From b1c8f765fa6e2af0d185d2a20dc68c7567c916eb Mon Sep 17 00:00:00 2001
From: "Michael Hirsch, Ph.D" <scivision@users.noreply.github.com>
Date: Mon, 2 Dec 2019 11:22:18 -0500
Subject: [PATCH] intel/intel-cl: use appropriate buildtype options

This puts appropriate default options across buildtype for Intel and
Intel-Cl compilers, for C, C++ and Fortran. Prior to this PR, the
behavior of Intel compilers vs. GNUlike was not the same, in
particular, debug traceback available by default for GNUlike compilers
was not present with Intel compilers.
---
 mesonbuild/compilers/fortran.py      | 13 +--------
 mesonbuild/compilers/mixins/intel.py | 43 +++++++++++++++++++++++++---
 2 files changed, 40 insertions(+), 16 deletions(-)

diff --git a/mesonbuild/compilers/fortran.py b/mesonbuild/compilers/fortran.py
index 3003fcd1b..fdd620426 100644
--- a/mesonbuild/compilers/fortran.py
+++ b/mesonbuild/compilers/fortran.py
@@ -273,6 +273,7 @@ class SunFortranCompiler(FortranCompiler):
 
 
 class IntelFortranCompiler(IntelGnuLikeCompiler, FortranCompiler):
+
     def __init__(self, exelist, version, for_machine: MachineChoice,
                  is_cross, info: 'MachineInfo', exe_wrapper=None,
                  **kwargs):
@@ -326,15 +327,6 @@ class IntelClFortranCompiler(IntelVisualStudioLikeCompiler, FortranCompiler):
     file_suffixes = ['f90', 'f', 'for', 'ftn', 'fpp']
     always_args = ['/nologo']
 
-    BUILD_ARGS = {
-        'plain': [],
-        'debug': ["/Zi", "/Od"],
-        'debugoptimized': ["/Zi", "/O1"],
-        'release': ["/O2"],
-        'minsize': ["/Os"],
-        'custom': [],
-    }
-
     def __init__(self, exelist, version, for_machine: MachineChoice,
                  is_cross, target: str, info: 'MachineInfo', exe_wrapper=None,
                  **kwargs):
@@ -367,9 +359,6 @@ class IntelClFortranCompiler(IntelVisualStudioLikeCompiler, FortranCompiler):
     def get_module_outdir_args(self, path) -> List[str]:
         return ['/module:' + path]
 
-    def get_buildtype_args(self, buildtype: str) -> List[str]:
-        return self.BUILD_ARGS[buildtype]
-
 
 class PathScaleFortranCompiler(FortranCompiler):
     def __init__(self, exelist, version, for_machine: MachineChoice,
diff --git a/mesonbuild/compilers/mixins/intel.py b/mesonbuild/compilers/mixins/intel.py
index 72c6fdfec..cf26a14a9 100644
--- a/mesonbuild/compilers/mixins/intel.py
+++ b/mesonbuild/compilers/mixins/intel.py
@@ -14,8 +14,10 @@
 
 """Abstractions for the Intel Compiler families.
 
-Intel provides both a posix/gcc-like compiler (ICC) and an msvc-like compiler
-(ICL).
+Intel provides both a posix/gcc-like compiler (ICC) for MacOS and Linux,
+with Meson mixin IntelGnuLikeCompiler.
+For Windows, the Intel msvc-like compiler (ICL) Meson mixin
+is IntelVisualStudioLikeCompiler.
 """
 
 import os
@@ -30,9 +32,18 @@ if typing.TYPE_CHECKING:
 
 # XXX: avoid circular dependencies
 # TODO: this belongs in a posix compiler class
+# NOTE: the default Intel optimization is -O2, unlike GNU which defaults to -O0.
+# this can be surprising, particularly for debug builds, so we specify the
+# default as -O0.
+# https://software.intel.com/en-us/cpp-compiler-developer-guide-and-reference-o
+# https://software.intel.com/en-us/cpp-compiler-developer-guide-and-reference-g
+# https://software.intel.com/en-us/fortran-compiler-developer-guide-and-reference-o
+# https://software.intel.com/en-us/fortran-compiler-developer-guide-and-reference-g
+# https://software.intel.com/en-us/fortran-compiler-developer-guide-and-reference-traceback
+# https://gcc.gnu.org/onlinedocs/gcc/Optimize-Options.html
 clike_optimization_args = {
-    '0': [],
-    'g': [],
+    '0': ['-O0'],
+    'g': ['-O0'],
     '1': ['-O1'],
     '2': ['-O2'],
     '3': ['-O3'],
@@ -43,6 +54,15 @@ clike_optimization_args = {
 # Tested on linux for ICC 14.0.3, 15.0.6, 16.0.4, 17.0.1, 19.0.0
 class IntelGnuLikeCompiler(GnuLikeCompiler):
 
+    BUILD_ARGS = {
+        'plain': [],
+        'debug': ["-g", "-O0", "-traceback"],
+        'debugoptimized': ["-g", "-O1", "-traceback"],
+        'release': ["-O2"],
+        'minsize': ["-Os"],
+        'custom': [],
+    }
+
     def __init__(self):
         super().__init__()
         # As of 19.0.0 ICC doesn't have sanitizer, color, or lto support.
@@ -96,11 +116,23 @@ class IntelGnuLikeCompiler(GnuLikeCompiler):
     def get_profile_use_args(self) -> typing.List[str]:
         return ['-prof-use']
 
+    def get_buildtype_args(self, buildtype: str) -> typing.List[str]:
+        return self.BUILD_ARGS[buildtype]
+
 
 class IntelVisualStudioLikeCompiler(VisualStudioLikeCompiler):
 
     """Abstractions for ICL, the Intel compiler on Windows."""
 
+    BUILD_ARGS = {
+        'plain': [],
+        'debug': ["/Zi", "/Od", "/traceback"],
+        'debugoptimized': ["/Zi", "/O1", "/traceback"],
+        'release': ["/O2"],
+        'minsize': ["/Os"],
+        'custom': [],
+    }
+
     def __init__(self, target: str):
         super().__init__(target)
         self.id = 'intel-cl'
@@ -133,3 +165,6 @@ class IntelVisualStudioLikeCompiler(VisualStudioLikeCompiler):
 
     def openmp_flags(self) -> typing.List[str]:
         return ['/Qopenmp']
+
+    def get_buildtype_args(self, buildtype: str) -> typing.List[str]:
+        return self.BUILD_ARGS[buildtype]