From 02ed9e6895c6524afa23caa2ac1d2b48d1739e0a Mon Sep 17 00:00:00 2001
From: matt rice <ratmice@gmail.com>
Date: Sat, 7 Sep 2019 07:50:36 -0700
Subject: [PATCH] add mechanism for forcing frame pointer.

---
 src/lib.rs    | 31 +++++++++++++++++++++++++++++++
 tests/test.rs | 32 +++++++++++++++++++++++++++++++-
 2 files changed, 62 insertions(+), 1 deletion(-)

diff --git a/src/lib.rs b/src/lib.rs
index 3c78420..44ec005 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -105,6 +105,7 @@ pub struct Build {
     out_dir: Option<PathBuf>,
     opt_level: Option<String>,
     debug: Option<bool>,
+    force_frame_pointer: Option<bool>,
     env: Vec<(OsString, OsString)>,
     compiler: Option<PathBuf>,
     archiver: Option<PathBuf>,
@@ -209,8 +210,17 @@ impl ToolFamily {
             }
             ToolFamily::Gnu | ToolFamily::Clang => {
                 cmd.push_cc_arg("-g".into());
+            }
+        }
+    }
+
+    /// What the flag to force frame pointers.
+    fn add_force_frame_pointer(&self, cmd: &mut Tool) {
+        match *self {
+            ToolFamily::Gnu | ToolFamily::Clang => {
                 cmd.push_cc_arg("-fno-omit-frame-pointer".into());
             }
+            _ => (),
         }
     }
 
@@ -286,6 +296,7 @@ impl Build {
             out_dir: None,
             opt_level: None,
             debug: None,
+            force_frame_pointer: None,
             env: Vec::new(),
             compiler: None,
             archiver: None,
@@ -758,6 +769,17 @@ impl Build {
         self
     }
 
+    /// Configures whether the compiler will emit instructions to store
+    /// frame pointers during codegen.
+    ///
+    /// This option is automatically enabled when debug information is emitted.
+    /// Otherwise the target platform compiler's default will be used.
+    /// You can use this option to force a specific setting.
+    pub fn force_frame_pointer(&mut self, force: bool) -> &mut Build {
+        self.force_frame_pointer = Some(force);
+        self
+    }
+
     /// Configures the output directory where all object files and static
     /// libraries will be located.
     ///
@@ -1348,6 +1370,11 @@ impl Build {
             family.add_debug_flags(cmd);
         }
 
+        if self.get_force_frame_pointer() {
+            let family = cmd.family;
+            family.add_force_frame_pointer(cmd);
+        }
+
         // Target flags
         match cmd.family {
             ToolFamily::Clang => {
@@ -2227,6 +2254,10 @@ impl Build {
         })
     }
 
+    fn get_force_frame_pointer(&self) -> bool {
+        self.force_frame_pointer.unwrap_or_else(|| self.get_debug())
+    }
+
     fn get_out_dir(&self) -> Result<PathBuf, Error> {
         match self.out_dir.clone() {
             Some(p) => Ok(p),
diff --git a/tests/test.rs b/tests/test.rs
index 778ee21..def11f0 100644
--- a/tests/test.rs
+++ b/tests/test.rs
@@ -39,10 +39,40 @@ fn gnu_opt_level_s() {
 }
 
 #[test]
-fn gnu_debug() {
+fn gnu_debug_fp_auto() {
     let test = Test::gnu();
     test.gcc().debug(true).file("foo.c").compile("foo");
     test.cmd(0).must_have("-g");
+    test.cmd(0).must_have("-fno-omit-frame-pointer");
+}
+
+#[test]
+fn gnu_debug_fp() {
+    let test = Test::gnu();
+    test.gcc().debug(true).file("foo.c").compile("foo");
+    test.cmd(0).must_have("-g");
+    test.cmd(0).must_have("-fno-omit-frame-pointer");
+}
+
+#[test]
+fn gnu_debug_nofp() {
+    let test = Test::gnu();
+    test.gcc()
+        .debug(true)
+        .force_frame_pointer(false)
+        .file("foo.c")
+        .compile("foo");
+    test.cmd(0).must_have("-g");
+    test.cmd(0).must_not_have("-fno-omit-frame-pointer");
+
+    let test = Test::gnu();
+    test.gcc()
+        .force_frame_pointer(false)
+        .debug(true)
+        .file("foo.c")
+        .compile("foo");
+    test.cmd(0).must_have("-g");
+    test.cmd(0).must_not_have("-fno-omit-frame-pointer");
 }
 
 #[test]