[PATCH 1/2] Fix C/107926: Wrong error message when initializing char array

[PATCH 1/2] Fix C/107926: Wrong error message when initializing char array

[apinski]

From: Andrew Pinski <apinski@marvell.com>

The problem here is the code which handles {"a"} is supposed
to handle the case where the is something after the string but
it only handles the case where there is another string so
we go down the other path and error out saying "excess elements
in struct initializer" even though this was a character array.
To fix this, we need to move the ckeck if the initializer is
a string after the check for array and initializer.

OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions.

Thanks,
Adnrew Pinski

gcc/c/ChangeLog:

	PR c/107926
	* c-typeck.cc (process_init_element):
	Move the ceck for string cst until
	after the error message.

gcc/testsuite/ChangeLog:

	PR c/107926
	* gcc.dg/init-excess-3.c: New test.
---
 gcc/c/c-typeck.cc                    | 15 ++++++++++-----
 gcc/testsuite/gcc.dg/init-excess-3.c | 15 +++++++++++++++
 2 files changed, 25 insertions(+), 5 deletions(-)
 create mode 100644 gcc/testsuite/gcc.dg/init-excess-3.c

diff --git a/gcc/c/c-typeck.cc b/gcc/c/c-typeck.cc
index e06f052..0fc382c 100644
--- a/gcc/c/c-typeck.cc
+++ b/gcc/c/c-typeck.cc
@@ -10623,17 +10623,22 @@ process_init_element (location_t loc, struct c_expr value, bool implicit,
 
   /* Handle superfluous braces around string cst as in
      char x[] = {"foo"}; */
-  if (string_flag
-      && constructor_type
+  if (constructor_type
       && !was_designated
       && TREE_CODE (constructor_type) == ARRAY_TYPE
       && INTEGRAL_TYPE_P (TREE_TYPE (constructor_type))
       && integer_zerop (constructor_unfilled_index))
     {
       if (constructor_stack->replacement_value.value)
-	error_init (loc, "excess elements in %<char%> array initializer");
-      constructor_stack->replacement_value = value;
-      return;
+	{
+	  error_init (loc, "excess elements in %<char%> array initializer");
+	  return;
+	}
+      else if (string_flag)
+	{
+	  constructor_stack->replacement_value = value;
+	  return;
+	}
     }
 
   if (constructor_stack->replacement_value.value != NULL_TREE)
diff --git a/gcc/testsuite/gcc.dg/init-excess-3.c b/gcc/testsuite/gcc.dg/init-excess-3.c
new file mode 100644
index 0000000..7741261
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/init-excess-3.c
@@ -0,0 +1,15 @@
+/* Test for various cases of excess initializers for char arrays,
+   bug 107926. */
+/* { dg-do compile } */
+/* { dg-options "" } */
+
+
+char s0[] = {"abc",1}; /* { dg-error "array initializer|near init" } */
+char s1[] = {"abc","a"}; /* { dg-error "array initializer|near init" } */
+char s2[] = {1,"abc"}; /* { dg-error "array initializer|near init|computable at load time" } */
+/* { dg-warning "integer from pointer without a cast" "" { target *-*-* } .-1 } */
+
+char s3[5] = {"abc",1}; /* { dg-error "array initializer|near init" } */
+char s4[5] = {"abc","a"}; /* { dg-error "array initializer|near init" } */
+char s5[5] = {1,"abc"}; /* { dg-error "array initializer|near init|computable at load time" } */
+/* { dg-warning "integer from pointer without a cast" "" { target *-*-* } .-1 } */
-- 
1.8.3.1

[PATCH 2/2] Improve error message for excess elements in array initializer from {"a"}

[apinski]

From: Andrew Pinski <apinski@marvell.com>

So char arrays are not the only type that be initialized from {"a"}.
We can have wchar_t (L"") and char16_t (u"") types too. So let's
print out the type of the array instead of just saying char.

Note in the testsuite I used regex . to match '[' and ']' as
I could not figure out how many '\' I needed.

OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions.

gcc/c/ChangeLog:

	* c-typeck.cc (process_init_element): Print out array type
	for excessive elements.

gcc/testsuite/ChangeLog:

	* gcc.dg/init-bad-1.c: Update error message.
	* gcc.dg/init-bad-2.c: Likewise.
	* gcc.dg/init-bad-3.c: Likewise.
	* gcc.dg/init-excess-3.c: Likewise.
	* gcc.dg/pr61096-1.c: Likewise.
---
 gcc/c/c-typeck.cc                    |  2 +-
 gcc/testsuite/gcc.dg/init-bad-1.c    |  2 +-
 gcc/testsuite/gcc.dg/init-bad-2.c    |  2 +-
 gcc/testsuite/gcc.dg/init-bad-3.c    |  2 +-
 gcc/testsuite/gcc.dg/init-excess-3.c | 12 ++++++------
 gcc/testsuite/gcc.dg/pr61096-1.c     |  2 +-
 6 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/gcc/c/c-typeck.cc b/gcc/c/c-typeck.cc
index 0fc382c..f1a1752 100644
--- a/gcc/c/c-typeck.cc
+++ b/gcc/c/c-typeck.cc
@@ -10631,7 +10631,7 @@ process_init_element (location_t loc, struct c_expr value, bool implicit,
     {
       if (constructor_stack->replacement_value.value)
 	{
-	  error_init (loc, "excess elements in %<char%> array initializer");
+	  error_init (loc, "excess elements in %qT initializer", constructor_type);
 	  return;
 	}
       else if (string_flag)
diff --git a/gcc/testsuite/gcc.dg/init-bad-1.c b/gcc/testsuite/gcc.dg/init-bad-1.c
index 0da10c3..7c80006 100644
--- a/gcc/testsuite/gcc.dg/init-bad-1.c
+++ b/gcc/testsuite/gcc.dg/init-bad-1.c
@@ -18,7 +18,7 @@ char s[1] = "x";
 char s1[1] = { "x" };
 char t[1] = "xy"; /* { dg-warning "initializer-string for array of 'char' is too long" } */
 char t1[1] = { "xy" }; /* { dg-warning "initializer-string for array of 'char' is too long" } */
-char u[1] = { "x", "x" }; /* { dg-error "excess elements in 'char' array initializer" } */
+char u[1] = { "x", "x" }; /* { dg-error "excess elements in 'char.1.' initializer" } */
 /* { dg-message "near init" "near" { target *-*-* } .-1 } */
 
 int i = { };
diff --git a/gcc/testsuite/gcc.dg/init-bad-2.c b/gcc/testsuite/gcc.dg/init-bad-2.c
index 4775c48..57fd9f9 100644
--- a/gcc/testsuite/gcc.dg/init-bad-2.c
+++ b/gcc/testsuite/gcc.dg/init-bad-2.c
@@ -19,7 +19,7 @@ char s[1] = "x";
 char s1[1] = { "x" };
 char t[1] = "xy"; /* { dg-warning "initializer-string for array of 'char' is too long" } */
 char t1[1] = { "xy" }; /* { dg-warning "initializer-string for array of 'char' is too long" } */
-char u[1] = { "x", "x" }; /* { dg-error "excess elements in 'char' array initializer" } */
+char u[1] = { "x", "x" }; /* { dg-error "excess elements in 'char.1.' initializer" } */
 /* { dg-message "near init" "near" { target *-*-* } .-1 } */
 
 int j = { 1 };
diff --git a/gcc/testsuite/gcc.dg/init-bad-3.c b/gcc/testsuite/gcc.dg/init-bad-3.c
index c5c338d..c22e8ec 100644
--- a/gcc/testsuite/gcc.dg/init-bad-3.c
+++ b/gcc/testsuite/gcc.dg/init-bad-3.c
@@ -19,7 +19,7 @@ char s[1] = "x";
 char s1[1] = { "x" };
 char t[1] = "xy"; /* { dg-error "initializer-string for array of 'char' is too long" } */
 char t1[1] = { "xy" }; /* { dg-error "initializer-string for array of 'char' is too long" } */
-char u[1] = { "x", "x" }; /* { dg-error "excess elements in 'char' array initializer" } */
+char u[1] = { "x", "x" }; /* { dg-error "excess elements in 'char.1.' initializer" } */
 /* { dg-message "near init" "near" { target *-*-* } .-1 } */
 
