vx7r2cert: move linker switches from spec files to runtime.xml

This centralises vx7r2cert linker switches options to the vx7r2cert target
file. Use the loader property to differentiate between full RTP linking
(used outside Workbench) and partial RTP linking (used inside Workbench).

Issue: eng/toolchain/bb-runtimes#70

vx7r2cert/__init__.py

@@ -3,12 +3,6 @@
 
 
 class Vx7r2Cert(Target):
-    def __init__(self, is_rtp):
-        self._is_rtp = is_rtp
-        self._rtp_suffix = "-rtp" if self._is_rtp else ""
-        super(Vx7r2Cert, self).__init__()
-        self.add_gnat_sources("src/s-macres__vx7r2cert.adb")
-
     @property
     def has_command_line_arguments(self):
         return True
@@ -32,26 +26,21 @@ def is_legacy_format(self):
     def has_libc(self, profile):
         return True
 
-    def dump_runtime_xml(self, rts_name, rts):
-        compiler_package = """
-            -- Prevent optimizations turning some loop patterns into
-            -- libc calls, e.g. string length computations into strlen,
-            -- as these introduce undesirable (for cert) dependencies
-            -- against external symbols.
-            package Compiler is
-              Common_Required_Switches :=
-                ("-fno-tree-loop-distribute-patterns");
-              for Leading_Required_Switches ("Ada") use
-                Compiler'Leading_Required_Switches ("Ada") &
-                Common_Required_Switches;
-              for Leading_Required_Switches ("C") use
-                Compiler'Leading_Required_Switches ("C") &
-                Common_Required_Switches;
-            end Compiler;
-        """
-        return readfile(f"vx7r2cert/runtime{self._rtp_suffix}.xml") % {
-            "compiler": compiler_package
-        }
+    @property
+    def loaders(self):
+        if self._is_rtp:
+            # We reuse the existing LOADER infrastructure to select between
+            # full and partial linking options.
+            return ("FULL_LINK", "PARTIAL_LINK")
+        else:
+            return None
+
+    @property
+    def compiler_switches(self):
+        if self._is_rtp:
+            return ("-mrtp",)
+        else:
+            return ()
 
     def amend_rts(self, rts_profile, cfg):
         if self._is_rtp:
@@ -62,6 +51,41 @@ def amend_rts(self, rts_profile, cfg):
                 "-D_WRS_VXCERT_RTP",
             ]
 
+    def dump_runtime_xml(self, rts_name, rts):
+        cnt = super(Vx7r2Cert, self).dump_runtime_xml(rts_name, rts)
+
+        if self._is_rtp:
+            cnt = cnt.replace(
+                "   package Linker is",
+                '   VSB_Dir := external ("VSB_DIR");\n\n   package Linker is\n',
+            )
+            cnt = cnt.replace("_vsb_dir_env_", '" & VSB_DIR & "')
+
+        return cnt
+
+    def __init__(self, is_rtp):
+        self._is_rtp = is_rtp
+        self._rtp_suffix = "-rtp" if self._is_rtp else ""
+        super(Vx7r2Cert, self).__init__()
+
+        self.add_gnat_sources("src/s-macres__vx7r2cert.adb")
+
+        if self._is_rtp:
+            # Provide the required switches to perform a full RTP link.
+            # Switches for partial link are performed by the GNATbench
+            # makefiles.
+            self.add_linker_switch("-nodefaultlibs", loader="FULL_LINK")
+            self.add_linker_switch("-nostartfiles", loader="FULL_LINK")
+            self.add_linker_switch("-l:certRtp.o", loader="FULL_LINK")
+            self.add_linker_switch(
+                "-L_vsb_dir_env_/usr/lib/common/objcert", loader="FULL_LINK"
+            )
+            self.add_linker_switch(
+                "-T_vsb_dir_env_/usr/ldscripts/rtp.ld", loader="FULL_LINK"
+            )
+        else:
+            self.add_linker_switch("-nostdlib")
+
 
 class Vx7r2Cert64(Vx7r2Cert):
     def __init__(self, is_rtp):
@@ -72,9 +96,6 @@ def is_64bit(self):
 
 
 class AArch64Vx7r2Cert(Vx7r2Cert64):
-    def __init__(self, is_rtp=False):
-        super(AArch64Vx7r2Cert, self).__init__(is_rtp)
-
     @property
     def target(self):
         return "aarch64-vx7r2"
@@ -104,11 +125,11 @@ def amend_rts(self, rts_profile, conf):
             "-fno-omit-frame-pointer",
         ]
 
