automation/eclair: extend existing deviations of MISRA C Rule 16.3

Update ECLAIR configuration to deviate more cases where an
unintentional fallthrough cannot happen.

Tag Rule 16.3 as clean for arm.

Signed-off-by: Federico Serafini <federico.serafini@bugseng.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>

diff --git a/automation/eclair_analysis/ECLAIR/deviations.ecl b/automation/eclair_analysis/ECLAIR/deviations.ecl
index 1aa8277066ea6356faa43a6f59db1ec3cd611f11..9051f41602827b318b083fb82826f77e9037b744 100644 (file)
--- a/automation/eclair_analysis/ECLAIR/deviations.ecl
+++ b/automation/eclair_analysis/ECLAIR/deviations.ecl
@@ -461,14 +461,30 @@ therefore it is deemed better to leave such files as is."
 -config=MC3R1.R16.2,reports+={deliberate, "any_area(any_loc(file(x86_emulate||x86_svm_emulate)))"}
 -doc_end
 
--doc_begin="Switch clauses ending with continue, goto, return statements are
-safe."
--config=MC3R1.R16.3,terminals+={safe, "node(continue_stmt||goto_stmt||return_stmt)"}
+-doc_begin="Statements that change the control flow (i.e., break, continue, goto, return) and calls to functions that do not return the control back are \"allowed terminal statements\"."
+-stmt_selector+={r16_3_allowed_terminal, "node(break_stmt||continue_stmt||goto_stmt||return_stmt)||call(property(noreturn))"}
+-config=MC3R1.R16.3,terminals+={safe, "r16_3_allowed_terminal"}
+-doc_end
+
+-doc_begin="An if-else statement having both branches ending with an allowed terminal statement is itself an allowed terminal statement."
+-stmt_selector+={r16_3_if, "node(if_stmt)&&(child(then,r16_3_allowed_terminal)||child(then,any_stmt(stmt,-1,r16_3_allowed_terminal)))"}
+-stmt_selector+={r16_3_else, "node(if_stmt)&&(child(else,r16_3_allowed_terminal)||child(else,any_stmt(stmt,-1,r16_3_allowed_terminal)))"}
+-stmt_selector+={r16_3_if_else, "r16_3_if&&r16_3_else"}
+-config=MC3R1.R16.3,terminals+={safe, "r16_3_if_else"}
+-doc_end
+
+-doc_begin="An if-else statement having an always true condition and the true branch ending with an allowed terminal statement is itself an allowed terminal statement."
+-stmt_selector+={r16_3_if_true, "r16_3_if&&child(cond,definitely_in(1..))"}
+-config=MC3R1.R16.3,terminals+={safe, "r16_3_if_true"}
+-doc_end
+
+-doc_begin="A switch clause ending with a statement expression which, in turn, ends with an allowed terminal statement is safe."
+-config=MC3R1.R16.3,terminals+={safe, "node(stmt_expr)&&child(stmt,node(compound_stmt)&&any_stmt(stmt,-1,r16_3_allowed_terminal||r16_3_if_else||r16_3_if_true))"}
 -doc_end
 
--doc_begin="Switch clauses ending with a call to a function that does not give
-the control back (i.e., a function with attribute noreturn) are safe."
--config=MC3R1.R16.3,terminals+={safe, "call(property(noreturn))"}
+-doc_begin="A switch clause ending with a do-while-false the body of which, in turn, ends with an allowed terminal statement is safe.
+An exception to that is the macro ASSERT_UNREACHABLE() which is effective in debug build only: a switch clause ending with ASSERT_UNREACHABLE() is not considered safe."
+-config=MC3R1.R16.3,terminals+={safe, "!macro(name(ASSERT_UNREACHABLE))&&node(do_stmt)&&child(cond,definitely_in(0))&&child(body,any_stmt(stmt,-1,r16_3_allowed_terminal||r16_3_if_else||r16_3_if_true))"}
 -doc_end
 
 -doc_begin="Switch clauses ending with pseudo-keyword \"fallthrough\" are

diff --git a/automation/eclair_analysis/ECLAIR/tagging.ecl b/automation/eclair_analysis/ECLAIR/tagging.ecl
index 4d0ac9484816b6b1cd3c6089848740e101575160..b8448938e66a2498a71de27f91051237468975ea 100644 (file)
--- a/automation/eclair_analysis/ECLAIR/tagging.ecl
+++ b/automation/eclair_analysis/ECLAIR/tagging.ecl
@@ -112,7 +112,7 @@ if(string_equal(target,"x86_64"),
 )
 
 if(string_equal(target,"arm64"),
-    service_selector({"additional_clean_guidelines","MC3R1.R16.6||MC3R1.R2.1||MC3R1.R5.3||MC3R1.R7.3"})
+    service_selector({"additional_clean_guidelines","MC3R1.R2.1||MC3R1.R5.3||MC3R1.R7.3||MC3R1.R16.3||MC3R1.R16.6"})
 )
 
 -reports+={clean:added,"service(clean_guidelines_common||additional_clean_guidelines)"}

diff --git a/docs/misra/deviations.rst b/docs/misra/deviations.rst
index d51aa422b537cc2aaa20698ba745d5929f82f197..b66c271c4e7c15f402d5f8b55e2abff8f8067a02 100644 (file)
--- a/docs/misra/deviations.rst
+++ b/docs/misra/deviations.rst
@@ -415,12 +415,34 @@ Deviations related to MISRA C:2012 Rules:
      - Tagged as `deliberate` for ECLAIR.
 
    * - R16.3
-     - Switch clauses ending with continue, goto, return statements are safe.
+     - Statements that change the control flow (i.e., break, continue, goto,
+       return) and calls to functions that do not return the control back are
+       \"allowed terminal statements\".
      - Tagged as `safe` for ECLAIR.
 
    * - R16.3
-     - Switch clauses ending with a call to a function that does not give
-       the control back (i.e., a function with attribute noreturn) are safe.
+     - An if-else statement having both branches ending with one of the allowed
+       terminal statemets is itself an allowed terminal statements.
+     - Tagged as `safe` for ECLAIR.
+
+   * - R16.3
+     - An if-else statement having an always true condition and the true
+       branch ending with an allowed terminal statement is itself an allowed
+       terminal statement.
+     - Tagged as `safe` for ECLAIR.
+
+   * - R16.3
+     - A switch clause ending with a statement expression which, in turn, ends
+       with an allowed terminal statement (e.g., the expansion of
+       generate_exception()) is safe.
+     - Tagged as `safe` for ECLAIR.
+
+   * - R16.3
+     - A switch clause ending with a do-while-false the body of which, in turn,
+       ends with an allowed terminal statement (e.g., PARSE_ERR_RET()) is safe.
+       An exception to that is the macro ASSERT_UNREACHABLE() which is
+       effective in debug build only: a switch clause ending with
+       ASSERT_UNREACHABLE() is not considered safe.
      - Tagged as `safe` for ECLAIR.
 
    * - R16.3