 int j = { 1 };
diff --git a/gcc/testsuite/gcc.dg/init-excess-3.c b/gcc/testsuite/gcc.dg/init-excess-3.c
index 7741261..c03a984 100644
--- a/gcc/testsuite/gcc.dg/init-excess-3.c
+++ b/gcc/testsuite/gcc.dg/init-excess-3.c
@@ -4,12 +4,12 @@
 /* { dg-options "" } */
 
 
-char s0[] = {"abc",1}; /* { dg-error "array initializer|near init" } */
-char s1[] = {"abc","a"}; /* { dg-error "array initializer|near init" } */
-char s2[] = {1,"abc"}; /* { dg-error "array initializer|near init|computable at load time" } */
+char s0[] = {"abc",1}; /* { dg-error "'char..' initializer|near init" } */
+char s1[] = {"abc","a"}; /* { dg-error "'char..' initializer|near init" } */
+char s2[] = {1,"abc"}; /* { dg-error "'char..' initializer|near init|computable at load time" } */
 /* { dg-warning "integer from pointer without a cast" "" { target *-*-* } .-1 } */
 
-char s3[5] = {"abc",1}; /* { dg-error "array initializer|near init" } */
-char s4[5] = {"abc","a"}; /* { dg-error "array initializer|near init" } */
-char s5[5] = {1,"abc"}; /* { dg-error "array initializer|near init|computable at load time" } */
+char s3[5] = {"abc",1}; /* { dg-error "'char.5.' initializer|near init" } */
+char s4[5] = {"abc","a"}; /* { dg-error "'char.5.' initializer|near init" } */
+char s5[5] = {1,"abc"}; /* { dg-error "'char.5.' initializer|near init|computable at load time" } */
 /* { dg-warning "integer from pointer without a cast" "" { target *-*-* } .-1 } */
diff --git a/gcc/testsuite/gcc.dg/pr61096-1.c b/gcc/testsuite/gcc.dg/pr61096-1.c
index f41789c..90ffb80 100644
--- a/gcc/testsuite/gcc.dg/pr61096-1.c
+++ b/gcc/testsuite/gcc.dg/pr61096-1.c
@@ -47,7 +47,7 @@ __extension__ int a15[10] = {[2 ... 1] = 4 }; /* { dg-error "31:empty index rang
 __extension__ int a16[10] = {[2 ... 100] = 4 }; /* { dg-error "31:array index range in initializer exceeds array bounds" } */
 int a17[] = { .B = 1 }; /* { dg-error "15:field name not in record or union initializer" } */
 int a18[] = { e }; /* { dg-error "15:initializer element is not constant" } */
-char a19[1] = { "x", "x" }; /* { dg-error "22:excess elements in 'char' array initializer" } */
+char a19[1] = { "x", "x" }; /* { dg-error "22:excess elements in 'char.1.' initializer" } */
 
 void
 bar (void)
-- 
1.8.3.1

Re: [PATCH 2/2] Improve error message for excess elements in array initializer from {"a"}

[Segher Boessenkool]

Hi!

On Wed, Nov 30, 2022 at 09:18:15AM -0800, apinski--- via Gcc-patches wrote:
> Note in the testsuite I used regex . to match '[' and ']' as
> I could not figure out how many '\' I needed.

Don't use double quotes then :-)  Inside double quotes all of command
substitution, variable substitution, and backslash substitution are
performed.  In a regexp you typically want none of this.  You usually do
want the whitespace to be significant, so it is good to quote it in
braces though (unless you like quoting all your whitespace).

> -char u[1] = { "x", "x" }; /* { dg-error "excess elements in 'char' array initializer" } */
> +char u[1] = { "x", "x" }; /* { dg-error "excess elements in 'char.1.' initializer" } */

char u[1] = { "x", "x" }; /* { dg-error {excess elements in 'char[1]' initializer} } */

See <https://www.tcl.tk/man/tcl8.6.13/TclCmd/Tcl.html> for a very short
page that has *all* Tcl syntax!


