if (unsigned PICLevel = getCodeGenOpts().PICLevel) {
+    fortranOptions.predefinitions.emplace_back("__PIC__", std::to_string(PICLevel));
+    fortranOptions.predefinitions.emplace_back("__pic__", std::to_string(PICLevel));
+    if (getCodeGenOpts().IsPIE) {
+      fortranOptions.predefinitions.emplace_back("__PIE__", std::to_string(PICLevel));
+      fortranOptions.predefinitions.emplace_back("__pie__", std::to_string(PICLevel));
+    }
+  }
+
   // Add predefinitions based on extensions enabled
   if (frontendOptions.features.IsEnabled(
           Fortran::common::LanguageFeature::OpenACC)) {
diff --git a/flang/test/Preprocessing/defines_pic_compiler.F90 b/flang/test/Preprocessing/defines_pic_compiler.F90
new file mode 100644
index 0000000000000..9b17f329a56d5
--- /dev/null
+++ b/flang/test/Preprocessing/defines_pic_compiler.F90
@@ -0,0 +1,31 @@
+! Check that the pie/pic/PIE/PIC macros are defined properly through the compiler driver
+
+! RUN: %flang -fpic -dM -E -o - %s \
+! RUN:   | FileCheck --check-prefix=CHECK-PIC1 %s
+! CHECK-PIC1: #define __PIC__ 1
+! CHECK-PIC1-NOT: #define __PIE__
+! CHECK-PIC1: #define __pic__ 1
+! CHECK-PIC1-NOT: #define __pie__
+!
+! RUN: %flang -fPIC -dM -E -o - %s \
+! RUN:   | FileCheck --check-prefix=CHECK-PIC2 %s
+! CHECK-PIC2: #define __PIC__ 2
+! CHECK-PIC2-NOT: #define __PIE__
+! CHECK-PIC2: #define __pic__ 2
+! CHECK-PIC2-NOT: #define __pie__
+!
+! RUN: %flang -fpie -dM -E -o - %s \
+! RUN:   | FileCheck --check-prefix=CHECK-PIE1 %s
+! CHECK-PIE1: #define __PIC__ 1
+! CHECK-PIE1: #define __PIE__ 1
+! CHECK-PIE1: #define __pic__ 1
+! CHECK-PIE1: #define __pie__ 1
+!
+! RUN: %flang -fPIE -dM -E -o - %s \
+! RUN:   | FileCheck --check-prefix=CHECK-PIE2 %s
+! CHECK-PIE2: #define __PIC__ 2
+! CHECK-PIE2: #define __PIE__ 2
+! CHECK-PIE2: #define __pic__ 2
+! CHECK-PIE2: #define __pie__ 2
+
+integer, parameter :: pic_level = __pic__
diff --git a/flang/test/Preprocessing/defines_pic_frontend.F90 b/flang/test/Preprocessing/defines_pic_frontend.F90
new file mode 100644
index 0000000000000..ad871e0acfab3
--- /dev/null
+++ b/flang/test/Preprocessing/defines_pic_frontend.F90
@@ -0,0 +1,38 @@
+! Check that the pie/pic/PIE/PIC macros are defined properly through the frontend driver
+
+! RUN: %flang_fc1 -dM -E -o - %s \
+! RUN:   | FileCheck %s
+! CHECK-NOT: #define __PIC__
+! CHECK-NOT: #define __PIE__
+! CHECK-NOT: #define __pic__
+! CHECK-NOT: #define __pie__
+!
+! RUN: %flang_fc1 -pic-level 1 -dM -E -o - %s \
+! RUN:   | FileCheck --check-prefix=CHECK-PIC1 %s
+! CHECK-PIC1: #define __PIC__ 1
+! CHECK-PIC1-NOT: #define __PIE__
+! CHECK-PIC1: #define __pic__ 1
+! CHECK-PIC1-NOT: #define __pie__
+!
+! RUN: %flang_fc1 -pic-level 2 -dM -E -o - %s \
+! RUN:   | FileCheck --check-prefix=CHECK-PIC2 %s
+! CHECK-PIC2: #define __PIC__ 2
+! CHECK-PIC2-NOT: #define __PIE__
+! CHECK-PIC2: #define __pic__ 2
+! CHECK-PIC2-NOT: #define __pie__
+!
+! RUN: %flang_fc1 -pic-level 1 -pic-is-pie -dM -E -o - %s \
+! RUN:   | FileCheck --check-prefix=CHECK-PIE1 %s
+! CHECK-PIE1: #define __PIC__ 1
+! CHECK-PIE1: #define __PIE__ 1
+! CHECK-PIE1: #define __pic__ 1
+! CHECK-PIE1: #define __pie__ 1
+!
+! RUN: %flang_fc1 -pic-level 2 -pic-is-pie -dM -E -o - %s \
+! RUN:   | FileCheck --check-prefix=CHECK-PIE2 %s
+! CHECK-PIE2: #define __PIC__ 2
+! CHECK-PIE2: #define __PIE__ 2
+! CHECK-PIE2: #define __pic__ 2
+! CHECK-PIE2: #define __pie__ 2
+
+integer, parameter :: pic_level = __pic__

[github-actions]

✅ With the latest revision this PR passed the C/C++ code formatter.

[tblah]

LGTM, thank you for contributing this!

[tblah]

But see the windows CI failure, at a glance it seems relevant.

[imciner2]

Yea, the Windows CI failure was because I had both a compiler driver and frontend driver test, and the compiler driver doesn't actually support this on Windows. So I've changed it to be just the frontend driver now, which is also what clang only tests for this option as well.

[tblah]

Thanks. Do you want help to merge?

[imciner2]

Thanks. Do you want help to merge?

Yes please. If you could squash merge this, that would be wonderful.

[github-actions]

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