-
-class ArmVx7r2Cert(Vx7r2Cert):
     def __init__(self, is_rtp=False):
-        super(ArmVx7r2Cert, self).__init__(is_rtp)
+        super(AArch64Vx7r2Cert, self).__init__(is_rtp)
+
 
+class ArmVx7r2Cert(Vx7r2Cert):
     @property
     def target(self):
         return "arm-vx7r2"
@@ -137,11 +158,11 @@ def amend_rts(self, rts_profile, conf):
             "-fno-omit-frame-pointer",
         ]
 
-
-class PPCVx7r2Cert(Vx7r2Cert):
     def __init__(self, is_rtp=False):
-        super(PPCVx7r2Cert, self).__init__(is_rtp)
+        super(ArmVx7r2Cert, self).__init__(is_rtp)
+
 
+class PPCVx7r2Cert(Vx7r2Cert):
     @property
     def target(self):
         return "ppc-vx7r2"
@@ -160,11 +181,11 @@ def system_ads(self):
                 "light-tasking": "system-vxworks7-ppc-ravenscar-sfp.ads",
             }
 
-
-class PPC64Vx7r2Cert(Vx7r2Cert64):
     def __init__(self, is_rtp=False):
-        super(PPC64Vx7r2Cert, self).__init__(is_rtp)
+        super(PPCVx7r2Cert, self).__init__(is_rtp)
+
 
+class PPC64Vx7r2Cert(Vx7r2Cert64):
     @property
     def target(self):
         return "ppc64-vx7r2"
@@ -183,11 +204,11 @@ def system_ads(self):
                 "light-tasking": "system-vxworks7-ppc64-ravenscar-sfp.ads",
             }
 
-
-class X86Vx7r2Cert(Vx7r2Cert):
     def __init__(self, is_rtp=False):
-        super(X86Vx7r2Cert, self).__init__(is_rtp)
+        super(PPC64Vx7r2Cert, self).__init__(is_rtp)
+
 
+class X86Vx7r2Cert(Vx7r2Cert):
     @property
     def target(self):
         return "x86-vx7r2"
@@ -206,11 +227,11 @@ def system_ads(self):
                 "light-tasking": "system-vxworks7-x86-ravenscar-sfp.ads",
             }
 
-
-class X86_64Vx7r2Cert(Vx7r2Cert64):
     def __init__(self, is_rtp=False):
-        super(X86_64Vx7r2Cert, self).__init__(is_rtp)
+        super(X86Vx7r2Cert, self).__init__(is_rtp)
+
 
+class X86_64Vx7r2Cert(Vx7r2Cert64):
     @property
     def target(self):
         return "x86_64-vx7r2"
@@ -239,6 +260,13 @@ def amend_rts(self, rts_profile, conf):
             "-fno-omit-frame-pointer",
         ]
 
+    def __init__(self, is_rtp=False):
+        super(X86_64Vx7r2Cert, self).__init__(is_rtp)
+
+
+# RTP note: the -Wl,--defsym=__wrs_rtp_base= linker switch is defined in the
+# gprconfig_kb database.
+
 
 class AArch64Vx7r2Cert_RTP(AArch64Vx7r2Cert):
     def __init__(self):
@@ -253,11 +281,13 @@ def __init__(self):
 class PPCVx7r2Cert_RTP(PPCVx7r2Cert):
     def __init__(self):
         super(PPCVx7r2Cert_RTP, self).__init__(is_rtp=True)
+        self.add_linker_switch("-lgnu", loader="FULL_LINK")
 
 
 class PPC64Vx7r2Cert_RTP(PPC64Vx7r2Cert):
     def __init__(self):
         super(PPC64Vx7r2Cert_RTP, self).__init__(is_rtp=True)
+        self.add_linker_switch("-lgnu", loader="FULL_LINK")
 
 
 class X86Vx7r2Cert_RTP(X86Vx7r2Cert):