Segher

Re: [PATCH 2/2] Improve error message for excess elements in array initializer from {"a"}

[Andreas Schwab]

On Nov 30 2022, Segher Boessenkool wrote:

> char u[1] = { "x", "x" }; /* { dg-error {excess elements in 'char[1]' initializer} } */

That won't work, as '[1]' is a bracket expression only matching '1'.
You'll need {... 'char\[1\]' ...}.

-- 
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510  2552 DF73 E780 A9DA AEC1
"And now for something completely different."

Re: [PATCH 2/2] Improve error message for excess elements in array initializer from {"a"}

[Segher Boessenkool]

On Thu, Dec 01, 2022 at 12:17:30AM +0100, Andreas Schwab wrote:
> On Nov 30 2022, Segher Boessenkool wrote:
> 
> > char u[1] = { "x", "x" }; /* { dg-error {excess elements in 'char[1]' initializer} } */
> 
> That won't work, as '[1]' is a bracket expression only matching '1'.
> You'll need {... 'char\[1\]' ...}.

Heh.  Yeah, char\[1].  Sorry.


Segher

Re: [PATCH 2/2] Improve error message for excess elements in array initializer from {"a"}

[Jeff Law]

On 11/30/22 10:18, apinski--- via Gcc-patches wrote:
> From: Andrew Pinski <apinski@marvell.com>
> 
> So char arrays are not the only type that be initialized from {"a"}.
> We can have wchar_t (L"") and char16_t (u"") types too. So let's
> print out the type of the array instead of just saying char.
> 
> Note in the testsuite I used regex . to match '[' and ']' as
> I could not figure out how many '\' I needed.
> 
> OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions.
> 
> gcc/c/ChangeLog:
> 
> 	* c-typeck.cc (process_init_element): Print out array type
> 	for excessive elements.
> 
> gcc/testsuite/ChangeLog:
> 
> 	* gcc.dg/init-bad-1.c: Update error message.
> 	* gcc.dg/init-bad-2.c: Likewise.
> 	* gcc.dg/init-bad-3.c: Likewise.
> 	* gcc.dg/init-excess-3.c: Likewise.
> 	* gcc.dg/pr61096-1.c: Likewise.
OK
jeff

Re: [PATCH 1/2] Fix C/107926: Wrong error message when initializing char array

[Jakub Jelinek]

On Wed, Nov 30, 2022 at 09:18:14AM -0800, apinski--- via Gcc-patches wrote:
> gcc/c/ChangeLog:
> 
> 	PR c/107926
> 	* c-typeck.cc (process_init_element):
> 	Move the ceck for string cst until
> 	after the error message.

Just a ChangeLog nit, not a patch review for which I defer to C FE
maintainers/reviewers.
s/ceck/check/, plus don't start the description uselessly on a next line
when half of it would fit on the first line after ):.
 	* c-typeck.cc (process_init_element): Move the check for string cst
	until after the error message.

	Jakub

Re: [PATCH 1/2] Fix C/107926: Wrong error message when initializing char array

[Jeff Law]

On 11/30/22 10:18, apinski--- via Gcc-patches wrote:
> From: Andrew Pinski <apinski@marvell.com>
> 
> The problem here is the code which handles {"a"} is supposed
> to handle the case where the is something after the string but
> it only handles the case where there is another string so
> we go down the other path and error out saying "excess elements
> in struct initializer" even though this was a character array.
> To fix this, we need to move the ckeck if the initializer is
> a string after the check for array and initializer.
> 
> OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions.
> 
> Thanks,
> Adnrew Pinski
> 
> gcc/c/ChangeLog:
> 
> 	PR c/107926
> 	* c-typeck.cc (process_init_element):
> 	Move the ceck for string cst until
> 	after the error message.
> 
> gcc/testsuite/ChangeLog:
> 
> 	PR c/107926
> 	* gcc.dg/init-excess-3.c: New test.
OK
jeff